Communication method and apparatus

Abstract

A communication method and apparatus, relating to the technical field of communications. In the method, a first communication apparatus performs, on the basis of a first reference vector in a first pre-coding matrix, phase calibration on a first vector to be calibrated of the first pre-coding matrix to obtain a second pre-coding matrix, compresses the second pre-coding matrix to obtain second information, and sends the second information. The method can improve the compression efficiency of a pre-coding matrix and meet the requirements of ultra-large-scale MIMO.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202411974859.2, filed 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, in this method, the first communication device performs phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain a second precoding matrix; compresses the second precoding matrix to obtain second information; and sends the second information.

[0008] In this application, the phase calibration of the precoding matrix can be achieved through the first reference vector. The phase calibration of the precoding vectors (such as the first calibration vector) corresponding to one or more subbands in the first precoding matrix can improve the compression efficiency of the precoding matrix and meet the requirements of ultra-large-scale MIMO.

[0009] Optionally, the first precoding matrix corresponds to the channel information. Since compressing the precoding matrix with phase abrupt changes can lead to a deterioration in the feedback performance of the channel information, this method can improve the problem of feedback performance deterioration caused by phase abrupt changes in the precoding matrix, thereby improving the compression efficiency of the channel information and improving the feedback performance of the channel information.

[0010] Optionally, the channel information corresponding to the first precoding matrix may refer to channel information (such as CSI) that can be represented by a precoding matrix (such as the first precoding matrix mentioned above).

[0011] In conjunction with the first aspect, in one possible implementation, the first precoding matrix includes a first sub-matrix corresponding to a first spatial stream (layer), wherein the first sub-matrix includes a first reference vector, the first reference vector corresponds to a first sub-band, and the first sub-band is the sub-band with the highest frequency, the lowest frequency, or the median frequency among all sub-bands corresponding to the first sub-matrix; or, the first reference vector is a vector in the first sub-matrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first sub-matrix with a frequency higher than the first vector to be calibrated.

[0012] In this application, subbands can be replaced by subcarriers, precoding resource groups (PRGs), RBs, or other frequency domain units; this application does not limit this.

[0013] In this embodiment, the first sub-band is the sub-band with the highest or lowest frequency among all sub-bands corresponding to the first sub-matrix. That is, the vector corresponding to the highest or lowest frequency sub-band in the first sub-matrix is ​​selected as the reference vector. This method facilitates information caching and phase calibration. For example, if the sub-bands are arranged in descending order of frequency, then the highest or lowest frequency sub-band in the first sub-matrix is ​​also the sub-band on both sides. Using the sub-bands on both sides as references ensures that the vectors requiring calibration are all located on one side, facilitating information caching and phase calibration.

[0014] In this embodiment, the first sub-band is the sub-band with the median frequency among all the sub-bands corresponding to the first sub-matrix (referred to as the middle sub-band). That is to say, the vector corresponding to the sub-band with the median frequency in the first sub-matrix is ​​selected as the reference vector. This method can reduce the cumulative error.

[0015] For example, suppose there are K subbands, where K is a positive integer, and the subbands are arranged in descending order of frequency. If the middle subband (K / 2 or K / 2+1) is selected, the furthest subband is separated by K / 2 subbands. If the lowest or highest frequency subband is selected, the furthest subband is separated by K-1 subbands. Therefore, selecting the middle subband minimizes the cumulative error caused by the frequency spacing.

[0016] Optionally, the first submatrix includes multiple vectors, with different vectors corresponding to different subbands; that is, multiple vectors correspond to multiple subbands. All the subbands corresponding to the first submatrix mentioned above refer to these multiple subbands.

[0017] In conjunction with the first aspect, in one possible implementation, the method further includes: a first communication device sending or receiving first information, wherein the first information is used to indicate a first reference vector.

[0018] In this application, the first information may be sent to the first communication device by other devices (such as the second communication device) or may be determined by the first communication device. This application does not limit this.

[0019] In conjunction with the first aspect, in one possible implementation, the first information is used to indicate the first reference vector, including: the first information is used to indicate the first sub-band, the first sub-band corresponding to the first reference vector; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated.

[0020] In this embodiment of the application, the first information is used to indicate the first reference vector, which may mean: the first information is used to indicate the first sub-band, the first sub-band corresponds to the first reference vector, for example, the first information is the sequence number of the first sub-band; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated, for example, the first information may be used to indicate the frequency relationship between the first reference vector and the first vector to be calibrated, then the first reference vector can be determined based on the first information and the frequency of the first vector to be calibrated.

[0021] In conjunction with the first aspect, in one possible implementation, the first precoding matrix includes v sub-matrices, each sub-matrix corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes a first reference vector and a first calibration vector.

[0022] In conjunction with the first aspect, in one possible implementation, the first vector to be calibrated is some or all of the vectors in the first submatrix except for the first reference vector.

[0023] In conjunction with the first aspect, in one possible implementation, the above-mentioned phase calibration of the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix includes: determining a first phase difference between the first reference vector and the first vector to be calibrated; and performing phase calibration on the first vector to be calibrated in the first precoding matrix based on the first phase difference to obtain the second precoding matrix.

[0024] In conjunction with the first aspect, in one possible implementation, the above-mentioned phase calibration of the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix includes: performing a first processing on the first coding matrix to obtain a third precoding matrix, the third precoding matrix including a second reference vector, the second reference vector corresponding to the first reference vector; and performing phase calibration on the second vector to be calibrated in the third precoding matrix based on the second reference vector to obtain the second precoding matrix, the second vector to be calibrated corresponding to the first vector to be calibrated.

[0025] Optionally, the second reference vector corresponding to the first reference vector may mean that the second reference vector is a vector obtained by performing a first processing on the first reference vector; the second vector to be calibrated corresponding to the first vector to be calibrated may mean that the second vector to be calibrated is a vector obtained by performing a first processing on the first vector to be calibrated.

[0026] For example, the first processing includes at least one of a sampling operation or a dimensionality reduction transformation.

[0027] For example, the sampling operation or dimensionality reduction transformation targets the antenna dimension of the first precoding matrix.

[0028] In this embodiment of the application, a smaller precoding matrix (such as a third precoding matrix) and reference vector (such as a second reference vector) are obtained through the first processing (or transformation operation), which can reduce the complexity of the phase calibration operation and save computing resources on the first communication device side.

[0029] In this application, the first reference vector can also be called the original precoding vector, the second reference vector can also be called the vector obtained after transforming the original precoding vector (referred to as the transformed vector), the first precoding matrix can also be called the original precoding matrix, and the third precoding matrix can also be called the precoding matrix obtained after transformation. This application does not limit the names of the first reference vector, the second reference vector, the first precoding matrix, and the third precoding matrix.

[0030] In conjunction with the first aspect, in one possible implementation, the above-mentioned phase calibration of the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix includes: performing a first processing on the first coding matrix to obtain a third precoding matrix, the third precoding matrix including a second reference vector, the second reference vector corresponding to the first reference vector; and performing phase calibration on the first vector to be calibrated based on the second reference vector to obtain the second precoding matrix.

[0031] In conjunction with the first aspect, in one possible implementation, the above-mentioned phase calibration of the second vector to be calibrated in the third precoding matrix based on the second reference vector to obtain the second precoding matrix includes: determining the second phase difference between the second reference vector and the second vector to be calibrated; and performing phase calibration of the second vector to be calibrated in the third precoding matrix based on the second phase difference to obtain the second precoding matrix.

[0032] In conjunction with the first aspect, in one possible implementation, the method further includes: receiving or sending third information, the third information being used to indicate a first process, the first process including at least one of a sampling operation or a dimensionality reduction transformation.

[0033] Optionally, at least the related information in the first, second, or third message can be sent separately or carried in the same message; this application does not limit this.

[0034] For example, if the first communication device is a terminal device, then at least one of the first, second, or third information can be CSI feedback, and at least one of the first, second, or third information can be indicated by uplink control information (UCI); if the first communication device is a network device, then at least one of the first, second, or third information can be a transmit precoding matrix indicator (TPMI), and at least one of the first, second, or third information can be indicated by downlink control information (DCI), medium access control-control element (MAC-CE), or radio resource control (RRC).

[0035] In conjunction with the first aspect, in one possible implementation, the first process includes a sampling operation, and the third information is further used to indicate at least one of equidistant sampling, sampling interval, or starting antenna number; or, the third information is further used to indicate unequal-spacing sampling and / or sampling information, the sampling information including a bitmap corresponding to the sampling antenna position or the sampling antenna number.

[0036] In this embodiment, by dynamically configuring information related to the first reference vector (i.e., the aforementioned first information) and / or information related to the first processing (i.e., the aforementioned third information), a more flexible phase calibration operation can be achieved. This allows for adaptation of relevant parameters according to different scenario requirements, resulting in better phase calibration performance. For example, when computational resources are limited, the first processing (such as sampling operations and / or dimensionality reduction transformations) can be configured to reduce computational complexity during phase calibration. When computational resources are abundant, the first processing can be omitted, and the original precoding matrix (i.e., the first precoding matrix) can be processed directly.

[0037] In conjunction with the first aspect, in one possible implementation, the first process includes a dimensionality reduction transformation, and the third information is further used to indicate one or more dimensionality reduction matrices, the one or more dimensionality reduction matrices including the dimensionality reduction matrix used in the dimensionality reduction transformation.

[0038] 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.

[0039] Taking the application of this method to a second communication device as an example, the method involves obtaining second information, which is obtained by compressing a second precoding matrix; and obtaining a second precoding matrix based on the second information. The second precoding matrix is ​​obtained by performing phase calibration on a first vector to be calibrated in the first precoding matrix based on a first reference vector in the first precoding matrix.

[0040] Optionally, if the first communication device is a network device, the second communication device can be a terminal; or, if the first communication device is a terminal, the second communication device can be a network device or a terminal.

[0041] In conjunction with the second aspect, in one possible implementation, obtaining the second precoding matrix based on the second information includes: decompressing the second information to obtain the second precoding matrix.

[0042] In conjunction with the second aspect, in one possible implementation, obtaining the second precoding matrix based on the second information includes: decompressing the second information to obtain a third precoding matrix; and performing a second processing on the third precoding matrix to obtain the second precoding matrix.

[0043] In conjunction with the second aspect, in one possible implementation, the method further includes: receiving or sending third information, the third information being used to indicate a first process, the first process including at least one of a sampling operation or a dimensionality reduction transformation, the first process corresponding to a second process, wherein the second process corresponding to the sampling operation is an interpolation operation, and the second process corresponding to the dimensionality reduction transformation is an up-dimensional transformation; the above-mentioned second processing of the third precoding matrix to obtain a second precoding matrix includes: performing a second processing on the third precoding matrix based on the third information to obtain a second precoding matrix.

[0044] In conjunction with the second aspect, in one possible implementation, the first process includes a sampling operation, and the third information is further used to indicate at least one of equidistant sampling, sampling interval, or starting antenna number; or, the third information is further used to indicate unequal-interval sampling and / or sampling information, the sampling information including a bit map corresponding to the antenna position or the number of the sampling antenna.

[0045] In conjunction with the second aspect, in one possible implementation, the first process includes a dimensionality reduction transformation, and the third information is further used to indicate one or more dimensionality reduction matrices, the one or more dimensionality reduction matrices including the dimensionality reduction matrix used in the dimensionality reduction transformation.

[0046] In conjunction with the second aspect, in one possible implementation, the first precoding matrix includes a first sub-matrix corresponding to the first spatial stream, wherein the first sub-matrix includes a first reference vector, the first reference vector corresponds to a first sub-band, and the first sub-band is the sub-band with the highest frequency, the lowest frequency, or the median frequency among all sub-bands corresponding to the first sub-matrix; or, the first reference vector is a vector in the first sub-matrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first sub-matrix with a frequency higher than the first vector to be calibrated.

[0047] In conjunction with the second aspect, in one possible implementation, the method further includes: sending or receiving first information, wherein the first information is used to indicate a first reference vector.

[0048] In conjunction with the second aspect, in one possible implementation, the first information is used to indicate the first reference vector, including: the first information is used to indicate the first sub-band, the first sub-band corresponding to the first reference vector; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated.

[0049] In conjunction with the second aspect, in one possible implementation, the first precoding matrix includes v sub-matrices, each sub-matrix corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes a first reference vector and a first calibration vector.

[0050] In conjunction with the second aspect, in one possible implementation, the first vector to be calibrated is some or all of the vectors in the first submatrix other than the first reference vector.

[0051] 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.

[0052] 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.

[0053] Optionally, the communication device further includes a transceiver for sending and receiving information.

[0054] Optionally, the communication device further includes a memory storing computer programs or instructions; the processor and transceiver are used to invoke the computer programs or instructions in the memory, causing the communication device to implement the methods shown in any of the first or second aspects, or any possible implementation of any of the aspects.

[0055] In one possible design, the communication device can be a chip that implements the above method or a device containing a chip.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] In a seventh aspect, this application provides a computer program product, including a computer program or instructions, which, when read and executed by a computer or processor, cause the computer to perform any of the methods of the first aspect to the second aspect, or any possible implementation thereof.

[0063] 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.

[0064] 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

[0065] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0066] Figure 2 is a schematic diagram of the architecture of the communication system provided in this application;

[0067] 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;

[0068] Figure 4 is a flowchart illustrating the compression scheme provided in an embodiment of this application;

[0069] Figure 5A is a flowchart illustrating a communication method provided in an embodiment of this application;

[0070] Figure 5B is a flowchart illustrating step S501 provided in an embodiment of this application.

[0071] Figures 6A to 6C are schematic diagrams of the precoding matrix provided in the embodiments of this application;

[0072] Figures 7A and 7B are schematic diagrams related to the first process provided in the embodiments of this application;

[0073] Figure 8 is a schematic diagram of the relevant implementation of step S504 provided in the embodiment of this application;

[0074] Figure 9 is a schematic diagram of another communication method provided by example in an embodiment of this application;

[0075] Figure 10 is a schematic diagram of yet another communication method provided by an exemplary embodiment of this application;

[0076] Figure 11 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0077] Figure 12 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0078] Figure 13 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application. Detailed Implementation

[0079] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 is determined solely based on A; B can also be determined based on A and / or other information.

[0086] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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 configured 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).

[0093] 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.

[0094] For example, please refer to Figure 2, which is a schematic diagram of the architecture of the communication system provided in this application. Figure 2 is only a schematic diagram, and the communication system (such as an O-RAN system) may also include other components besides those shown in Figure 2. As shown in Figure 2, the access network device (e.g., it may be an eNB, gNB, or next-generation access network device) communicates with the core network elements in the CN through a backhaul link and communicates with the terminal through the air interface.

[0095] 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.

[0096] 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 may have some core network functions. 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, 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 1. Channel Information

[0113] Channel information represents information that reflects channel characteristics and channel quality.

[0114] 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.

[0115] 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.

[0116] As an example, CSI includes at least one of the following: channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), CSI-RS resource indicator (CRI), layer indicator (LI), reference signal received power (RSRP), signal to interference plus noise ratio (SINR), synchronization signal / physical broadcast channel block resource indicator (SSBRI), etc.

[0117] 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.

[0118] 2. Channel matrix and precoding matrix

[0119] 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.

[0120] 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.

[0121] Ultra-large-scale MIMO is one of the evolutionary trends of future cellular systems (such as 6G systems), and its antenna configuration will further increase: the base station (BS) side will be equipped with thousands of antenna elements; the user equipment (UE) side will also be equipped with more antenna elements (such as 16, 32, etc.) to support more spatial streams. Furthermore, with the increase in carrier frequency, the bandwidth available for allocation in the wireless system will further increase, and the number of subcarriers, resource blocks (RBs), etc., will increase dramatically, significantly increasing the number of frequency points for channel state information (CSI) to be fed back. In this situation, the total size of CSI (such as the BS-side precoding matrix obtained after SVD of the channel matrix at different frequency points (such as subbands, subcarriers, RBs, etc.)) increases significantly, and the data acquired in a single instance reaches millions or even tens of millions of symbols. The data processing and feedback face challenges such as high processing complexity and large data transmission volume, which can be addressed by designing low-complexity decomposition schemes and CSI compression.

[0122] For example, see Figure 4, which is a flowchart of a 3GPP Type II compression scheme for the BS-side precoding matrix. This 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 BS-side precoding matrix, 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 (e.g., selecting matrices W1 and W2 as the codebooks). 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.

[0123] The inventors of this application discovered through research that as the bandwidth increases, the frequency domain characteristics change more significantly. The precoding vectors of adjacent sub-bands, subcarriers, or RBs (i.e., the row or column vectors in the BS-side precoding matrix corresponding to a specific sub-band, subcarrier, or RB) may experience phase abrupt changes. Existing CSI compression schemes (such as 3GPP Type II) do not fully consider this issue, which can lead to deterioration of CSI feedback performance in certain scenarios, ultimately affecting precoding performance.

[0124] The embodiments of this application can address the problem of large variations in the frequency domain characteristics of ultra-large-scale MIMO CSI by designing phase calibration schemes for precoding vectors (such as the first vector to be calibrated) in different subbands, thereby improving the compression efficiency and feedback performance of CSI.

[0125] It should be noted that in the description of this application, "instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information (such as the first information, second information, third 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 indicating other information, where there is a correlation between the other information and the information to be instructed. Another example is that only a part of the information to be instructed can be indicated, while the other parts are known, pre-agreed upon, or deducible. Furthermore, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent.

[0126] 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.

[0127] Please refer to Figure 5A, which is a flowchart illustrating a communication method provided in an embodiment of this application. As shown in Figure 5A, the communication method may include the following steps:

[0128] Step S501: The first communication device performs phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix.

[0129] In some embodiments of this application, before step S501, the first communication device acquires the first precoding matrix. This application does not limit the method by which the first communication device acquires the first precoding matrix or the first precoding matrix itself.

[0130] Optionally, the first precoding matrix includes v sub-matrices, each corresponding to a spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes a first reference vector and a first vector to be calibrated. For example, the first vector to be calibrated can be any part or all of the vectors in the first sub-matrix except for the first reference vector.

[0131] For example, as shown in Figure 6A, 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 6A exemplarily shows a submatrix W1 of the first precoding matrix.

[0132] For example, referring to Figure 5B, step S501 may include some or all of the following steps S5011 to S5014:

[0133] Step S5011: The first communication device determines the reference vector (i.e., the first reference vector) corresponding to the first vector to be calibrated.

[0134] The following provides two possible implementations of the first communication device determining the first reference vector (i.e., implementation 1 and implementation 2 below).

[0135] Implementation method 1: The first communication device can use the vector corresponding to the first sub-band as the reference vector (i.e., the first reference vector) of the first vector to be calibrated. The first sub-band can be a fixed sub-band, such as a sub-band with a fixed frequency.

[0136] For example, the first precoding matrix includes a first sub-matrix corresponding to the first spatial stream. The first sub-matrix includes a first reference vector, which corresponds to a first sub-band. The first sub-band is the sub-band with the highest frequency (referred to as sub-band 1 for ease of description) or the sub-band with the lowest frequency (referred to as sub-band 2 for ease of description) or the sub-band with the median frequency (referred to as sub-band 3 for ease of description) among all the sub-bands corresponding to the first sub-matrix.

[0137] For example, the first sub-band can be a sub-band with a frequency higher than a first threshold, a sub-band with a frequency lower than a second threshold, or a sub-band with a frequency within a preset range, among all the sub-bands corresponding to the first sub-matrix.

[0138] Another example is that the first sub-band can be the sub-band with the frequency closest to sub-band 1 among all the sub-bands corresponding to the first sub-matrix, or the sub-band with the frequency closest to sub-band 2 among all the sub-bands corresponding to the first sub-matrix, or the sub-band with the frequency closest to sub-band 3 among all the sub-bands corresponding to the first sub-matrix.

[0139] Figure 6B exemplarily illustrates the precoding matrix W corresponding to the l-th spatial stream in the first precoding matrix (see Figure 6A). l The first reference vector can be the precoding matrix W. l The precoded vector w l1 w l(K / 2) or w lK Any one of them. Among them, w l1 For W l The first column corresponds to the first sub-band in the frequency domain; w l(K / 2) For W l The K / 2th column corresponds to the K / 2th sub-band in the frequency domain; w lK For W l The Kth column corresponds to the Kth subband in the frequency domain. Assuming the frequencies of subbands 1 through K gradually increase, then w l1 It is W l The subband with the lowest frequency among all corresponding subbands, w l(K / 2) It is W lThe median subband among all corresponding subbands, w lK It is W l The subband with the highest frequency among all corresponding subbands. W l It can be the precoding matrix corresponding to any spatial stream in the first precoding matrix.

[0140] Assume the first submatrix mentioned above is W. l Therefore, the above subband 1 is w lK The above sub-band 2 is w l1 The above sub-band 3 is w l(K / 2) .

[0141] The illustrations in this application (Figure 6B) exemplarily show that the subband number increases from left to right and the subband frequency increases from left to right. In other embodiments of this application, the subband number may also decrease from left to right, and / or the subband frequency may also decrease from left to right. This application does not limit this.

[0142] Optionally, the first subband may be predefined (as specified in the protocol); or, the first subband may be indicated by other devices, such as the second communication device, as described in the relevant description of the first information below; or, the first subband may be determined by the first communication device, which is not limited in this application.

[0143] Optionally, the first subband can be determined based on bandwidth, where bandwidth can refer to the bandwidth corresponding to the first precoding matrix, such as the size of the K subbands mentioned above. For example, when the configured bandwidth is large, selecting the middle subband (such as subband 3 mentioned above) as a reference can reduce the cumulative error of phase calibration; when the configured bandwidth is small, the subbands on both sides (such as subband 1 and subband 2 mentioned above) can be selected as references to facilitate information caching and phase calibration.

[0144] Optionally, the first subband can be determined based on the singular values ​​of subband 1 and subband 2. For example, the first subband can be the subband with the larger singular value between subband 1 and subband 2. The singular values ​​are obtained during RB-by-RB SVD of the channel matrix H. This method selects the subband with the larger singular value as a reference, which provides higher robustness. In other embodiments of this application, the first subband can also be the subband with the smaller singular value between subband 1 and subband 2; this application does not limit this to the latter.

[0145] Optionally, in implementation method 1, any vector to be calibrated in the matrix (such as the first sub-matrix) corresponding to the same spatial flow can correspond to the reference vector corresponding to the same sub-band. Therefore, implementation method 1 can also be called using a fixed sub-band.

[0146] Implementation method 2: The first communication device can determine the reference vector of the first vector to be calibrated as the first reference vector based on the correlation between the first reference vector and the first vector to be calibrated.

[0147] Optionally, the association between the first reference vector and the first vector to be calibrated can be: the first reference vector is a vector in the first submatrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first submatrix with a frequency higher than the first vector to be calibrated.

[0148] Optionally, the association between the first reference vector and the first vector to be calibrated can be as follows: the first reference vector is the vector in the first submatrix whose frequency is closest to the first vector to be calibrated, and the frequency of the first reference vector is lower than that of the first vector to be calibrated; or, the first reference vector is the vector in the first submatrix whose frequency is closest to the first vector to be calibrated, and the frequency of the first reference vector is higher than that of the first vector to be calibrated. For example, assuming that the vectors in the first submatrix whose frequencies are closest to the first vector to be calibrated are vector 1 and vector 2, where the frequency of vector 1 is lower than that of the first vector to be calibrated and the frequency of vector 2 is higher than that of the first vector to be calibrated, the association between the first reference vector and the first vector to be calibrated can be: the first reference vector is vector 1, or the first reference vector is vector 2.

[0149] Optionally, the association between the first reference vector and the first vector to be calibrated can be predefined (as specified in the protocol); or it can be indicated by other devices, such as the second communication device, as described in the relevant description of the first information below; or it can be determined by the first communication device, which is not limited in this application.

[0150] Figure 6C exemplarily illustrates the precoding matrix W corresponding to the l-th spatial stream in the first precoding matrix (see Figure 6A). l W l Including precoded vector w lk w l(k-1) and w l(k+1) , where w lk For W l The k-th column corresponds to the k-th sub-band in the frequency domain; w l(k-1) For W l The (k-1)th column corresponds to the (k-1)th sub-band in the frequency domain; w l(k+1) For W l The (k+1)th column corresponds to the (k+1)th sub-band in the frequency domain. Assume the first vector to be calibrated is w. lk The first reference vector can be w l(k-1) or w l(k+1) .

[0151] Assuming the frequencies of subband 1 to subband K gradually increase, W lThe vector in the first submatrix (also called the first submatrix) whose frequency is closest to the first vector to be calibrated but whose frequency is lower than the first vector to be calibrated is w. l(k-1) So, at this point, w can be... l(k-1) Called located at w lk The vector on the left; W l The vector whose frequency is closest to the first vector to be calibrated and whose frequency is higher than the first vector to be calibrated is w. l(k+1) So, at this point, w can be... l(k+1) Called located at w lk The vector on the right. Therefore, the aforementioned first reference vector, which is the vector in the first submatrix whose frequency is closest to the first vector to be calibrated and whose frequency is lower than the first vector to be calibrated, can mean: the first reference vector is the vector in the first submatrix located to the left of the first vector to be calibrated; the aforementioned first reference vector, which is the vector in the first submatrix whose frequency is closest to the first vector to be calibrated and whose frequency is higher than the first vector to be calibrated, can mean: the first reference vector is the vector in the first submatrix located to the right of the first vector to be calibrated.

[0152] For example, the first vector to be calibrated is multiple vectors in the first submatrix. In implementation method 1, the reference vectors corresponding to different vectors to be calibrated are different.

[0153] Optionally, the subbands corresponding to different precoding vectors in the first precoding matrix are arranged according to their frequency.

[0154] In one possible implementation, the first communication device can send or receive first information, wherein the first information is used to indicate a first reference vector. For example, the first communication device receives first information sent from a second communication device, and then the first communication device uses the first reference vector indicated by the first information as the reference vector corresponding to the first vector to be calibrated.

[0155] For example, the first information used to indicate the first reference vector may refer to: the first information used to indicate the first sub-band, the first sub-band corresponding to the first reference vector, for example, the first information may be the sequence number of the first sub-band; or, the first information used to indicate the association between the first reference vector and the first vector to be calibrated, for example, the first information may be 1 bit of information, which is used to indicate whether it is the left or right side.

[0156] Step S5012: The first communication device determines whether to perform the first processing on the first reference vector. If yes, it executes steps S5013 and S5014; otherwise, it executes steps S5013 and S5014.

[0157] For ease of description, this application refers to steps S5013 and S5014 as processing mode 1, and step S5015 as processing mode 2.

[0158] Step S5012 is optional. The first communication device does not execute step S5012 and directly uses processing mode 1 or processing mode 2 to perform phase calibration.

[0159] Optionally, the first communication device may receive fourth information, which indicates whether to perform first processing on the first reference vector, or in other words, the fourth information indicates whether to adopt processing mode 1 or processing mode 2.

[0160] In one implementation, the first communication device may first perform a first processing on the first encoding matrix to obtain a third precoding matrix, the third precoding matrix including a second reference vector, the second reference vector corresponding to the first reference vector (referred to as the first processing process); then, based on the second reference vector, perform phase calibration on the second vector to be calibrated in the third precoding matrix to obtain a second precoding matrix, the second vector to be calibrated corresponding to the first vector to be calibrated (referred to as the phase calibration process).

[0161] Step S5013: The first communication device performs a first processing on the first encoding matrix to obtain a third precoding matrix. The third precoding matrix includes a second reference vector and a second vector to be calibrated. The second reference vector corresponds to the first reference vector, and the second vector to be calibrated corresponds to the first vector to be calibrated.

[0162] Optionally, the first processing includes at least one of a sampling operation or a dimensionality reduction transformation.

[0163] In one implementation, the first precoding matrix includes v sub-matrices corresponding to the aforementioned v spatial streams, and the first processing of the first encoding matrix by the first communication device may refer to performing the first processing on the aforementioned v sub-matrices.

[0164] For example, the sampling operation process can be seen in Figure 7A. The first communication device can perform a sampling operation on the matrix corresponding to each spatial stream in the first precoding matrix (as shown in Figure 6A) to obtain the third precoding matrix. Figure 7A exemplarily shows the sampling operation on the matrix W1 corresponding to the first spatial stream in the first precoding matrix, resulting in the submatrix W1 corresponding to W1. sub，1 As shown in Figure 7B, the three dimensions of the third precoding matrix correspond to N' transmit antennas, v spatial streams, and K subbands, respectively. The third precoding matrix includes v submatrices, which correspond to v spatial streams. v, N', and K are all positive integers, and N > N'.

[0165] That is to say, the precoding matrix W corresponding to the l-th spatial stream in the first precoding matrix. lFor 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 first precoding matrix.

[0166] 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.

[0167] 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 energy, and obtain the sampling method with the highest energy as the selected sampling configuration.

[0168] Another example of the dimensionality reduction transformation process can be seen in Figure 7B. The first communication device can perform a sampling operation on the matrix corresponding to each spatial stream in the first precoding matrix (as shown in Figure 6A) to obtain the third precoding matrix. Figure 7B exemplarily illustrates the dimensionality reduction of the matrix W1 corresponding to the first spatial stream in the first 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 first precoding matrix. sub,l Let Q be the precoding matrix corresponding to the l-th spatial stream in the third precoding matrix. As shown in Figure 7B, the three dimensions of the third precoding matrix correspond to N' transmit antennas, v spatial streams, and K subbands, respectively. The third precoding matrix includes v submatrices, each corresponding to a v spatial stream, where v, N', and K are all positive integers, and N > N'. Optionally, the first communication device can configure or dynamically determine the dimensionality reduction matrix Q. l, for W l Dimension reduction yields the submatrix W sub,l (W sub,l =W l *Q l ).

[0169] 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.

[0170] 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.

[0171] Optionally, the first communication device performs subsequent operations after performing the sampling operation or dimensionality reduction transformation. For example, the first communication device may further transform the original matrix W based on the reference vector in the submatrix. l Or the sampling matrix W sub,l Phase calibration is performed to obtain the phase-calibrated matrix W'. l or W' sub, l For the phase-calibrated matrix W' l or W' sub,l Further compression yields the compressed bitstream. See below for details; we will not elaborate further here.

[0172] As another example, the first communication device can perform sampling and dimensionality reduction operations on the first precoding matrix to obtain a third precoding matrix. The processes of sampling and dimensionality reduction operations are described above and will not be repeated here. This application does not limit the order in which the first communication device performs the sampling and dimensionality reduction operations.

[0173] Optionally, the method by which the first communication device determines the first processing may be: the first communication device determines it itself, or it is instructed by another device (such as the second device instructing third information), or it is stipulated by the protocol, and this application does not limit it in this regard.

[0174] Optionally, the first communication device may receive or send third information, which is used to instruct the first processing, the first processing including at least one of sampling operation or dimensionality reduction transformation.

[0175] For example, if the first process includes a sampling operation, the third information may also be used to indicate at least one of equal-spaced sampling (or regular sampling), sampling interval, or starting antenna number; or, the third information may also be used to indicate unequal-spaced sampling (or irregular sampling) and / or sampling information, wherein the sampling information includes a bitmap corresponding to the sampling antenna position or the sampling antenna number. The sampling information may include one or more sampling antenna numbers.

[0176] For example, the third information is used to indicate equally spaced sampling, and the first communication device can perform equally spaced sampling on the first precoding matrix. The specific sampling interval or starting antenna number can be preset or determined by other messages. Alternatively, the first indication is used to indicate the sampling interval, and the first communication device can perform equally spaced sampling on the first precoding matrix according to the sampling interval. The specific starting antenna number can be preset or determined by other messages. Or, the first indication is used to indicate the starting antenna number, and the first communication device can perform equally spaced sampling on the first precoding matrix according to the starting antenna number. The specific sampling interval can be preset or determined by other messages. Or, the first indication is used to indicate both the sampling interval and the starting antenna number, and the first communication device can perform equally spaced sampling on the first precoding matrix according to both the sampling interval and the starting antenna number.

[0177] For example, if the first process includes equally spaced sampling, then the third information is used to indicate the sampling interval and the starting antenna number. Table 1 illustrates an 8*6 precoding matrix W. l With a sampling interval of 2 and a starting index of 1, the submatrix W is obtained based on the precoding matrix information corresponding to the TX or BS antennas with indices 1, 3, 5, and 7. sub,l (i.e., the gray part in Table 1).

[0178] For example, if the first process includes unequal-interval sampling, then the third information is used to indicate the sampling antenna position. Taking Table 1 as an example, the first communication device can select antennas with serial numbers 1, 3, 5, and 7 in Table 1. The selected antennas can be represented by a bitmap, a set of indices, or a random seed. For example, the selected antennas can be represented as 10101010 by the bitmap, or as {1, 3, 5, 7} by the set of indices. The random seed is used to determine the sampling method. For example, the first and second communication devices can interact with the random seed to determine the sampling method, and determine the sampling antenna position based on the sampling method. Alternatively, the first communication device can select antennas with serial numbers 1, 2, 5, and 6 in Table 1, and their bitmap representation would be 11001100.

[0179] Table 1

[0180] Optionally, if the first processing includes a sampling operation, the first communication device may perform the sampling operation using a specified sampling configuration; or, the first communication device may dynamically select the sampling configuration to use from a set of sampling configurations (including multiple sampling configurations). Optionally, the first communication device (e.g., UE) may also inform the second communication device (e.g., BS) of the sampling configuration used by the first communication device through indication information. For example, this indication information may be fed back to the second communication device along with second information (e.g., CSI compressed bitstream), and the second communication device may use the same sampling configuration for interpolation operations during decoding.

[0181] For example, the sampling configuration may include indication information indicating equally spaced sampling or indicating unequally spaced sampling; and / or, specific sampling information. For example, specific sampling information may include at least one of the sampling interval or the starting antenna number, or a bitmap corresponding to the sampling antenna position or the sampling antenna number.

[0182] For example, if the first process includes a dimensionality reduction transformation, the third information can also be used to indicate one or more dimensionality reduction matrices, including the dimensionality reduction matrix used in the dimensionality reduction transformation. For instance, if the third information indicates a dimensionality reduction matrix (referred to as dimensionality reduction matrix 1 for convenience), then dimensionality reduction matrix 1 is the dimensionality reduction matrix used by the first communication device when performing a dimensionality reduction transformation on the first precoded matrix. The third information can be dimensionality reduction matrix 1, or the protocol can preset multiple selectable dimensionality reduction matrices, and the third information can be the index of dimensionality reduction matrix 1. As another example, if the third information indicates multiple dimensionality reduction matrices (or a set of dimensionality reduction matrices), then the first communication device can dynamically select one dimensionality reduction matrix from this set, such as selecting W. sub,l The dimensionality reduction matrix with the highest energy.

[0183] Optionally, if the dimension reduction matrix is ​​selected by the first communication device, the first communication device (e.g., UE) can also inform the second communication device (e.g., BS) of the dimension reduction matrix used by the first communication device through indication information. For example, the indication information can be fed back to the second communication device together with the second information (e.g., CSI compressed bitstream), and the second communication device can use the same dimension reduction matrix to perform the dimension up operation during decoding.

[0184] S5014: The first communication device performs phase calibration on the first vector to be calibrated in the first precoding matrix or the second vector to be calibrated in the third precoding matrix based on the second reference vector to obtain the second precoding matrix.

[0185] In one implementation, the first communication device can determine a second phase difference between a second reference vector and a second vector to be calibrated; based on the second phase difference, phase calibration is performed on the first vector to be calibrated in the first precoding matrix (referred to as calibration method 2-1) or on the second vector to be calibrated in the third precoding matrix (referred to as calibration method 2-2) to obtain a second precoding matrix. This process can be exemplarily described in calibration method 2 below, and will not be elaborated here.

[0186] In calibration method 2-1, the second precoding matrix is ​​obtained based on the first precoding matrix. Assuming the sub-band corresponding to the first vector to be calibrated is the sub-band to be calibrated, then the first and second precoding matrices are identical except for the precoding vector corresponding to the sub-band to be calibrated. In calibration method 2-2, the third precoding matrix is ​​obtained based on the first precoding matrix. Assuming the sub-band corresponding to the first vector to be calibrated is the sub-band to be calibrated, then the first and third precoding matrices are identical except for the precoding vector corresponding to the sub-band to be calibrated.

[0187] Optionally, the selection of calibration mode 2-1 or calibration mode 2-2 by the first communication device can be determined by the first communication device, specified by a protocol, or indicated by other devices (such as the second communication device). For example, the second communication device sends a fifth message to the first communication device, the fifth message indicating calibration mode 2-1 or calibration mode 2-2.

[0188] Step S5015: The first communication device performs phase calibration on the first vector to be calibrated in the first precoding matrix based on the first phase difference between the first reference vector and the first vector to be calibrated, and obtains the second precoding matrix.

[0189] In one implementation, the first communication device can determine a first phase difference between a first reference vector and a first vector to be calibrated; based on the first phase difference, the first vector to be calibrated in the first precoding matrix is ​​phase-calibrated to obtain a second precoding matrix. This process can be exemplarily described in calibration method 1 below, and will not be elaborated here.

[0190] Step S502: The first communication device compresses the second precoding matrix to obtain the second information.

[0191] This application does not limit the compression method used in step S502. For example, it can be the Type II compression scheme shown in Figure 4.

[0192] The second information may also be referred to as a compressed bitstream or compressed bitstream or other, and this application does not limit it.

[0193] For example, the second piece of information could be PMI.

[0194] Step S503: The first communication device sends second information to the second communication device. Correspondingly, the second communication device receives the second information from the first communication device.

[0195] Step S504: The second communication device obtains the second precoding matrix based on the second information.

[0196] Step S504 is an optional step, which is indicated by a dashed box in Figure 5A.

[0197] For example, referring to Figure 8, step S504 includes the following possible implementations:

[0198] In one implementation (Case 1), the second precoding matrix corresponding to the second information is obtained by phase calibration of the first precoding matrix. Therefore, the second communication device can decompress the second information to obtain the second precoding matrix, such as W'1,…,W' v Furthermore, the second precoding matrix can be used for data transmission (e.g., for downlink precoding operations). For example, the second precoding matrix is ​​obtained by performing phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector (i.e., executing processing mode 1, step S5015) or by performing phase calibration on the first vector to be calibrated in the first precoding matrix using the second reference vector (i.e., executing processing mode 2).

[0199] In another implementation (Case 2), the second precoding matrix corresponding to the second information is obtained by phase calibration of the third precoding matrix (i.e., the first communication device performs phase calibration on the third precoding matrix based on the second reference vector), and the dimensionality reduction matrix or sampling configuration is directly given through the configuration information; then, the second communication device (or decoder) can, according to the configuration information, decompress the second information (i.e., the third precoding matrix, such as W') sub,1 …,W' sub,v Interpolation or dimensionality increase is performed to obtain the second precoding matrix.

[0200] In another implementation (Case 3), the second precoding matrix corresponding to the second information is obtained by phase calibration of the third precoding matrix (i.e., the first communication device performs phase calibration on the third precoding matrix based on the second reference vector), and the first communication device sends an indication of the first sampling configuration or the first dimensionality reduction configuration to the second communication device. Then, the second communication device can decompress the second information based on this indication (i.e., the third precoding matrix, such as W'). sub,1 …,W' sub,v Interpolation or dimensionality increase is performed to obtain the second precoding matrix.

[0201] The following provides an example of two phase calibration methods (calibration method 1 and calibration method 2) in step S501 above.

[0202] Calibration method 1: The first communication device performs phase calibration on the first precoding matrix based on the first reference vector.

[0203] S1: The first communication device calculates the first phase difference based on the first reference vector and the first calibration vector.

[0204] For example, let w be the first vector to be calibrated. lk Lowest frequency subband w l1 Taking the first reference vector as an example, the first phase difference δ lk It can be determined using the following formula 1-1: δ lk =phase(w lk H *w l1 / (||w lk ||*||w l1 ||)) (Formula 1-1)

[0205] Where phase(·) represents the phase operation of a complex number, and the result ranges from -π to π; ||·|| represents the modulus operation of a complex vector, obtaining the length information of the complex vector; w lk H It refers to w lk Perform conjugate transpose; wlk W is the precoding matrix corresponding to the l-th spatial stream in the first precoding matrix (see Figure 6A). l The k-th column of the precoding vector; w l1 For W l The first column of the precoding vector can be seen in Figures 6A and 6B regarding the first precoding matrix and W. l w l1 The relevant information will not be repeated here.

[0206] For example, let w be the first vector to be calibrated. lk The reference vector w corresponding to the left adjacent sub-band l(k-1) The first reference vector w l1 For example, the first phase difference δ lk It can be determined using the following formula 1-2: δ lk =phase(w lk H *w l(k-1) / (||w lk ||*||w l(k-1) ||)) (Formula 1-2)

[0207] S2: The first communication device performs phase calibration on the first vector to be calibrated in the first precoding matrix according to the first phase difference, and obtains the second precoding matrix.

[0208] For example, the first communication device can employ a coarse phase alignment method. For instance, the first communication device can compare a first phase difference with a first value (such as π / 2), and perform phase alignment on the first vector to be calibrated based on the comparison result. For example, if |δ lk If |>π / 2, then W' in the second precoding matrix l The precoded vector w' of the k-th column lk =-w lk The first vector to be calibrated in the first precoding matrix, w lk Change to -w lk We obtain the second precoding matrix; otherwise, w' lk =w lk The first precoding matrix is ​​obtained by keeping the first vector to be calibrated unchanged.

[0209] Optionally, the above-described phase coarse alignment method can be applied to schemes with low complexity processing requirements.

[0210] Another example is that the first communication device can employ a method of precise phase alignment, for example, by using the following formulas 1-3 to align w. lk Phase calibration is performed to obtain the vector w' corresponding to the k-th subband in the second precoding matrix. lk w'lk =exp(-i*(δ) lk +△ lk ))*w lk (Formula 1-3)

[0211] Where i is the imaginary number symbol, △ lk It can be 0 or other values ​​(the same or different for each stream) to achieve a certain phase difference control (the value can be agreed upon in advance by the protocol, or configured through signaling such as RRC and MAC, which is not restricted here).

[0212] In this application, w lk It can be W l The above calibration process can be performed on any precoding vector in the first precoding matrix, that is, on all the vectors to be calibrated in the precoding matrix corresponding to any spatial flow in the first precoding matrix, to obtain the second precoding matrix.

[0213] Calibration Method 2: The first communication device performs phase calibration on the first precoding matrix or the third precoding matrix based on the second transform vector.

[0214] S1: The first communication device calculates the second phase difference based on the second transformation vector and the second calibration vector.

[0215] For example, let the second vector to be calibrated be w sub,lk The highest frequency subband w sub,lK Taking the second reference vector as an example, the second phase difference δ lk It can be determined using the following formula 2-1: δ lk =phase(w sub,lk H *w sub,lK / (||w sub,lk ||*||w sub,lK ||)) (Formula 2-1)

[0216] Among them, w sub,lk The precoding matrix W corresponding to the l-th spatial stream in the third precoding matrix. sub,l The precoding vector in the k-th column (the k-th column can be W) sub,l (any column); w sub,lK The precoding matrix W corresponding to the l-th spatial stream in the third precoding matrix. sub,l The precoded vector in the Kth column.

[0217] Another example is using the second vector to be calibrated as w. sub,lk Taking the right-side adjacent sub-band wsub,l(k+1) as the second reference vector as an example, the second phase difference δ lk It can be determined using the following formula 2-2:

[0218] Phase difference δ lk =phase(w sub,lk H *wsub,l(k+1) / (||w sub,lk ||*||wsub,l(k+1)||))(Formula 2-2)

[0219] S2: The first communication device performs phase calibration on the second vector to be calibrated in the third precoding matrix according to the second phase difference, and obtains the second precoding matrix.

[0220] For example, the first communication device can employ a coarse phase alignment method. For instance, the first communication device can compare a first phase difference with a first value (such as π / 2), and perform phase alignment on the second vector to be calibrated based on the comparison result. For example, if |δ lk If |>π / 2, then W' in the second precoding matrix sub,l The precoded vector w' of the k-th column sub,lk =-w sub,lk The second vector to be calibrated in the third precoding matrix is ​​w. sub,lk Change to -w sub,lk We obtain the second precoding matrix; otherwise, w' sub,lk =w sub,lk The second precoding matrix is ​​obtained by keeping the second vector to be calibrated unchanged in the third precoding matrix.

[0221] Optionally, the above-described phase coarse alignment method can be applied to schemes with low complexity processing requirements.

[0222] Another example is that the first communication device can employ a method of precise phase alignment, for example, by using the following formulas 1-3 to align w. lk Phase calibration is performed to obtain the vector w' corresponding to the k-th subband in the second precoding matrix. lk w' sub,lk =exp(-i*(δ) lk +△ lk ))*w sub,lk (Formula 2-3)

[0223] Where i is the imaginary number symbol, △ lk It can be 0 or other values ​​(the same or different for each stream) to achieve a certain phase difference control (the value can be agreed upon in advance by the protocol, or configured through signaling such as RRC and MAC, which is not restricted here).

[0224] In this application, w sub,lk It can be W sub,l Any precoding vector in the third precoding matrix can be calibrated in the way described above, that is, all vectors to be calibrated in the precoding matrix corresponding to any spatial flow in the third precoding matrix, to obtain the second precoding matrix.

[0225] In some embodiments of this application, the first communication device may also perform phase calibration on the first vector to be calibrated in the first precoding matrix based on the second phase difference to obtain the second precoding matrix.

[0226] For example, the first communication device can employ a coarse phase alignment method. For instance, the first communication device can compare a first phase difference with a first value (such as π / 2), and perform phase alignment on the first vector to be calibrated based on the comparison result. For example, if |δ lk If |>π / 2, then W' in the second precoding matrix l The precoded vector w' of the k-th column lk =-w lk The first vector to be calibrated in the first precoding matrix, w lk Change to -w lk We obtain the second precoding matrix; otherwise, w' lk =w lk The first precoding matrix is ​​obtained by keeping the first vector to be calibrated unchanged.

[0227] Optionally, the embodiments shown in Figure 5A above can also be applied to O-RAN scenarios. It should be understood that in O-RAN scenarios, the network devices in the embodiments shown in Figure 5A can be replaced by CU (e.g., CU-CP or CU-UP) or DU or RU, etc.

[0228] The communication method provided in this application will be described exemplarily below with reference to Figures 9 and 10.

[0229] Figure 9 is a schematic diagram of another communication method provided by an exemplary embodiment of this application.

[0230] As shown in Figure 9, the first communication device can perform RB-by-RB SVD on the channel matrix H to obtain a first precoding matrix. Then, the first communication device can determine the reference vector corresponding to the vector to be calibrated in the first precoding matrix through implementation mode 1 or implementation mode 2. The specific details of implementation mode 1, implementation mode 2, and the correspondence between the vector to be calibrated and the reference vector (such as the correspondence between the first vector to be calibrated and the first reference vector) can be found above. Furthermore, the first communication device can perform phase calibration on each vector to be calibrated in the first precoding matrix based on the reference vector corresponding to that vector to obtain a second precoding matrix. The phase calibration process can be exemplarily described in the relevant content of processing mode 2 and calibration mode 1 described above. The second precoding matrix is ​​then compressed to obtain second information; this application does not limit the compression method. Finally, the first communication device can send the second information.

[0231] Optionally, multiple vectors to be calibrated can correspond to the same reference vector. For example, in implementation method 1, all vectors to be calibrated in the matrix corresponding to the same spatial flow in the first precoding matrix can correspond to the same reference vector, such as w. l1 or w l(K / 2) or w lK Alternatively, the reference vector corresponding to each vector to be calibrated can be different. For example, in implementation method 2, the reference vector corresponding to each vector to be calibrated is the pre-encoded vector to the left or right of that vector, such as w. lk The corresponding reference vector can be w l(k-1) or w l(k+1) .

[0232] Figure 10 is a schematic diagram of another communication method provided by example in an embodiment of this application.

[0233] As shown in Figure 10, the first communication device can perform RB-by-RB SVD on the channel matrix H to obtain a first precoding matrix; then, the first communication device can perform a first processing on the first precoding matrix to obtain a third precoding matrix, the process of which can be exemplarily referred to the relevant content in Figures 7A and 7B; then, the first precoding matrix is ​​phase-calibrated according to the second reference vector in the third precoding matrix to obtain a second precoding matrix W'. l Alternatively, phase calibration can be performed on the third precoding matrix based on the second reference vector to obtain the second precoding matrix W'. sub,l The phase calibration process can be exemplarily referred to in the relevant content of the above processing mode 1 and calibration method 2; the second precoding matrix is ​​compressed to obtain the second information, and this application does not limit the compression method; finally, the first communication device can send the second information.

[0234] It should be noted that, since the l-th spatial stream can be any spatial stream in the precoding matrix (such as the first precoding matrix, the second precoding matrix, or the third precoding matrix), this application can also use W l This represents the first precoding matrix, represented by W'. l This represents the second precoding matrix, represented by W' sub,l This represents the third precoding matrix.

[0235] The second reference vector in the third precoding matrix is ​​obtained by processing the first reference vector in the first precoding matrix. For a detailed introduction to the first and second reference vectors, please refer to the above text.

[0236] The communication device provided in this application will now be described in detail with reference to Figures 11 to 13.

[0237] 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.

[0238] Figures 11 to 13 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 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.

[0239] As shown in Figure 11, 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 11.

[0240] 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.

[0241] 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.

[0242] 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: perform phase calibration on the first vector to be calibrated of the first precoding matrix based on the first reference vector in the first precoding matrix to obtain a second precoding matrix; compress the second precoding matrix to obtain second information; and the transceiver unit 1520 is used to send the second information.

[0243] In one possible implementation, the processing unit 1510 is specifically configured to: determine a first phase difference between a first reference vector and a first vector to be calibrated; and perform phase calibration on the first vector to be calibrated in the first precoding matrix based on the first phase difference to obtain a second precoding matrix. In another possible implementation, the processing unit 1510 is specifically configured to: perform a first processing on the first coding matrix to obtain a third precoding matrix, the third precoding matrix including a second reference vector corresponding to the first reference vector; and perform phase calibration on the second vector to be calibrated in the third precoding matrix based on the second reference vector to obtain a second precoding matrix, the second vector to be calibrated corresponding to the first vector to be calibrated.

[0244] In one possible implementation, the processing unit 1510 is specifically used to: determine a second phase difference between a second reference vector and a second vector to be calibrated; and perform phase calibration on the second vector to be calibrated in the third precoding matrix based on the second phase difference to obtain a second precoding matrix.

[0245] In one possible implementation, the transceiver unit 1520 is further configured to: receive or send third information, the third information being used to indicate a first process, the first process including at least one of a sampling operation or a dimensionality reduction transformation.

[0246] In one possible implementation, the first processing includes a sampling operation, and the third information is further used to indicate at least one of equal-spaced sampling, sampling interval, or starting antenna number; or, the third information is further used to indicate unequal-spaced sampling and / or sampling information, the sampling information including a bitmap corresponding to the sampling antenna position or the sampling antenna number.

[0247] In one possible implementation, the first processing includes a dimension reduction transformation, and the third information is also used to indicate one or more dimension reduction matrices, which include the dimension reduction matrices used in the dimension reduction transformation.

[0248] In one possible implementation, the first precoding matrix includes a first submatrix corresponding to the first spatial stream, wherein the first submatrix includes a first reference vector, the first reference vector corresponds to a first subband, and the first subband is the subband with the highest frequency, the lowest frequency, or the median frequency among all the subbands corresponding to the first submatrix; or, the first reference vector is a vector in the first submatrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first submatrix with a frequency higher than the first vector to be calibrated.

[0249] In one possible implementation, the transceiver unit 1520 is further configured to: send or receive first information, wherein the first information is used to indicate a first reference vector.

[0250] In one possible implementation, the first information is used to indicate the first reference vector, including: the first information is used to indicate the first sub-band, the first sub-band corresponding to the first reference vector; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated.

[0251] In one possible implementation, the first precoding matrix includes v sub-matrices, each corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes a first reference vector and a first calibration vector.

[0252] In one possible implementation, the first vector to be calibrated is some or all of the vectors in the first submatrix except for the first reference vector.

[0253] 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 the processing unit 1510 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) chip or a SIP chip containing a modem core. The function of the transceiver unit 1520 can be implemented by transceiver circuitry.

[0254] 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.

[0255] 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 obtain the second precoding matrix based on the second information; wherein, the second precoding matrix is ​​obtained by performing phase calibration on the first vector to be calibrated of the first precoding matrix based on the first reference vector in the first precoding matrix.

[0256] In one possible implementation, the processing unit 1510 is specifically used to decompress the second information to obtain the second precoding matrix.

[0257] In one possible implementation, the processing unit 1510 is specifically used to: decompress the second information to obtain a third precoding matrix; and perform a second processing on the third precoding matrix to obtain a second precoding matrix.

[0258] In one possible implementation, the transceiver unit 1520 is further configured to receive or send third information, the third information being used to indicate a first process, the first process including at least one of a sampling operation or a dimension reduction transformation, the first process corresponding to a second process, wherein the second process corresponding to the sampling operation is an interpolation operation, and the second process corresponding to the dimension reduction transformation is a dimension increase transformation.

[0259] In one possible implementation, the processing unit 1510 is specifically used to: perform a second processing on the third precoding matrix based on the third information to obtain a second precoding matrix.

[0260] In one possible implementation, the first processing includes a sampling operation, and the third information is further used to indicate at least one of equal-spaced sampling, sampling interval, or starting antenna number; or, the third information is further used to indicate unequal-spaced sampling and / or sampling information, the sampling information including a bit map corresponding to the antenna position or the number of the sampling antenna.

[0261] In one possible implementation, the first processing includes a dimension reduction transformation, and the third information is also used to indicate one or more dimension reduction matrices, which include the dimension reduction matrices used in the dimension reduction transformation.

[0262] In one possible implementation, the first precoding matrix includes a first submatrix corresponding to the first spatial stream, wherein the first submatrix includes a first reference vector, the first reference vector corresponds to a first subband, and the first subband is the subband with the highest frequency, the lowest frequency, or the median frequency among all the subbands corresponding to the first submatrix; or, the first reference vector is a vector in the first submatrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first submatrix with a frequency higher than the first vector to be calibrated.

[0263] In one possible implementation, the transceiver unit 1520 is further configured to send or receive first information, wherein the first information is used to indicate a first reference vector.

[0264] In one possible implementation, the first information is used to indicate the first reference vector, including: the first information is used to indicate the first sub-band, the first sub-band corresponding to the first reference vector; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated.

[0265] In one possible implementation, the first precoding matrix includes v sub-matrices, each corresponding to a v spatial stream, where v is a positive integer; the v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes a first reference vector and a first calibration vector.

[0266] In one possible implementation, the first vector to be calibrated is some or all of the vectors in the first submatrix except for the first reference vector.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] As shown in Figure 12, 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.

[0272] 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.

[0273] 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.

[0274] 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.

[0275] As shown in Figure 13, 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 13), and an antenna 1733.

[0276] 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] For example, when the computer program is executed by a computer, it enables the computer to implement the method executed by the first communication device or the second communication device in the above method embodiments.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] 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.

[0286] Optionally, the processor is coupled to the memory via an interface.

[0287] Optionally, the chip device may also include a memory in which computer programs or computer instructions are stored.

[0288] 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.

[0289] 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.

[0290] 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.

[0291] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0292] 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: Based on the first reference vector in the first precoding matrix, the first vector to be calibrated in the first precoding matrix is ​​phase-calibrated to obtain the second precoding matrix; The second precoding matrix is ​​compressed to obtain the second information; Send the second message.

2. The method of claim 1, wherein, The step of performing phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix includes: Determine the first phase difference between the first reference vector and the first vector to be calibrated; Based on the first phase difference, the first vector to be calibrated in the first precoding matrix is ​​phase-calibrated to obtain the second precoding matrix.

3. The method of claim 1, wherein, The step of performing phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix to obtain the second precoding matrix includes: The first encoding matrix is ​​subjected to a first processing to obtain a third precoding matrix, the third precoding matrix including a second reference vector, the second reference vector corresponding to the first reference vector; Based on the second reference vector, the second vector to be calibrated in the third precoding matrix is ​​phase-calibrated to obtain the second precoding matrix, wherein the second vector to be calibrated corresponds to the first vector to be calibrated.

4. The method of claim 3, wherein, The step of performing phase calibration on the second vector to be calibrated in the third precoding matrix based on the second reference vector to obtain the second precoding matrix includes: Determine the second phase difference between the second reference vector and the second vector to be calibrated; Based on the second phase difference, the second vector to be calibrated in the third precoding matrix is ​​phase-calibrated to obtain the second precoding matrix.

5. The method according to claim 3 or 4, characterized in that, The method further includes: Receive or send third information, the third information being used to indicate the first processing, the first processing including at least one of sampling operation or dimensionality reduction transformation.

6. A communication method characterized by comprising: The method includes: Obtain the second information, which is obtained by compressing the second precoding matrix; Based on the second information, the second precoding matrix is ​​obtained; The second precoding matrix is ​​obtained by performing phase calibration on the first vector to be calibrated in the first precoding matrix based on the first reference vector in the first precoding matrix.

7. The method of claim 6, wherein, The process of obtaining the second precoding matrix based on the second information includes: The second information is decompressed to obtain the second precoding matrix.

8. The method of claim 6, wherein, The process of obtaining the second precoding matrix based on the second information includes: The second information is decompressed to obtain the third precoding matrix; The third precoding matrix is ​​subjected to a second processing to obtain the second precoding matrix.

9. The method of claim 8, wherein, The method further includes: Receive or send third information, the third information being used to indicate the first processing, the first processing including at least one of sampling operation or dimensionality reduction transformation, the first processing corresponding to the second processing, wherein the second processing corresponding to the sampling operation is an interpolation operation, and the second processing corresponding to the dimensionality reduction transformation is an up-dimensional transformation; The second processing of the third precoding matrix to obtain the second precoding matrix includes: Based on the third information, the third precoding matrix is ​​subjected to a second processing to obtain the second precoding matrix.

10. The method according to claim 5 or 9, characterized in that, The first processing includes a sampling operation, and the third information is further used to indicate at least one of equal-spaced sampling, sampling interval, or starting antenna number; Alternatively, the third information may also be used to indicate unequal-spacing sampling and / or sampling information, the sampling information including a bitmap corresponding to the antenna position or the sequence number of the sampling antenna.

11. The method according to claim 5, 9, or 10, characterized in that, The first process includes a dimensionality reduction transformation, and the third information is further used to indicate one or more dimensionality reduction matrices, the one or more dimensionality reduction matrices including the dimensionality reduction matrix used in the dimensionality reduction transformation.

12. The method according to any one of claims 1-11, characterized in that, The first precoding matrix includes a first sub-matrix corresponding to the first spatial stream, wherein the first sub-matrix includes the first reference vector, the first reference vector corresponds to a first sub-band, and the first sub-band is the sub-band with the highest frequency, the lowest frequency, or the median frequency among all the sub-bands corresponding to the first sub-matrix. Alternatively, the first reference vector is a vector in the first submatrix with a frequency lower than the first vector to be calibrated; or, the first reference vector is a vector in the first submatrix with a frequency higher than the first vector to be calibrated.

13. The method according to any one of claims 1-12, characterized in that, The method further includes: Sending or receiving first information, wherein the first information is used to indicate the first reference vector.

14. The method of claim 13, wherein, The first information is used to indicate the first reference vector, including: the first information is used to indicate a first sub-band, the first sub-band corresponding to the first reference vector; or, the first information is used to indicate the association between the first reference vector and the first vector to be calibrated.

15. The method of any one of claims 1-14, wherein, The first precoding matrix includes v sub-matrices, each of which corresponds to a spatial stream, where v is a positive integer; The v spatial streams include a first spatial stream, and the first sub-matrix corresponding to the first spatial stream includes the first reference vector and the first vector to be calibrated.

16. The method of claim 15, wherein, The first vector to be calibrated is any part or all of the vectors in the first submatrix except for the first reference vector.

17. A communications device, characterized by Includes modules or units for performing the method according to any one of claims 1 to 16.

18. A communications device, characterized by 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 uses logic circuits or execution code instructions to cause the communication device to implement the method as described in any one of claims 1 to 16.

19. A readable storage medium, characterized by, 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 16.

20. A computer program product, characterised in that, Includes a computer 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 16.

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