Communication method and apparatus

Abstract

A communication method and apparatus, which relate to the technical field of communications. In the method, a first communication apparatus can acquire a first precoding matrix, wherein the first precoding matrix comprises a first sub-matrix corresponding to a first spatial stream and a second sub-matrix corresponding to a second spatial stream, the vector, which corresponds to a first time-frequency unit in the first sub-matrix, being a first vector, and the vector, which corresponds to a first time-frequency unit in the second sub-matrix, being a second vector; the first communication apparatus calibrates the first precoding matrix to obtain a second precoding matrix, wherein the second precoding matrix comprises a third sub-matrix corresponding to the first spatial stream, the vector, which corresponds to a first time-frequency unit in the third sub-matrix, being a second vector; and the first communication apparatus sends first information, wherein the first information is obtained by means of compressing the second precoding matrix. The method can improve the compression efficiency of channel information (such as a precoding matrix) and improve the feedback performance of the channel information.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202411960667.6, filed with the State Intellectual Property Office of China on December 26, 2024, 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. 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 improve the compression efficiency of channel information and enhance the feedback performance of channel information.

[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 communication device (or, as can be expressed, that the method can be executed by the first communication device). The first communication 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 functions; or, the first communication 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 functions.

[0007] Taking the application of this method to a first communication device as an example, the first communication device can obtain a first precoding matrix, wherein the first precoding matrix includes a first sub-matrix corresponding to a first spatial stream and a second sub-matrix corresponding to a second spatial stream. The vector corresponding to the first time-frequency unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​a second vector. The first communication device calibrates the first precoding matrix to obtain a second precoding matrix, wherein the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​a second vector. The first communication device sends first information, which is obtained by compression based on the second precoding matrix.

[0008] In this embodiment, the vector corresponding to the first time-frequency unit may include multiple vectors, such as a first vector (abbreviated as vector 1) and a second vector (which becomes vector 2). Before calibration, vector 1 is located in the matrix corresponding to the first spatial flow (abbreviated as flow 1) (i.e., the first sub-matrix mentioned above), and vector 2 is located in the matrix corresponding to the second spatial flow (abbreviated as flow 2) (i.e., the second sub-matrix mentioned above). After calibration, vector 2 is located in the matrix corresponding to the first spatial flow. This application does not limit the position of vector 1 after calibration.

[0009] In other words, the flow position of vector 2 has been calibrated (from flow 2 to flow 1), and the flow order of multiple vectors corresponding to the first time-frequency unit in the precoding matrix has been calibrated.

[0010] This method can calibrate the streaming order of vectors corresponding to the first time-frequency unit in the precoding matrix (such as the first and second vectors mentioned above), which can meet the needs of multi-space streaming scenarios. It can improve the poor compression performance caused by poor streaming order of vectors in the precoding matrix, as well as problems such as ill-conditioned matrix and excessive fitting error, improve the compression efficiency of channel information (such as the precoding matrix), and improve the feedback performance of channel information.

[0011] In other words, the first precoding matrix includes a first vector set corresponding to the first time-frequency unit, and the first vector set includes a first vector and a second vector. In the first precoding matrix, the first vector corresponds to a first spatial stream, and the second vector in the first precoding matrix corresponds to a second spatial stream. The first communication device calibrates the first precoding matrix to obtain a second precoding matrix. The second precoding matrix includes a second vector set corresponding to the second time-frequency unit, and the second vector set includes a first vector and a second vector. In the first precoding matrix, the first vector corresponds to a second spatial stream or other spatial streams (such as a third spatial stream), and the second vector in the first precoding matrix corresponds to a first spatial stream.

[0012] In this application, the correspondence between a spatial flow and a vector means that the vector lies on the matrix corresponding to the spatial flow, or that the matrix corresponding to the spatial flow includes the vector.

[0013] The first time-frequency unit can be any time-frequency unit in the first precoding matrix. The first precoding matrix can include one or more time-frequency units, and each time-frequency unit can correspond to multiple vectors. For ease of description, the vectors corresponding to a time-frequency unit can be referred to as a vector set (such as the first vector set mentioned above). Therefore, the first precoding matrix can be calibrated according to the stream order of one vector set or the stream order of multiple vector sets. This application does not limit this.

[0014] For example, assuming the time-frequency unit is a sub-band, then one of the vector sets included in the first precoding matrix corresponds to a sub-band. A vector set includes multiple vectors, and each of the multiple vectors corresponds to a stream. In this embodiment of the application, the first communication device can calibrate the stream order of at least one vector set corresponding to a sub-band, that is, the correspondence between at least one vector set (such as the first vector and the second vector) and the stream has been calibrated.

[0015] In another example, assuming the time-frequency unit is a time slot, then one of the vector sets in the first precoding matrix mentioned above corresponds to a time slot. A vector set includes multiple vectors, and each of the multiple vectors corresponds to a stream. In this embodiment of the application, the first communication device can calibrate the stream order of at least one vector set corresponding to a time slot, that is, the correspondence between at least one vector set (such as the first vector and the second vector) and the stream has been calibrated.

[0016] Optionally, the second precoding matrix includes a fourth submatrix corresponding to the second spatial stream, where the vector corresponding to the first time-frequency unit in the fourth submatrix is ​​the first vector. That is, in the first precoding matrix, the first vector (vector 1) corresponding to the first time-frequency unit in the first submatrix corresponding to the first spatial stream (stream 1) and the second vector (vector 2) corresponding to the first time-frequency unit in the second submatrix corresponding to the second spatial stream (stream 2) have their positions interchanged. Simply put, before calibration, stream 1 corresponds to vector 1, and stream 2 corresponds to vector 1; after calibration, stream 1 corresponds to vector 2, and stream 2 corresponds to vector 1.

[0017] Alternatively, the vector corresponding to the first time-frequency unit in the aforementioned fourth sub-matrix can be the vector corresponding to the first time-frequency unit in other spatial flows (such as the first precoding matrix and the second precoding matrix, which also include a third spatial flow), and the second vector can be the vector corresponding to the first time-frequency unit in other spatial flows (such as the third vector corresponding to the third spatial flow, referred to as vector 3). That is to say, before calibration, flow 1 corresponds to vector 1, flow 2 corresponds to vector 1, and flow 3 corresponds to vector 3; after calibration, flow 1 corresponds to vector 2, flow 2 corresponds to vector 3, and flow 3 corresponds to vector 1.

[0018] It should be noted that, for ease of description, in this application, the precoding matrix before calibration is referred to as the first precoding matrix, and the precoding matrix obtained by calibration based on the first precoding matrix is ​​referred to as the second precoding matrix; the matrix corresponding to the first spatial stream before calibration is referred to as the first sub-matrix, and the matrix corresponding to the first spatial stream after calibration is referred to as the third sub-matrix. That is to say, after calibration, the matrix corresponding to the first spatial stream changes from the first sub-matrix to the third sub-matrix; the matrix corresponding to the second spatial stream before calibration is referred to as the second sub-matrix, and the matrix corresponding to the second spatial stream after calibration is referred to as the fourth sub-matrix. That is to say, after calibration, the matrix corresponding to the second spatial stream changes from the second sub-matrix to the fourth sub-matrix.

[0019] In conjunction with the first aspect, in one possible implementation, the correlation between the first vector and at least one vector in the first submatrix other than the first vector does not satisfy the first condition. For example, at least one vector can be a neighboring vector of the first vector in the first submatrix, and the first condition can be that the correlation between the first vector and the neighboring vector is higher than a first value; or, the first condition can be that the correlation between the first vector and other vectors corresponding to the same time-frequency unit of the neighboring vector is lower than a second value. This application does not limit the first condition, and specific examples of the first condition can be found in the criteria in step S905 below. The first value and the second value are set thresholds, and this application does not limit the specific values ​​of the first value and the second value.

[0020] Here, the adjacent vectors of the first vector refer to the vectors in the first submatrix that are closest to the first vector in frequency or time.

[0021] Optionally, the time-frequency unit corresponding to the first vector is the aforementioned first time-frequency unit.

[0022] Optionally, in the first precoding matrix prior to this application, the correlation patterns (such as at least one of a matrix, vector, or function) formed by vectors corresponding to different time-frequency units in the same stream in the frequency domain and / or time domain do not conform to a certain rule. For example, the correlation between the first vector in the first sub-matrix corresponding to the first spatial stream in the first precoding matrix and other vectors in the first sub-matrix (such as adjacent vectors of the first vector in the first sub-matrix) is low. After calibration, in the second precoding matrix, the correlation patterns (such as at least one of a matrix, vector, or function) formed by vectors corresponding to different time-frequency units in the same stream in the frequency domain and / or time domain conform to a certain rule. For example, the correlation between the first vector in the third sub-matrix corresponding to the first spatial stream in the second precoding matrix and other vectors in the third sub-matrix (such as adjacent vectors of the first vector in the third sub-matrix) is low.

[0023] Optionally, the correlation of vectors in at least one submatrix corresponding to a spatial flow in the first precoding matrix is ​​lower than the correlation of vectors in the submatrix corresponding to the same spatial flow in the second precoding matrix. For example, the correlation of vectors in the first submatrix corresponding to the first spatial flow in the first precoding matrix is ​​lower than the correlation of vectors in the third submatrix corresponding to the first spatial flow in the second precoding matrix.

[0024] Optionally, the first communication device sends first information, which is obtained based on the second precoding matrix. This can mean that the first communication device sends first information based on the second precoding matrix.

[0025] In this application, a vector may also be referred to as a vector or a precoding vector; if the above-mentioned time-frequency unit (such as the first time-frequency unit) is a frequency domain unit, then the precoding matrix (such as the first precoding matrix) may also be referred to as a subband precoding or a subband precoding matrix, and this application does not limit it in this regard.

[0026] In conjunction with the first aspect, in one possible implementation, the aforementioned time-frequency unit is a frequency domain unit or a time domain unit. For example, the frequency domain unit can be a subband, subcarrier, precoding resource group (PRG), RB, or other frequency domain unit; the time domain unit can be a slot, symbol, or other time domain unit, which is not limited in this application.

[0027] In this embodiment, if the aforementioned time-frequency unit is a frequency domain unit, the present embodiment can improve the difficulty of performing flow-by-flow frequency domain compression during frequency domain compression by calibrating the flow order of the vectors corresponding to the first frequency domain unit in the precoding matrix. Furthermore, this problem affects frequency domain compression performance (requiring more basis vectors, i.e., more bits, for compression at the same precision, resulting in lower precision for the same overhead), and for compression algorithms based on the smooth variation of the flow in the frequency domain, problems such as matrix ill-conditioning and excessive fitting errors may occur. Therefore, the present embodiment can also improve compression performance and address the aforementioned problems of matrix ill-conditioning and excessive fitting errors.

[0028] In this embodiment of the application, if the above-mentioned time-frequency unit is a time-domain unit, then this embodiment of the application can improve the problem of difficulty in performing stream-by-stream frequency-domain compression during time-domain compression by calibrating the flow order of the vector corresponding to the first time-domain unit in the precoding matrix.

[0029] In this application, the compression processing mode of the first communication device after calibrating the first precoding matrix is ​​a newly defined compression processing mode in this application, which can correspond to the operation of stream order calibration in the time domain and / or frequency domain.

[0030] The operation of stream order calibration in the frequency domain corresponds to a frequency domain unit. Specifically, the first communication device can acquire a first precoding matrix, which includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream. The vector corresponding to the first frequency domain unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first frequency domain unit in the second sub-matrix is ​​a second vector. The first communication device calibrates the first precoding matrix to obtain a second precoding matrix, which includes a third sub-matrix corresponding to the first spatial stream. The vector corresponding to the first frequency domain unit in the third sub-matrix is ​​a second vector. The first communication device then sends first information, which is obtained by compressing the second precoding matrix.

[0031] The operation of stream sequence calibration in the time domain corresponds to a time domain unit. Specifically, the first communication device can acquire a first precoding matrix, which includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream. The vector corresponding to the first time domain unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first time domain unit in the second sub-matrix is ​​a second vector. The first communication device calibrates the first precoding matrix to obtain a second precoding matrix, which includes a third sub-matrix corresponding to the first spatial stream. The vector corresponding to the first time domain unit in the third sub-matrix is ​​a second vector. The first communication device then sends first information, which is obtained by compressing the second precoding matrix.

[0032] In conjunction with the first aspect, in one possible implementation, the method further includes: the first communication device can send first indication information and / or second indication information, wherein the first indication information is used to indicate a first spatial stream and / or a second spatial stream, and the second indication information is used to indicate a first time-frequency unit.

[0033] In this embodiment, after calibrating the precoding matrix, the first communication device can instruct the second communication device on the calibrated time-frequency unit (such as the first time-frequency unit mentioned above) and the spatial stream corresponding to the vector of the calibrated time-frequency unit (such as the first spatial stream and / or the second spatial stream mentioned above). This method is beneficial for the second communication device to subsequently process the precoding matrix (such as calibration) or configure the parameters of the calibrated spatial stream, such as configuring a modulation and coding scheme (MCS) or quadrature amplitude modulation (QAM), which can help improve the rate / throughput / spectral efficiency of MIMO transmission.

[0034] Optionally, at least one of the first instruction information and the second instruction information and the aforementioned first information may be carried in the same signaling message or may be sent separately; this application does not limit this.

[0035] In conjunction with the first aspect, in one possible implementation, the difference between the first parameter of the first spatial stream and the second spatial stream is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal to interference plus noise ratio (SINR) or singular value, channel quality indication (CQI) or MCS.

[0036] In this embodiment, the first communication device can indicate to the second communication device a spatial stream that satisfies the above condition (i.e., the difference between the first parameters of the two spatial streams is greater than a first threshold of the first parameters). For ease of description, the two spatial streams that satisfy the above condition can be considered as strong and weak streams. This method can indicate the strong and weak streams with calibrated order to the second communication device, which can process based on the indication, thereby improving the problem of poor transmission performance caused by strong and weak streams being assigned excessively high / low MCS and QAM.

[0037] Alternatively, the first communication device may simply indicate to the second communication device the strong and weak streams that have been calibrated in sequence (such as the first spatial stream and the second spatial stream that meet the above conditions). This method can reduce communication overhead while improving transmission performance.

[0038] Optionally, a spatial flow that does not meet the above conditions can be called a similar intensity flow. Even if the first communication device calibrates the similar intensity flow, the first communication device may not report the calibration information of the similar intensity flow.

[0039] In conjunction with the first aspect, in one possible implementation, the method further includes: the first communication device can send third indication information, the third indication information being used to indicate the ability to calibrate the first precoded matrix.

[0040] In this embodiment of the application, the first communication device can indicate its ability to calibrate the precoding matrix (hereinafter referred to as calibration capability) to the second communication device, which is beneficial to the information alignment between the first and second communication devices, so that the second communication device can instruct calibration operations based on the calibration capability of the first communication device, thereby improving the accuracy of the calibration operation.

[0041] In conjunction with the first aspect, in one possible implementation, the method further includes: a first communication device can receive fourth indication information, the fourth indication information being used to indicate a calibration operation; the first communication device calibrates the first precoding matrix, including: calibrating the first precoding matrix based on the calibration operation.

[0042] Optionally, the first communication device may perform calibration based on the aforementioned fourth indication information, or it may determine the calibration operation itself; this application does not limit this.

[0043] In conjunction with the first aspect, in one possible implementation, the method further includes, prior to: a first communication device receiving a first reference signal; the first communication device acquiring a first precoding matrix, including: obtaining a third precoding matrix based on the first reference signal; and performing a first processing on the third precoding matrix to obtain the first precoding matrix, the first processing including a sampling operation and / or a dimensionality reduction operation.

[0044] For example, the sampling operation or dimensionality reduction transformation targets the antenna dimension of the first precoding matrix.

[0045] In this embodiment of the application, the first communication device can perform the first processing on the precoding matrix before calibrating the precoding matrix, thereby reducing the size of the precoding matrix and helping to reduce computational complexity.

[0046] Secondly, this application provides a communication method that can be applied to a second communication device (or, as can be expressed, that the method can be executed by the second communication device). The second communication 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.

[0047] Taking the application of this method to a second communication device as an example, in this method, the second communication device acquires first information; the second communication device decompresses the first information to obtain a second precoding matrix; wherein, the second precoding matrix is ​​obtained by calibrating the first precoding matrix, the first precoding matrix includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream, the vector corresponding to the first time-frequency unit in the first sub-matrix is ​​the first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​the second vector; the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​the second vector.

[0048] In conjunction with the second aspect, in one possible implementation, the time-frequency unit is either a frequency domain unit or a time domain unit.

[0049] In conjunction with the second aspect, in one possible implementation, the method further includes: a second communication device acquiring first indication information and / or second indication information, wherein the first indication information is used to indicate a first spatial stream and / or a second spatial stream, and the second indication information is used to indicate a first time-frequency unit.

[0050] In conjunction with the second aspect, in one possible implementation, the difference between the first parameter of the first spatial stream and the second spatial stream is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, channel quality indicator (CQI) or modulation and coding scheme (MCS).

[0051] In conjunction with the second aspect, in one possible implementation, the method further includes: a second communication device receiving third indication information, the third indication information being used to indicate the capability to calibrate the first precoding matrix.

[0052] In conjunction with the second aspect, in one possible implementation, the method further includes: a second communication device sending fourth indication information, the fourth indication information being used to indicate a calibration operation, the first precoded matrix being obtained based on the calibration operation.

[0053] In conjunction with the second aspect, in one possible implementation, the method further includes, prior to: a second communication device transmitting a first reference signal, wherein the first precoding matrix is ​​obtained based on the first reference signal.

[0054] In conjunction with the second aspect, in one possible implementation, the method further includes: the second communication device calibrating the second precoding matrix to obtain the first precoding matrix.

[0055] In conjunction with the second aspect, in one possible implementation, the method further includes: a second communication device performing a second processing on the second precoding matrix to obtain a first precoding matrix, the second processing including interpolation operations and / or dimensionality increase operations.

[0056] 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.

[0057] 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.

[0058] Optionally, the communication device further includes a transceiver for sending and receiving information.

[0059] 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.

[0060] In one possible design, the communication device can be a chip that implements the above method or a device containing a chip.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] In a sixth aspect, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer or processor, implement the method shown in any of the first to second aspects, or any possible implementation thereof.

[0067] In a seventh aspect, this application provides a computer program product, including a program or instructions that, when read and executed by a computer, cause the computer to perform any of the methods of the first aspect to the second aspect, or any possible implementation thereof.

[0068] 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.

[0069] Ninthly, this application provides a communication system that may include a first communication device and a second communication device. The first communication device is used to perform the method shown in the first aspect or any possible implementation thereof. The second communication device is used to perform the method shown in the second aspect or any possible implementation thereof. Attached Figure Description

[0070] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0071] Figure 2 is a schematic diagram of the architecture of a communication system provided in this application;

[0072] 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;

[0073] Figure 4A is a schematic diagram of a channel information granularity provided in an embodiment of this application;

[0074] Figure 4B is a flowchart of the 3GPP Type II compression scheme;

[0075] Figure 5A is a schematic diagram of uncalibrated compression provided in an embodiment of this application;

[0076] Figure 5B is a schematic diagram of a compression calibration provided in an embodiment of this application;

[0077] Figure 6 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0078] Figure 7 is a schematic diagram of obtaining a first precoding matrix according to an embodiment of this application;

[0079] Figures 8A and 8B are schematic diagrams related to the first process provided in the embodiments of this application;

[0080] Figure 9 is a schematic diagram of another communication method provided by an exemplary embodiment of this application;

[0081] Figure 10 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0082] Figure 11 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0083] Figure 12 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application. Detailed Implementation

[0084] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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) or transmit / receive 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 in-vehicle equipment. 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.

[0097] 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).

[0098] 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.

[0099] For example, please refer to Figure 2, which is a schematic diagram of the architecture of a 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] A terminal is a device or module that connects to the aforementioned communication system and possesses corresponding communication functions. Terminals can also be referred to as terminal equipment, user equipment (UE), user devices, access terminals, user units, user stations, mobile stations, mobile stations (MS), remote stations, remote terminals, mobile devices, user terminals, terminal units, terminal stations, terminal devices, wireless communication equipment, user agents, or user devices, etc. Terminals typically contain communication modules, circuits, or chips that perform the corresponding communication functions. They can 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), the 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 1. Channel Information

[0118] Channel information represents information that reflects channel characteristics and channel quality.

[0119] As an example, channel information includes at least one of the following: channel state information (CSI), channel time-varying information, channel frequency offset information, or channel information obtained by multiplying CSI by a precoding matrix. The following explanation primarily uses CSI as an example of channel information; however, it is understood that any information reflecting channel characteristics and channel quality is applicable to the embodiments of this application.

[0120] Taking the method of obtaining downlink CSI through uplink feedback from terminal devices on the network side as an example, specifically, the network side sends downlink reference signals to the terminal devices, and the terminal devices receive the downlink reference signals. Since the terminal devices know the transmission information of the downlink reference signals, they can estimate (or measure) the downlink channel that the downlink reference signals have passed through based on the received downlink reference signals. Then, based on the measurement, the terminal devices can obtain the downlink channel matrix, generate CSI, and feed the CSI back to the network side.

[0121] As an example, CSI includes at least one of the following: CQI, precoding matrix indicator (PMI), rank indicator (RI), CSI-RS resource indicator (CRI), layer indicator (LI), reference signal received power (RSRP), SINR, synchronization signal / physical broadcast channel block resource indicator (SSBRI), etc.

[0122] 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.

[0123] 2. Channel matrix and precoding matrix

[0124] 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.

[0125] 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.

[0126] In MIMO systems, each transmit antenna (virtual or physical) has an independent channel. For example, in the uplink and downlink, to achieve channel quality measurement in a multi-antenna system, NR systems define various pilot symbols: Channel State Information-Reference Signal (CSI-RS), Demodulation Reference Signal (DMRS), and Sounding Reference Signal (SRS). DMRS assists in demodulating the physical downlink shared channel (PDSCH). CSI-RS is used for downlink channel measurement corresponding to each physical antenna port. The receiver performs channel estimation for each antenna port transmitted by the base station and uses the estimation results for CSI feedback. CSI includes relevant information such as CQI, PMI, LI, and RI. During uplink channel measurement, the base station (BS) estimates the uplink channel using the received SRS and can use this information to perform frequency selection resource scheduling, power control, timing estimation and modulation / coding scheme order selection, and downlink precoding generation in TDD.

[0127] The high accuracy and low overhead of CSI feedback are crucial for achieving high transmission throughput in downlink MIMO. In future communication scenarios, the overhead of CSI feedback will increase rapidly with the increase in the number of antennas and bandwidth.

[0128] Typically, CSI feedback includes RI, PMI, and CQI. PMI is used to provide feedback on the UE's proposed precoding matrix (such as a second precoding matrix); CQI is used to provide feedback on the channel quality received by the UE, and is usually an index value corresponding to a specific modulation and coding scheme (MCS). In existing protocols, CQI is provided per codeword (or per stream in the case of one codeword per stream). CQI granularity is usually coarser than PMI granularity. For example, see Figure 4A, which is a schematic diagram of channel information granularity provided in an embodiment of this application, where a rectangle represents a PRG. Figure 4A exemplarily shows that for PMI, eight PRGs form a subband; each PRG can correspond to a precoding matrix.

[0129] Regarding PMI in CSI feedback, there are currently two common feedback methods: Type I and Type II codebooks. Type I codebooks use a feedback method that only provides the codebook index, while Type II codebooks use a feedback method that combines the codebook index with quantization coefficients.

[0130] For example, see Figure 4B, which is a flowchart of the 3GPP Type II compression scheme. The process may include: First, performing SVD decomposition on the two-dimensional data corresponding to each RB (or frequency point, subcarrier) of the downlink channel matrix H to obtain the decomposition result; extracting v singular vectors corresponding to the TX dimension from the decomposition result (i.e., forming the precoding matrix on the BS side, where v corresponds to the number of spatial streams in the precoding); then, performing Discrete Fourier Transform (DFT) codebook projection and dimensionality reduction operations on the two-dimensional data W corresponding to each spatial stream (for example, the selected codebooks are matrices W1 and W2). f (corresponding to the transmit antenna dimension and frequency domain dimension respectively), to obtain the coefficient matrix W'2, and then perform quantization and compression operations on the coefficient matrix; the final feedback information (i.e., compressed bitstream) may include matrices W1 and W... f Each column corresponds to the sequence number of the DFT codebook and the coefficients and indication information in W'2.

[0131] The inventors of this application discovered through research that, whether it is the R16 Type II codebook feedback scheme based on DFT codebook index and quantization coefficients, or some other compression algorithms based on frequency domain patterns, when compressing the precoding matrix in the frequency / time domain, they all encounter the problem of difficulty in stream-by-stream frequency domain compression due to the transposition of the stream order, thus affecting the frequency domain compression performance. That is, more basis vectors, i.e. more bits, are needed for compression at the same precision, and the precision is lower at the same overhead. In addition, for compression algorithms based on the smooth change law of the stream in the frequency domain, problems such as ill-conditioned matrix and excessive fitting error will occur.

[0132] This application's embodiments address the problems of poor frequency domain compression performance in CSI compression feedback caused by the reordering of streams in large-scale MIMO scenarios, as well as matrix ill-conditioning and excessive fitting errors that may occur in new compression algorithms based on the smooth change law of streams in the frequency domain, by defining a new compression processing mode that corresponds to a "time domain / frequency domain upstream order calibration" pre-operation criterion.

[0133] This application can also use the subband sequence number and flow calibration information for flow calibration via UE feedback, which solves the problem that strong and weak flows with swapped order may be assigned too high / too low MCS and QAM, resulting in impaired transmission performance.

[0134] Optionally, this application can calibrate the precoding matrix for scenarios where the singular values ​​of the SVD decomposition are close. For example, in line-of-sight (LOS) path scenarios, such as in cluster delay line (CDL) models (e.g., the channel model CDL-D), the two paths with the strongest energy have close power. For instance, these two paths usually correspond to the first and second streams of the precoding matrix (i.e., the first and second columns of the precoding matrix). In some subbands, their order may be swapped. For example, the vectors corresponding to the same subband in the first and second streams of the precoding matrix may be swapped, such as the vector corresponding to the subband in the first stream being interchanged with the vector corresponding to the subband in the second stream. If the precoding matrix is ​​directly compressed stream-by-stream in the frequency domain, due to the orthogonal streams, twice the basis vectors are required, which leads to a large compression overhead.

[0135] In this application, the first communication device can calibrate the precoding matrix to reduce the overhead of frequency domain stream-by-stream compression.

[0136] Optionally, the UE can perform flow sequence calibration transparently to the BS. Since this calibration does not affect the MCS and modulation order in the CQI, the UE may not notify the BS of the relevant information regarding flow sequence calibration. For example, if the MCS and modulation order in the CQI of the flow corresponding to the UE's flow sequence calibration are relatively close, the UE may not notify the BS of the relevant information regarding flow sequence calibration.

[0137] Optionally, this application can calibrate the precoding matrix for scenarios where the channel experiences fading in the frequency domain. For example, non-line of sight (NLOS) scenarios (such as the channel model CDL-A) can lead to the exchange of strong and weak streams. If the precoding matrix is ​​directly compressed in the frequency domain stream by stream, the orthogonal streams would require twice the number of basis vectors, resulting in a large compression overhead.

[0138] In this application, the first communication device can calibrate the precoding matrix to reduce the overhead of frequency domain stream-by-stream compression.

[0139] In this application, the UE can also feed back the subband number and flow calibration information to the BS after performing flow order calibration. For example, in the scenario where the order of strong and weak flows is swapped, the UE can feed back the subband number and flow calibration information to the BS. This can prevent the BS from being unaware that the order of strong and weak flows has been swapped and still configuring MCS and QAM based on coarse-grained CQI feedback. It can also prevent the swapped flows from being assigned excessively high / low MCS and QAM, which would lead to impaired transmission performance.

[0140] Figure 5A is a schematic diagram of uncalibrated compression provided in an embodiment of this application. The first precoding matrix is ​​an uncalibrated precoding matrix. Figures 5A and 5B exemplarily show that the first precoding matrix includes sub-matrices corresponding to layer 1 and layer 2. It should be understood that the first precoding matrix may also include sub-matrices corresponding to more layers. This application does not limit the number of sub-matrices corresponding to layers in the first precoding matrix. In Figures 5A and 5B, the correlation patterns (matrix / vector / function) formed by vectors corresponding to the same color sub-bands in the frequency domain of the precoding matrices (such as the first precoding matrix and the second precoding matrix) conform to a certain rule, such as high correlation. The correlation patterns (matrix / vector / function) formed by vectors corresponding to sub-bands of different colors in the frequency domain do not conform to a certain rule, such as low correlation. As can be seen, in the first precoding matrix, there are vectors with different colors in the sub-matrix corresponding to layer 1 and the sub-matrix corresponding to layer 2. That is, there is a problem of low correlation between the vectors corresponding to different sub-bands in the same matrix (or the correlation of the stream in the frequency domain is abrupt or the flatness of the stream in the frequency domain is poor). At this time, if the first precoding matrix is ​​directly compressed as shown in Figure 5A, the number of compressed bits is large and the compression performance is poor.

[0141] Figure 5B is a schematic diagram of compression calibration provided in an embodiment of this application. A first communication device can calibrate a first precoding matrix to obtain a second precoding matrix. As shown in Figure 5B, in the second precoding matrix, the vectors corresponding to each sub-band in the sub-matrix corresponding to layer 1 have the same color, and the vectors corresponding to each sub-band in the sub-matrix corresponding to layer 2 have the same color. That is to say, the vectors corresponding to different sub-bands in the same first-order matrix have a high correlation. Then, the first communication device compresses the second precoding matrix. At this time, the number of compressed bits is smaller, and the compression performance is better. The correlation pattern (matrix / vector / function) formed by the vectors corresponding to different sub-bands in the same first-order matrix in the frequency domain conforms to a certain rule, such as high correlation. High correlation can mean that the flow has good flatness in the frequency domain, or that the correlation of the flow in the frequency domain gradually decreases with the frequency domain interval (rather than there is a sudden change).

[0142] It should be noted that Figures 5A and 5B take frequency domain calibration as an example. This application is also applicable to time domain calibration. For time domain calibration, the sub-bands in Figures 5A and 5B can be replaced with time domain units, such as time slots or symbols.

[0143] 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 instruction information, second instruction information, third 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, 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.

[0144] 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 communication device and a first communication device as examples to illustrate the execution of the interaction, but this application does not limit the execution of the interaction. For example, the method executed by the second communication device in this application can also be implemented by a module (e.g., a circuit, chip, or chip system) in the second communication device, or by a logic node, logic module, or software that can implement all or part of the functions of the second communication device; the method executed by the first communication device in this application can also be implemented by a communication / processing module in the first communication device, or by a circuit or chip (such as a modem chip (also known as a baseband chip), or a SoC chip / SIP chip containing a modem core) in the first communication device responsible for communication / processing functions.

[0145] Please refer to Figure 6, which is a flowchart illustrating a communication method provided in an embodiment of this application. As shown in Figure 6, the communication method may include the following steps:

[0146] Step S601: The first communication device acquires a first precoding matrix, wherein the first precoding matrix includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream, the vector corresponding to the first time-frequency unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​a second vector.

[0147] Optionally, the time-frequency unit can be a frequency domain unit or a time domain unit. For example, a frequency domain unit can refer to a subband, subcarrier, PRG, or RB; as another example, a time domain unit can be a time slot or a symbol.

[0148] In one possible implementation, the first communication device receives a first reference signal; then, based on the first reference signal, obtains a first precoding matrix. For example, the first communication device may receive a first reference signal (such as CSI-RS or SRS); then, based on the first reference signal, estimate a channel matrix (i.e., H, a complex matrix of the number of receive antenna ports multiplied by the number of transmit antenna ports); and perform a first operation on the channel matrix to obtain the precoding matrix. Exemplarily, the first operation may be SVD decomposition (Singular Value Decomposition).

[0149] Optionally, 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 a second spatial stream; the first precoding matrix corresponds to K time-frequency units, that is, the v sub-matrices include vectors corresponding to K time-frequency units, where K is a positive integer.

[0150] In other words, the first precoding matrix comprises K vector sets, each vector set corresponding to a time-frequency unit, and each vector set comprises v vectors, which correspond to v spatial flows. Vectors corresponding to the same spatial flow form one of the aforementioned v sub-matrices. For example, the v vectors corresponding to the first spatial flow are also the first sub-matrix corresponding to the first spatial flow.

[0151] This application does not limit the method by which the first communication device obtains the first precoding matrix.

[0152] For example, as shown in Figure 7, the first precoding matrix can be obtained by performing RB-by-RB SVD on the channel matrix H. The three dimensions of the first precoding matrix correspond to N transmit antennas, v spatial streams, and K subbands, respectively. The first precoding matrix includes v submatrices, each corresponding to a spatial stream, where v, N, and K are all positive integers. Figure 7 exemplarily shows a submatrix W1 of the first precoding matrix.

[0153] In another possible implementation, the first communication device receives a first reference signal from the second communication device; then, based on the first reference signal, a third precoding matrix is ​​obtained; then, the third precoding matrix undergoes a first processing to obtain a first precoding matrix, the first processing including sampling operations and / or dimensionality reduction operations. That is, the method performs sampling operations and / or dimensionality reduction operations before calibrating the precoding matrix. Optionally, the first communication device may also directly calibrate the precoding matrix without performing sampling operations and / or dimensionality reduction operations; this application does not limit this.

[0154] For example, the sampling operation process can be seen in Figure 8A. The first communication device can perform a sampling operation on the matrix corresponding to each spatial stream in the third precoding matrix to obtain the first precoding matrix. Figure 8A exemplarily shows the sampling operation on the matrix W1 corresponding to the first spatial stream in the third precoding matrix, resulting in the submatrix W1 corresponding to W1. sub，1 As shown in Figure 8A, the three dimensions of the first precoding matrix correspond to N' transmit antennas, v spatial streams, and K subbands, respectively. The first precoding matrix includes v submatrices, which correspond to v spatial streams. v, N', and K are all positive integers, and N > N'.

[0155] That is to say, the precoding matrix W corresponding to the l-th spatial stream in the third precoding matrix. l For example, the first communication device can intercept W l A subset of rows (sampling along the corresponding antenna dimension) yields the submatrix W. sub,l Among them, W l It can be any submatrix in the third precoding matrix.

[0156] Optionally, the sampling pattern of the antenna sampling can be determined according to configuration information 1 (or sampling configuration). For example, configuration information 1 is used to indicate a specified sampling pattern; or, for example, configuration information 1 is used to indicate multiple sampling options, each sampling option corresponding to a sampling pattern. Therefore, the first communication device (such as a UE) can dynamically select from the configured multiple sampling options. The aforementioned configuration information 1 can be pre-stored by the first communication device or sent to the first communication device by other devices (such as the first communication device itself), and this application does not limit this.

[0157] This application does not limit the selection criteria for the sampling method of the first communication device. For example, the first communication device can choose W. sub,l The sampling configuration with the highest energy. For example, the first communication device can traverse all sampling methods, and each sampling method can yield a submatrix W. sub,l Calculate W sub,l Energy (e.g., expressed by the L2 norm: ||W) sub,l ||2) ; Assuming there are X sampling methods, X energies can be obtained, where X is a positive integer; Sort the X sampling methods according to their energies and obtain the sampling method with the highest energy as the selected sampling configuration.

[0158] Another exemplary dimensionality reduction process can be seen in Figure 8B. The first communication device can perform a sampling operation on the matrix corresponding to each spatial stream in the third precoding matrix to obtain the first precoding matrix. Figure 8B exemplarily illustrates the dimensionality reduction of the matrix W1 corresponding to the first spatial stream in the third precoding matrix, resulting in the submatrix W1. sub，1 This dimensionality reduction operation can be performed using W. sub,l =W l *Q l It indicates that, among them, W l W is the precoding matrix corresponding to the l-th spatial stream in the third precoding matrix. sub,l Let be the precoding matrix corresponding to the l-th spatial stream in the first precoding matrix. As shown in Figure 8A, the three dimensions of the first precoding matrix correspond to N' transmit antennas, v spatial streams, and K subbands, respectively. The first precoding matrix includes v submatrices, each corresponding to a v spatial stream. v, N', and K are all positive integers, and N > N'.

[0159] Optionally, the first communication device can be configured or dynamically determined based on the dimensionality reduction matrix Q. l , for W l Dimension reduction yields the submatrix W sub,l (W sub,l =W l *Q l ).

[0160] Optionally, the dimensionality reduction transformation pattern is determined based on configuration information 2. For example, configuration information 2 (or dimensionality reduction configuration) is used to specify a dimensionality reduction matrix; or configuration information 2 is used to indicate multiple dimensionality reduction matrices, in which case the first communication device (such as a UE) can dynamically select from the configured multiple dimensionality reduction matrices. The aforementioned configuration information 2 may be pre-stored by the first communication device, or it may be sent to the first communication device by other devices (such as the first communication device), and this application does not limit this.

[0161] For example, the process by which the first communication device (such as a UE) dynamically selects from multiple configured dimensionality reduction matrices can be as follows: the first communication device traverses all dimensionality reduction transformation methods, and each dimensionality reduction transformation method can obtain a submatrix W. sub,l Calculate W sub,l Energy (e.g., expressed by the L2 norm: ||W) sub,l ||2) Suppose there are X ways to reduce dimensions, which can yield X energies, where X is a positive integer; sort the X ways to reduce dimensions according to their energies, and obtain the way to reduce dimensions with the highest energy as the selected dimensionality reduction configuration.

[0162] Optionally, the first communication device may calibrate only the spatial streams that satisfy the second condition, wherein the second condition is: the difference between the first parameters of the two spatial streams is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, CQI or MCS.

[0163] Step S602: The first communication device calibrates the first precoding matrix to obtain a second precoding matrix, wherein the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​the second vector.

[0164] In some embodiments of this application, the first communication device may send a third indication message to the second communication device before performing step S602. The third indication message is used to indicate the ability to calibrate the first precoding matrix.

[0165] In some embodiments of this application, the first communication device may receive fourth indication information from the second communication device before executing step S602. The fourth indication information is used to indicate a calibration operation; then, based on the calibration operation, the first precoding matrix is ​​calibrated. This application does not limit the method by which the second communication device determines the calibration operation; for example, it may be determined based on the calibration capability of the first communication device or based on data requirements.

[0166] For example, the first communication device may send a third indication message to the second communication device, the third indication message being used to indicate the capability to calibrate the first precoding matrix; correspondingly, the second communication device receives the aforementioned third indication message, and then determines a calibration operation based on the third indication message; furthermore, the second communication device sends a fourth indication message to the first communication device, the fourth indication message being used to indicate the calibration operation.

[0167] Step S603: The first communication device sends first information to the second communication device. The first information is obtained by compression based on the second precoding matrix.

[0168] Correspondingly, the second communication device receives the first information from the first communication device.

[0169] In some embodiments of this application, the first communication device may also send first indication information and / or second indication information to the second communication device, wherein the first indication information is used to indicate the first spatial stream and / or the second spatial stream, and the second indication information is used to indicate the first time-frequency unit.

[0170] For example, if the first communication device is a terminal device (such as a UE), then at least one of the first information, the first indication information, or the second indication information can be CSI feedback, and at least one of the first information, the first indication information, or the second indication information can be indicated by uplink control information (UCI); if the first communication device is a network device (such as a BS), then at least one of the first information, the first indication information, or the second indication information can be a transmit precoding matrix indicator (TPMI), and at least one of the first information, the first indication information, or the second indication information can be indicated by downlink control information (DCI) or medium access control-control element (MAC-CE) / RRC.

[0171] Optionally, the spatial stream indicated by the first indication information satisfies the second condition, that is, the first communication device only indicates the spatial stream that satisfies the second condition to the second communication device. The second condition is: the difference between the first parameters of the two spatial streams is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, CQI or MCS.

[0172] Step S604: The second communication device decompresses the first information to obtain the second precoding matrix.

[0173] Step S604 is an optional step.

[0174] In one possible implementation, the second communication device acquires first indication information and / or second indication information, the first indication information being used to indicate a first spatial stream and / or a second spatial stream, and the second indication information being used to indicate a first time-frequency unit.

[0175] Optionally, the second communication device may assign QAM and / or MCS to the spatial stream (such as the first spatial stream and the second spatial stream) of the second precoding matrix based on the aforementioned first indication information and / or second indication information. For example, if the aforementioned first indication information and / or second indication information are used to indicate calibrated strong and weak stream information, then the second communication device may assign QAM and / or MCS to the strong and weak streams to avoid the spatial streams being assigned excessively high / low MCS and QAM, thereby improving transmission performance.

[0176] Optionally, the second communication device can calibrate the second precoding matrix to obtain the first precoding matrix.

[0177] Optionally, the second communication device can perform a second processing on the second precoding matrix to obtain a first precoding matrix. The second processing includes interpolation operations and / or dimensionality increase operations. For example, if the first communication device performs a first processing (such as sampling operations and / or dimensionality reduction operations) on the precoding matrix before calibration, then the second communication device can perform the inverse operation of the first processing (i.e., the second processing) on ​​the received precoding matrix. For example, the inverse operation of the sampling operation (or the second processing corresponding to the sampling operation) is an interpolation operation, and the inverse operation of the dimensionality reduction operation (or the second processing corresponding to the dimensionality reduction operation) is a dimensionality reduction operation.

[0178] The method embodiments shown in Figure 6 above include many possible implementation schemes. Some of these implementation schemes will be illustrated below with reference to Figure 9. It should be noted that related concepts, operations or logical relationships not explained in Figure 9 can be referred to the corresponding descriptions in the embodiments shown in Figure 6.

[0179] In this application, the embodiment shown in FIG9 can be used as a separate embodiment, and the embodiments shown in FIG9 can be used without relying on the technical solution of FIG6; some steps in the embodiments shown in FIG6 can also be used as separate embodiments.

[0180] The communication method provided in this application will be described exemplarily below with reference to Figure 9.

[0181] Figure 9 is a schematic diagram of another communication method provided by an exemplary embodiment of this application. Steps S901, S902, S908, and S909 are all optional steps.

[0182] As shown in Figure 9, the communication method may include the following steps:

[0183] Step S901: The first communication device sends a third instruction message to the second communication device.

[0184] Correspondingly, the second communication device receives third instruction information from the first communication device.

[0185] The third indication information is used to indicate the ability of the first communication device to calibrate the precoding matrix (hereinafter referred to as the capability of the first communication device).

[0186] For example, the capability of the first communication device may refer to supporting channel information feedback in a first mode or not supporting channel information feedback in the first mode, wherein the first mode refers to a processing mode in which channel information (such as a first precoding matrix) is calibrated and then compressed. Alternatively, the capability of the first communication device may refer to supporting calibration of channel information (such as a first precoding matrix) or not supporting calibration of channel information. For example, a third indication information of 0 indicates that calibration of channel information is not supported; a third indication information of 1 indicates that calibration of channel information is supported.

[0187] Optionally, the first mode may refer to calibration in the time domain and / or calibration in the frequency domain. Calibration in the time domain refers to stream-order calibration of multiple vectors corresponding to at least one time-domain unit in the precoding matrix; calibration in the frequency domain refers to stream-order calibration of multiple vectors corresponding to at least one frequency-domain unit in the precoding matrix.

[0188] Optionally, the first mode may also specifically indicate a calibration operation (or calibration metric) for calibrating the channel information.

[0189] Furthermore, the capability of the first communication device can also refer to: not supporting calibration of channel information, or calibration operations (or calibration criteria) for calibrating channel information. For example, a third indication information of 0 indicates that calibration of channel information is not supported; a third indication information of 1 indicates a first type of calibration operation; and a third indication information of 2 indicates a second type of calibration operation. This application does not limit the calibration operation; an exemplary example can be found in step S905.

[0190] Another exemplary case is that the third indication information can be used to indicate the capability level of the first communication device. Among them, different capability levels can correspond to different metrics. For example, the capability level of the first communication device can be determined based on at least one of the following parameters, such as antenna dimension, number of ports, frequency domain bandwidth, number of subbands, or frequency domain density of reference signals (such as CSI-RS). For example, if the capability level of the first communication device is determined based on the antenna dimension, when the number of transmit antennas increases, the precoding vector becomes longer, and the computational complexity of the corresponding stream order calibration is also greater. Then, the higher the capability level of the first communication device; and / or, if the capability level of the first communication device is determined based on the number of ports, the larger the number of ports, the greater the computational complexity of the corresponding stream order calibration. Then, the higher the capability level of the first communication device; and / or, if the capability level of the first communication device is determined based on the frequency domain bandwidth, number of subbands, and CSI-RS frequency domain density, the larger the bandwidth, the more the number of subbands, and the higher the CSI-RS frequency domain density, the greater the computational complexity of the corresponding stream order calibration. Then, the higher the capability level of the first communication device.

[0191] Exemplarily, the metrics based on stream order calibration include metric A1, metric A2, and metric A3 in step S905. Since from the perspective of computational complexity, metric A1 < metric A2 < metric A3, when the capability level of the first communication device is relatively high, a metric with a higher computational complexity can be selected. It should be understood that the higher the computational complexity, the higher the requirements for the computing and storage capabilities of the first communication device (such as UE).

[0192] Another exemplary case is that the stream order calibration based on per-stream / stream combination includes Metric B0 to Metric B3 in step S905. When the capability level of the first communication device is relatively low, the stream order calibration based on per-stream / stream combination can be selected. It should be understood that when the total number of streams is the same, the computational complexity of per-stream is greater than that of stream combination for the corresponding stream order calibration.

[0193] Exemplarily, the second communication device is a network device (such as a base station), and the first communication device is a terminal device (UE). The third indication information can be used to indicate the capability of the terminal device. Then, step S903 above can be: The terminal device reports the capability of the terminal device to the network device.

[0194] Step S902: The second communication device sends the fourth indication information to the first communication device.

[0195] Correspondingly, the first communication device receives the fourth indication information from the second communication device.

[0196] Among them, the fourth indication information is used to indicate the calibration operation.

[0197] For example, the fourth indication information can be used to instruct the first communication device to use the first mode. Then, the above step S902 can be: the second communication device instructs the first communication device to use the first mode, that is, the second communication device instructs the first communication device to calibrate the channel information (such as the first precoding matrix) and then compress it.

[0198] Optionally, the fourth indication information can also be used to indicate that both time-domain stream order calibration and frequency-domain stream order calibration are performed simultaneously; or only one type of calibration is performed.

[0199] In other embodiments of this application, if the first communication device does not support the first mode, the second communication device may instruct the first communication device to use the conventional CSI compression processing mode, that is, the conventional CSI feedback method based on Type I or Type II codebooks.

[0200] Optionally, the fourth indication information can also be used to indicate the first threshold.

[0201] Step S903: The second communication device sends a first reference signal to the first communication device.

[0202] Correspondingly, the first communication device receives a first reference signal from the second communication device.

[0203] For example, if the second communication device is a network device (such as a base station), the first communication device is a terminal device (UE), and the first reference signal can be CSI-RS, then the above step S903 can be: the network device sends CSI-RS to the terminal device.

[0204] In another example, if the second communication device is a terminal device (UE), the first communication device is a network device (such as a base station), and the first reference signal can be SRS, then the above step S903 can be: the terminal device sends SRS to the network device.

[0205] Optionally, the network device can send more than one time slot of CSI-RS to allow the terminal device to perform a CSI feedback.

[0206] For example, a network device can send a CSI-RS for one time slot, and then the terminal device can perform CSI measurement and time-domain prediction based on the CSI-RS, and add the result of the time-domain prediction to the CSI feedback.

[0207] Step S904: The first communication device acquires the first precoding matrix based on the first reference signal.

[0208] For example, step S904 can be found in the relevant content of step S601, and will not be repeated here.

[0209] Step S905: The first communication device calibrates the first precoding matrix to obtain the second precoding matrix.

[0210] Optionally, when the first communication device performs stream order calibration on the first precoding matrix, it may operate based on a metric indicated in the first mode. Several metrics are illustrated below.

[0211] In the first implementation, the first communication device can perform frequency domain compression on a stream-by-stream basis on the first precoding matrix. This implementation can be calibrated according to any one of the following criteria, Metric A1 to Metric A3. Each stream corresponding to the first precoding matrix corresponds to a sequence number.

[0212] In this embodiment of the application, the precoding vector of the stream with sequence number k in the m-th subband is denoted as... ).in, Used to represent the complex field, nTX represents the number of transmit antenna ports (i.e., the number of Tx t).

[0213] Metric A1: For streams with the same sequence number, the correlation between the precoding vectors of two adjacent subbands is higher than the threshold A1. This can also be described as the first vector having a higher correlation with its adjacent vector than a first value, i.e., the first value being the threshold A1. This application does not limit the value of the threshold A1.

[0214] In other words, the correlation between the precoding vectors of two adjacent sub-bands in the frequency domain within the sub-matrix corresponding to the same spatial flow in the second precoding matrix is ​​higher than the threshold A1. Here, "adjacent in the frequency domain" means that sub-band 1 can be the sub-band with the closest frequency to sub-band 2 among all sub-bands corresponding to the spatial flow (or one of the two sub-bands with the closest frequency domain), then sub-band 1 and sub-band 2 are adjacent sub-bands.

[0215] Optionally, the threshold A1 can be a fixed value, or different values ​​can be set for different stream numbers.

[0216] Optionally, the threshold A1 can be configured via RRC / MAC-CE / DCI / protocol predefined.

[0217] Metric A2: The correlation between P(k,m) and P(k,m+1) must be higher than the correlation between P(k,m) and P(k',m+1), and this holds for any k'>k.

[0218] Where k' represents all spatial flows other than k.

[0219] Metric A3: For any subband m, it must be guaranteed that... Maximum, where C(·,·) represents calculating the correlation between two vectors, K represents the total number of flows, w m It is a weighting coefficient.

[0220] Optionally, w m The values ​​are all 1; or some are 1 and some are 0.

[0221] Optionally, the sub-band numbers of Metric A1 to Metric A3 can be calibrated sequentially from smallest to largest by default, or sequentially from largest to smallest, or a certain sub-band (e.g., the first / last / middle sub-band) can be fixed as the reference, and all other sub-bands can be calibrated relative to the reference sub-band.

[0222] Alternatively, the aforementioned correlation can also be measured by cosine similarity, vector angle, or vector Euclidean distance.

[0223] In the first implementation, the first communication device can perform frequency domain compression on the first precoding matrix according to stream combinations. In this implementation, calibration can be performed according to any one of the following criteria from Metric B0 to Metric B3. That is, the spatial stream corresponding to the first precoding matrix can be divided into multiple stream combinations, each stream combination includes one or more spatial streams, and each stream combination corresponds to a group number.

[0224] Metric B0: The metric based on flow-by-flow calibration can be used entirely. However, when reporting calibration information (such as the first indication information), it can be reported in the form of flow combination. For example, if a flow in flow combination 1 with group number 1 has been calibrated, when the first communication device reports the first indication information, the first indication information may include indication information for indicating flow combination 1, such as group number 1.

[0225] Metric B1: For streams in the same sequence group, the minimum (or average / maximum) correlation of the precoding vector sets of two adjacent subbands is higher than the threshold B1. This application does not limit the value of the threshold B1.

[0226] Among them, the same sequence number group refers to the flow in the same flow combination. The flow in the same flow combination has the same group number, which is the group number of the flow combination.

[0227] In other words, assuming the stream combination includes *a* streams, taking two adjacent subbands as subband 1 and subband 2 as an example, each of the *a* vectors corresponding to subband 1 in the *a* streams is combined with any one of the *a* vectors corresponding to subband 2 in the *a* streams, resulting in multiple vector combinations. The correlation of each vector combination is calculated, resulting in multiple correlations. The minimum (or average / maximum) value among these multiple correlations is taken as the correlation of the stream combination. For any stream combination among all stream combinations corresponding to the first precoding matrix, the correlation of this stream combination is higher than the threshold B1.

[0228] Metric B2: The lowest / highest / average / weighted average correlation of {P(k,m)} and {P(k,m+1)} must be higher than the lowest / highest / average / weighted average correlation of {P(k,m)} and {P(k',m+1)}, for any k' > k. Here, {P(k,m)} represents the set of precoding vectors in the m-th subband of the stream with the k-th sequence number (i.e., the combination of streams with sequence number k).

[0229] Metric B3: For any m, it must be guaranteed that... Maximum, where C(·,·) represents calculating the correlation between two vectors, K represents the total number of subbands, w m It is a weighting coefficient. The min function can also be replaced with the max or mean function, etc.

[0230] Optionally, when the first communication device performs stream order calibration on the first precoding matrix, it must satisfy the requirement that the correlation of streams with the same sequence number (or sequence number group) in the frequency domain is higher than a certain threshold. That is, the correlation of streams with the same sequence number (or sequence number group) in the frequency domain in the second precoding matrix is ​​higher than a certain threshold. Here, the correlation of streams with the same sequence number in the frequency domain refers to the correlation between vectors corresponding to subbands within the same stream in the precoding matrix; the correlation of streams with the same sequence number group in the frequency domain refers to the correlation of the combination of streams with that sequence number.

[0231] Optionally, when the first communication device performs stream order calibration on the first precoding matrix in the time domain, it must satisfy the requirement that the correlation between streams with the same sequence number (or sequence number group) in the time domain is higher than a certain threshold. That is to say, the correlation between streams with the same sequence number (or sequence number group) in the second precoding matrix in the frequency domain is higher than a certain threshold.

[0232] Optionally, time-domain flow sequence calibration can be performed regardless of whether time-domain compression is performed on multiple CSI-RS or time-domain prediction is performed on a single CSI-RS.

[0233] In some embodiments of this application, the second communication device is a network device (such as a base station), the first communication device is a terminal device (UE), the first reference signal can be CSI-RS, the network device can first measure CSI-RS, then calculate the first precoding matrix and perform dimensionality reduction, then perform stream order calibration on the first precoding matrix, and then perform CSI compression.

[0234] Optionally, when the first communication device performs stream order calibration on the first precoding matrix, the length of the first precoding matrix vector for a certain stream may not be the number of transmit antennas (ports), but may be a positive integer value less than or equal to the number of transmit antennas. For example, the length of the vector corresponding to a subband in the precoding matrix may be the number of transmit antennas before dimensionality reduction, but less than the number of transmit antennas after dimensionality reduction.

[0235] Optionally, when the first communication device performs stream order calibration on the first precoding matrix, it must satisfy that the correlation between streams with the same sequence number (or sequence number group) in the frequency domain is higher than a certain threshold.

[0236] Optionally, the first condition can be at least one of the criteria selected from Metric A1, Metric A2, Metric A3, Metric B0, Metric B1, Metric B2, or Metric B3. Alternatively, if the first precoding matrix does not satisfy at least one of the criteria (i.e., the first condition), the first precoding matrix is ​​calibrated to obtain a second precoding matrix that satisfies the first condition.

[0237] Step S906: The first communication device compresses the second precoding matrix to obtain the first information.

[0238] This application does not limit the compression method used in step S906; for example, it can be a Type II compression scheme.

[0239] Step S907: The first communication device sends the first information to the second communication device.

[0240] Correspondingly, the second communication device receives the first information from the first communication device.

[0241] For example, if the second communication device is a network device (such as a base station) and the first communication device is a terminal device (UE), and the first information can be CSI, then step S907 can be: the network device sends CSI to the terminal device.

[0242] Step S908: The first communication device sends the first instruction information and the second instruction information to the second communication device.

[0243] Correspondingly, the second communication device receives the first instruction information and the second instruction information sent from the first communication device.

[0244] The second indication information is used to indicate the subband corresponding to the vector being calibrated in the first precoding matrix. The second indication information can also be referred to as the subband information for which the stream order is swapped. The first indication information is used to indicate the spatial stream corresponding to the vector being calibrated in the first precoding matrix. The first indication information can also be referred to as the stream information for which the order is swapped in the subband.

[0245] Optionally, the aforementioned first information, first instruction information, and second instruction information may be carried in the same signaling message or may be sent separately; this application does not limit this.

[0246] Optionally, the second indication information is used to indicate some or all of the subbands where flow sequence calibration has occurred. For example, the first communication device may only feed back the subband sequence number of the strong and weak flow sequence exchange to the second communication device, while the subband sequence number of the similar intensity flow sequence exchange may not be fed back. The distinction between "strong and weak flow" and "similar intensity flow" can be defined based on the difference between the equivalent channel strength / SINR / singularity of the flow being greater than (less than) a certain threshold.

[0247] For example, the threshold can be indicated by a combination of flows or all flows (e.g., setting a threshold for each flow combination; or, a threshold for all flows), and can be configured via RRC / MAC-CE / DCI / protocol predefined, etc.

[0248] For example, the second indication information can be one or more sub-band numbers, or the information can include a sub-band number and at least one incremental information, whereby the sub-band number and the incremental information can identify other sub-bands. For instance, if the sub-band numbers that need to be fed back among 16 sub-bands are {5,7,11}, the second indication information can be {5,7,11}, or it can be {5,+2,+4} (i.e., incremental feedback sub-band numbers).

[0249] Optionally, the number of subbands indicated by the first indication information is less than the second threshold. This method can limit the number of feedback subband sequence numbers, and this threshold can be configured through RRC / MAC-CE / DCI / protocol predefined methods, etc.

[0250] The following examples illustrate two possible implementations of the first instruction information.

[0251] In one possible implementation, the first communication device can feed back the mapping relationship of the flow order before and after calibration in the sub-band to the second communication device. That is, the first indication information can be at least one sequence, each sequence corresponding to a sub-band. For example, the sequence corresponding to the first sub-band is used to indicate the positional relationship of each vector in the vector set corresponding to the first sub-band before and after calibration (i.e., the mapping relationship of the flow order before and after calibration in the sub-band). For example, the vector set corresponding to the first sub-band includes 4 vectors, which correspond to 4 spatial flows respectively. Their mapping relationship before and after calibration is {1→1,2→3,3→2,4→4}, which means that: vector 1 corresponds to flow 1 (no calibration occurred), vector 2 is calibrated from corresponding flow 2 to corresponding flow 3, vector 3 is calibrated from corresponding flow 3 to corresponding flow 2, and vector 4 corresponds to flow 4 (no calibration occurred). The first indication information can be "1,3,2,4".

[0252] In one possible implementation, the first communication device may only feed back the flow sequence number for which flow order calibration is performed to the second communication device. For example, if only the 2nd and 3rd flows were swapped in {1→1,2→3,3→2,4→4}, then only "3,2" can be fed back.

[0253] Optionally, the number of spatial streams indicated by the first indication information is less than a third threshold. This method can limit the number of sequentially exchanged streams fed back, and this threshold can be configured via RRC / MAC-CE / DCI / protocol predefined methods, etc.

[0254] Step S909: The second communication device sends data to the first communication device.

[0255] Correspondingly, the first communication device receives data from the second communication device.

[0256] In one implementation, the second communication device decompresses the first information to obtain a second precoding matrix; then, the second communication device sends data based on the second precoding matrix.

[0257] Optionally, the second communication device may also allocate QAM and / or MCS to the spatial stream (such as the first spatial stream and the second spatial stream) of the second precoding matrix based on the aforementioned first indication information and / or second indication information; and then, the second communication device transmits data based on the second precoding matrix.

[0258] Optionally, the second communication device can calibrate the second precoding matrix to obtain the first precoding matrix; then, the second communication device transmits data based on the first precoding matrix.

[0259] For example, if the second communication device is a network device (such as a base station) and the first communication device is a terminal device (UE), then the above step S909 can be: the network device sends a PDSCH to the terminal device.

[0260] The communication device provided in this application will now be described in detail with reference to Figures 10 to 12.

[0261] 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.

[0262] Figures 10 to 12 are schematic diagrams illustrating the possible structures of communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the first or second communication device (e.g., a base station) in the above-described method embodiments, and thus also achieve the beneficial effects of the above-described 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 a RAN node 110a or 110b shown in Figure 1. Optionally, it can also be a module (e.g., a chip) applied to the first or second communication device.

[0263] As shown in Figure 10, 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 1530 for storing device program code and / or data, not shown in Figure 10.

[0264] 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.

[0265] The communication device 1500 is used to implement the function of the first communication device in the method embodiment shown in FIG5A above. For example, the first communication device can be a terminal or a communication module in the terminal, or a circuit or chip in the terminal responsible for communication function. Alternatively, the communication device 1500 is used to implement the function of the second communication device in the method embodiment shown in FIG5A above. For example, the second communication 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.

[0266] When the communication device 1500 is used to implement the function of the first communication device in the method embodiment shown in FIG5A: the processing unit 1510 is used to: obtain a first precoding matrix, wherein the first precoding matrix includes a first sub-matrix corresponding to a first spatial stream and a second sub-matrix corresponding to a second spatial stream, the vector corresponding to the first time-frequency unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​a second vector; calibrate the first precoding matrix to obtain a second precoding matrix, wherein the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​a second vector;

[0267] The transceiver unit 1520 is used to: send first information, which is obtained by compression based on the second precoding matrix.

[0268] In one possible implementation, the time-frequency unit is either a frequency domain unit or a time domain unit.

[0269] In one possible implementation, the transceiver unit 1520 is further configured to: transmit first indication information and / or second indication information, wherein the first indication information is used to indicate a first spatial stream and / or a second spatial stream, and the second indication information is used to indicate a first time-frequency unit.

[0270] In one possible implementation, the difference between the first parameter of the first spatial stream and the second spatial stream is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, CQI or MCS.

[0271] In one possible implementation, the transceiver unit 1520 is further configured to: transmit third indication information, the third indication information being used to indicate the capability to calibrate the first precoding matrix.

[0272] In one possible implementation, the transceiver unit 1520 is further configured to: receive fourth indication information, the fourth indication information being used to indicate a calibration operation; and the processing unit 1510 is specifically configured to: calibrate the first precoding matrix based on the calibration operation.

[0273] In one possible implementation, transceiver unit 1520 is further configured to: receive a first reference signal; processing unit 1510 is specifically configured to: obtain a third precoding matrix based on the first reference signal; and perform a first processing on the third precoding matrix to obtain a first precoding matrix, the first processing including sampling operations and / or dimensionality reduction operations. In one possible design, when the communication device 1500 is a first communication device or a communication module within a first communication device, the function of 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) chip or a SIP chip containing a modem core. The function of transceiver unit 1520 can be implemented by transceiver circuitry.

[0274] In one possible design, when the communication device 1500 is a circuit or chip responsible for communication functions in the first communication 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.

[0275] When the communication device 1500 is used to implement the function of the second communication device in the method embodiment shown in FIG5A: the transceiver unit 1520 is used to acquire second information, which is obtained by compressing the second precoding matrix; the processing unit 1510 is used to acquire first information; decompress the first information to obtain the second precoding matrix; wherein, the second precoding matrix is ​​obtained by calibrating the first precoding matrix, the first precoding matrix includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream, the vector corresponding to the first time-frequency unit in the first sub-matrix is ​​the first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​the second vector; the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​the second vector.

[0276] In one possible implementation, the time-frequency unit is either a frequency domain unit or a time domain unit.

[0277] In one possible implementation, the transceiver unit 1520 is further configured to: acquire first indication information and / or second indication information, wherein the first indication information is used to indicate a first spatial stream and / or a second spatial stream, and the second indication information is used to indicate a first time-frequency unit.

[0278] In one possible implementation, the difference between the first parameter of the first spatial stream and the second spatial stream is greater than the first threshold corresponding to the first parameter; wherein the first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, CQI or MCS.

[0279] In one possible implementation, the transceiver unit 1520 is further configured to: receive third indication information, the third indication information being used to indicate the capability to calibrate the first precoding matrix.

[0280] In one possible implementation, the transceiver unit 1520 is further configured to: send fourth indication information, the fourth indication information being used to indicate a calibration operation, the first precoding matrix being obtained based on the calibration operation.

[0281] In one possible implementation, the transceiver unit 1520 is further configured to: transmit a first reference signal, wherein the first precoding matrix is ​​obtained based on the first reference signal.

[0282] In one possible implementation, the processing unit 1510 is also used to calibrate the second precoding matrix to obtain the first precoding matrix.

[0283] In one possible implementation, the processing unit 1510 is further configured to perform a second processing on the second precoding matrix to obtain a first precoding matrix, wherein the second processing includes interpolation operations and / or dimensionality increase operations.

[0284] For a more detailed description of the above-mentioned processing unit 1510 and transceiver unit 1520, please refer to the relevant description in the method embodiment shown in FIG5A.

[0285] 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.

[0286] 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.

[0287] In one example, storage unit 1530 may include random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory and / or registers, etc.

[0288] As shown in Figure 11, 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.

[0289] When the communication device 1600 is used to implement the method shown in FIG5A, 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.

[0290] When the aforementioned communication device is a chip applied to the first communication device, the first communication device chip implements the functions of the first communication device in the above method embodiments. The first communication device chip receives information sent to the first communication device by the second communication device through other modules (such as radio frequency modules or antennas) in the first communication device; or, the first communication device chip sends information to other modules (such as radio frequency modules or antennas) in the first communication device, and this information is sent from the first communication device to the second communication device.

[0291] When the aforementioned communication device is a module applied to the second communication device, the second communication device module implements the functions of the second communication device in the above method embodiments. The second communication device module receives information from other modules (such as a radio frequency module or antenna) in the second communication device, the information being sent from the first communication device to the second communication device; or, the second communication device module sends information to other modules (such as a radio frequency module or antenna) in the second communication device, the information being sent from the second communication device to the first communication device. Here, the second communication device module can be the baseband chip of the second communication device, or it can be a CU, DU, or other module, or it can be a device under an open radio access network (O-RAN) architecture, such as an open CU, open DU, etc.

[0292] As shown in Figure 12, 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 communication 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 12), and an antenna 1733.

[0293] 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.

[0294] 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.

[0295] Processor 1710 is used to execute processing operations on the first communication device side in the embodiment shown in FIG. 5A. Transceiver 1730 is used to execute transmit / receive operations on the first communication device side in the embodiment shown in FIG. 5A. Alternatively, processor 1710 is used to execute network-side processing operations in the embodiment shown in FIG. 5A. Transceiver 1730 is used to execute transmit / receive operations on the network side in the embodiment shown in FIG. 5A.

[0296] 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 communication device can be understood as the chip's output, and the receiving operation of the first communication device in the above method embodiments can be understood as the chip's input. Similarly, in the above method embodiments, the transmitting operation of the second communication device can be understood as the chip's output, and the receiving operation of the second communication device in the above method embodiments can be understood as the chip's input.

[0297] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the method executed by the first communication device or the second communication device in the above-described method embodiments.

[0298] For example, when the computer program is executed by a computer, it enables the computer to implement the method performed by the first communication device or the second communication device in the above method embodiments.

[0299] This application also provides a computer program product containing a program or instructions, which, when executed by a computer, causes the computer to implement the method executed by the first communication device or the second communication device in the above method embodiments.

[0300] This application also provides a communication system, which includes a first communication device and a second communication device as described in the above embodiments. The first communication device is used to perform some or all of the operations performed by the first communication device in the above method embodiments, and the second communication device is used to perform some or all of the operations performed by the second communication device in the above method embodiments.

[0301] 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 FIG5A above.

[0302] In one possible implementation, the input of the chip device corresponds to the receiving operation in the embodiment shown in FIG5A above, and the output of the chip device corresponds to the transmitting operation in the embodiment shown in FIG5A above.

[0303] Optionally, the processor is coupled to the memory via an interface.

[0304] Optionally, the chip device may also include a memory in which computer programs or computer instructions are stored.

[0305] 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.

[0306] 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 storage medium can reside in an ASIC. Additionally, the ASIC can reside in a second communication device or a first communication device. The processor and storage medium can also exist as discrete components in the second or first communication device.

[0307] 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.

[0308] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0309] 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 by comprising: The method includes: Obtain a first precoding matrix, wherein the first precoding matrix includes a first sub-matrix corresponding to a first spatial stream and a second sub-matrix corresponding to a second spatial stream, wherein the vector corresponding to the first time-frequency unit in the first sub-matrix is ​​a first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​a second vector; The first precoding matrix is ​​calibrated to obtain a second precoding matrix, wherein the second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​the second vector; Send the first information, which is obtained by compression based on the second precoding matrix.

2. The method of claim 1, wherein, The time-frequency unit is either a frequency domain unit or a time domain unit.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Send a first indication message and / or a second indication message, wherein the first indication message is used to indicate the first spatial stream and / or the second spatial stream, and the second indication message is used to indicate the first time-frequency unit.

4. The method according to any one of claims 1-3, characterized in that, The difference between the first parameter of the first spatial flow and the second spatial flow is greater than the first threshold corresponding to the first parameter; The first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, channel quality indicator (CQI) or modulation and coding scheme (MCS).

5. The method according to any one of claims 1-4, characterized in that, The method further includes: Send a third indication message, which indicates the ability to calibrate the first precoded matrix.

6. The method according to any one of claims 1-5, characterized in that, The method further includes: Receive a fourth indication message, which is used to indicate a calibration operation; The calibration of the first precoding matrix includes: calibrating the first precoding matrix based on the calibration operation.

7. The method according to any one of claims 1-6, characterized in that, Prior to the method, it also includes: Receive the first reference signal; The step of obtaining the first precoding matrix includes: obtaining a third precoding matrix based on the first reference signal; The third precoding matrix is ​​subjected to a first processing to obtain the first precoding matrix. The first processing includes sampling operations and / or dimensionality reduction operations.

8. A communication method characterized by comprising: The method includes: Obtain first information; The first information is decompressed to obtain the second precoding matrix; The second precoding matrix is ​​obtained by calibrating the first precoding matrix. The first precoding matrix includes a first sub-matrix corresponding to the first spatial stream and a second sub-matrix corresponding to the second spatial stream. The vector corresponding to the first time-frequency unit in the first sub-matrix is ​​the first vector, and the vector corresponding to the first time-frequency unit in the second sub-matrix is ​​the second vector. The second precoding matrix includes a third sub-matrix corresponding to the first spatial stream, and the vector corresponding to the first time-frequency unit in the third sub-matrix is ​​the second vector.

9. The method according to claim 8, characterized in that, The time-frequency unit is either a frequency domain unit or a time domain unit.

10. The method according to claim 8 or 9, characterized in that, The method further includes: Acquire first indication information and / or second indication information, wherein the first indication information is used to indicate the first spatial flow and / or the second spatial flow, and the second indication information is used to indicate the first time-frequency unit.

11. The method according to any one of claims 8-10, characterized in that, The difference between the first parameter of the first spatial flow and the second spatial flow is greater than the first threshold corresponding to the first parameter; The first parameter includes at least one of the following: equivalent channel strength, signal-to-interference-plus-noise ratio or singular value, channel quality indicator (CQI) or modulation and coding scheme (MCS).

12. The method according to any one of claims 8-11, characterized in that, The method further includes: Receive third indication information, which indicates the ability to calibrate the first precoding matrix.

13. The method according to any one of claims 8-12, characterized in that, The method further includes: A fourth indication message is sent, which is used to indicate a calibration operation, and the first precoding matrix is ​​obtained based on the calibration operation.

14. The method according to any one of claims 8-13, characterized in that, Prior to the method, it also includes: A first reference signal is transmitted, and the first precoding matrix is ​​obtained based on the first reference signal.

15. The method according to any one of claims 8-14, characterized in that, The method further includes: The second precoding matrix is ​​calibrated to obtain the first precoding matrix.

16. The method according to any one of claims 8-15, characterized in that, The method further includes: The second precoding matrix is ​​subjected to a second processing to obtain the first precoding matrix. The second processing includes interpolation operations and / or dimensionality increase operations.

17. The method according to any one of claims 1-16, characterized in that, The second precoding matrix includes a fourth sub-matrix corresponding to the second spatial stream, wherein the vector corresponding to the first time-frequency unit in the fourth sub-matrix is ​​either the first vector or the vector corresponding to the first time-frequency unit in the third spatial stream.

18. The method according to any one of claims 1-17, characterized in that, The correlation between the first vector and at least one vector in the first submatrix other than the first vector does not satisfy the first condition.

19. A communication device, characterized in that, Includes modules or units for performing the method according to any one of claims 1 to 18.

20. 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 18.

21. 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 18.

22. A computer program product, characterized in that, Includes a program or instructions that, when the computer program product is run on an electronic device, cause the electronic device to perform the method as described in any one of claims 1 to 18.

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