Communication method and apparatus

Abstract

A communication method and apparatus, which relate to the technical field of communications. The method comprises: acquiring a first precoding matrix, wherein the first precoding matrix corresponds to a first frequency band; acquiring first information, wherein the first information is used for indicating a first parameter and a second parameter, the first parameter is used for indicating a sub-band width corresponding to the first frequency band, and the second parameter is used for indicating a frequency-domain granularity corresponding to the first precoding matrix; and on the basis of the first information, sending first channel information, wherein the first channel information comprises second information, the second information is used for indicating N precoding vectors, the N precoding vectors are determined from among M first precoding vectors on the basis of the second parameter, the M first precoding vectors belong to the first precoding matrix, the M first precoding vectors correspond to M sub-bands, and the M sub-bands are determined on the basis of the first frequency band and the first parameter, M and N being positive integers. The method can ensure the feedback performance while reducing the overheads of channel information feedback.

Description

Communication methods and devices

[0001] [Revised in accordance with Rule 91, 22.01.2026] This application claims priority to Chinese Patent Application No. 202510121021.7, filed on January 24, 2025, with the China National Intellectual Property Administration, entitled “Communication Method and Apparatus”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0003] Configuring ultra-large-scale multiple-input multiple-output (MIMO) arrays is one of the future evolution trends of cellular systems. In MIMO, the base station will be equipped with thousands of antenna elements, while the terminal side will also be equipped with more antenna elements (such as 16 or 32) to support more spatial streams (layers). In addition, with the increase in carrier frequency, the bandwidth that can be allocated to the wireless communication system will further increase, and the number of subcarriers and resource blocks (RBs) will increase dramatically. This will lead to a sharp increase in the amount of channel information to be fed back (such as channel state information (CSI)). If the existing CSI processing scheme is continued, it will be unable to meet the CSI feedback requirements of MIMO. Summary of the Invention

[0004] This application provides a communication method and apparatus that can reduce the feedback overhead of channel information while ensuring feedback performance.

[0005] The present application is described below from different aspects. It should be understood that the different implementation methods and beneficial effects described below can be referenced from each other.

[0006] In a first aspect, this application provides a communication method that can be applied to a first device (or, in other words, the method can be executed by the first device). The first device can be a terminal or a communication module / processing module in the terminal, or a circuit or chip in the terminal (such as a modem chip, also known as a baseband chip, or a system-on-a-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip, etc.), or a module or software that can realize all or part of the terminal's functions; or, the first device can be a network device, or a module in the network device (such as a module, circuit, chip, or chip system, etc.), or a logical node, logical module, or software that can realize all or part of the network device's functions.

[0007] In this application, a first device is used to transmit first channel information, and a second device is used to receive the first channel information. For example, if the first device is a network device, the second device can be a terminal; or, if the first device is a terminal, the second device can be a network device.

[0008] Taking the application of this method to a first device as an example, the method involves the first device acquiring a first precoding matrix, which corresponds to a first frequency band; acquiring first information, wherein the first information is used to indicate a first parameter and a second parameter, the first parameter indicating the sub-band width corresponding to the first frequency band, and the second parameter indicating the frequency domain granularity corresponding to the first precoding matrix; and transmitting first channel information based on the first information, the first channel information including the second information, the second information indicating N precoding vectors, the N precoding vectors being determined from M first precoding vectors based on the second parameter, the M first precoding vectors belonging to the first precoding matrix, the M first precoding vectors corresponding to M sub-bands, the M sub-bands being determined based on the first frequency band and the first parameter, and M and N being positive integers.

[0009] In this application, a first device can determine first channel information (or channel information to be fed back) through first information, wherein the first channel information includes N precoding vectors determined from a first precoding matrix; and then, transmit the first channel information. This method, through the first information, can flexibly determine one or more precoding vectors (including the aforementioned N precoding vectors) from the first precoding matrix. One or more precoding vectors can be used to predict unfeeded channel information (i.e., the unfeeded first precoding vector). In this application, if the frequency bandwidth of the first frequency band is large and / or the frequency fluctuation of the channel is large, the number of precoding vectors determined based on the first and second parameters can be large (i.e., N is large). Therefore, one of the N precoding vectors needs to predict less channel information. Since less channel information corresponds to a smaller frequency bandwidth, the smaller frequency bandwidth results in less channel information. With smaller fluctuations, this method avoids predicting channel information with a large frequency domain width based on a single precoding vector. Therefore, the channel information predicted based on each precoding vector is more accurate, leading to more accurate predictions of unreturned channel information based on N precoding vectors. This improves the poor prediction performance and precoding performance loss caused by the large frequency domain width of the first frequency band and / or large frequency domain fluctuations of the channel. Furthermore, this method does not require feedback of the complete original channel information (i.e., the first precoding matrix), but only a portion of the precoding vectors (e.g., N precoding vectors) from the first precoding matrix, reducing the feedback overhead of channel information. Thus, this method can maintain feedback performance while reducing the feedback overhead of channel information.

[0010] Optionally, the first information can be dynamically configured, and the number of feedback precoding vectors (i.e., the aforementioned N precoding vectors) is determined based on the first information. That is, this application supports dynamically configuring more or fewer precoding vectors, which can improve the feedback accuracy of channel information. Optionally, N can be greater than 1. This method can mitigate the iteration error caused by iteratively predicting other unfeeded vectors by feeding back one precoding vector, thereby improving prediction accuracy and feedback performance.

[0011] Optionally, the first precoding matrix corresponds to the second channel information (or original channel information). For example, the second channel information (such as CSI) can be represented by a precoding matrix (such as the first precoding matrix mentioned above).

[0012] In this application, a subband is a frequency domain unit or frequency domain interval defined in this application, also referred to as a sub-frequency band. This frequency domain unit corresponds to a precoding vector in the precoding matrix, that is, one precoding vector corresponds to one subband. This application does not limit the name of the subband. For example, a subband can also be called a frequency domain unit, frequency domain width, or frequency domain interval, etc. This application does not limit the width of the subband. For example, the width of the subband can be several resource elements (REs), several subcarriers, several precoding resource groups (PRGs), several RBs, or several other frequency domain units. The width of the subband can be dynamically configured or preset. This application does not limit the configuration method of the subband width.

[0013] In this application, one precoding vector corresponds to one subband. The precoding vector can also be called a subband precoding vector. This application does not limit the name of the precoding vector, and it can also be called a precoding vector, etc.

[0014] For example, the frequency domain granularity corresponding to the first precoding matrix mentioned above can refer to: the frequency domain granularity used to process the first precoding matrix; or, the frequency domain granularity used to determine the precoding vector to be fed back (e.g., N precoding vectors) from the first precoding matrix (e.g., M first precoding vectors), that is, using the frequency domain granularity to determine the precoding vector to be fed back from the first precoding matrix; or, the frequency domain granularity used to determine the subband to be fed back from the first frequency band corresponding to the first precoding matrix, that is, using the frequency domain granularity to determine the subband to be fed back from the first frequency band corresponding to the first precoding matrix.

[0015] Optionally, the first precoding matrix corresponds to the second channel information (or raw channel information). For example, the second channel information (such as CSI) can be represented by a precoding matrix (such as the first precoding matrix mentioned above). Then, the frequency domain granularity corresponding to the first precoding matrix mentioned above can refer to the frequency domain granularity used in feeding back (or reporting, transmitting, or processing) channel information (such as the second channel information).

[0016] In conjunction with the first aspect, in one possible implementation, the frequency domain granularity is based on sub-bands as frequency domain units, the second parameter is g, and the second parameter is used to indicate that the frequency domain granularity corresponding to the first precoding matrix is ​​g sub-bands, and one of the precoding vectors in each of the M first precoding vectors belongs to N precoding vectors, where g is a positive integer.

[0017] For example, the second parameter mentioned above, used to indicate that the frequency domain granularity corresponding to the first precoding matrix is ​​g sub-bands, can mean: the second parameter is used to indicate that the frequency domain granularity used for the feedback channel information (such as the second channel information or the first precoding matrix) is g sub-bands; or, the second parameter is used to indicate that a precoding vector corresponding to one sub-band is fed back in every g sub-bands of the first frequency band (or M sub-bands); or, in other words, one of the precoding vectors in every g precoding vectors of the M first precoding vectors is the precoding matrix to be fed back.

[0018] For example, the first device, based on the second parameter g, determines one precoding vector from each of the g precoding vectors of the M first precoding vectors as the precoding vector to be fed back, thus obtaining the aforementioned N precoding vectors. Here, the M first precoding vectors correspond to M subbands, and the N precoding vectors correspond to N subbands within the M subbands. That is, the first device, based on the second parameter g, determines N subbands from the M subbands, and then determines the precoding vectors corresponding to these N subbands as the aforementioned N precoding vectors.

[0019] It should be noted that if M is not an integer multiple of g, then among the M first precoding vectors, there are also p subbands that feed back one precoding vector, where p is less than g and p is a positive integer. That is, in one portion of the M first precoding vectors, one of every g precoding vectors belongs to the N precoding vectors, and in another portion of the M first precoding vectors, one of every p precoding vectors belongs to the N precoding vectors. For example, the first device can determine one precoding vector from every g precoding vectors in the M first precoding vectors as the precoding vector to be fed back (i.e., one of the N precoding vectors). If the number of remaining first precoding vectors is p, then the first device can determine one precoding vector from p precoding vectors as the precoding vector to be fed back.

[0020] In one implementation, the first device can first divide the M first precoding vectors into N groups of vectors. Then, a precoding vector is selected from each group of vectors to obtain the above N precoding vectors. The number of vectors in the N groups of vectors is less than or equal to g.

[0021] For example, in the aforementioned N groups of vectors, there exists a group with p precoded vectors, while the other N-1 groups each have g vectors. In this latter group, one precoded vector out of every p precoded vectors belongs to all N precoded vectors. Conversely, in the other N-1 groups, one precoded vector out of every g precoded vectors belongs to all N precoded vectors. In conjunction with the first aspect, in one possible implementation, the first information is obtained by the first device from the second device, or the first information is determined by the first device.

[0022] This application does not limit the method by which the first device obtains the first information. For example, the first information may be obtained by the first device from the second device or other devices, or the first information may be calculated by the first device.

[0023] For example, the first device can be a terminal, and the accuracy of the feedback can be guaranteed by having the terminal determine the first information.

[0024] For example, if the first device is a terminal and the second device is a network device, the terminal can obtain the first information from the network device. This method can save the terminal's computing resources.

[0025] In conjunction with the first aspect, in one possible implementation, the method further includes: a first device receiving first indication information, the first indication information being used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix.

[0026] For example, if the historical channel information stored by the second device becomes invalid, the second device sends a first indication message to the first device. For instance, if the time elapsed since the acquisition of the historical channel information stored by the second device exceeds a preset time, then the channel information becomes invalid.

[0027] This application does not limit the names of the first parameter, the second parameter, and the first indication information. For example, the first parameter can be called the frequency domain reporting granularity, the second parameter can be called the reporting subband size or subband width, and the first indication information can be called the availability indicator, the reference parameter reporting indicator, or the recommendation indicator, etc.

[0028] In conjunction with the first aspect, in one possible implementation, the method further includes: a first device receiving first indication information and third information, the third information being used to indicate the sub-band width corresponding to the first frequency band determined by the second device and the frequency domain granularity corresponding to the first precoding matrix; the first device determining a third precoding matrix based on the third information; if the correlation between the third precoding matrix and the first precoding matrix is ​​lower than a preset threshold, the first device determining the first information, such as calculating the aforementioned first and second parameters; if the correlation between the third precoding matrix and the first precoding matrix is ​​lower than the preset threshold, the third information is determined as the first information.

[0029] In conjunction with the first aspect, in one possible implementation, if the first information is determined by the first device, then the first channel information also includes the first information.

[0030] In conjunction with the first aspect, in one possible implementation, if the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then L, k, and g are positive integers.

[0031] in, Used to represent rounding up.

[0032] In conjunction with the first aspect, in one possible implementation, the M first precoding vectors correspond to the same spatial stream.

[0033] It should be noted that this application primarily uses a sub-matrix (i.e., M first precoding vectors or M second precoding vectors) corresponding to a single spatial stream (referred to as the first spatial stream for ease of description) as an example for illustration. If the first precoding matrix includes sub-matrices corresponding to multiple spatial streams, the processing procedure for sub-matrices corresponding to other spatial streams can refer to the processing procedure for the first sub-matrix (i.e., M first precoding vectors or M second precoding vectors) corresponding to the first spatial stream. The processing procedures for sub-matrices corresponding to different spatial streams within the first precoding matrix can be the same or different. This processing procedure includes precoding vector feedback and prediction, among other things.

[0034] Optionally, N can be greater than 1, meaning that for the same spatial flow, multiple precoding vectors are fed back, and these multiple precoding vectors are used to predict precoding vectors corresponding to different frequency bands in the first frequency band. This method, through staged prediction, can reduce accumulated errors and performance loss under conditions of large frequency domain fluctuations. For example, it can improve the iteration error caused by predicting other unfeeded vectors of the same spatial flow by feeding back a precoding vector, thereby improving prediction accuracy and feedback performance.

[0035] For example, the first precoding matrix includes v submatrices, each corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first submatrix corresponding to the first spatial stream includes the aforementioned M precoding matrices. The first spatial stream can be any one of the v spatial streams, and the first submatrix can be any one of the submatrices in the first precoding matrix.

[0036] For example, the second information is used to indicate N precoding vectors in any of the above sub-matrices, or the second information is used to indicate N precoding vectors in at least one of the above sub-matrices, or the second information is used to indicate N precoding vectors in each of the above v sub-matrices. The sub-matrices can be two-dimensional matrices, with the two dimensions corresponding to the transmit antenna dimension and the frequency domain dimension (i.e., the number of sub-bands), respectively.

[0037] Optionally, the second information is used to indicate the precoding vector to be fed back in each of the above v sub-matrices. The number of precoding vectors to be fed back in each sub-matrice can be the same, which is N, or they can be different. This application does not limit this.

[0038] In this embodiment of the application, the second information is used to indicate the N precoded vectors in each of the above v sub-matrices. That is to say, for each spatial flow (or each layer), multiple precoded vectors can be reported. This method can calibrate the quantization feedback error and improve the feedback accuracy.

[0039] Optionally, the number of precoding vectors included in each of the above v sub-matrices may be different or the same; and / or, the number of precoding vectors to be reported in each of the above v sub-matrices may be the same, such as N, or different, and this application does not limit this. That is to say, each sub-matrix (or each spatial stream) may have its corresponding first information, and the first information corresponding to different sub-matrices (or different spatial streams) may be the same or different.

[0040] In conjunction with the first aspect, in one possible implementation, the second information is also used to indicate at least one transformation function, which is determined based on M first precoding vectors.

[0041] Optionally, the at least one transformation function and the N precoding vectors are used to predict (or determine or infer) the unreturned precoding vectors. Understandably, the inferred precoding vectors may be the same as or different from the M first precoding vectors in the first precoding matrix, due to deviations caused by inference errors, etc.

[0042] For example, the above-mentioned at least one transformation function can be a single transformation function, that is, N precoded vectors correspond to the same transformation function. This method can reduce the amount of feedback data.

[0043] As another example, the above-mentioned at least one transformation function can be multiple transformation functions, that is, at least two of the N precoding vectors correspond to different transformation functions. This method can determine the corresponding transformation function for different precoding vectors, and the above-mentioned at least one transformation function and the above-mentioned N precoding vectors can be used to predict the accuracy of unfeeded precoding vectors.

[0044] For example, N precoding vectors can correspond to one transform function, that is, the transform function and the precoding vectors are used to determine the precoding vectors that have not been fed back; N precoding vectors can also correspond to multiple transform functions, such as at least two precoding vectors in the N precoding vectors corresponding to different transform functions. Based on each precoding vector in the N precoding vectors and the transform function corresponding to that precoding vector, several precoding vectors (these several precoding vectors are the precoding vectors that have not been fed back) are predicted to obtain M second precoding vectors, and the M second precoding vectors include the N precoding vectors and the precoding vectors that have not been fed back.

[0045] In conjunction with the first aspect, in one possible implementation, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, which are determined based on M first precoded vectors.

[0046] In conjunction with the first aspect, in one possible implementation, N precoding vectors are used to determine (or predict, deduce, or recover) the unreturned precoding vectors.

[0047] For example, the N precoding vectors can be the precoding vectors fed back from the first submatrix of the first precoding matrix (or the precoding vectors to be fed back), and the N precoding vectors are used to determine the precoding vectors that are not fed back in the first submatrix. It should be understood that the precoding vectors that are not fed back determined by the second device based on the N precoding vectors may not be exactly the same as the other vectors (i.e., the actual precoding vectors that are not fed back) among the M first precoding vectors mentioned above.

[0048] For example, if the first device is a terminal, the aforementioned first channel information may be CSI feedback, and the aforementioned first channel information may be indicated by uplink control information (UCI).

[0049] As another example, if the first device is a network device, then the aforementioned first channel information may be a transmit precoding matrix indicator (TPMI), which may be indicated by downlink control information (DCI), medium access control-control element (MAC-CE), or radio resource control (RRC).

[0050] Secondly, this application provides a communication method that can be applied to a second device (or, in other words, the method can be executed by the second device). The second device can be a terminal or a communication module / processing module in the terminal, or a circuit or chip in the terminal (such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core), or a module or software that can realize all or part of the terminal functions; or a network device, or a module in the network device (such as a module, circuit, chip, or chip system), or a logical node, logical module, or software that can realize all or part of the network device functions.

[0051] Taking the application of this method to a second device as an example, the second device acquires first channel information, which includes second information. The second information is used to indicate N precoding vectors. Based on the first and second information, a second precoding matrix is ​​determined. The second precoding matrix corresponds to a first frequency band. The first information is used to indicate a first parameter and a second parameter. The first parameter is used to indicate the subband width corresponding to the first frequency band, and the second parameter is used to indicate the frequency domain granularity corresponding to the second precoding matrix. The second precoding matrix includes M second precoding vectors, which are determined based on the N precoding vectors and the second parameter. The M second precoding vectors correspond to M subbands, which are determined based on the first frequency band and the first parameter. M and N are positive integers.

[0052] In this application, the second device can predict the complete original channel information based on the second information and the first channel information (or the feedback channel information) to obtain the second precoding matrix. This method can flexibly determine one or more precoding vectors (including the aforementioned N precoding vectors) from the first precoding matrix. This method can improve the problem of poor prediction performance caused by insufficient feedback precoding vectors and / or large frequency domain fluctuations of the channel. This method does not require feedback of the complete original channel information (i.e., the first precoding matrix), but only requires feedback of a portion of the precoding vectors in the first precoding matrix, which can reduce the feedback overhead of channel information. Therefore, this method can achieve both reduced feedback overhead of channel information and guaranteed feedback performance.

[0053] In conjunction with the second aspect, in one possible implementation, the M second precoding vectors include the N precoding vectors and the unfeeded precoding vectors.

[0054] In conjunction with the second aspect, in one possible implementation, the first information is obtained by the second device from the first device, or the first information is determined by the second device.

[0055] In conjunction with the second aspect, in one possible implementation, the method further includes:

[0056] Send a first instruction message, which is used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the second precoding matrix.

[0057] In conjunction with the second aspect, in one possible implementation, if the first information is determined by the second device, the method further includes: the second device sending the first information.

[0058] In conjunction with the second aspect, in one possible implementation, if the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then

[0059] In conjunction with the second aspect, in one possible implementation, the M second precoding vectors correspond to the same spatial stream.

[0060] In conjunction with the second aspect, in one possible implementation, the second information is also used to indicate at least one transformation function, and the M second precoding vectors are determined based on at least one transformation function, N precoding vectors, and the second parameter.

[0061] In conjunction with the second aspect, in one possible implementation, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, wherein the M second precoding vectors are determined based on at least one eigenvalue matrix, at least one eigenvector matrix, N precoding vectors, and a second parameter.

[0062] In conjunction with the second aspect, in one possible implementation, the method further includes: the second device determining to send first indication information based on at least one of historical channel information, feedback period of channel information, prediction requirements of channel information, prediction requirements for the motion state of the first device, or accuracy requirements of channel information.

[0063] For example, if the historical channel information stored by the second device becomes invalid, the second device sends a first indication message to the first device, wherein the historical channel information is from the first device. For instance, if the time elapsed since the acquisition of the historical channel information stored by the second device exceeds a preset time, then the channel information becomes invalid.

[0064] Thirdly, this application provides a communication device comprising units, modules, or means for implementing any of the methods in the first to second aspects, or any possible implementations of any of the aspects, wherein the modules, units, or means may be implemented by software, by hardware, or by a combination of software and hardware.

[0065] Fourthly, this application provides a communication device including a processor. The processor is configured to cause the communication device to implement the methods shown in any of the first to second aspects, or any possible implementation thereof.

[0066] Optionally, the communication device further includes a transceiver for sending and receiving information.

[0067] Optionally, the communication device further includes a memory storing a computer program; the processor and transceiver are used to invoke the computer program in the memory, causing the communication device to implement the method shown in any of the first or second aspects, or any possible implementation thereof.

[0068] In one possible design, the communication device can be a chip that implements the above method or a device containing a chip.

[0069] Fifthly, this application provides a communication device comprising one or more processors, which implement, via logic circuits or execution code instructions, any of the methods described in the first or second aspects, or any possible implementation thereof.

[0070] Optionally, the communication device further includes an interface circuit for receiving signals from other communication devices outside the communication device and transmitting them to the processor, or sending signals from the processor to other communication devices outside the communication device.

[0071] Optionally, the communication device may further include a memory for storing part or all of the computer programs or instructions necessary to implement the functions involved in the first aspect above.

[0072] The aforementioned communication device may be a terminal, a communication module in a terminal, or a chip in a terminal that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0073] The aforementioned communication device may be a network device, a module (e.g., a circuit, chip, or chip system) in a network device, or a logical node, logical module, or software that can realize all or part of the functions of a network device.

[0074] Sixthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer, implement the method shown in any of the first to second aspects, or any possible implementation thereof.

[0075] In a seventh aspect, this application provides a computer program product that, when read and executed by a computer, causes the computer to perform any of the methods in the first aspect to the second aspect, or any possible implementation thereof.

[0076] Eighthly, this application provides a chip system including at least one processor and an interface, the processor being configured to read and execute a computer program or instructions in a memory, wherein when the computer program or instructions are executed, the chip performs the method described in any one of the first to second aspects, or any possible implementation thereof.

[0077] Ninthly, this application provides a communication system that may include a first device and a second device. The first device is used to perform the method shown in the first aspect or any possible implementation thereof. The second device is used to perform the method shown in the second aspect or any possible implementation thereof. Attached Figure Description

[0078] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0079] Figure 2 is a schematic diagram of the architecture of the communication system provided in this application;

[0080] Figure 3 is a schematic diagram of the network element function division and protocol layer structure of an O-RAN device provided in this application;

[0081] Figure 4 is a flowchart illustrating the compression scheme provided in an embodiment of this application;

[0082] Figure 5 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0083] Figure 6 is a flowchart illustrating the process of determining N precoding vectors according to an embodiment of this application;

[0084] Figure 7 is a schematic diagram of a method for determining second information provided in this application;

[0085] Figure 8 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0086] Figure 9 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0087] Figure 10 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application. Detailed Implementation

[0088] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0089] In the description of this application, terms such as "first" and "second" are used only to distinguish different objects, not to describe a specific order. Furthermore, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0090] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0091] In this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0092] It is understood that in this application, "when," "if," and "if" all refer to the device making a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to make a judgment when it is implemented, nor do they imply any other limitations.

[0093] In this application, the use of singular pronouns for elements is intended to indicate "one or more," rather than "one and only one," unless otherwise specified. The terms "system" and "network" in the embodiments of this application are used interchangeably.

[0094] It is understood that in the embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. Determining B based on A does not mean that B can be determined solely based on A; B can also be determined based on A and / or other information.

[0095] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0096] The technical solutions of the embodiments of this application can be applied to various communication systems, such as: frequency division duplex (FDD) systems, time division duplex (TDD) systems, public land mobile network (PLMN) systems, LTE-Advanced (LTE-A) systems, the 5th generation (5G) systems, new radio (NR) systems, machine-to-machine (M2M) systems, or other future communication systems, or other wireless communication systems that adopt wireless access technologies, etc., all of which can adopt the technical solutions of the embodiments of this application.

[0097] Please refer to Figure 1, which is a schematic diagram of the architecture of the communication system applied in the embodiments of this application. It should be noted that Figure 1 is a possible, non-limiting system schematic diagram. As shown in Figure 1, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 10 may also include an Internet 300. RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal (120a-120j in Figure 1, collectively referred to as 120). RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). Terminal 120 is wirelessly connected to RAN node 110. RAN node 110 is connected to core network 200 wirelessly or via a wired connection. The core network elements in core network 200 and RAN nodes 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions, or they can be a single physical device integrating some core network element functions and some RAN node 110 functions. Terminals can be interconnected with each other, and RAN nodes 110 can be interconnected with each other via wired or wireless means. Figure 1 is only a schematic diagram. This communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices. Each device may also include different functional units, which are not shown in Figure 1.

[0098] RAN 100 can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication systems, or future-oriented evolution systems. RAN 100 can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0099] RAN node 110, sometimes also referred to as a radio access network device, access network apparatus, network equipment, RAN entity, or access node, constitutes part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station. For terminals 120j accessing RAN 100 through network element 120i, network element 120i is a base station; but for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes both referred to as communication devices. For example, network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and network elements 120a-120j can be understood as communication devices with terminal functions.

[0100] In this application, the aforementioned RAN node 110 may also be referred to as a network device.

[0101] In this application, the first device can be the RAN node 110 mentioned above, and the second device can be the terminal 120 mentioned above; or, the second device can be the RAN node 110 mentioned above, and the first device can be the terminal 120 mentioned above.

[0102] For example, the first device is a network device and the second device is a terminal.

[0103] In another example, the first device is a terminal and the second device is a network device.

[0104] In one possible scenario, RAN node 110 can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system. RAN node 110 can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, RAN node 110 can also be a server, a wearable device, a vehicle, or an in-vehicle device. For example, the access network device in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of RAN node 110 in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). In this application, RAN node 110 can also be a logical node, logical module, or software that can implement all or part of the functions of RAN node 110.

[0105] In another possible scenario, multiple RAN nodes 110 collaborate to assist the terminal in achieving wireless access, with each RAN node 110 implementing a portion of the base station's functions. For example, a RAN node 110 can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0106] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0107] For example, please refer to Figure 2, which is a schematic diagram of the architecture of the communication system provided in this application. Figure 2 is only a schematic diagram, and the communication system (such as an O-RAN system) may also include other components besides those shown in Figure 2. As shown in Figure 2, the access network device (e.g., it may be an eNB, gNB, or next-generation access network device) communicates with the core network elements in the CN through a backhaul link and communicates with the terminal through the air interface.

[0108] Specifically, the BBU in the access network device communicates with the core network elements in the CN via a backhaul link, and the RU in the access network device communicates with at least one terminal via an air interface. The BBU communicates with at least one RU via a fronthaul link. The BBU and RU may or may not be co-located. The BBU includes at least one CU and at least one DU, which can communicate via at least one midhaul link.

[0109] Figure 3 illustrates a schematic diagram of the network element function division and protocol layer structure of an O-RAN device. In some examples, the CU is a logical node carrying the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, and other control functions of the access network device. The CU connects to network nodes such as the core network through interfaces, which can be interfaces such as E2 interfaces. Optionally, the CU can have some functions of the core network. The CU (e.g., the PDCP layer and higher layers) connects to the DU (e.g., the RLC layer and lower layers) through interfaces, which can be interfaces such as F1 interfaces. In some examples, these interfaces (e.g., the F1 interface) can provide control plane (C-Plane) and user plane (U-Plane) functions (e.g., interface management, system information management, user equipment (UE) context management, RRC message transmission, etc.). F1AP is the application protocol of the F1 interface, and in some examples, it defines the signaling procedures of F1. The F1 interface supports the control plane F1-C and the user plane F1-U.

[0110] In some examples, the CU can be split into CU-CP (control unit-control plane) and CU-UP (control unit-user plane). CU-CP is a logical node carrying the RRC layer and PDCP-C (control plane part of PDCP) layer, used to implement the CU's control plane functions. CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements in the core network can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. The AMF network element is responsible for mobility management in the mobile network, such as terminal location updates, terminal registration with the network, and terminal handover. CU-UP is a logical node carrying the SDAP layer and PDCP-U (user plane part of PDCP) layer, used to implement the CU's user plane functions. CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements in the core network, such as the user plane function (UPF) in a 5G system, are responsible for data forwarding and receiving in the terminal. The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0111] In some examples, a DU is a logical node that carries the radio link control (RLC) layer, medium access control (MAC) layer, higher physical layer (Higher PHY) layer, and other functions. In some examples, a DU can control at least one RU. The DU connects to the RU through interfaces, which can be fronthaul interfaces. In some examples, the Higher PHY layer includes the PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0112] In some examples, the RU is a logical node that carries both lower physical layer (PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP transmission reception point (TRP), a remote radio head (RRH), or other similar entities. In some examples, the Low-PHY includes PHY processing functions such as Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more terminals via a wireless link.

[0113] The DU and RU can be co-located or not. The DU and RU exchange control plane and user plane information via a fronthaul link through the Lower-Layer Split CUS-Plane (LLS-CUS) interface. LLS-CUS may include LLS-C and LLS-U interfaces providing the control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and RU. The DU and RU exchange management information via an LLS-M interface on the fronthaul link; the management plane (M-Plane) refers to non-real-time management operations between the DU and RU.

[0114] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0115] A terminal is a device or module that connects to the aforementioned communication system and possesses corresponding communication functions. A terminal can also be referred to as a user equipment (UE), user terminal, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication device, user agent, or user equipment, etc. A terminal typically contains communication modules, circuits, or chips that perform the corresponding communication functions. It may also be configured with program instructions for performing these functions. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, transportation vehicle with wireless communication function, communication module, roadside unit (RSU) with terminal function, etc. The embodiments of this application do not limit the device form of the terminal.

[0116] For ease of description, the following description uses a base station as an example of RAN node 110. Base stations and terminals can be fixed or mobile. Base stations and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0117] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0118] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0119] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0120] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also susceptible to interference from signals from neighboring cells.

[0121] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "base station sending information" can be understood as the base station sending information to another device (such as a terminal), or it can be understood as logical module 1 in the base station sending information to logical module 2 in the base station.

[0122] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "base station receiving information" can be understood as the base station receiving information from another device (such as a terminal), or it can be understood as logical module 1 in the base station receiving information from logical module 2 in the base station.

[0123] The communication between different devices involved in this application can refer to direct communication between different devices (i.e., without the need for relaying or forwarding by other devices), or communication between different devices through other devices (i.e., requiring relaying or forwarding by other devices), or communication between a functional unit within a device and other devices through another functional unit. In other words, "sending information to… (e.g., a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the destination of the information being the terminal. This can include sending information directly or indirectly to the terminal. "Receiving information from… (e.g., a terminal)" or "receiving information from… (e.g., a terminal)" or "receiving information sent (e.g., by a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the source of the information being the terminal. This can include receiving information directly or indirectly from the terminal. Information may undergo necessary processing between the source and destination, such as format changes, analog-to-digital conversion, amplification, filtering, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be elaborated further here.

[0124] In this application, the term "determine" encompasses a wide variety of actions. For example, "determine" may include recovery, prediction, derivation, selection, calculation, processing, research, searching (e.g., searching in a table, database, or other data structure), discovery, and the like. Furthermore, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. Moreover, "determine" may also include parsing, selection, selection, establishment, and similar actions. The aforementioned wide variety of actions, such as recovery, prediction, derivation, calibration, calculation, processing, derivation, research, searching, parsing, selection, selection, establishment, and similar actions, may be replaced with "determine".

[0125] To facilitate understanding of the embodiments of this application, some knowledge / terms used in the solutions of this application are introduced below. It should be noted that these explanations are for the purpose of making the embodiments of this application easier to understand, and should not be regarded as limiting the scope of protection claimed by this application.

[0126] 1. Channel Information

[0127] Channel information represents information that reflects channel characteristics and channel quality.

[0128] As an example, channel information includes at least one of the following: CSI, time-varying channel information, channel frequency offset information, or channel information obtained by multiplying CSI by the precoding matrix. It is understood that information reflecting channel characteristics and channel quality is applicable to the embodiments of this application.

[0129] Taking the example of a network device (or network side) obtaining downlink CSI through uplink feedback from a terminal, specifically, the network device sends a downlink reference signal to the terminal, and the terminal receives the downlink reference signal. Since the terminal knows the transmission information of the downlink reference signal, the terminal can estimate (or measure) the downlink channel that the downlink reference signal has passed through based on the received downlink reference signal. Then, based on this measurement, the terminal can obtain the downlink channel matrix, generate CSI, and feed the CSI back to the network device.

[0130] As an example, CSI includes at least one of the following: channel quality indication (CQI), precoding matrix indicator (PMI), rank indicator (RI), CSI-RS resource indicator (CRI), layer indicator (LI), reference signal receiving power (RSRP), signal to interference plus noise ratio (SINR), synchronization signal / physical broadcast channel block resource indicator (SSBRI), etc.

[0131] An uplink channel is a channel used for transmitting signals from a terminal to a network device, while a downlink channel is a channel used for transmitting signals from a network device to a terminal. For example, uplink channel information can refer to the Channel Identity System (CSI) of the uplink channel, and downlink channel information can refer to the Channel Identity System (CSI) of the downlink channel. Typically, the CSI can include indication information of the channel matrix or precoding matrix.

[0132] 2. Channel matrix and precoding matrix

[0133] The channel matrix represents the channel response of the transmitting and receiving ends. It can be a three-dimensional matrix (i.e., the matrix has 3 dimensions), with the three dimensions corresponding to the transmit antenna, receive antenna, and subcarrier, respectively. Optionally, the channel matrix can also be a four-dimensional matrix (i.e., the matrix has 4 dimensions), for example, with the four dimensions corresponding to the transmit antenna, receive antenna, subcarrier, and time, respectively.

[0134] The precoding matrix (such as the first precoding matrix) can be obtained by performing singular value decomposition (SVD) on the channel matrix. For example, for a three-dimensional channel matrix, the precoding matrix can be obtained by performing SVD on the channel matrix subcarrier by subcarrier. More specifically, the operation can be to perform SVD on the two-dimensional matrix corresponding to each subcarrier (the two dimensions correspond to the transmit antenna and the receive antenna, respectively). The resulting left singular value matrix corresponds to the two-dimensional precoding matrix used for transmitting data (the two dimensions correspond to the transmit antenna and the spatial stream, respectively). By concatenating the two-dimensional precoding matrices of all subcarriers, the precoding matrix (the three dimensions correspond to the transmit antenna, the spatial stream, and the subcarrier, respectively) can be obtained.

[0135] Ultra-large-scale MIMO is one of the evolutionary trends of future cellular systems (such as 6G systems), and its antenna configuration will further increase: the base station (BS) side will be equipped with thousands of antenna elements; the UE side will also be equipped with more antenna elements (such as 16, 32, etc.) to support more spatial streams. In addition, with the increase in carrier frequency, the bandwidth that the wireless system can allocate will further increase, the number of subcarriers, RBs, etc. will increase dramatically, and the number of frequency points to be fed back CSI will increase significantly. Under these circumstances, the total size of CSI (such as the BS-side precoding matrix obtained by performing SVD on the channel matrix per frequency point (which can be a subband, subcarrier, RB, or other frequency domain unit)) increases significantly, and the data acquired in a single acquisition reaches the level of millions or even tens of millions of symbols. Its data processing and feedback face problems such as high processing complexity and large data transmission volume.

[0136] Therefore, how to efficiently compress and transmit CSI information, reduce feedback overhead, and ensure system performance is a current research hotspot.

[0137] In wireless communication networks, frequency domain prediction, as an important technique, can effectively utilize the correlation of the channel in the frequency domain to obtain the channel index (CSI) of unknown frequencies by analyzing and predicting information from known frequencies. This method not only reduces the amount of feedback data and communication overhead but also improves system performance and stability. CSI feedback schemes based on frequency domain prediction are gradually becoming a research hotspot, providing new ideas and methods for solving the problems of spectral efficiency and channel capacity in wireless communication.

[0138] For example, see Figure 4, which is a schematic diagram of a CSI feedback process. This process is a CSI compressed feedback processing flow based on Dynamic Mode Decomposition (DMD), where the transmit antenna dimension is N. TX The receiving antenna dimension is N RX The number of sub-bands is N sub .

[0139] The process may include: (1) The UE receives the CSI-RS sent by the BS. Based on the received CSI-RS, the original channel matrix information of different subbands can be obtained. This channel matrix information can be represented by the channel matrix H. The right singular vector matrix of the channel matrix H of each subband is obtained by the SVD decomposition method, that is, the precoding matrix 1. The matrix dimension becomes (N TX (2) Compress the precoding matrix 1 to obtain the precoding matrix 2. For example, compress the precoding vector matrix W of each layer in the precoding matrix 1. l Compression is performed to obtain the precoding matrix W for each layer in precoding matrix 2. sub,l According to the predefined protocol, the BS and UE are pre-configured or the UE obtains the compression matrix Q through online training. l (or dimensionality reduction matrix Q) l ), then use Q l Compression (or dimensionality reduction), W sub,l =Q l H W l (3) Calculate the transformation matrix for each layer. Taking the l-th layer as an example, the transformation matrix of the l-th layer is G. l The feedback information reported by the UE to the BS may include the precoding vector w corresponding to the first subband of each layer. 1,l and the transformation matrix G l Alternatively, the transformation matrix G can be obtained by construction. l Approximate eigendecomposition G l ≈ψ l Λ l ψ l H This facilitates the calculation of the matrix multiplication w mentioned above. k,l ≈ψ l Λ l k–1 ψ l H w 1,l , of which Λ l This represents a diagonal matrix composed of eigenvalues. In this case, the feedback information reported by the UE to the BS is the precoding vector w corresponding to the first subband of each layer. 1,l , eigenvalue matrix Λ of the transformation matrixl and the eigenvector matrix ψ l .

[0140] The inventors of this application have discovered through research that the performance of the frequency domain compression CSI feedback scheme based on DMD (as shown in Figure 4) and the CSI frequency domain prediction scheme based on AI models and other methods all depend on the frequency domain flatness characteristics of the channel. For channels with large frequency domain fluctuations and / or channels with large frequency domain bandwidth, the prediction performance of this type of method is poor.

[0141] This application embodiment uses first information to flexibly determine one or more precoding vectors (such as the N precoding vectors mentioned above) from a first precoding matrix. These one or more precoding vectors can be used to predict the original channel information. The first information indicates a first parameter and a second parameter. The first parameter indicates the sub-band width corresponding to the first frequency band, and the second parameter indicates the frequency domain granularity corresponding to the first precoding matrix. This method can improve the problem of poor prediction performance caused by a large frequency domain width corresponding to the first precoding matrix and / or large frequency domain fluctuations in the channel. It can reduce the feedback overhead of channel information while ensuring feedback performance.

[0142] Optionally, in this embodiment of the application, a first parameter and a second parameter g can be added to the channel information feedback reporting configuration. The first parameter and the second parameter are used to indicate that the first device (such as UE) feeds back a precoding vector corresponding to a sub-band every g sub-bands.

[0143] Optionally, embodiments of this application may further configure first indication information to instruct the first device to provide a recommended reporting subband size and frequency domain reporting granularity based on the measured channel information. That is, the first and second parameters can be determined by the first device. This method takes into account that if the second device (e.g., a base station) configures the reporting subband size and frequency domain reporting granularity based on historical information, the reporting subband size and frequency domain reporting granularity may become invalid. This method, by having the first device determine the first and second parameters, can ensure feedback accuracy.

[0144] It should be noted that in the description of this application, "instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information (such as the first information, second information, first instruction information, etc., as described below) is called the information to be instructed. In specific implementation, there are many ways to instruct the information to be instructed. For example, the information to be instructed can be directly instructed, where the information to be instructed itself or its index is used. Alternatively, the information to be instructed can be indirectly indicated by instructing other information, where there is a correlation between the other information and the information to be instructed. Another example is that only a part of the information to be instructed can be indicated, while the other parts are known, pre-agreed upon, or deducible. Furthermore, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent.

[0145] The communication method and apparatus provided in this application will be further described below with reference to the accompanying drawings. It is understood that this application uses a second device and a first device as examples to illustrate the interaction, but this application does not limit the entities that can be used to illustrate the interaction.

[0146] Please refer to Figure 5, which is a flowchart illustrating a communication method provided in an embodiment of this application. As shown in Figure 5, the communication method may include the following steps:

[0147] Step S501: The first device acquires the first precoding matrix, which corresponds to the first frequency band.

[0148] For example, the first precoding matrix includes v submatrices, each corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first submatrix corresponding to the first spatial stream includes the aforementioned M precoding vectors.

[0149] The first precoding matrix can be a three-dimensional matrix composed of v two-dimensional matrices. That is, the above submatrices can be two-dimensional matrices, with the two dimensions corresponding to the transmit antenna dimension and the frequency domain dimension (i.e., the number of subbands), respectively. The first spatial stream can be any one of the v spatial streams, and the first submatrix can be any one of the submatrices in the first precoding matrix.

[0150] In one implementation, a first device can receive a first reference signal; channel estimation is performed based on the first reference signal to obtain raw channel information. For example, this raw channel information can be represented by the channel matrix H in Figure 4; processing the raw channel information yields precoding matrix 1. For example, as shown in Figure 4, performing RB-wise SVD on the channel matrix H yields precoding matrix 1; compressing precoding matrix 1 (e.g., sampling or dimensionality reduction) yields precoding matrix 2. For example, as shown in Figure 4, compressing the precoding matrix based on the compression matrix yields precoding matrix 2. The three dimensions of precoding matrix 1 correspond to N respectively. TX One transmit antenna, v spatial streams, and N sub The three dimensions of precoding matrix 2 correspond to r transmit antennas, v spatial streams, and N subbands, respectively. sub There are several subbands, and r is less than N. TX .

[0151] Optionally, the first precoding matrix can be either precoding matrix 1 or precoding matrix 2.

[0152] For example, the first precoding matrix corresponding to the first frequency band can mean that: the working frequency band or measurement frequency band of the first precoding matrix is ​​the first frequency band, or the working frequency domain or measurement frequency band for obtaining the second channel information corresponding to the first precoding matrix is ​​the first frequency band.

[0153] Step S502: The first device acquires first information, wherein the first information is used to indicate the first parameter and the second parameter, the first parameter is used to indicate the sub-band width corresponding to the first frequency band, and the second parameter is used to indicate the frequency domain granularity corresponding to the first precoding matrix.

[0154] This application does not limit the execution order of steps S501 and S502, that is, this application does not limit the order in which the first device acquires the first precoding matrix and the first information. For example, the first device may execute step S501 first and then step S502, that is, the first device acquires the first precoding matrix first and then acquires the first information; or, the first device may execute step S502 first and then step S501, that is, the first device acquires the first information first and then acquires the first precoding matrix; or, the first device may execute steps S501 and S502 simultaneously, that is, the first device acquires the first information and the first precoding matrix simultaneously.

[0155] For example, the first parameter mentioned above is used to indicate that the sub-band width corresponding to the first frequency band is k frequency domain units, where k is a positive integer. Then, the first parameter can refer to: indicating that the first frequency band is processed so that at least one sub-band has a sub-band width of k frequency domain units.

[0156] For example, the first device can divide the first frequency band into several sub-bands based on the first parameter, with equal or unequal intervals. Among these sub-bands, at least one sub-band has a width of k frequency domain units.

[0157] For example, the first parameter can be k frequency domain units, or the first parameter can be k, or the first parameter can be the index corresponding to k frequency domain units. For instance, if the frequency domain units indicated by the first parameter are specified in the negotiation or agreement between the first device and the second device, then the first parameter can be k. If the default frequency domain unit is RE, then the first parameter k refers to k REs.

[0158] Optionally, the aforementioned k frequency domain units may be k REs, k subcarriers, k PRGs, k RBs, or k other frequency domain units.

[0159] For example, the second parameter, used to indicate that the frequency domain granularity corresponding to the first precoding matrix is ​​g subbands, can mean that: in the submatrix corresponding to a spatial flow in the first precoding matrix, a precoding vector is fed back for every g subbands; or, in the first frequency band corresponding to the first precoding matrix, a precoding vector (or a set of precoding vectors) corresponding to each subband is fed back for every g subbands. If the first precoding matrix corresponds to multiple spatial flows, then the set of precoding vectors corresponding to a subband includes the precoding vectors corresponding to each of the multiple spatial flows.

[0160] It should be noted that if M is not an integer multiple of g, then in the submatrix corresponding to a spatial stream in the first precoding matrix, there are also p subbands that feed back a precoding vector, where p is less than g, and p and g are positive integers. For example, if M is 99 and g is 10, then the first device can determine one precoding vector corresponding to every 10 subbands from the M first precoding vectors as the precoding vector to be fed back. If the remaining number of first precoding vectors is 9, then one precoding vector corresponding to a subband is determined from these 9 first precoding vectors as the precoding vector to be fed back. The resulting precoding vector to be fed back is the aforementioned N precoding vectors.

[0161] Optionally, the second parameter may correspond to one or more spatial streams (such as all spatial streams) in the first precoding matrix. In this case, the second parameter is used to indicate that the frequency domain granularity corresponding to the first precoding matrix is ​​g sub-bands. This can mean that a precoding vector is fed back for every g sub-bands in the sub-matrix corresponding to the spatial stream of the second parameter.

[0162] For example, if the second parameter g is 2 and the first parameter k is 2, it means that the subband width is 2 REs and the precoding vector corresponding to each subband is reported for every 2 subbands; if the second parameter g is 12 and the first parameter k is 4, it means that the subband width is 1 RB (12 REs) and the precoding vector corresponding to each subband is reported for every 4 subbands.

[0163] Optionally, the first information is obtained by the first device from the second device, or the first information is determined by the first device.

[0164] For example, if the first information is obtained by the first device from the second device, the first information may include a first parameter and a second parameter; or, the first information may also be an index that indicates the first parameter and the second parameter.

[0165] Table 1 illustrates the correspondence between multiple indices and the first and second parameters. The first information can be any index in Table 1, which is used to indicate parameter combination.

[0166] For example, if the first information is index 1, then the first parameter is 1 and the second parameter is 16. If the frequency domain unit corresponding to the first parameter is RE, then the first parameter is used to indicate that the sub-band width corresponding to the first frequency band is 1 RE, and the second parameter is used to indicate that the frequency domain granularity corresponding to the above-mentioned first precoding matrix is ​​16 sub-bands. This method reduces feedback overhead by indicating the first and second parameters through indexes.

[0167] For example, the correspondence between multiple indices and the first and second parameters (as shown in Table 1 above) can be determined by the second device. For instance, the second device can construct Table 1, obtain Table 1 from other devices, or store Table 1. For the first device, after determining the first and second parameters, the second device can determine the index based on Table 1, and then send first information to the first device, where the first information is the index. For example, if the second device determines the first parameter to be 1 and the second parameter to be 16 based on at least one of the first device's historical channel information, the feedback period of the channel information, the prediction requirements of the channel information, the prediction requirements for the motion state of the first device, or the accuracy requirements of the channel information, then the index sent by the second device to the first device based on Table 1 can be 0.

[0168] Optionally, the first device may receive first indication information, which is used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix; and then, determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix, that is, obtain the first information.

[0169] For example, if the first device receives the aforementioned first indication information but does not receive the first information, the first device can determine the first information. Optionally, after determining the first information, the first device can use the first information to process the first precoding matrix, and can also report the first information. In this case, the first information can also be referred to as recommended parameters.

[0170] In another example, if the first device receives the first information but does not receive the first indication information, then the first device does not need to perform the "determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix", but directly uses the first information to process the first precoding matrix.

[0171] For example, if the first device (such as a terminal) receives configuration information sent by the second device (such as a network device) that includes reported configuration parameters but does not include the first indication information, then the terminal processes the first precoding matrix based on the reported configuration parameters. That is, the reported configuration parameters sent by the network device are determined as the first information. For example, the reported configuration parameters can be the aforementioned first parameter and second parameter, or the reported configuration parameters can be used to indicate the aforementioned first parameter and second parameter.

[0172] In another example, the first device receives third information and the aforementioned first indication information sent by the second device. The third information indicates a third parameter and a fourth parameter. The third parameter indicates the sub-band width corresponding to the first frequency band, and the fourth parameter indicates the frequency domain granularity corresponding to the first precoding matrix. If the first device determines that the third information is unavailable, it performs the "determination of the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix" to obtain the first information. This first information indicates the first parameter and the second parameter. The first parameter indicates the sub-band width corresponding to the first frequency band, and the second parameter indicates the frequency domain granularity corresponding to the first precoding matrix. The first information is then used to process the first precoding matrix. The first parameter differs from the third parameter, and / or the second parameter differs from the fourth parameter. If the first device determines that the third information is available, it does not need to perform the "determination of the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix," but instead determines the third information as the first information and directly uses the first information to process the first precoding matrix.

[0173] For example, if the first device (such as a terminal) receives configuration information sent by the second device (such as a network device) including reported configuration parameters (i.e., the aforementioned third information) and first indication information, the terminal first determines whether the reported configuration parameters are available. If the reported configuration parameters are unavailable, the terminal determines the first information itself. If the reported configuration parameters are available, the terminal determines the reported configuration parameters as the first information.

[0174] This application does not limit the principles for determining whether the reported configuration parameters are usable. For example, the first device can calculate feedback information based on the reported configuration parameters obtained from the second device. The feedback information may include the precoding vector and transformation function selected from the measured precoding matrix. Then, performance prediction is performed based on the feedback information, such as precoding vector recovery based on the selected precoding vector and transformation function, and the error between the recovered precoding matrix and the measured precoding matrix is ​​calculated, such as the mean-square error (MSE). If the performance predicted based on the reported configuration parameters does not meet the performance requirements, such as if the above error exceeds a preset value, then the reported configuration parameters are determined to be unusable. If the performance predicted based on the reported configuration parameters meets the performance requirements, such as if the above error does not exceed a preset value, then the reported configuration parameters are determined to be usable. This application may also refer to the usable configuration information as the first information.

[0175] This application does not limit the method of transmitting the first parameter, the second parameter, and the first indication information. For example, at least one of the first parameter, the second parameter, or the first indication information can be indicated by MAC-CE; or at least one of the first parameter, the second parameter, or the first indication information can be indicated by RRC signaling, such as configuring relevant parameters by CSI-reportConfig information cells; or at least one of the first parameter, the second parameter, or the first indication information can be configured by DCI; or the transmission of the first parameter, the second parameter, and the first indication information can be achieved based on a combination of at least two of MAC-CE, RRC signaling, or DCI.

[0176] For example, the first parameter, the second parameter, and the first indication information may be carried in the same message or in different messages, and this application does not limit this.

[0177] For example, the first indication information can be a field in the first message. The above "not receiving the first indication information" can mean that the field is defaulted. The default field is used to indicate that the first device does not need to perform "determining the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix", or in other words, it does not need to determine or report the recommended parameters.

[0178] Step S503: The first device sends first channel information to the second device based on the first information. The first channel information includes second information. The second information is used to indicate N precoding vectors. The N precoding vectors are determined from M first precoding vectors based on the second parameter. The M first precoding vectors belong to the first precoding matrix. The M first precoding vectors correspond to M subbands. The M subbands are determined based on the first frequency band and the first parameter. M and N are positive integers.

[0179] Correspondingly, the second device receives the first channel information sent by the first device.

[0180] For example, the second information can be N precoded vectors; or, the second information can be obtained by performing a first process on the N precoded vectors, whereby the first process includes quantization or other operations. In other words, the second information is the N precoded vectors after the first process, such as the N precoded vectors after quantization.

[0181] Among them, the M subbands include N subbands, and the N subbands correspond one-to-one with the N precoding vectors, where M≥N.

[0182] Optionally, the second information is used to indicate the N precoding vectors corresponding to the N subbands.

[0183] For example, the second information is used to indicate N precoding vectors and N subbands, with a one-to-one correspondence between the N precoding vectors and the N subbands. For instance, the second information includes the subband indices of the N subbands and the precoding vector corresponding to each subband index.

[0184] Another example is that the second information may include N precoding vectors, excluding the subband indices of the N subbands. Optionally, the correspondence between the N precoding vectors and the N subbands can be determined by the second device. For example, the N precoding vectors may be, in sequence, the precoding vector v'1 corresponding to subband index 1, the precoding vector v'2 corresponding to subband index g+1, and so on. g+1 The precoding vector v' corresponding to subband index 2g+1 2g+1 ..., the precoding vector v' corresponding to subband index (N-1)g+1 (N-1)g+1 .

[0185] In one implementation, the first device may determine N precoding vectors from a first precoding matrix based on first information; and then transmit first channel information, which includes second information used to indicate the N precoding vectors.

[0186] For example, N precoding vectors are used to determine the precoding vectors that have not been fed back.

[0187] For example, Figure 6 is a flowchart illustrating the determination of N precoding vectors according to an embodiment of this application.

[0188] S5031: The first device determines M sub-bands based on the first frequency band and the first parameters. The M sub-bands correspond to M first precoding vectors, and the M first precoding vectors belong to the first precoding matrix.

[0189] For example, if the first frequency band has L frequency domain units and the first parameter is k, then Where L and k are positive integers.

[0190] In this application, the first parameter k can mean that the first parameter is used to indicate that the sub-band width corresponding to the first frequency band is k frequency domain units, or that the first parameter is used to indicate that the sub-band width of at least one sub-band obtained based on the first frequency band is k frequency domain units; the units of k frequency domain units and L frequency domain units are the same, such as RE, then k frequency domain units refer to k REs, and L frequency domain units refer to L REs.

[0191] For example, if the first frequency band has 200 REs (i.e., L = 200) and the first parameter is k = 2, then the total number of sub-bands can be determined as follows: That is, 100 subbands; if the second parameter = 10, then the second parameter is used to indicate that a precoding vector corresponding to each subband is fed back every 10 subbands. Optionally, the second device can divide the first frequency band into M subbands with equal or unequal spacing. For example, if L is an integer multiple of M, then the second device can divide the first frequency band into M subbands with equal spacing, and the subband width of each subband is k frequency domain units. Alternatively, if L is not an integer multiple of M, then the second device can divide the first frequency band into M subbands with unequal spacing, and the subband width of each subband is equal to or less than k frequency domain units.

[0192] Optionally, the precoding vectors corresponding to the M sub-bands in the first precoding matrix are the aforementioned M first precoding vectors. In other words, the first device determines the M sub-bands based on the first frequency band and the first parameters, which means the first device determines the M first precoding vectors based on the first frequency band and the first parameters.

[0193] For example, the above M first precoding vectors correspond to the same spatial stream.

[0194] S5032: The first device determines N precoding vectors from M first precoding vectors based on the second parameter.

[0195] In one implementation, the first device can determine the number N of precoded vectors to be fed back based on the second parameters g and M, for example... g is a positive integer; then, according to the first rule, the M first precoding vectors can be divided into N groups of vectors; according to the second rule, a precoding vector can be selected from each of the N groups of vectors to obtain the above N precoding vectors.

[0196] For example, suppose the M first precoding vectors are vector 1, vector 2, up to vector M, and the frequencies of the subbands corresponding to vectors 1 to M increase sequentially (or the frequencies of the subbands corresponding to vectors 1 to M decrease sequentially). The first rule mentioned above can be: divide the M first precoding vectors in the order of vector 1 to vector M, and group them into groups of g vectors. That is, vectors 1 to g are the first group of vectors, vectors g+1 to 2g+1 are the second group of vectors, and so on, until the number of undivided vectors is less than or equal to g, and then the undivided vectors are determined as the Nth group of vectors.

[0197] As another example, the first rule described above can be related to the correlation of subband precoding vectors. For instance, the correlation of precoding vectors in each of the N groups of vectors is higher than a first threshold. For example, the first device can group M first precoding vectors whose correlation is higher than the first threshold based on the correlation of the subband precoding vectors.

[0198] For example, the second rule mentioned above could be: determining the vector with the lowest frequency in each of the N sets of vectors as the N precoding vectors, or determining the vector with the lowest frequency in each of the N sets of vectors as the N precoding vectors.

[0199] Optionally, the selection of sub-bands may differ depending on the frequency domain prediction method (such as neural networks or transformation function-based prediction). For example, the second rule mentioned above may differ for different frequency domain prediction methods.

[0200] In one implementation, the second information includes the subband indices of N subbands and the precoding vector corresponding to each subband index. Therefore, before executing step S503 (i.e. sending the second information), the first device can first determine the subband indices that need to be reported and the precoding vector corresponding to each subband index.

[0201] For example, the first device (such as a UE) can select a number of subbands at equal intervals based on the second parameter. Assuming the total number of subbands is M, the number of reported subbands is N, and the second parameter = g, then... The N subband indices reported by the first device can be {1, g+1, 2g+1, ..., (N-1)g+1}, and the N precoding vectors reported by the first device can be the precoding vector v'1 corresponding to subband index 1, and the precoding vector v'1 corresponding to subband index g+1. g+1 The precoding vector v' corresponding to subband index 2g+1 2g+1 ..., the precoding vector v' corresponding to subband index (N-1)g+1 (N-1)g+1 .

[0202] In this embodiment of the application, the precoding vector v'1 is used to predict the precoding vector corresponding to subband index 2 to the precoding vector corresponding to subband index g, v' g+1 This is used to predict the precoding vectors from subband index g+2 to subband index 2g, and so on, v' (N-1)g+1 The precoding vectors are used from the precoding vector corresponding to subband index (N-1)g to the precoding vector corresponding to subband index M. In other words, N precoding vectors are used to predict the precoding vectors corresponding to different frequency bands in the first frequency band. For example, precoding vector v'1 is used to predict the precoding vector corresponding to the subband from subband index 2 to subband index g in the first frequency band. This method, through staged prediction by frequency band, can reduce error accumulation and improve the feedback accuracy of channel information.

[0203] For example, if the measurement band (working band) corresponding to the first precoding matrix contains 200 REs, that is, the first band has 200 REs, and the first parameter is subbandSize = 2, then the total number of subbands can be determined as follows: That is, there are 100 subbands, with subband indices {1, 2, ..., 100}. If the second parameter = 10, then the subband indices reported by the first device are {1, 11, 21, ..., 91}, and the N precoding vectors reported by the first device are the precoding vectors corresponding to the subband indices {1, 11, 21, ..., 91}, such as the precoding vector v'1 corresponding to subband index 1, and the precoding vector v'1 corresponding to subband index 11. 11 The precoding vector v' corresponding to subband index 21 21 ..., the precoding vector v' corresponding to subband index 91 91 .

[0204] Optionally, if the first indication information is configured, the first device (e.g., UE) can calculate the first parameter and the second parameter based on the second channel information (e.g., the measured CSI result), and report them together with the first channel information (e.g., CSI feedback information) or through other means to the second device (e.g., BS).

[0205] S5033: The first device sends first channel information to the second device. The first channel information includes second information, which is used to indicate N precoding vectors.

[0206] For example, the first precoding matrix includes v sub-matrices, each corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes the aforementioned M first precoding vectors. The first spatial stream can be any one of the v spatial streams, and the first sub-matrix can be any one of the sub-matrices in the first precoding matrix.

[0207] Optionally, the second information is used to indicate v groups of precoding vectors, each group of precoding vectors corresponding to one of v spatial streams, each group of precoding vectors belonging to a submatrix corresponding to the spatial stream of that group of precoding vectors, and each group of precoding vectors including N precoding vectors. Each group of precoding vectors is used to determine the unfelt precoding vectors in the submatrix corresponding to the spatial stream of that group of precoding vectors. That is, the first precoding matrix includes v×M precoding vectors, the first device only feeds back v×N precoding vectors using the second information, and the second device predicts the unfelt vectors in the submatrix to which each group of precoding vectors belongs, obtaining v×M second precoding vectors (i.e., the second precoding matrix). The specific prediction process can be found in step S504.

[0208] Optionally, the second information is also used to indicate at least one transformation function, which is determined based on M first precoding vectors.

[0209] Optionally, at least one of the above transformation functions is used to determine the unfeeded precoded vector.

[0210] Optionally, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, which are determined based on M first precoding vectors.

[0211] Optionally, the aforementioned at least one eigenvalue matrix and at least one eigenvector matrix are used to determine the unreturned precoded vector.

[0212] Optionally, if the first information is determined by the first device, the first channel information may further include the first information.

[0213] Step S504: The second device determines a second precoding matrix based on the first information and the second information. The second precoding matrix corresponds to the first frequency band. The second precoding matrix includes M second precoding vectors. The M second precoding vectors are determined based on N precoding vectors and the second parameter. The M second precoding vectors correspond to M subbands. The M subbands are determined based on the first frequency band and the first parameter.

[0214] The first precoding matrix and the second precoding matrix may be the same or different, and this application does not impose any limitation on this. It should be understood that the first precoding matrix and the second precoding matrix may differ due to actual transmission and prediction errors.

[0215] For example, the second device can determine M sub-bands based on the first frequency band and the first parameter, and the M sub-bands correspond to M second precoding vectors; then, based on N precoding vectors and the second parameter, it can determine unfeeded precoding vectors, and the M second precoding vectors include the N precoding vectors and the unfeeded precoding vectors.

[0216] For example, if the first frequency band has L frequency domain units and the first parameter is k, then

[0217] Optionally, the second device can divide the first frequency band into M sub-bands with equal or unequal spacing. For example, see the method described in S5031.

[0218] Optionally, if the second parameter is g, then the number of unfeeded precoding vectors determined based on one of the N precoding vectors is less than or equal to g-1.

[0219] For example, if M is a multiple of N, then the number of non-feedback precoding vectors determined based on one of the N precoding vectors is equal to g-1, and the number of non-feedback precoding vectors determined based on the N precoding vectors is N(g-1).

[0220] For example, if M is not a multiple of N, then the number of unfeeded precoding vectors determined based on one of the N precoding vectors is equal to or less than g-1.

[0221] For example, two implementations for determining M second precoding vectors are described below.

[0222] In one implementation, the second information is also used to indicate at least one transform function, and the M second precoding vectors are determined based on at least one transform function, N precoding vectors, and a second parameter. Therefore, the second device can determine the unfeeded precoding vectors, i.e., determine the M second precoding vectors, based on at least one transform function, N precoding vectors, and the second parameter.

[0223] For example, the above-mentioned at least one transformation function is f(), and the N precoding vectors are v'1, v'2, v'3, v'4, v'5, v'6, v'7, v'8, v'9, v'1 ... g+1 ,…,v' (N-1)g+1 The second parameter is g, and the M second precoding vectors can satisfy the following formula (1-1):

[0224] Where, vector v' i Let v' be the i-th precoding vector among M second precoding vectors, where i is a positive integer. The i-th vector is any one of the M second precoding vectors, i.e., vector v'. iUsed to represent M second precoding vectors; vector v'1 is the first precoding vector among N precoding vectors, v' g+1 Let v' be the (g+1)th precoding vector among N precoding vectors. (N-1)g+1 It is the (N-1)g+1th precoding vector among N precoding vectors.

[0225] In other words, the second device can determine the unfeeded precoding vectors based on at least one transform function, N precoding vectors, and the second parameter, using the above formula (1-1), that is, determine M second precoding vectors.

[0226] It should be noted that the above formula (1-1) is only an exemplary implementation provided by this application and should not be construed as limiting this application. The above formula (1-1) takes at least one transformation function as a change function f() as an example.

[0227] In this application, at least one transformation function can be multiple functions.

[0228] For example, at least one transformation function can be f1(), f2(), ..., f N (), N precoding vectors are v'1, v' g+1 ,…,v' (N-1)g+1 The M second precoding vectors can satisfy the following formula (1-2):

[0229] The meaning of each parameter can be found in the explanation of formula (1-1) above.

[0230] For example, the i-th precoding vector mentioned above refers to the precoding vector corresponding to the i-th subband.

[0231] For example, the second device can determine the unfeeded precoding vectors, i.e., determine M second precoding vectors, based on at least one transform function, N precoding vectors, a second parameter, and the subband indices corresponding to the N precoding vectors.

[0232] Optionally, the second information can be used to indicate the N precoding vectors and the subband indices corresponding to the N precoding vectors, or the second device can determine the correspondence between the N precoding vectors and the subbands based on the second parameter. For example, the N precoding vectors correspond to subband index 1, subband index g+1, subband index 2g+1, ..., subband index (N-1)g+1 in sequence.

[0233] For example, assuming the total number of subbands is M, the number of reported subbands is N, and the second parameter of the frequency domain reporting granularity is g, then... The reported subband index is {1, g+1, 2g+1, ..., (N-1)g+1}. Then, the second device can determine N based on the first and second parameters, where the first and second parameters can be sent from the second device (e.g., BS) to the first device (e.g., UE) or from the first device to the second device. Furthermore, the second device can obtain M second precoding vectors based on N, the precoding vectors corresponding to one or more subbands, and the transform function f(.), as shown in formula (1-1) above. Each subband corresponds to one precoding vector; i is the subband index, v'... i This is used to represent the precoding vector corresponding to the calculated i-th subband; vector v'1 is the precoding vector corresponding to subband index 1, v' g+1 Let g be the precoding vector corresponding to subband index g+1, ..., v' (N-1)g+1 This is the precoding vector corresponding to subband index (N-1)g+1.

[0234] Optionally, the CSI feedback information obtained by the second device may also include the frequency domain reporting granularity (such as the second parameter or the fourth parameter) and the reporting subband width (such as the first parameter or the third parameter) recommended by the first device.

[0235] For example, see Figure 7, which is a schematic diagram of determining second information provided in this application. In this application, the second information can also be referred to as feedback information. Taking the l-th layer as an example, the second information may include the N precoding vectors corresponding to the l-th layer and the transformation function G corresponding to the l-th layer. l The first precoding matrix can be either precoding matrix 1 or precoding matrix 2 as described above. The first precoding matrix includes sub-matrices corresponding to v spatial streams. Taking the l-th spatial stream (i.e., the l-th layer) as an example, the first device can determine M first precoding vectors from the sub-matrices corresponding to the l-th spatial stream (see S5031 for an example), determine N precoding vectors from the M first precoding vectors (see S5032 for an example), and determine the transformation function G based on the M first precoding vectors and the N precoding vectors. l .

[0236] In another implementation, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, and the M second precoding vectors are determined based on at least one eigenvalue matrix, at least one eigenvector matrix, N precoding vectors, and the second parameter.

[0237] For example, the aforementioned at least one eigenvalue matrix is ​​Λ l At least one eigenvector matrix is ​​ψ l The M second precoding vectors can satisfy the following formula (2):

[0238] Among them, v'i,l This is used to represent the precoding vector recovered from the precoding vector corresponding to the i-th subband of layer l in the second precoding matrix. The N precoding vectors are v'1, v'... g+1 ,…,v' (N-1)g+1 .

[0239] It should be noted that formula (2) is illustrated by taking the example that the eigenvalue matrix and eigenvector matrix corresponding to the N groups of vectors are the same. In this application, the eigenvalue matrix and / or eigenvector matrix corresponding to different groups of vectors in the N groups of vectors may also be different. This application does not limit this.

[0240] In formula (2), the first vector in each group of vectors (v'1, v') g+1 ,…,v' (N-1)g+1 Taking the reported precoding vectors (i.e., N precoding vectors) as an example, the first vector in a group can be the vector with the highest or lowest frequency in that group. In other embodiments of this application, the N precoding vectors can also be vectors whose frequency is at the median value in the N groups of vectors, or vectors determined by other methods, and this application does not limit them.

[0241] This application can be applied to the CSI compressed feedback method based on DMD.

[0242] Optionally, in this application, the precoded vector matrix W of each of the N groups of vectors in each layer can be based on the CSI compression feedback method of DMD. l Perform compression feedback. The method for obtaining N sets of vectors can be exemplarily described in step S5032.

[0243] For example, the first device can be a first device, and the second device can be a second device. According to the protocol predefined, the second device and the first device can be pre-configured, or the first device can obtain the compression matrix Q through online training. l The first device can use Q l For the compression of the first precoding matrix, W sub,l =Q l H W l Then, the first device calculates the transformation matrix G for each group. l The feedback information includes the precoding vector w of the first subband of each group. 1,l and the transformation matrix G l The precoding vector corresponding to the first subband of each group can refer to the precoding vector corresponding to the subband with the lowest or highest frequency domain in that group of precoding vectors.

[0244] Alternatively, the transformation matrix G can be obtained by construction. l Approximate eigendecomposition G l ≈ψl Λ l ψ l H , among which, Λ l This represents a diagonal matrix composed of eigenvalues. In this case, the feedback information is the precoded vector w. 1,l , eigenvalue matrix Λ of the transformation matrix l and the eigenvector matrix ψ l It should be understood that this is because precoding vector recovery involves matrix G. l The chain multiplication of these matrices, if directly quantized and fed back, may cause error accumulation during the recovery process. The aforementioned approximate eigendecomposition facilitates the calculation of this matrix chain multiplication w. k,l ≈ψ l Λ l k ψ l H w 1,l This reduces errors during the recovery process.

[0245] Taking the recovery process of a precoded vector as an example, the recovery method is as follows:

[0246] Among them, v' 1,l The precoding vector v' is used to represent the precoding vector recovered based on the precoding vector corresponding to the first subband of layer l fed back by the UE. i,l This is used to represent the precoding vector corresponding to the i-th subband of the predicted layer l.

[0247] The formulas in this application are merely examples. In other embodiments of this application, other formulas or other methods (such as neural networks) may be used to predict precoded vectors, such as non-iterative prediction methods.

[0248] For example, the number of reported sub-bands N can be determined by the first parameter and the second parameter, where g is the second parameter representing the frequency domain reporting granularity.

[0249] Compared with the scheme in Figure 4, the eigenvalue matrix Λ of the feedback information transformation matrix... l and the eigenvector matrix ψ l The subband precoding vector remains unchanged, but is determined by w. 1,l Change to w 1,l ,w g+1,l ,…,w(N-1)g+1,l.

[0250] Optionally, the first information is obtained by the second device from the first device, or the first information is determined by the second device.

[0251] Optionally, if the first information is determined by the second device, the second device may send the first information to the first device.

[0252] Optionally, the second device may send a first indication message to the first device, the first indication message being used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the second precoding matrix.

[0253] This application does not limit whether the second device sends the first instruction information. For example, the second device may send the first instruction information as stipulated by the protocol, or the second device may determine on its own whether to send the first instruction information.

[0254] This application does not limit the criteria by which the second device determines whether to send the first indication information. For example, the criteria may be related to at least one of the following: historical channel information (such as CSI), the current channel information feedback period of the system (such as the CSI feedback period), the prediction requirements of channel information, the prediction requirements of the motion state of the first device (such as the terminal), or the accuracy requirements of channel information (such as CSI).

[0255] For example, if the CSI information that the second device (e.g., a base station) can store has not expired, such as if the time since the last CSI report is short (high probability of still being valid), or if the time interval between the acquisition time of the CSI information from the first device stored by the second device and the current time is less than a preset duration, then the CSI information stored by the second device is considered not to have expired. In this case, the second device can directly specify the first information, i.e., the second device does not send the first indication information. If the CSI information stored by the first device has expired, such as if the time since the last CSI report is long (possibly expired), or if the time interval between the acquisition time of the CSI information from the first device stored by the second device and the current time is not less than a preset duration, then the second device can send the first indication information. The first indication information is used to indicate that the first device (e.g., a terminal) should first calculate the feedback information (such as the above N precoding vectors and at least one transformation function) according to the parameters specified by the second device (i.e., the above-mentioned reporting configuration parameters), and then check whether the performance of the feedback information meets the requirements. If it does, it should be fed back directly; otherwise, the first device should calculate the first information itself. Optionally, the M second precoding vectors correspond to the same spatial stream.

[0256] It should be noted that this application primarily uses a sub-matrix (i.e., M first precoding vectors or M second precoding matrix vectors) corresponding to a single spatial stream (referred to as the first spatial stream for ease of description) as an example for illustration. If the first precoding vector matrix includes sub-matrices corresponding to multiple spatial streams, the processing procedure for the sub-matrices corresponding to other spatial streams can refer to the processing procedure for the first sub-matrix (i.e., M first precoding matrix vectors or M second precoding matrix vectors) corresponding to the first spatial stream. The processing procedures for sub-matrices corresponding to different spatial streams within the first precoding vector matrix can be the same or different. This processing procedure includes precoding vector feedback and prediction, among other things.

[0257] The communication device provided in this application will now be described in detail with reference to Figures 8 to 10.

[0258] It is understood that, in order to achieve the functions in the above embodiments, the communication device includes hardware structures and / or software modules corresponding to each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0259] Figures 8 to 10 are schematic diagrams illustrating possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the first or second device in the above method embodiments, and thus also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be one of the terminals 120a-120j shown in Figure 1, or it can be RAN node 110a or 110b shown in Figure 1. Optionally, it can also be a module (such as a chip) applied to the first or second device.

[0260] As shown in Figure 8, the communication device 1500 includes a processing unit 1510 and a transceiver unit 1520. The transceiver unit 1520 and the processing unit 1510 can be software, hardware, or a combination of both. Optionally, the communication device 1500 may further include a storage unit for storing device program code and / or data, not shown in Figure 8.

[0261] The transceiver unit 1520 can implement sending and / or receiving functions. Optionally, the transceiver unit 1520 can also be called a communication unit or an acquisition unit, etc. The transceiver unit 1520 may further include a receiving unit and / or a sending unit, wherein the receiving unit is used to implement the receiving function, and the sending unit is used to implement the sending function. Optionally, the transceiver unit 1520 can be used to receive information sent by other devices, and can also be used to send information to other devices.

[0262] In one implementation, the communication device 1500 is used to implement the function of the first device in the method embodiment shown in FIG5 above. For example, the first device can be a terminal or a communication module in the terminal, or a circuit or chip in the terminal responsible for communication functions. Alternatively, the communication device 1500 is used to implement the function of the second device in the method embodiment shown in FIG5 above. For example, the second device can be a network device, a module in the network device (e.g., a circuit, a chip, or a chip system), or a logic node, logic module, or software that can implement all or part of the functions of the network device.

[0263] In another implementation, the communication device 1500 is used to implement the function of the first device in the method embodiment shown in FIG5 above. For example, the first device can be a network device, a module in the network device (e.g., a circuit, a chip or a chip system, etc.), or a logic node, logic module or software that can implement all or part of the functions of the network device, etc. Alternatively, the communication device 1500 is used to implement the function of the second device in the method embodiment shown in FIG5 above. For example, the second device can be a terminal or a communication module in the terminal, or a circuit or chip in the terminal that is responsible for communication functions.

[0264] When the communication device 1500 is used to implement the function of the first device in the method embodiment shown in FIG5: the processing unit 1510 is used to: obtain a first precoding matrix, the first precoding matrix corresponding to a first frequency band; obtain first information, wherein the first information is used to indicate a first parameter and a second parameter, the first parameter is used to indicate the sub-band width corresponding to the first frequency band, and the second parameter is used to indicate the frequency domain granularity corresponding to the first precoding matrix; the transceiver unit 1520 is used to send first channel information to the second device based on the first information, the first channel information including the second information, the second information being used to indicate N precoding vectors, the N precoding vectors being determined from M first precoding vectors based on the second parameter, the M first precoding vectors belonging to the first precoding matrix, the M first precoding vectors corresponding to M sub-bands, the M sub-bands being determined based on the first frequency band and the first parameter, and M and N being positive integers.

[0265] Alternatively, the processing unit 1510 is configured to: acquire a first precoding matrix, the first precoding matrix corresponding to a first frequency band; and the transceiver unit 1520 is configured to: acquire first information, wherein the first information is used to indicate a first parameter and a second parameter, the first parameter is used to indicate the sub-band width corresponding to the first frequency band, and the second parameter is used to indicate the frequency domain granularity corresponding to the first precoding matrix; and based on the first information, send first channel information to a second device, the first channel information including the second information, the second information being used to indicate N precoding vectors, the N precoding vectors being determined from M first precoding vectors based on the second parameter, the M first precoding vectors belonging to the first precoding matrix, the M first precoding vectors corresponding to M sub-bands, the M sub-bands being determined based on the first frequency band and the first parameter, and M and N being positive integers.

[0266] In one possible implementation, the first information is obtained by the first device from the second device, or the first information is determined by the first device.

[0267] In one possible implementation, the transceiver unit 1520 is further configured to: receive first indication information, the first indication information being used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix.

[0268] Optionally, if the first information is determined by the first device, the first channel information may further include the first information.

[0269] For example, if the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then L, k, and g are positive integers.

[0270] Optionally, the M first precoding vectors correspond to the same spatial stream.

[0271] Optionally, the second information is also used to indicate at least one transformation function, which is determined based on M first precoding vectors.

[0272] Optionally, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, which are determined based on M first precoding vectors.

[0273] Yes, N precoding vectors are used to determine the precoding vectors that have not been fed back.

[0274] In one possible design, when the communication device 1500 is a first device or a communication module within a first device, the functionality of the processing unit 1510 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) or SIP chip containing a modem core. The functionality of the transceiver unit 1520 can be implemented by transceiver circuitry.

[0275] In one possible design, when the communication device 1500 is a circuit or chip responsible for communication functions in the first device, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing unit 1510 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the transceiver unit 1520 can be implemented by interface circuitry or data transceiver circuitry on the aforementioned chip.

[0276] When the communication device 1500 is used to implement the function of the second device in the method embodiment shown in FIG5: the transceiver unit 1520 is used to: acquire first channel information, the first channel information including second information, the second information being used to indicate N precoding vectors; the processing unit 1510 is used to: determine a second precoding matrix based on the first information and the second information, wherein the second precoding matrix corresponds to a first frequency band, the first information is used to indicate a first parameter and a second parameter, the first parameter is used to indicate the subband width corresponding to the first frequency band, the second parameter is used to indicate the frequency domain granularity corresponding to the second precoding matrix; the second precoding matrix includes M second precoding vectors, the M second precoding vectors are determined based on the N precoding vectors and the second parameter, the M second precoding vectors correspond to M subbands, the M subbands are determined based on the first frequency band and the first parameter, and M and N are positive integers.

[0277] In one possible implementation, the M second precoding vectors comprise the N precoding vectors and the unfeeded precoding vectors.

[0278] Optionally, the first information is obtained by the second device from the first device, or the first information is determined by the second device.

[0279] In one possible implementation, the transceiver unit 1520 is further configured to: send first indication information, the first indication information being used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the second precoding matrix.

[0280] In one possible implementation, if the first information is determined by the second device, the transceiver unit 1520 is also used to: send the first information.

[0281] For example, if the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then

[0282] Optionally, the M second precoding vectors correspond to the same spatial stream.

[0283] Optionally, the second information is also used to indicate at least one transformation function, and the M second precoding vectors are determined based on at least one transformation function, N precoding vectors, and the second parameter.

[0284] Optionally, the second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, wherein the M second precoding vectors are determined based on at least one eigenvalue matrix, at least one eigenvector matrix, N precoding vectors, and a second parameter.

[0285] For a more detailed description of the processing unit 1510 and the transceiver unit 1520, please refer to the relevant description in the method embodiment shown in Figure 5.

[0286] It is understood that the division of units in the above-described device is merely a logical functional division. Each function can correspond to a functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into a single physical entity, or they can be distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0287] In one example, the functional unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as: one or more application-specific integrated circuits (ASICs), or one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0288] In one example, the storage unit described in this application may include random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, and / or registers, etc.

[0289] As shown in Figure 9, the communication device 1600 includes a processor 1610, and optionally an interface circuit 1620. The processor 1610 and the interface circuit 1620 are coupled to each other. It is understood that the interface circuit 1620 can be a transceiver or an input / output interface. Optionally, the communication device 1600 may also include a memory 1630 for storing computer programs or instructions executed by the processor 1610, or storing input data required by the processor 1610 to execute instructions, or storing data generated by the processor 1610 after executing computer programs or instructions.

[0290] When the communication device 1600 is used to implement the method shown in FIG5, the processor 1610 is used to implement the function of the processing unit 1510, and the interface circuit 1620 is used to implement the function of the transceiver unit 1520.

[0291] When the aforementioned communication device is a chip applied to the first device, the first device chip implements the functions of the first device in the above method embodiments. The first device chip receives information sent to the first device by the second device through other modules (such as radio frequency modules or antennas) in the first device; or, the first device chip sends information to other modules (such as radio frequency modules or antennas) in the first device, and this information is sent from the first device to the second device.

[0292] When the aforementioned communication device is a module applied to the second device, the second device module implements the functions of the second device in the above method embodiments. The second device module receives information from other modules (such as a radio frequency module or antenna) in the second device, information sent from the first device to the second device; or, the second device module sends information to other modules (such as a radio frequency module or antenna) in the second device, information sent from the second device to the first device. Here, the second device module can be the baseband chip of the second device, or a CU, DU, or other module, or a device under an open radio access network (O-RAN) architecture, such as an open CU, open DU, etc.

[0293] As shown in Figure 10, the communication device includes a processor 1710, a memory 1720, and a transceiver 1730. The processor 1710 is mainly used for processing communication protocols and communication data; controlling the first / second device; executing software programs; and processing data from the software programs. The memory 1720 can store computer program code, software programs, and data. The transceiver 1730 includes a transmitter 1731, a receiver 1732, radio frequency circuitry (not shown in Figure 10), and an antenna 1733.

[0294] The processor 1710 can also be called a processing unit, processing board, processing module, or processing device. The transceiver 1730 can also be called a transceiver unit, transceiver, or transceiver device.

[0295] Optionally, the device in transceiver 1730 used to implement the receiving function can be considered a receiving module, and the device in transceiver 1730 used to implement the transmitting function can be considered a transmitting module. That is, transceiver 1730 includes a receiver and / or a transmitter. A transceiver may also be called a transceiver unit, transceiver module, or transceiver circuit, etc. A receiver may also be called a receiver unit, receiving module, or receiving circuit, etc. A transmitter may also be called a transmitter, transmitting module, or transmitting circuit, etc.

[0296] The processor 1710 is used to execute the processing actions of the first device in the embodiment shown in FIG. 5; the transceiver 1730 is used to execute the transmission and reception actions of the first device in the embodiment shown in FIG. 5. Alternatively, the processor 1710 is used to execute the processing actions of the second device in the embodiment shown in FIG. 5; the transceiver 1730 is used to execute the transmission and reception actions of the second device in the embodiment shown in FIG. 5.

[0297] When the communication device 1700 is a chip, the chip includes a processor and a transceiver. The transceiver can be an input / output circuit or a communication interface. The processor can be a processing module integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the transmitting operation of the first device can be understood as the chip's output, and the receiving operation of the first device can be understood as the chip's input. Similarly, in the above method embodiments, the transmitting operation of the second device can be understood as the chip's output, and the receiving operation of the second device can be understood as the chip's input.

[0298] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the method executed by the first device or the second device in the above method embodiments.

[0299] For example, when the computer program is executed by a computer, it enables the computer to implement the method performed by the first device or the second device in the above method embodiments.

[0300] This application also provides a computer program product containing a program or instructions, which, when executed by a computer, causes the computer to perform the method executed by the first device or the second device in the above method embodiments.

[0301] This application also provides a communication system, which includes a first device and a second device as described in the above embodiments. The first device is used to perform some or all of the operations performed by the first device in the above method embodiments, and the second device is used to perform some or all of the operations performed by the second device in the above method embodiments.

[0302] This application also provides a chip device, including a processor, for calling a computer program or computer instructions stored in the memory, so that the processor executes the method provided in the embodiment shown in FIG5 above.

[0303] In one possible implementation, the input of the chip device corresponds to the receiving operation in the embodiment shown in FIG5 above, and the output of the chip device corresponds to the sending operation in the embodiment shown in FIG5 above.

[0304] Optionally, the processor is coupled to the memory via an interface.

[0305] Optionally, the chip device may also include a memory in which computer programs or computer instructions are stored.

[0306] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0307] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a second device or a first device. The processor and the storage medium can also exist as discrete components in the second device or the first device.

[0308] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0309] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0310] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, The method includes: Obtain the first precoding matrix, which corresponds to the first frequency band; Obtain first information, wherein the first information is used to indicate a first parameter and a second parameter, the first parameter is used to indicate the sub-band width corresponding to the first frequency band, and the second parameter is used to indicate the frequency domain granularity corresponding to the first precoding matrix. Based on the first information, first channel information is transmitted. The first channel information includes second information, which is used to indicate N precoding vectors. The N precoding vectors are determined from M first precoding vectors based on the second parameter. The M first precoding vectors belong to the first precoding matrix. The M first precoding vectors correspond to M subbands. The M subbands are determined based on the first frequency band and the first parameter, where M and N are positive integers.

2. The method according to claim 1, characterized in that, The first information is obtained by the first device from the second device, or the first information is determined by the first device.

3. The method according to claim 1 or 2, characterized in that, The method further includes: The device receives a first indication message, which instructs the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the first precoding matrix.

4. The method according to any one of claims 1-3, characterized in that, If the first information is determined by the first device, then the first channel information also includes the first information.

5. The method according to any one of claims 1-4, characterized in that, If the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then L, k, and g are positive integers.

6. The method according to any one of claims 1-5, characterized in that, The M first precoding vectors correspond to the same spatial stream.

7. The method according to any one of claims 1-6, characterized in that, The second information is also used to indicate at least one transformation function, which is determined based on the M first precoding vectors.

8. The method according to any one of claims 1-6, characterized in that, The second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, which are determined based on the M first precoding vectors.

9. The method according to any one of claims 1-8, characterized in that, The N precoding vectors are used to determine the precoding vectors that have not been fed back.

10. The method according to any one of claims 1-9, characterized in that, The frequency domain granularity is based on sub-bands as frequency domain units. The second parameter is g, which indicates that the frequency domain granularity corresponding to the first precoding matrix is ​​g sub-bands. In the M first precoding vectors, one of the g precoding vectors belongs to the N precoding vectors, where g is a positive integer.

11. A communication method, characterized in that, The method includes: Obtain first channel information, the first channel information including second information, the second information being used to indicate N precoding vectors; Based on the first information and the second information, a second precoding matrix is ​​determined, wherein the second precoding matrix corresponds to a first frequency band, the first information is used to indicate a first parameter and a second parameter, the first parameter is used to indicate the sub-band width corresponding to the first frequency band, and the second information is used to indicate the frequency domain granularity corresponding to the second precoding matrix; The second precoding matrix includes M second precoding vectors, which are determined based on the N precoding vectors and the second parameter. The M second precoding vectors correspond to M subbands, which are determined based on the first frequency band and the first parameter. M and N are positive integers.

12. The method according to claim 11, characterized in that, The M second precoding vectors include the N precoding vectors and the precoding vectors that have not been fed back.

13. The method according to claim 11 or 12, characterized in that, The first information is obtained by the second device from the first device, or the first information is determined by the second device.

14. The method according to claim 11 or 13, characterized in that, The method further includes: Send a first indication message, which is used to instruct the first device to determine the sub-band width corresponding to the first frequency band and the frequency domain granularity corresponding to the second precoding matrix.

15. The method according to any one of claims 11-14, characterized in that, If the first information is determined by the second device, the method further includes: Send the first message.

16. The method according to any one of claims 11-15, characterized in that, If the first frequency band has L frequency domain units and the first parameter is k, then And / or, if the second parameter is g, then 17. The method according to any one of claims 11-16, characterized in that, The M second precoding vectors correspond to the same spatial stream.

18. The method according to any one of claims 11-17, characterized in that, The second information is also used to indicate at least one transformation function. The M second precoding vectors are determined based on the at least one transformation function, the N precoding vectors, and the second parameter.

19. The method according to any one of claims 11-17, characterized in that, The second information is also used to indicate at least one eigenvalue matrix and at least one eigenvector matrix, wherein the M second precoding vectors are determined based on the at least one eigenvalue matrix, the at least one eigenvector matrix, the N precoding vectors, and the second parameter.

20. The method according to any one of claims 11-19, characterized in that, The frequency domain granularity is based on sub-bands as frequency domain units. The second parameter is g, which indicates that the frequency domain granularity corresponding to the first precoding matrix is ​​g sub-bands. In the M first precoding vectors, one of the g precoding vectors belongs to the N precoding vectors, where g is a positive integer.

21. A communication device, characterized in that, Includes modules or units for performing the method according to any one of claims 1 to 20.

22. A communication device, characterized in that, The device includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices and transmit them to the processor or to send signals from the processor to other communication devices, and the processor is used through logic circuits or executing code instructions to cause the communication device to implement the method as described in any one of claims 1 to 20.

23. A readable storage medium, characterized in that, Used to store computer programs or instructions, which are executed by one or more processors, causing an apparatus including the one or more processors to perform the method as described in any one of claims 1 to 20.

24. A computer program product, characterized in that, When the computer program product is run on an electronic device, it causes the electronic device to perform the method as described in any one of claims 1 to 20.

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