Communication method and apparatus

Abstract

The present application provides a communication method and apparatus, which can improve the performance of codebooks. The method comprises: a terminal device receives first configuration information, wherein the first configuration information is used for configuring reference signal resources corresponding to P port groups, and each of the P port groups comprises a plurality of antenna ports; and the terminal device sends precoding matrix indicator (PMI) information, wherein the PMI information is determined on the basis of channel measurement results of the reference signal resources, the PMI information indicates a first parameter and a parameter combination corresponding to one of the P port groups, the first parameter indicates amplitude and / or phase coefficients corresponding to the P port groups, the PMI information is used for determining precoding matrices corresponding to the P port groups, and P is an integer greater than 1.

Description

Communication method and apparatus

[0001] Cross-reference to related applications

[0002] This application claims priority to the Chinese Patent Application No. 202411388802.4, filed on September 30, 2024, and entitled "A communication method and apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method and apparatus. BACKGROUND

[0004] Multi-input multi-output (MIMO) technology, as a key technology of wireless communication, can be used to meet the demand of high-speed transmission. Through the process of channel measurement (or channel estimation), the network device can calculate the precoding information between the network device and the terminal device by using the channel information obtained by the channel measurement process, and the subsequent MIMO communication between the network device and the terminal device can be realized through the precoding information.

[0005] Taking the downlink channel measurement process implemented by the network device based on the downlink reference signal as an example, the network device sends resource configuration information and reporting configuration information to the terminal device. The resource configuration information is the information related to the measurement resource, and the network device sends the downlink signal (for example, the downlink reference signal) on the resource configured by the resource configuration information, and the terminal device can measure the downlink signal to determine the quality of each resource. The reporting configuration information refers to the information related to the reporting of the measurement result. The reporting configuration information includes codebook configuration information related to the codebook, and the terminal device performs measurement and feedback based on the codebook configuration information. The current codebook configuration cannot adapt to the transmission mode of mixed transmission in the beam domain and the antenna domain, resulting in a decrease in the performance of the codebook in the mixed transmission scenario. SUMMARY

[0006] The present application provides a communication method and apparatus, which can improve the performance of the codebook.

[0007] In a first aspect, this application provides a communication method applied to a terminal device, comprising: receiving first configuration information, the first configuration information being used to configure reference signal resources corresponding to P port groups, each of the P port groups including multiple antenna ports, wherein P is a positive integer; transmitting precoding matrix indication (PMI) information, the PMI information being determined based on channel measurement results of the reference signal resources, the PMI information indicating a first parameter and / or a parameter combination corresponding to one of the P port groups, the first parameter indicating amplitude and / or phase coefficients corresponding to the P port groups, and the PMI information being used to determine the precoding matrix corresponding to the P port groups; wherein P is an integer greater than 1.

[0008] The parameters indicated by the PMI information include the identity matrix and the frequency domain discrete Fourier transform (DFT) matrix, which can be adapted to the transmission method that uses a hybrid beam domain and antenna domain transmission, thereby improving the codebook performance.

[0009] In one possible design, the P port groups include N in the first dimension. g,1 Port groups and the second dimension N g,2 P port groups; each of the P port groups includes N1 antenna ports in the first dimension and N2 antenna ports in the second dimension; wherein, N g,1 The N g,2 Both N1 and N2 are positive integers. This design can be applied to two-dimensional hybrid digital-analog beamforming (HBF) architectures.

[0010] In one possible design, the first configuration information includes the N. g,1 The N g,2 The design includes indication information for the value of at least one of the parameters N1 and N2. This design enables dynamic indication of port group parameters, providing greater flexibility.

[0011] In one possible design, the first parameter W p The first parameter W corresponds to the K columns in the frequency domain Discrete Fourier Transform (DFT) matrix. p The dimension is (N) g,1 N g,2 ×K), w p,k Corresponding to the k-th column in the K columns, the w p,k Satisfy the following formula:

[0012] in, k1×N g,2 ×O4+k2=c k ;

[0013] Wherein, ck indicating the w p,k an index in the precoding matrix; the O3 and the O4 are preconfigured or indicated in the first configuration information; the K is a positive integer, and the k is an integer from 1 to K.

[0014] In such a design, the DFT matrix is used between the port groups (or subarrays), which can adapt to the transmission mode of antenna domain transmission between the port groups. Optionally, in this design, the following step can be performed: receiving information indicating the value of the K; wherein the value of the K is less than or equal to the number of spatial domain bases of the precoding matrix.

[0015] In a possible design, the first parameter corresponds to W p , the parameter combination corresponding to one port group in the P port groups includes a second parameter W1 and a third parameter W2; and the precoding matrix W satisfies at least one of the following formulas:

[0016] or,

[0017] or,

[0018] In an implementation of this design, the second parameter W1 corresponds to 1 column or L1 columns in the unit matrix, and the second parameter W2 corresponds to 1 column or L2 columns in the single-frequency-domain discrete Fourier transform (DFT) matrix; or, the second parameter W1 corresponds to 1 column or L1 columns in the DFT matrix, and the second parameter W2 corresponds to 1 column or L2 columns in the unit matrix; wherein the values of the L1 and the L2 are determined based on the number of spatial domain bases of the precoding matrix.

[0019] In another implementation of this design, the second parameter W1 satisfies the following formula: wherein the W'1 is a frequency-domain discrete Fourier transform (DFT) matrix, and the W''1 is a unit matrix; or, the W'1 is a unit matrix, and the W''1 is a DFT matrix.

[0020] In such a design, the unit matrix is used within the port group (or within the subarray), which can adapt to the transmission mode of beam domain transmission within the port.

[0021] In a possible design, the first parameter corresponds to W p , the parameter combination corresponding to one port group in the P port groups includes a second parameter W1, a fourth parameter and a fifth parameter The precoding matrix W satisfies at least one of the following formulas:

[0022] Or,

[0023] Or,

[0024] In one implementation of the design, the second parameter W1 corresponds to one column or L1 columns in an identity matrix, and the fourth parameter corresponds to one column or L2 columns in a single-frequency-domain discrete Fourier transform (DFT) matrix; or, the second parameter W1 corresponds to one column or L1 columns in a DFT matrix, and the fourth parameter corresponds to one column or L2 columns in an identity matrix; where the values of L1 and L2 are determined based on the number of spatial-domain bases of the precoding matrix.

[0025] In another implementation of the design, the second parameter W1 satisfies the following formula: where W'1 is a DFT matrix, and W"1 is an identity matrix; or, W'1 is an identity matrix, and W"1 is a DFT matrix.

[0026] In such a design, the identity matrix is used within a port group (or submatrix), which can adapt to the transmission mode of using beam-domain transmission within a port.

[0027] In one possible design, the precoding matrix W satisfies the following formula:

[0028] The first parameter includes I G and The I G is an identity matrix, and the indicates the phase combining coefficients between different port groups and the same beam, and the is a diagonal matrix or an identity matrix; the parameter combination corresponding to one port group in the P port groups includes the W1, the and the

[0029] In such a design, the identity matrix exists between the I G and in different port groups (or submatrices), and the DFT matrix is used for W1 within a port group, which can adapt to the transmission mode of using beam-domain between submatrices and antenna-domain within a port.

[0030] In one possible design, P is 1, the PMI information indicates the parameter combination corresponding to one port group, the parameter combination corresponding to the one port group includes a sixth parameter W'1, a seventh parameter W"1, and a third parameter W2, and the precoding matrix W satisfies the following formula:

[0031] wherein W'1 is a DFT matrix (or a spatial domain basis, or an IDFT matrix), and W"1 is an identity matrix; or, W'1 is an identity matrix, and W"1 is a DFT matrix (or a spatial domain basis, or an IDFT matrix).

[0032] In a possible design, P is 1, and the PMI information indicates a parameter combination corresponding to one port group, where the parameter combination corresponding to the one port group includes the sixth parameter W'1, the seventh parameter W"1, the fourth parameter and the fifth parameter The precoding matrix W satisfies the following equation:

[0033] wherein W'1 is a DFT matrix (or a spatial domain basis, or an IDFT matrix), and W"1 is an identity matrix; or, W'1 is an identity matrix, and W"1 is a DFT matrix (or a spatial domain basis, or an IDFT matrix).

[0034] In a second aspect, the present application provides a communication method, applied to a network device, including: sending first configuration information, where the first configuration information is used to configure reference signal resources corresponding to P port groups, each of the P port groups includes a plurality of antenna ports, and P is a positive integer; and receiving precoding matrix indication (PMI) information, where the PMI information is determined according to a channel measurement result of the reference signal resources, the PMI information indicates a first parameter and / or a parameter combination corresponding to one port group of the P port groups, the first parameter indicates amplitude and / or phase coefficients corresponding to the P port groups, and the PMI information is used to determine a precoding matrix corresponding to the P port groups; and wherein P is an integer greater than 1.

[0035] Some possible designs can be understood with reference to the designs described in the first aspect, and details are not described herein again.

[0036] In a third aspect, the present application provides a communication apparatus, which can be a terminal device, a device, a module or a chip in a terminal device, or an apparatus capable of being used with a terminal device. In one design, the communication apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the first aspect, which can be hardware circuitry, software, or a combination of hardware circuitry and software. In one design, the communication apparatus can include a processing module and a communication module, where the communication module includes a sending unit and a receiving unit. Optionally, the communication module can also be replaced by a transceiver module or a transceiver unit, and the processing module can also be replaced by a processing unit.

[0037] The communication module is configured to receive first configuration information, the first configuration information being used to configure reference signal resources corresponding to P port groups, each of the P port groups comprising a plurality of antenna ports, P being a positive integer;

[0038] The processing module is configured to send, through the communication module, precoding matrix indicator (PMI) information determined according to a channel measurement result of the reference signal resources, the PMI information indicating a first parameter and / or a parameter combination corresponding to one of the P port groups, the first parameter indicating amplitude and / or phase coefficients corresponding to the P port groups, the PMI information being used to determine a precoding matrix corresponding to the P port groups; wherein P is an integer greater than 1.

[0039] The PMI information indicates a unit matrix and a discrete Fourier transform (DFT) matrix in the parameters, which can adapt to a transmission mode of hybrid transmission in a beam domain and an antenna domain, and improve the performance of the codebook.

[0040] In a possible design, the P port groups comprise N g,1 port groups in a first dimension and N g,2 port groups in a second dimension; each of the P port groups comprises N g,1 antenna ports in the first dimension and N g,2 antenna ports in the second dimension; wherein N g,1 , N g,2 , N p , and N p are positive integers. This design can be applied to a two-dimensional hybrid digital-analog beamforming (HBF) architecture.

[0041] In a possible design, the first configuration information comprises indication information of a value of at least one of N g,1 , N g,2 , N p , and N p . Through such a design, the parameters of the port grouping can be dynamically indicated, which is more flexible.

[0042] In a possible design, the first parameter W p corresponds to a Kth column in a discrete Fourier transform (DFT) matrix, the dimension of the first parameter W p is (N g,1 N g,2 × K), w p,k corresponds to a kth column in the K columns, and the w p,k satisfy the following formula:

[0043] wherein, k1×N g,2 × O4+k2=c k ;

[0044] wherein the c k indicates the w p,k an index in the precoding matrix; the O3 and the O4 are preconfigured or indicated in the first configuration information; the K is a positive integer, and the k is an integer from 1 to K.

[0045] In such a design, the DFT matrix is used between the port groups (or subarrays), which can adapt to the transmission mode of antenna domain transmission between the port groups. Optionally, in this design, the following step can be performed: receiving information indicating the value of the K; wherein the value of the K is less than or equal to the number of spatial domain bases of the precoding matrix.

[0046] In a possible design, the first parameter corresponds to W p , the parameter combination corresponding to one port group in the P port groups includes a second parameter W1 and a third parameter W2; and the precoding matrix W satisfies at least one of the following formulas:

[0047] or,

[0048] or,

[0049] In an implementation of this design, the second parameter W1 corresponds to 1 column or L1 columns in the unit matrix, and the second parameter W2 corresponds to 1 column or L2 columns in the single-frequency-domain discrete Fourier transform (DFT) matrix; or, the second parameter W1 corresponds to 1 column or L1 columns in the DFT matrix, and the second parameter W2 corresponds to 1 column or L2 columns in the unit matrix; wherein the values of the L1 and the L2 are determined based on the number of spatial domain bases of the precoding matrix.

[0050] In another implementation of this design, the second parameter W1 satisfies the following formula: wherein the W'1 is a frequency-domain discrete Fourier transform (DFT) matrix, and the W''1 is a unit matrix; or, the W'1 is a unit matrix, and the W''1 is a DFT matrix.

[0051] In such a design, the unit matrix is used in the port group (or in the subarray), which can adapt to the transmission mode of beam domain transmission in the port.

[0052] In a possible design, the first parameter corresponds to W p , the parameter combination corresponding to one port group in the P port groups includes a second parameter W1, a fourth parameter and a fifth parameter The precoding matrix W satisfies at least one of the following formulas:

[0053] Or,

[0054] Or,

[0055] In one implementation of the design, the second parameter W1 corresponds to one column or L1 columns in an identity matrix, and the fourth parameter corresponds to one column or L2 columns in a DFT matrix; or, the second parameter W1 corresponds to one column or L1 columns in a DFT matrix, and the fourth parameter corresponds to one column or L2 columns in an identity matrix; where the values of L1 and L2 are determined based on the number of spatial bases of the precoding matrix.

[0056] In another implementation of the design, the second parameter W1 satisfies the following formula: where W'1 is a DFT matrix, and W"1 is an identity matrix; or, W'1 is an identity matrix, and W"1 is a DFT matrix.

[0057] In this design, the identity matrix is used within a port group (or subarray), which can adapt to the beam-domain transmission within a port.

[0058] In one possible design, the precoding matrix W satisfies the following formula:

[0059] The first parameter includes I G and The I G is an identity matrix, and the indicates the phase combining coefficients between different port groups and the same beam, and the is a diagonal matrix or an identity matrix; the parameter combination corresponding to one port group in the P port groups includes the W1, the and the

[0060] In this design, the identity matrix exists between the I G and in the P port groups, and the W1 in the port group uses a DFT matrix, which can adapt to the transmission mode of using the beam domain between subarrays and the antenna domain within a port.

[0061] In one possible design, P is one, the PMI information indicates one port group corresponding parameter combination, the one port group corresponding parameter combination includes the sixth parameter W'1, the seventh parameter W"1, and the third parameter W2, and the precoding matrix W satisfies the following equation:

[0062] W'1W"1W2= W, where W'1is a DFT matrix (or a spatial domain basis, or an IDFT matrix), W"1is an identity matrix, or W'1is an identity matrix and W"1is a DFT matrix (or a spatial domain basis, or an IDFT matrix).

[0063] In one possible design, P is one, the PMI information indicates one port group corresponding parameter combination, the one port group corresponding parameter combination includes the sixth parameter W'1, the seventh parameter W"1, the fourth parameter and the fifth parameter The precoding matrix W satisfies the following equation:

[0064] W'1W"1W4W5= W, where W'1is a DFT matrix (or a spatial domain basis, or an IDFT matrix), W"1is an identity matrix, or W'1is an identity matrix and W"1is a DFT matrix (or a spatial domain basis, or an IDFT matrix).

[0065] In a fourth aspect, a communication apparatus is provided. The communication apparatus can be a network device, or a device, a module, or a chip in a network device, or a device capable of matching with the network device. In one design, the communication apparatus can include a module corresponding to each of the methods / applications / steps / actions described in the second aspect. The module can be hardware circuitry, software, or a combination of hardware circuitry and software. In one design, the communication apparatus can include a processing module and a communication module including a transmitting unit and a receiving unit. Optionally, the communication module can also be referred to as a transceiver module or a transceiver unit, and the processing module can also be referred to as a processing unit.

[0066] The processing module is configured to send, via the communication module, first configuration information, where the first configuration information is used to configure reference signal resources corresponding to P port groups, each of the P port groups includes a plurality of antenna ports, and P is a positive integer.

[0067] The communication module is configured to receive precoding matrix indication (PMI) information, the PMI information being determined according to a channel measurement result of the reference signal resource, the PMI information indicating a first parameter and / or a parameter combination corresponding to one of the P port groups, the first parameter indicating amplitude and / or phase coefficients corresponding to the P port groups, and the PMI information being used to determine a precoding matrix corresponding to the P port groups; wherein P is an integer greater than 1.

[0068] Some possible designs can be understood with reference to the designs described in the third aspect, and thus, the present application does not repeat them here.

[0069] In a fifth aspect, the present application provides a communication device, comprising at least one processor and a memory; the memory is configured to store computer programs or instructions, and when the device is running, the at least one processor executes the computer programs or instructions to make the communication device perform the method of the first aspect or any of the embodiments of the first aspect, or perform the method of the second aspect or any of the embodiments of the second aspect.

[0070] In a sixth aspect, the present application provides another communication device, comprising: a logic circuit and an input / output interface; wherein the input / output interface can be understood as an interface circuit, and the logic circuit can be used to run code instructions to perform the method of the first aspect or any of the embodiments of the first aspect, or perform the method of the second aspect or any of the embodiments of the second aspect.

[0071] In a seventh aspect, the present application further provides a computer readable storage medium, and the computer readable storage medium stores computer readable instructions, and when the computer readable instructions are running on a computer, the computer executes the method of the first aspect or any of the possible designs in the first aspect, or executes the method of the second aspect or any of the possible designs in the second aspect.

[0072] In an eighth aspect, the present application provides a computer program product comprising instructions, and when the computer program product is running on a computer, the computer executes the method of the first aspect or any of the embodiments of the first aspect, or executes the method of the second aspect or any of the embodiments of the second aspect.

[0073] In a ninth aspect, the present application provides a chip system, which comprises a processor and can further comprise a memory, and is used to implement the method described in the first aspect or any of the possible designs in the first aspect, or execute the method described in the second aspect or any of the possible designs in the second aspect. The chip system can be composed of a chip, or can comprise a chip and other discrete devices.

[0074] In a tenth aspect, the present application provides a communication system, the system comprising a terminal device and a satellite, the communication system being configured to perform the method of the first aspect or any possible design of the first aspect, or perform the method of the second aspect or any possible design of the second aspect.

[0075] The technical effects achieved by the second aspect to the tenth aspect can refer to the technical effects achieved by the first aspect or any possible design of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0076] FIG. 1 is a schematic diagram of an architecture of a wireless communication system;

[0077] FIG. 2A is a schematic diagram of a structure of a network device;

[0078] FIG. 2B is a schematic diagram of logical function division of a network element;

[0079] FIG. 3 is a schematic diagram of a structure of a beamforming provided by an embodiment of the present application;

[0080] FIG. 4 is a schematic diagram of a beam distribution provided by an embodiment of the present application;

[0081] FIG. 5 is a schematic diagram of a flow of a communication method provided by an embodiment of the present application;

[0082] FIG. 6A is a schematic diagram of division of a port group provided by an embodiment of the present application;

[0083] FIG. 6B is a schematic diagram of distribution of an antenna port provided by an embodiment of the present application;

[0084] FIG. 7 is a schematic diagram of a structure of a communication apparatus in an embodiment of the present application;

[0085] FIG. 8 is a schematic diagram of a structure of a communication apparatus in an embodiment of the present application. DETAILED DESCRIPTION

[0086] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0087] The term "and / or" used in the application, indicates an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the front and rear associated objects. In addition, it should be understood that although the terms first, second, etc. may be used in the embodiments of the application to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish various objects from each other.

[0088] The terms "comprising" and "having" and any variations thereof described in the embodiments of the application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include other steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device. It should be noted that in the embodiments of the application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any method or design scheme described as "exemplary" or "for example" in the embodiments of the application should not be interpreted as more preferred or more advantageous than other methods or design schemes. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner.

[0089] The technology provided by the embodiments of the application can be applied to various communication systems, such as a universal mobile communication system (UMTS), a wireless local area network (WLAN), a wireless fidelity (Wi-Fi) system, a 4th generation (4G) mobile communication system such as a long term evolution (LTE) system, a 5th generation (5G) mobile communication system such as a new radio (NR) system, and a future communication system.

[0090] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can include additional devices, components, modules, etc., and / or can not include all of the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. In addition, combinations of these schemes can also be used.

[0091] In addition, in the embodiments of the present application, the words "exemplary", "for example", and the like are used solely to indicate examples, instances, or illustrations, and not preference or advantageousness over another embodiment or design. In fact, the word "exemplary" is used to present concepts in a concrete manner. In the embodiments of the present application, "of", "corresponding" and "corresponding" are sometimes mixed. It should be pointed out that when the difference is not emphasized, the meanings expressed are consistent.

[0092] A network element in a communication system can send a signal to another network element or receive a signal from another network element. The signal can include information or data, etc.; the network element can also be referred to as an entity, a network entity, a device, a communication device, a communication module, a node, a communication node, etc. In the embodiments of the present application, a network element is taken as an example for description. For example, the communication system can include at least one terminal device and at least one network device. The sending network element of the signal can be a network device, and the receiving network element of the signal can be a terminal device; or the sending network element of the signal can be a terminal device, and the receiving network element of the signal can be a network device. In addition, it can be understood that if the communication system includes multiple terminal devices, the multiple terminal devices can also send signals to each other, that is, the sending network element of the signal and the receiving network element of the signal can both be terminal devices.

[0093] FIG. 1 exemplarily shows an architecture schematic diagram of a communication system 10 to which the embodiments of the present application are applicable. As shown in FIG. 1, FIG. 1 is an architecture schematic diagram of a communication system 10 to which the embodiments of the present application are applicable. As shown in FIG. 1, the communication system includes a radio access network (RAN) 100 and a core network 200. Optionally, the communication system 10 can also include the Internet 300. The RAN 100 includes at least one RAN node (such as 110a and 110b in FIG. 1, collectively referred to as 110), and can also include at least one terminal (such as 120a-120j in FIG. 1, collectively referred to as 120). The RAN 100 can also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 1). The terminal 120 is connected to the RAN node 110 in a wireless manner, and the RAN node 110 is connected to the core network 200 in a wireless or wired manner. The core network device in the core network 200 and the RAN node 110 in the RAN 100 can be independent and different physical devices, or can be the same physical device integrated with the logical functions of the core network device and the logical functions of the RAN node. Terminals and terminals and RAN nodes and RAN nodes can be connected to each other through wired or wireless means.

[0094] The RAN 100 can be an evolved universal terrestrial radio access (E-UTRA) system, an NR system, and a future wireless access system defined in the 3rd generation partnership project (3GPP). The RAN 100 can also include two or more different wireless access systems described above. The RAN 100 can also be an open RAN (O-RAN).

[0095] The network device involved in the embodiments of the present application can be a RAN node. The RAN node, also known as a wireless access network device, a RAN entity or an access node, is used to help the terminal to access the communication system through a wireless manner. In an application scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, a next generation base station in a future communication system, or a base station in a future mobile communication system. The RAN node can be a macro base station (such as 110a in FIG. 1), a micro base station or an indoor station (such as 110b in FIG. 1), a relay node or a donor node.

[0096] The terminal device can be a device or module with corresponding communication functions to access the communication system described above. The terminal device can also be referred to as a user equipment (UE), a terminal, a user apparatus, an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a terminal unit, a terminal station, a terminal apparatus, a wireless communication device, a user agent or a user device. The terminal device is usually provided with a communication module, circuit or chip for executing corresponding communication functions, and a program instruction for executing corresponding communication functions.

[0097] For example, the terminal device in the embodiments of the present application can be a mobile phone, a personal digital assistant (PDA) computer, a laptop computer, a tablet computer (Pad), a drone, a computer with wireless transceiver function, a machine type communication (MTC) terminal, a virtual reality (VR) terminal, an augmented reality (AR) terminal, an internet of things (IoT) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home (such as a game console, a smart television, a smart speaker, a smart refrigerator, and a fitness equipment), a transport vehicle with wireless communication function, a communication module, a roadside unit (RSU) with terminal function. The embodiments of the present application do not limit the specific technology and specific device form of the terminal device.

[0098] The base station and the terminal can be fixed in position or movable. The base station and the terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on water surface; can also be deployed on an airplane, a balloon, and a man-made satellite. The embodiments of the present application do not limit the application scenarios of the base station and the terminal.

[0099] The roles of the base station and the terminal can be relative, for example, the helicopter or drone 120i in FIG. 1 can be configured as a mobile base station, and for those terminals 120j accessing the wireless access network 100 through 120i, the terminal 120i is a base station; but for the base station 110a, 120i is a terminal, that is, 110a and 120i communicate through a wireless air interface protocol. Of course, 110a and 120i can also communicate through a base station-to-base station interface protocol, at this time, relative to 110a, 120i is also a base station. Therefore, the base station and the terminal can be collectively referred to as a communication device, 110a and 110b in FIG. 1 can be referred to as a communication device with base station function, and 120a-120j in FIG. 1 can be referred to as a communication device with terminal function.

[0100] The base station and the terminal, the base station and the base station, the terminal and the terminal can communicate through a licensed spectrum, or through an unlicensed spectrum, or through both the licensed spectrum and the unlicensed spectrum; can communicate through a spectrum below 6 gigahertz (GHz), or through a spectrum above 6 GHz, or through both the spectrum below 6 GHz and the spectrum above 6 GHz. Embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0101] In embodiments of the present application, the functions of the base station can also be performed by a module (such as a chip) in the base station, or by a control subsystem containing the functions of the base station. The control subsystem containing the functions of the base station herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal can also be performed by a module (such as a chip or modem) in the terminal, or by a device containing the functions of the terminal.

[0102] In the present application, the base station sends a downlink signal or downlink information to the terminal, and the downlink information is carried on a downlink channel; the terminal sends an uplink signal or uplink information to the base station, and the uplink information is carried on an uplink channel. In order to communicate with the base station, the terminal needs to establish a wireless connection with the cell controlled by the base station. The cell with which the terminal establishes a wireless connection is called the service cell of the terminal. When the terminal communicates with the service cell, it will also be interfered by signals from neighboring cells.

[0103] The communication between the access network device and the terminal device can comply with a certain protocol layer structure. Illustratively, the protocol layer structure can include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure can include at least one of the following: a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media / medium access control (MAC) layer, or a physical (PHY) layer, etc. For example, the user plane protocol layer structure can include at least one of the following: a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer, etc.

[0104] Figure 2A is a schematic diagram of a network device to which embodiments of the present application can be applied. The RAN node includes one or more centralized units (CU), one or more distributed units (DU), and one or more radio units (RU). As an example, only one CU, DU, and RU are illustrated in Figure 2A. The CU here can complete the functions of the radio resource control protocol and the packet data convergence layer protocol PDCP of the base station, and can also complete the function of the service data adaptation protocol SDAP; the DU can complete the functions of the radio link control layer RLC and the medium access control layer MAC of the RAN, and can also complete part of the physical layer or the entire physical layer. For specific descriptions of the above-mentioned protocol layers, reference can be made to the relevant technical specifications of 3GPP. The RU can be used to implement the functions of transmitting and receiving radio frequency signals. The CU and the DU can be two independent units, or can be integrated into a baseband unit (BBU) in the same RAN node. The RU can be included in a radio frequency device, such as a remote radio unit (RRU) or an active antenna unit (AAU).

[0105] In Figure 2A, taking the example of the CU and the DU being integrated into the BBU, it is also shown that the BBU in the RAN communicates with the core network (Core Network) through a backhaul link (Backhaul), the CU and the DU in the BBU communicate through a midhaul link (Midhaul), and the BBU communicates with at least one RU through a front-haul link. The BBU and the RU can be co-located or not co-located. The radio unit RU in the RAN communicates with at least one UE through an air interface.

[0106] Optionally, the CU can be further divided into two types of RAN nodes, CU-Control Plane (CU-CP) and CU-User Plane (CU-UP). As shown in FIG. 2B, the CU-CP is a logical node carrying the RRC layer and the PDCP-C (control plane part of PDCP) layer, used to implement the control plane function of the CU. The CU-CP can interact with a network element in the core network for implementing the control plane function. The network element in the core network for implementing the control plane function can be an access and mobility function network element, such as an access and mobility management function (AMF) in a 5G system. The AMF network element is responsible for mobility management in a mobile network, such as location updating of a terminal device, registration of the terminal device to a network, handover of the terminal device, and the like. The CU-UP is a logical node carrying the SDAP layer and the PDCP-U (user plane part of PDCP) layer, used to implement the user plane function of the CU. The CU-UP can interact with a network element in the core network for implementing the user plane function. The network element in the core network for implementing the user plane function, for example, a user plane function (UPF) in a 5G system, is responsible for forwarding and receiving data in a terminal device. The above configuration of the CU and the DU is only an example, and the CU and the DU can be configured to have other functions according to needs. For example, the CU or the DU can be configured to have more protocol layer functions, or the CU or the DU can be configured to have partial processing functions of the protocol layers. For example, partial functions of the RLC layer and functions of the protocol layers above the RLC layer are arranged in the CU, and the remaining functions of the RLC layer and functions of the protocol layers below the RLC layer are arranged in the DU. For another example, the functions of the CU or the DU can be divided according to service types or other system requirements, for example, functions requiring to meet a shorter delay requirement in processing time are arranged in the DU, and functions not requiring to meet the delay requirement are arranged in the CU.

[0107] In some examples, the DU is a logical node carrying a radio link control (RLC) layer, a medium access control (MAC) layer, a higher physical layer (Higher PHY), and other functions. In some examples, the DU can control at least one RU. The DU is connected to the RU through some interfaces, which can be a front-haul interface. In some examples, the Higher PHY layer includes part of the PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, and the like.

[0108] In some examples, a RU is a logical node that hosts lower physical layer (Lower PHY) and radio frequency (RF) processing. In some examples, a RU can be a 3GPP transmission reception point or transmit / receive point (TRP) or a remote radio head (RRH) or other similar functional entity. In some examples, a Low-PHY includes portions of PHY processing such as fast Fourier transform (FFT), inverse fast Fourier transformation (IFFT), digital beamforming and filtering, and other processing functions. A RU communicates with one or more UEs over a wireless link.

[0109] A DU and a RU can or can not be co-located. A DU and a RU exchange control plane information and user plane information over a fronthaul link via a lower-layer split-control, user and synchronization (LLS-CUS) interface. The LLS-CUS can include a LLS-C interface and a LLS-U interface that provide a control plane (C-Plane) and a user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between a DU and a RU. A DU and a RU have a LLS-M interface of the fronthaul link to exchange management information, and the management plane (M-Plane) refers to non-real-time management operations between the DU and the RU.

[0110] A DU and a RU can cooperate to collectively implement the functionality of a PHY layer. A DU can be connected to one or more RUs. The functionality that a DU and a RU have can be configured in a number of ways depending on the design. For example, a DU is configured to implement baseband functionality and a RU is configured to implement mid- RF functionality. As another example, a DU is configured to implement high-layer functionality in a PHY layer and a RU is configured to implement low-layer functionality in the PHY layer or to implement the low-layer functionality and RF functionality. The high-layer functionality in the PHY layer can include a portion of the functionality of the PHY layer that is closer to the MAC layer, and the low-layer functionality in the PHY layer can include another portion of the functionality of the PHY layer that is closer to the mid-RF side.

[0111] In different systems, the RAN node can have different names, for example, in an O-RAN system, the CU can be referred to as an open CU (O-CU), the DU can be referred to as an open DU (O-DU), and the RU can be referred to as an open RU (O-RU). The CU-control panel (CU-CP) can also be referred to as an open CU-CP (O-CU-CP), and the CU-user panel (CU-UP) can also be referred to as an open CU-UP (O-CU-UP). The RAN node in the embodiments of the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node can be a server loaded with a corresponding software module. The embodiments of the present application do not limit the specific technology and specific equipment form adopted by the RAN node.

[0112] The related terms involved in the embodiments of the present application will be explained first. It should be noted that these explanations are to make the embodiments of the present application easier to understand, and should not be regarded as limiting the scope of protection required by the present application.

[0113] (1) Reference signal (RS).

[0114] The reference signal is also called the pilot signal. In a communication system, it is necessary to transmit and receive data, obtain system synchronization and feedback channel information, and estimate the uplink channel or the downlink channel. Channel estimation refers to the process of reconstructing or restoring the received signal in order to compensate for signal distortion caused by channel fading and noise-induced fading. It uses the reference signal known by the transmitter and the receiver to track the time-domain and frequency-domain changes of the channel. The above-mentioned reference signal is also called the reference signal, which is distributed in different resource elements (REs) in the time-frequency two-dimensional space within the orthogonal frequency division multiplexing (OFDM) symbol, and has a known amplitude and phase.

[0115] At the physical layer, the uplink communication can include transmission of uplink physical channels and uplink signals. Among them, the uplink physical channels include a random access channel (PRACH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), etc., and the uplink signals include a sounding reference signal (SRS), a physical uplink control channel demodulation reference signal (PUCCH-DMRS), a physical uplink shared channel demodulation reference signal (PUSCH-DMRS), a phase tracking reference signal (PTRS), an uplink positioning RS, etc.

[0116] At the physical layer, the downlink communication can include transmission of downlink physical channels and downlink signals. Among them, the downlink physical channels include a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), etc., and the downlink signals include a primary synchronization signal (PSS) / secondary synchronization signal (SSS), a physical downlink control channel demodulation reference signal (PDCCH-DMRS), a physical downlink shared channel demodulation reference signal (PDSCH-DMRS), a PTRS, a channel state information reference signal (CSI-RS), a cell reference signal (CRS), a tracking reference signal (TRS), a positioning RS, etc.

[0117] (2) Resource.

[0118] In the embodiments of the present application, the network device can configure a terminal device with a resource set / or a resource.

[0119] The resource set can include at least one of a CSI synchronization signal block (CSI-SSB) resource set, a CSI interference measurement (CSI-IM) resource set, a non zero power-channel state information reference signal (NZP-CSI-RS) resource set, or a zero power-channel state information reference signal (ZP-CSI-RS) resource set. Wherein, CSI refers to channel state information (CSI).

[0120] The reference signal in the embodiments of the present application can correspond to a resource, the reference signal can occupy the resource, and one resource can be referred to as a resource of the reference signal. The resource in the embodiments of the present application can include a frequency domain resource and / or a time domain resource, etc. The resource can also include at least one of a CSI-SSB resource, or a CSI-IM resource, or an NZP-CSI-RS resource, a ZP-CSI-RS resource, an SRS resource, a demodulation reference signal (DMRS) resource, a PTRS resource, a CRS resource, or a TRS resource. In the embodiments of the present application, the resource is taken as a channel state information reference signal (CSI-RS) resource as an example for description, the CSI-RS resource is also written as a channel state information reference signal (CSIRS) resource in the present document, and the CSIRS resource can also be replaced by other resources. The CSI-RS resource can also be understood as a resource occupied by the CSI-RS, and can also be replaced by a resource corresponding to the CSI-RS, or a resource of the CSI-RS.

[0121] (3) Beamforming.

[0122] A beam is a kind of communication resource. The beam can be a wide beam, or a narrow beam, or other types of beams. The technology of forming a beam can be referred to as beamforming technology. The beamforming technology refers to adjusting the amplitude and / or phase of a signal, so that the radiation signal radiated by the antenna array has a certain directivity, and higher antenna array gain can be achieved. Wherein, the main lobe of the radiation pattern of the antenna array can be referred to as a beam.

[0123] In the beamforming technology, the signal is filtered by a spatial domain transmission filter to realize the adjustment of amplitude and / or phase, and different spatial domain transmission filters with different spatial filtering parameters can realize beams in different directions. In the embodiments of the present application, the spatial filtering parameter can be replaced by a beam, or the spatial filtering parameter can be replaced by a spatial domain transmission filter. The spatial domain transmission filter can also be referred to as a spatial filter.

[0124] Specifically, the beamforming technology includes digital beamforming (DBF) technology, analog beamforming (ABF) technology and hybrid digital-analog beamforming (hybrid beamforming, HBF) technology. Among them, the DBF technology has multiple digital processing channels, and the phase (or amplitude and phase) of the signal is adjusted in the digital domain through each digital processing channel, so that the radiation signal radiated by the antenna has directionality. Therefore, for the DBF technology, the function of the above-mentioned spatial domain transmission filter can be realized through multiple digital processing channels. The ABF technology can simultaneously send signals through an antenna array composed of multiple antenna elements, each antenna element corresponds to a phase shifter, and the phase of each antenna element corresponding phase shifter is adjusted to realize that the radiation signal radiated by the antenna array has directionality. Therefore, for the ABF technology, the function of the above-mentioned spatial domain transmission filter can be realized through multiple phase shifters corresponding to multiple antenna elements in the antenna array. The HBF technology is a combination of ABF technology and DBF technology, which has multiple digital processing channels and multiple analog phase shifters. Therefore, for the hybrid beamforming technology, the function of the above-mentioned spatial domain transmission filter can be realized through multiple phase shifters corresponding to multiple antenna elements in the antenna array and multiple digital processing channels. However, the present application is not limited thereto, and the above-mentioned spatial domain transmission filter can also be realized by other technologies.

[0125] It can be understood that one or more antenna ports forming a beam can be regarded as an antenna port set or an antenna port group. For ease of description, the antenna port group corresponding to one or more antenna ports forming a beam is referred to as a port group hereinafter.

[0126] In an implementation manner, multiple digital channels perform the same digital weighting in the full frequency band, and the effect is similar to analog beamforming.

[0127] In another implementation, the digital channels (or digital weights) can be divided into multiple stages, the first stage performs the same digital weighting for the full band, and the second stage performs the weight weighting for the sub-band, and the effect is also equivalent to hybrid beamforming. For ease of understanding, FIG. 3 shows a schematic diagram of hybrid beamforming (or digital beamforming). In one way, as shown in FIG. 3, the digital channels are evenly divided into K1 (K1 is a positive integer) groups (or K1 sub-arrays, K1 port groups), and the number of digital channels in each group (or each sub-array, each port group) is the same, for example, K2 (K2 is a positive integer). Digital beamforming and analog beamforming can be regarded as two-stage beamforming. The first-stage beamforming is analog beamforming, and the weight of the first-stage beamforming is W0=[W0,0, W0,1, …, W0,K2-1], where the K2 elements correspond to the K2 digital channels, and the weight of the first-stage beamforming is broadband, and each group uses the same first-stage weight, that is, W0. The second-stage beamforming is digital beamforming, and the weight of the second-stage beamforming is W1=[W1,0, W1,1, …, W1,K1-1], where the K1 elements correspond to the K1 digital channels, and the weight of the second-stage beamforming is sub-band, and the second-stage weights are different between different groups (or different sub-arrays, different port groups), that is, the weight matrix corresponding to the digital channels is 0,0 W 0,1 …W 0,K2-1 ] where the K2 elements correspond to the K2 digital channels, and the weight of the first-stage beamforming is broadband, and each group uses the same first-stage weight, that is, W0. The second-stage beamforming is digital beamforming, and the weight of the second-stage beamforming is W1=[W 1,0 W 1,1 …W 0,K1-1 ] where the K1 elements correspond to the K1 digital channels, and the weight of the second-stage beamforming is sub-band, and the second-stage weights are different between different groups (or different sub-arrays, different port groups), that is, the weight matrix corresponding to the digital channels is or where, denotes the Kronecker product, and in FIG. 3 denotes the weight vector corresponding to the first-stage weight. It can be seen that different weight vectors correspond to different beam directions. Therefore, the network device can adjust the beam direction by adjusting the weight vector.

[0128] (4) Antenna port and port group

[0129] The antenna port can be simply referred to as a port, which can be understood as a virtual transmitting antenna recognized by the receiving end, or a virtual transmitting antenna that can be distinguished in space. A port can be pre-configured for each virtual antenna, and each virtual antenna can be a weighted combination of multiple physical antennas. One or more antenna ports can correspond to one reference signal, and therefore each antenna port can be referred to as a port of one reference signal, such as a CSI-RS port, a DMRS, an SRS port, and the like. In the embodiments provided in the present application, one antenna port can also be used to transmit multiple reference signals, for example, multiple reference signals can be sent through the antenna port by frequency division or time division.

[0130] Wherein, the antenna port is a logical concept, and one antenna port is generally corresponding to one physical antenna. The antenna port is usually associated with a reference signal, and its meaning can be understood as a transceiving interface on the channel experienced by the reference signal. For low frequency, one antenna port can correspond to one or more antenna elements, and these antenna elements jointly transmit the reference signal, and the receiving end can treat them as a whole and does not need to distinguish these antenna elements. For high frequency system, the antenna port can correspond to a beam, and similarly, the receiving end only needs to regard the beam as an interface and does not need to distinguish each antenna element.

[0131] In the protocol, the antenna port is usually represented by antenna port or port, and can also be represented by a resource (such as CSI-RS resource, SRS resource, DMRS resource, PTRS resource, CRS resource, TRS resource, synchronization signal block (SSB) resource, etc.) or a resource group. That is, the identification of the antenna port in the present application can be replaced by the identification of the above content, such as the identification of the resource, the identification of the pilot resource, the identification of the reference signal resource, etc.

[0132] In a possible design, multiple digital ports of the network device can be grouped to form multiple port groups. In a possible design, one reference signal resource (such as CSI-RS resource) corresponds to one port group, or multiple reference signal resources correspond to multiple port groups respectively. In another possible design, multiple reference signal resources correspond to one port group. Wherein, one port group corresponds to at least one digital port, for example, in the HBF architecture, the port group includes the antenna elements in the array connected by each digital port of the at least one digital port. Optionally, in the case that one port group corresponds to one analog beam, the multiple digital ports included in the same port group can be the multiple digital ports corresponding to the same analog beam; or, in the case that one port group corresponds to multiple analog beams, the multiple digital ports included in the same port group can be the digital ports corresponding to the multiple analog beams. Optionally, in the HBF architecture, the port group can also be replaced by the digital-analog port group.

[0133] The concept of port group can also be replaced by other names, such as subarray, resource group, resource set, pilot resource group, pilot resource set, reference signal resource group, reference signal resource set, port set, antenna port group, antenna port set, or antenna port set, and the like, and the embodiments of the present application are not limited thereto. In the embodiments of the present application, the port group can also be replaced by "port #A to port #B". Wherein port #A and port #B can be understood as an example of the index of the port. The antenna ports indicated by port #A to port #B can be understood as the antenna ports with indexes from #A to #B, and the indexes of these antenna ports are continuous. In the embodiments of the present application, the port set can also be replaced by the index of each antenna port included in the port set. In this case, the antenna ports included in the port set can be continuous antenna ports or discontinuous antenna ports.

[0134] (5) Precoding and codebook.

[0135] In a communication system, the throughput can be improved by increasing the system capacity by using multiple input multiple output (MIMO) technology. The mathematical expression is y = H x + n, where y is the received signal, H is the MIMO channel, x is the transmitted signal, and n is the noise. In a communication system with multiple antennas, the signals of multiple transmitting antennas are superimposed on any receiving antenna, so the method of transmitting signals at the transmitting end affects the performance of the system, and the recovery of the transmitted signal at the receiving end is often complex. In this context, precoding is used to reduce system overhead and maximize the system capacity of MIMO, and to reduce the complexity of the receiver to eliminate the effects of the channel. At this time, the mathematical expression is y = H x W + n, and W is the precoding matrix (or vector, or precoder). In order to simplify the implementation complexity, W can be selected from a pre-defined matrix (or vector) set, which is called codebook. The above signal transmission method is also called codebook-based transmission method. If the transmitting end can obtain all the information of H, W can be obtained by the transmitting end, and this signal transmission method is also called non-codebook (NCB) transmission method.

[0136] (6) Precoding matrix indicator (PMI) information.

[0137] The PMI information can be used to indicate a precoding matrix. The precoding matrix can be determined by the terminal device based on a channel matrix of one frequency domain unit, for example. The channel matrix can be determined by the terminal device through channel estimation or based on channel reciprocity. However, it should be understood that the specific method for determining the precoding matrix by the terminal device is not limited to the above description, and the specific implementation manner can be referred to the protocol. For the sake of brevity, the specific implementation manner is not listed here.

[0138] For example, the precoding matrix can be obtained by performing singular value decomposition (SVD) on the channel matrix or the covariance matrix of the channel matrix, or can also be obtained by performing eigenvalue decomposition (EVD) on the covariance matrix of the channel matrix. It should be understood that the above-mentioned methods for determining the precoding matrix are only examples and should not constitute any limitation on the present application.

[0139] It can be understood that, by the method provided by the embodiments of the present application, the network device can determine the CSI RS port, the discrete fourier transform (DFT) vector, and the combination coefficient of the space-frequency vector used to construct the precoding vector based on the feedback of the terminal device, and then determine the precoding matrix corresponding to each frequency domain unit. The precoding matrix can be directly used for downlink data transmission, or can be subjected to some beamforming methods, such as zero forcing (ZF), regularized zero-forcing (RZF), minimum mean-squared error (MMSE), maximum signal-to-leakage-and-noise (SLNR), etc., to obtain the final precoding matrix used for downlink data transmission. The present application does not make any limitation on this. In the absence of any specific description, the precoding matrix referred to in the following can be the precoding matrix determined based on the method provided by the present application.

[0140] It can be understood that the precoding matrix determined by the terminal device can be understood as the precoding matrix to be fed back. The terminal device can indicate the precoding matrix to be fed back through the PMI, so that the network device recovers the precoding matrix based on the PMI. It can be understood that the precoding matrix recovered by the network device based on the PMI can be the same as or similar to the precoding matrix to be fed back.

[0141] In the downlink channel measurement, the higher the approximation degree of the precoding matrix determined by the network device according to the PMI and the precoding matrix determined by the terminal device, the more suitable the precoding matrix determined by the network device for data transmission is to the channel state, and thus the reception quality of the signal can be improved.

[0142] (7) Precoding and codebook

[0143] In a MIMO system, the communication mathematical expression is y = H x + n, where y is a received signal, H is a MIMO channel, x is a transmitted signal, and n is noise. In a communication system with multiple antennas, the signals of multiple transmitting antennas are superimposed on any receiving antenna, and thus the method of transmitting signals at the transmitting end affects the performance of the system, and the recovery of the transmitted signal at the receiving end is often complex. In this context, precoding is used to reduce the system overhead and maximize the system capacity of the MIMO, and to reduce the complexity of the implementation of the receiver to eliminate the influence of the channel. At this time, the mathematical expression is y = H x W + n, and W is a precoding matrix (or vector). In order to simplify the implementation complexity, W can be selected from a pre-defined matrix (or vector) set, which is called a codebook, and this method is also called a codebook-based transmission method.

[0144] The codebook includes PMI indexes and precoding matrices, each PMI and precoding matrix corresponds to each other, and the corresponding precoding matrix can be determined according to the PMI of the CSI feedback.

[0145] (7.1) For the “Release 15” protocol proposed by 3GPP, in the type I codebook feedback, the PMI can specifically include the feedback of the precoding matrices of different transmission layers and different subbands. The precoding matrix to be fed back corresponding to one transmission layer and one subband can be represented as W: W = W1 x W2, the dimension of W is P CSI-RS x N3, W1 is a wideband precoding matrix, the dimension of which is P CSI-RS x 2L, and W2 is a subband precoding matrix, the dimension of which is 2L x N3. P CSI-RSN3 represents the number of CSI-RS ports, N3 represents the number of subbands or the number of PMIs, L represents the number of data streams transmitted and / or the number of spatial domain bases (or the number of precoders). Optionally, L can be the number of spatial domain bases in a single polarization, the number of spatial domain bases in a single subarray, or L can include the number of spatial domain bases in a single polarization and the number of spatial domain bases in a single subarray; 2L can be the number of spatial domain bases in a double polarization, the number of spatial domain bases in two subarrays, or L can include the number of spatial domain bases in a double polarization and the number of spatial domain bases in two subarrays. The codebook parameters used by the type I codebook can be understood with reference to Table 1 as follows.

[0146] Table 1

[0147] When the number of CSI-RS ports is less than or equal to 2, the feedback parameters of the codebook (including the codebook index and the number of layers) are as follows:

[0148] Table 2

[0149] When the number of CSI-RS ports is greater than 2, since the precoding matrix of the codebook, i.e., the number of weights, increases geometrically with the number of CSI-RS ports and the number of layers, the codebook is no longer suitable for being listed in an enumerated form, but is generated according to certain rules according to the relevant parameter configurations, that is, the codebook can be determined according to the relevant parameter configurations.

[0150] Taking the type I codebook as an example, in the case of codebookmode = 1, the codebook can be determined according to the following three steps: 1, determine the spatial domain beam set, i.e., all the weight sets in a codebook; 2, select the wideband beam group, i.e., determine the wideband precoding matrix W1; 3, beam selection and phase quantization adjustment, i.e., determine the subband precoding matrix W2.

[0151] Among them, the spatial domain beam set is determined by the parameter configurations in Table 3:

[0152] Table 3

[0153] N1 in Table 3 represents the number of logical antenna ports in a certain direction of the same polarization, which generally refers to the horizontal direction; N2 represents the number of logical antenna ports in another direction of the same polarization, which generally refers to the vertical direction; O1 represents the DFT oversampling multiple of the direction (horizontal direction) where N1 is located; O2 represents the DFT oversampling multiple of the direction (vertical direction) where N2 is located.

[0154] As shown in Table 3, taking P CSI-RS As shown in Table 3, taking P

[0155] The physical meaning of O1 and O2 is that the number of weight vectors is increased in the horizontal direction and the vertical direction through DFT oversampling, so that more weight vectors can be generated. The values of O1 and O2 also determine the beam density in the horizontal direction and the vertical direction when the antenna form is determined, i.e., when N1 and N2 are determined. The greater the values of O1 and O2, the smaller the step size of the beam when beam scanning is performed, and the higher the accuracy, but the cost is that the weight vectors are no longer orthogonal, i.e., there is interference between the beams formed by the weight vectors.

[0156] Figure 4 is a schematic diagram of a spatial beam index under 16 CSI-RS ports. As shown in Figure 4, (N1, N2) takes the value (4, 2), so that the spatial beams formed have a horizontal dimension of 4 and a vertical dimension of 2. (O1, O2) takes the value (4, 4), and each circle point corresponds to a DFT oversampled weight vector. Since different weight vectors can form beams in different directions, each circle point in Figure 4 corresponds to a different DFT beam. Among them, the weight vectors corresponding to the black circle points are mutually orthogonal, i.e., the DFT beams corresponding to the black circle points do not interfere with each other; and the weight vectors corresponding to the black circle points and the shaded circle points are no longer orthogonal, i.e., there is a certain interference between the DFT beams corresponding to the black circle points and the shaded circle points.

[0157] As shown in Figure 4, according to the position of each circle point in the horizontal direction and the vertical direction, the oversampled DFT beam index can be determined. l represents the DFT beam index in the horizontal direction, and m represents the DFT beam index in the vertical direction, for example, (l, m) = (0, 0) is used to indicate the DFT beam corresponding to the circle point marked with "1" in the spatial beam shown in Figure 4.

[0158] The wideband precoding matrix W1 is formed by DFT matrix oversampling, i.e., the DFT matrix obtains the required beamforming weight in space in an oversampled manner. The weight vectors of the lth beam in the horizontal direction and the mth beam in the vertical direction satisfy the following expression:

[0159] wherein v lis the weight vector in horizontal direction, and the length of the vector is N1. The number of weight vectors in horizontal direction is determined by the number of l, that is, l also represents the weight selected in horizontal direction.

[0160] u m is the weight vector in vertical direction, and the length of the vector is N2. The number of weight vectors in vertical direction is determined by the number of m, that is, m also represents the weight selected in vertical direction.

[0161] After confirming the weight group in horizontal direction and vertical direction, the selected weight group is determined. The result of the kronecker product of v l and u m is only the weight result on one group of polarized antennas, and there is usually a certain phase deviation on the other group of polarized antennas, which is determined by W2. Therefore, the final expression result of W1 is in the form of the latter sub-block diagonal matrix in the kronecker product of v l and u m .

[0162] The weight vector of the (l, m)th beam satisfies the following expression (3):

[0163] According to the above expression, the beam corresponding to W1 can be determined by calculating all possible values of l and m. The beam corresponding to W1 can be divided into two cases:

[0164] (1) multiple oversampled DFT beams, and any two beams are not orthogonal to each other, and the whole is represented by v l,m .

[0165] (2) multiple orthogonal DFT beams, which are distinguished by v l,m , v l′,m′ , v l″,m″ ...

[0166] Correspondingly, W1 satisfies the following expression (4):

[0167] wherein N represents the number of ports of CSI-RS, v represents the number of layers (or the number of streams), represents the power normalized coefficient, which is used to ensure that the total power on the antenna port remains unchanged before and after the weighting of beamforming. The number of ports of CSI-RS is the number of rows of wideband precoding matrix W1, which is twice the number of rows of v l,m ; the non-zero sub-diagonal block in the upper left corner of W1, that is, v l,m v l′,m′Each column represents a beam in a certain direction of the same polarized antenna.

[0168] When the number of CSI-RS ports is greater than 2, the PMI index includes a wideband indication i1 and a subband indication i2. The wideband indication i1 is a composite index, and the basic definition of the wideband indication i1 is as follows:

[0169] Wherein, i 1,1 is the first DFT beam (or spatial basis, or IDFT beam) fed back by the terminal device, and IDFT refers to inverse discrete fourier transform (IDFT). The corresponding horizontal coordinate position in the spatial beam index diagram shown in FIG. 4 corresponds to the horizontal index l described above; i 1,2 is the corresponding vertical coordinate position of the DFT beam (or spatial basis, or IDFT beam) in the spatial beam index diagram shown in FIG. 4, which corresponds to the vertical index m described above; i 1,3 is the offset of the other DFT beam fed back by the terminal device relative to the first DFT beam, i 1,3 includes the offset in the horizontal direction and the vertical direction; v represents the number of layers, and it should be noted that in the type I codebook, the number of spatial bases corresponds to the same value as the number of layers.

[0170] When the number of layers v is 2, i 1,3 The offsets in the horizontal direction and the vertical direction can be selected according to Table 4.

[0171] Table 4

[0172] In Table 4, k1 corresponds to the value of the offset of the other DFT beam relative to the first DFT beam in the horizontal direction, and k2 corresponds to the value of the offset of the other DFT beam relative to the first DFT beam in the vertical direction.

[0173] When the number of layers v is 3 or 4, and the number of CSI-RS ports is less than 16, i 1,3 The offsets in the horizontal direction and the vertical direction can be selected according to Table 5.

[0174] Table 5

[0175] It can be understood that for each CSI-RS resource, the terminal device needs to select a DFT beam (or spatial basis, or IDFT beam) from the spatial beam set according to the autocorrelation covariance matrix R hh of the frequency domain channel coefficient corresponding thereto, so as to determine the wideband precoding matrix W1.

[0176] The sub-band precoding matrix W2 is used for phase difference quantization and adjustment of the weight on another group of polarized antennas, and the sub-band index i2 fed back by the terminal device corresponds to W2. In the case of codebookmode = 1, when the layer number v is 1, the PMI content fed back by the terminal device to the network device is as shown in Table 6:

[0177] Table 6

[0178] wherein, that is, the precoding matrix determined according to the wide-band precoding matrix W1 and the sub-band precoding matrix W2 when the layer number v is 1. Specifically, P CSI-RS is the number of CSI-RS ports, and i 1,1 and i 1,2 can determine the horizontal index l and the vertical index m of the DFT beam in the spatial beam index map, so as to determine the weight vector of the (l, m) beam, n is the value corresponding to i2 fed back by the terminal device.

[0179] In the case of codebookmode = 1, when the layer number v is 2, the PMI content fed back by the terminal device to the network device is as shown in Table 7:

[0180] Table 7

[0181] wherein, that is, the precoding matrix determined according to the wide-band precoding matrix W1 and the sub-band precoding matrix W2 when the layer number v is 2. k1 and k2 are the horizontal direction and the vertical direction offset contained in i 1,3 , v l′,m′ is used to represent the orthogonal DFT beam different from v l,m , and the remaining parameters are consistent with Table 5, which will not be described here.

[0182] In the case of codebookmode = 1-2, when the layer number v is 3 and the number of CSI-RS ports is less than 16, the PMI content fed back by the terminal device to the network device is as shown in Table 8:

[0183] Table 8

[0184] wherein, that is, the precoding matrix determined according to the wide-band precoding matrix W1 and the sub-band precoding matrix W2 when the layer number v is 3 and the number of CSI-RS ports is less than 16. k1 and k2 are the horizontal direction and the vertical direction offset contained in i 1,3 , and the remaining parameters are consistent with Table 5 and Table 6, which will not be described here.

[0185] When the number of layers v and the number of CSI-RS ports are other possible values, the specific method for determining the precoding matrix can be found in the relevant content of 3GPP technical specification (TS) 38.214, which will not be elaborated here.

[0186] Furthermore, in one possible implementation, one or more DFT beams (or spatial basis, or IDFT beams) corresponding to W1 can be replaced with other vectors. For example, a column (or multiple columns) in W1 corresponds to a vector v. m v m Dimensions The m-th element is 1, and m is from 1 to... integers, All elements except the m-th element are 0. For example, v m Dimension P CSI-RS ×1, where the m-th and the... Each element is 1, and m is from 1 to P. CSI-RS integers, P CSI-RS All elements except the m-th element are 0.

[0187] (7.2) For the Release 16 codebook, the PMI indicates that the precoding matrix of each layer can be equivalently represented as: The dimension of W is P CSI-RS ×N3, the dimension of W1 is P CSI-RS ×2L, W1 indicates the wideband precoding matrix. The dimension is 2L×N3 (corresponding to W2 in Release 15, which is the precoding matrix for each subband). Among them, The dimension is 2L×M (or the compressed matrix). The dimension is M×N3 (which is the Mth row of an N3×N3 IDFT matrix, i.e., the N3×N3 DFT matrix W). f (the conjugate of column M in the text), where P CSI-RS For the number of CSI-RS ports, The number of IDFT basis vectors is selected, N3 is the number of subbands (or the number of PMIs) fed back by the PMI, and R is the number of precoding matrices on a single subband. During the final feedback, only the port or DFT codebook information related to W1 needs to be fed back. Related IDFT substrate selection information, The non-zero element in The precoding matrix can be denoted as W1. It can be understood that the above description of the precoding matrix is only as an example, and the remaining specific implementation and definitions can refer to the description of 5.2.2.2.1 in 3GPP TS 38.214.

[0188] The codebook of Release 16 is divided into two types: a normal codebook (or DFT codebook) and a port selection codebook. Among them, the W1 corresponding to the normal codebook is a DFT matrix, the codebook parameters used by the normal codebook can be understood with reference to Table 1 above, and the W1 corresponding to the normal codebook can be understood with reference to the description in (7.1) above. The W1 corresponding to the port selection codebook is an identity matrix, and the codebook parameters used by the port selection codebook can be understood with reference to Table 9 below.

[0189] Table 9

[0190] For the normal codebook, the precoding matrix of the lth layer and the subband t can be determined by the following formula (6):

[0191] wherein γ t,l is a power normalization coefficient, is a frequency domain basis index, M v is a frequency domain basis quantity, and correspond to spatial domain bases, L is a spatial domain basis quantity, and are inter-polarization amplitude factors, and correspond to amplitude coefficients, and correspond to phases. In the above formula, corresponds to W1, W1 corresponds to one or more DFT beams (or IDFT beams, spatial domain bases), corresponds to and correspond to wherein the information reported by the terminal is used to determine the following parameters: and and i = 0, 1, …, L-1, f = 0, 1, …, M v -1, M v are parameters determined according to the base station configuration information.

[0192] For the port selection codebook, the precoding matrix of the lth layer and the subband t can be determined by the following formula (7):

[0193] wherein i1,1 corresponding to the starting port index, i 1,1 may be reported by the terminal to the base station; d corresponds to a port interval factor, which can be indicated by the base station; has a dimension of where the mth element is 1, and m is an integer from 1 to , the integer, other elements in the P elements are 0, except for the mth element; or has a dimension of P CSI-RS × 1, where the mth and the element is 1, and m is an integer from 1 to P CSI-RS , the integer, P CSI-RS other elements in the P elements are 0, except for the mth element. Other parameters can be understood according to the description in the foregoing general codebook corresponding formula (6), and the embodiments of the present application do not repeat them.

[0194] As introduced above, it can be known that the PMI currently adopts a port selection codebook or a DFT codebook. The port selection codebook corresponds to the transmission mode of the access network side in the beam domain, and the DFT codebook corresponds to the transmission mode of the access network side in the antenna domain. For the HBF architecture, in the future, part of the full connection architecture or a new transmission mode, part of the subarray may adopt beam domain transmission, and the subarrays may adopt antenna domain transmission; or the subarrays may adopt antenna domain transmission, and the subarrays may adopt beam domain transmission. The existing codebook cannot match this new mode, resulting in reduced codebook performance.

[0195] Based on this, the embodiments of the present application provide a method, as shown in FIG. 5, which mainly includes the following steps.

[0196] S501, the network device sends first configuration information to the terminal device.

[0197] The first configuration information can be understood as the configuration of the reference signal, and the first configuration information is used to configure the reference signal resources corresponding to the P port groups, and the terminal device can measure the reference signal on the reference signal resources. For example, P reference signal resources are configured in the first configuration information, and the P port groups correspond to the P reference signal resources one by one, and the terminal device can measure the reference signal on the P reference signal resources to obtain the channel measurement results corresponding to the P port groups. The value of P is a positive integer. It can be understood that a port group includes multiple antenna ports. In a possible implementation, the port group (or panel, subarray) described in the present method corresponds to multiple subarrays in the HBF architecture.

[0198] For example, the value of P is greater than 1, and the total number of antenna ports is P CSI-RS = 2 × N g,1 × N1 × N g,2XN2, the antenna ports are divided into two dimensions of port groups, for example, the number of port groups in the first dimension is N g,1 , the number of port groups in the second dimension is N g,2 ; each port group has N1 and N2 antenna ports in two dimensions. In FIG. 6A, P = 4, N g,1 = 2, N g,2 = 2, N1 = 4 and N2 = 4 are taken as examples to illustrate the grouping of antenna ports, one antenna port corresponds to a dual-polarized antenna element, and the dashed line and the solid line represent different polarization directions. Optionally, the first dimension can be referred to as the horizontal dimension, and the second dimension can be referred to as the vertical dimension; or, the first dimension can be referred to as the vertical dimension, and the second dimension can be referred to as the horizontal dimension.

[0199] For another example, the value of P is 1, and the total number of antenna ports is P CSI-RS = 2 x N1 x N2, the antenna ports are divided into two dimensions, the number of antenna ports in the first dimension is N1, and the number of antenna ports in the second dimension is N2. In FIG. 6B, P = 1, N1 = 4 and N2 = 8 are taken as examples to illustrate the grouping of antenna ports, one antenna port corresponds to a dual-polarized antenna element, and the dashed line and the solid line represent different polarization directions. Optionally, the first dimension can be referred to as the horizontal dimension, and the second dimension can be referred to as the vertical dimension; or, the first dimension can be referred to as the vertical dimension, and the second dimension can be referred to as the horizontal dimension.

[0200] In a possible implementation, the network device can also indicate the value of at least one of N g,1 , N1, N g,2 and N2 in the first configuration information.

[0201] Optionally, the P port groups can correspond to the same digital port and / or the same analog beam. The embodiments of the present application do not limit this.

[0202] S502, the terminal device determines the PMI information according to the channel measurement result of the reference signal resource.

[0203] Wherein, the terminal device determines a precoding matrix used for data transmission (such as downlink data transmission) according to the channel measurement result of the reference signal resource, and the PMI information indicates the precoding matrix. The precoding matrix adopts a codebook form, and some possible codebook designs are introduced below.

[0204] Design 1, for P port groups, P is greater than 1, the precoding matrix (codebook) to be fed back for P port groups satisfies the following formula (8):

[0205] Wherein, W p indicates the amplitude and / or phase coefficient corresponding to the P port groups, for example, W pcorresponding to K columns in the DFT matrix, the W p has a dimension of (N g,1 N g,2 x K or P x K), N g,1 x N g,2 = P, the P rows of elements in the W p correspond to P port groups, and the K is a positive integer. p,k corresponding to a k-th column in the K columns, the k is an integer from 1 to K, the w p,k satisfies the following formula (9):

[0206] In the formula (9), k1x N g,2 x O4 + k2 = c k , the c k indicates an index of the w p,k in the precoding matrix, and the O3 and the O4 are preconfigured or indicated by a network device in first configuration information. Optionally, a value of K is less than or equal to a number of spatial domain bases corresponding to the precoding matrix, for example, K is a positive integer that can be divided by the number of spatial domain bases L.

[0207] In another implementation, K is 1, or 2, or 4.

[0208] In another implementation, K is a preset value, or K is a value indicated by a certain field of a base station, or a value determined according to indication information of the base station.

[0209] In another implementation, the W p is K columns in a unit matrix, the w p,k corresponding to a k-th column in the K columns, the k is an integer from 1 to K, the w p,k has a dimension of P x 1, wherein an m-th element is 1, the m is an integer from 1 to P, and other elements in the P elements except the m-th element are 0.

[0210] Exemplarily, values of N g,1 , N g,2 , O3, O4 can be understood with reference to a certain row in the following Table 10.

[0211] Table 10

[0212] It can be understood that N g,1 in the Table 10 represents a number of port groups in a first dimension, N g,2 represents a number of port groups in the first dimension; O3 represents a DFT oversampling multiple of a dimension in which N g,1 is located; and O4 represents a DFT oversampling multiple of a dimension in which N g,2The DFT oversampling factor in the dimension. Based on the design in Table 10, the network device can carry the index of a certain row in Table 10 in the first configuration information, and the terminal device can determine (N g,1 N g,2 The corresponding values ​​of (O3, O4); or the network device can carry (N) in the first configuration information. g,1 N g,2 If the values ​​of O3 and O4 are given, the terminal device can determine the corresponding (O3, O4) by consulting Table 10. It should also be understood that Table 10 only shows some combinations of O3 and O4 values. In actual applications, O3 and O4 can also have other values, such as (2, 2). This application embodiment does not limit this.

[0213] The following examples can be used to understand W1 and W2:

[0214] Example 11: One or more DFT beams (or spatial basis, or IDFT beams) corresponding to W1 can be replaced with other vectors. For example, the vector v corresponding to a certain column or multiple columns in W1. m v m The dimension is N1×1, where the m-th element is 1, m is an integer from 1 to N1, and all N1 elements except the m-th element are 0; or, v m Dimensions The m-th element is 1, and m is from 1 to... integers, All elements except the m-th element are 0; or, v m The dimension is N1×1, where the m-th and the... The m-th element is 1, and the m-th element is an integer from 1 to N1. All N1 elements except the m-th element are 0. W2 can be understood with reference to the definition in Release 15 of the protocol; this embodiment will not elaborate further.

[0215] Example 12, In one possible design, W'1 is a partial column of a DFT matrix, a partial column of an IDFT matrix, or a partial column of a spatial basis, and W"1 is a partial column of an identity matrix. The dimensions of W'1 and the dimensions of W"1 can be understood with reference to the following examples: the dimensions of W'1 is 2N1x2L, and the dimensions of W"1 is N2x1; or the dimensions of W'1 is N1x2L, and the dimensions of W"1 is 2N2x1; or the dimensions of W'1 is 2N1x1, and the dimensions of W"1 is N2x2L; or the dimensions of W'1 is N1x1, and the dimensions of W"1 is 2N2x2L; or the dimensions of W'1 is 2N1x2, and the dimensions of W"1 is N2xL; or the dimensions of W'1 is N1x2, and the dimensions of W"1 is 2N2xL. In another possible design, W'1 is a partial column of an identity matrix, and W"1 is a partial column of a DFT matrix, a partial column of an IDFT matrix, or a partial column of a spatial basis. The dimensions of W'1 and the dimensions of W"1 can be understood with reference to the following examples: the dimensions of W'1 is 2N1x2, and the dimensions of W"1 is N2xL; or the dimensions of W'1 is N1x2, and the dimensions of W"1 is 2N2xL; or the dimensions of W'1 is 2N1xL, and the dimensions of W"1 is N2x2; or the dimensions of W'1 is N1xL, and the dimensions of W"1 is 2N2x2; or the dimensions of W'1 is 2N1x2L, and the dimensions of W"1 is N2x1; or the dimensions of W'1 is N1x2L, and the dimensions of W"1 is 2N2x1. It is to be understood that W2 can be understood with reference to the definition in Release 15 of the protocol, and embodiments of the present application do not elaborate on this.

[0216] Example 13, W1 corresponds to 1 column of an identity matrix or L1 columns of an identity matrix, and W2 corresponds to 1 column of a DFT matrix (or a spatial basis, or an IDFT matrix) or L2 columns of an identity matrix. L1 and L2 are determined based on the number of spatial bases of a precoding matrix (or the number of Precoders), or are determined according to the selected total number of ports. Optionally, L1xL2=L, or L1xL2=2L, L indicating the number of spatial bases (or the number of Precoders).

[0217] Example 14, W1 corresponds to 1 column of a DFT matrix (or a spatial basis, or an IDFT matrix) or L1 columns of an identity matrix, and W2 corresponds to 1 column of an identity matrix or L2 columns of an identity matrix. L1 and L2 are determined based on the number of spatial bases of a precoding matrix (or the number of Precoders), or are determined according to the selected total number of ports. Optionally, L1xL2=L, or L1xL2=2L, L indicating the number of spatial bases (or the number of Precoders).

[0218] In addition, the above formula (8) can also be replaced by or, Or other variations of the formula, but the embodiments of this application are not limited to these.

[0219] Design 2: For P port groups, where P is greater than 1, the precoding matrix (codebook) to be fed back for the P port groups can satisfy the following formula (10):

[0220] Among them, W p The description can be understood with reference to the aforementioned Design 1, and the embodiments of this application will not be described in detail.

[0221] The following examples can be used to understand W1 and W2:

[0222] Example 21: One or more DFT beams (or spatial basis, or IDFT beams) corresponding to W1 can be replaced with other vectors. For example, the vector v corresponding to a certain column or multiple columns in W1. m v m The dimension is N1×1, where the m-th element is 1, m is an integer from 1 to N1, and all N1 elements except the m-th element are 0; or, v m Dimensions The m-th element is 1, and m is from 1 to... integers, All elements except the m-th element are 0; or, v m The dimension is N1×1, where the m-th and the... The first element is 1, and m is an integer from 1 to N1. All N1 elements except the m-th element are 0. The definitions in Release 16 of the protocol can be used for understanding, and the embodiments in this application will not be described in detail.

[0223] Example 22, W′1 is a DFT matrix (or spatial basis, or IDFT matrix), and W″1 is an identity matrix; or, W′1 is an identity matrix, and W″1 is a DFT matrix (or spatial basis, or IDFT matrix). The dimensions of W′1 and W″1 can be understood with reference to Example 12. The definitions in Release 16 of the protocol can be used for understanding, and the embodiments in this application will not be described in detail.

[0224] Example 23, W1 corresponds to column 1 of the identity matrix or column L1 of the identity matrix. L2 columns of the identity matrix. L1 and L2 are determined based on the number of spatial bases (or the number of precoders) of the precoding matrix, or determined according to the selected total number of ports. Optionally, L1 x L2 = L, or L1 x L2 = 2L, L indicates the number of spatial bases (or the number of precoders).

[0225] Example 24, W1 corresponds to 1 column of the DFT matrix (or spatial base, or IDFT matrix) or L1 columns of the identity matrix, L2 columns of the identity matrix. L1 and L2 are determined based on the number of spatial bases (or the number of precoders) of the precoding matrix, or determined according to the selected total number of ports. Optionally, L1 x L2 = L, or L1 x L2 = 2L, L indicates the number of spatial bases (or the number of precoders).

[0226] Design 3, for the case of P port groups, P is equal to 1, the precoding matrix (codebook) to be fed back for one port group can satisfy the following formula (11):

[0227] Wherein, W'1 is the DFT matrix (or spatial base, or IDFT matrix), and W"1 is the identity matrix; or, W'1 is the identity matrix, and W"1 is the DFT matrix (or spatial base, or IDFT matrix). The dimensions of W'1 and W"1 can be understood with reference to example 12; W2 can be understood with reference to the definition in the protocol Release 15, and the embodiments of the present application do not perform the description.

[0228] Design 4, for the case of P port groups, P is equal to 1, the precoding matrix (codebook) to be fed back for one port group can satisfy the following formula (12):

[0229] Wherein, W'1 is the DFT matrix (or spatial base, or IDFT matrix), and W"1 is the identity matrix; or, W'1 is the identity matrix, and W"1 is the DFT matrix (or spatial base, or IDFT matrix). The dimensions of W'1 and W"1 can be understood with reference to example 12; The definition in the protocol Release 16 can be understood, and the embodiments of the present application do not perform the description.

[0230] Design 5, for the case of P port groups, the precoding matrix (codebook) to be fed back for P port groups can satisfy the following formula (13):

[0231] Wherein, I G is the identity matrix, IG dimension of GxG, G indicates the number of port groups P, and G is equal to P. Taking the case that the port groups described in S501 are divided into the first dimension and the second dimension as an example, G = P = N g,1 xN g,2 . indicates the phase combining coefficient between different port groups and the same beam, is a diagonal matrix or a unit matrix, dimension of 2LGx2LG, L indicates the number of selected spatial domain bases of each port group. W1, and which can be understood according to the definition in the protocol Release 16, and the embodiments of the present application do not repeat them.

[0232] Design 6, for P port groups, the precoding matrix (codebook) to be fed back by the P port groups can satisfy the following formula (14):

[0233] wherein diag represents matrix block diagonalization, W1(p) represents the matrix corresponding to the pth port group, and the specific value of W1(p) and other parameters can be understood with reference to other embodiments of the present application.

[0234] Based on the above designs 1-5, it can be understood that the codebook indicated by the PMI information adopts the DFT matrix (or IDFT matrix, or spatial domain base), and the unit matrix, which can adapt to the transmission mode of mixed transmission in the beam domain and the antenna domain.

[0235] S503, the terminal device sends the PMI information to the network device.

[0236] In the first possible design, the PMI information indicates the combination of the first parameter and the parameter corresponding to one of the P port groups, and the first parameter indicates the amplitude and / or phase coefficient corresponding to the P port groups.

[0237] For example, corresponding to the design 1 and the design 2 described in S502, the first parameter corresponds to the aforementioned W p . Wherein, corresponding to the scheme of design 1 in S502, the combination of parameters corresponding to one of the P port groups includes the second parameter W1, the third parameter W2. Optionally, the PMI information includes W p related DFT codebook information, W1 related port and / or DFT codebook information, W2 related port and / or DFT codebook information. Corresponding to the scheme of design 2 in S502, the combination of parameters corresponding to one of the P port groups includes the second parameter W1, the fourth parameter and the fifth parameter Optionally, the PMI information includes W pRelated DFT codebook information, W1-related ports and / or DFT codebook information, Related IDFT substrate selection information, The non-zero element in It can also be called a non-zero coefficient matrix.

[0238] Understandably, in the example above, the W between port groups (subarrays) p Using a DFT matrix (or IDFT matrix, or spatial basis) can be adapted to transmission methods using the antenna domain. In the parameter combinations corresponding to one of the P port groups (within a subarray), an identity matrix is ​​used; for example, W1 or W2 uses an identity matrix. Employing a unit array allows for adaptation to beam-domain transmission methods. This design enables PMI information to be adapted to transmission methods employing a hybrid beam-domain and antenna-domain approach, improving codebook performance in hybrid transmission scenarios. For example, corresponding to design 5 described in S502, the first parameter includes I... G and The parameter combination corresponding to one of the P port groups includes the second parameter W1 and the fourth parameter. and the fifth parameter Optionally, the PMI information includes I G , Non-zero elements, W1-related ports and / or DFT codebook information, Related IDFT substrate selection information, The non-zero element in It can also be called a non-zero coefficient matrix.

[0239] It is understandable that in the example above, the I corresponding to the port groups (subarrays) G and The system contains an identity matrix, which can be adapted to the beam domain transmission method. The parameter combination corresponding to one of the P port groups (within the subarray) uses a DFT matrix (or IDFT matrix, or spatial basis), which can be adapted to the antenna domain transmission method. This design enables PMI information to be adapted to the transmission method of mixed beam domain and antenna domain transmission, which can improve the codebook performance in mixed transmission scenarios.

[0240] In a second possible design, corresponding to design 3 described in S502, the PMI information indicates one port group corresponding parameter combination, the one port group corresponding parameter combination includes the sixth parameter W'1, the seventh parameter W"1, and the third parameter W2. The PMI information includes W'1 related port or DFT codebook information, W"1 related port or DFT codebook information, W2 related port and / or DFT codebook information. Corresponding to design 4 described in S502, the PMI information indicates P port group corresponding sixth parameter W'1, seventh parameter W"1, fourth parameter and fifth parameter W'1 related port or DFT codebook information, W"1 related port or DFT codebook information, related IDFT basis selection information, non-zero elements (referred to as non-zero coefficient matrix) in .

[0241] It can be understood that, in the above examples, one parameter in W'1 and W"1 adopts a unit matrix, and the other parameter adopts a DFT matrix (or an IDFT matrix, or a spatial basis) can be adapted to a transmission mode using an antenna domain, and such a design makes the PMI information adapt to a transmission mode using a hybrid of a beam domain and an antenna domain, and can improve the performance of the codebook in a hybrid transmission scenario.

[0242] In actual application of the above method provided by the embodiments of the present application, part or all of the steps can be executed, or other schemes or steps can be combined, which are not limited in the embodiments of the present application.

[0243] Based on the same technical concept, as shown in FIG. 7, the embodiments of the present application further provide a communication device 700. For example, the communication device 700 can be a chip or a chip system. Optionally, in the embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices.

[0244] The communication device 700 can be used to realize the functions of any network element in the communication system described in the above examples. The communication device 700 can include at least one processor 710. Optionally, the processor 710 is coupled with a memory, which can be located in the device; or, the memory can be integrated with the processor; or, the memory can also be located outside the device. For example, the communication device 700 can further include at least one memory 720. The memory 720 stores necessary computer programs, computer programs or instructions and / or data for implementing any of the above examples; the processor 710 can execute the computer programs or instructions stored in the memory 720 to complete the method in any of the above examples.

[0245] The communication device 700 can further include a communication interface 730, through which the communication device 700 can exchange information with other devices. For example, the communication interface 730 can be a transceiver, a circuit, a bus, a module, a pin, or another type of communication interface. When the communication device 700 is a chip-type device or a circuit, the communication interface 730 in the communication device 700 can also be an input / output circuit that can input (or receive) information and output (or send) information. The processor can be an integrated processor or a microprocessor or an integrated circuit or a logic circuit. The processor can determine output information according to input information.

[0246] The coupling in the embodiments of the present application is indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 710 can operate in cooperation with the memory 720 and the communication interface 730. The specific connection medium between the processor 710, the memory 720 and the communication interface 730 is not limited in the embodiments of the present application.

[0247] Optionally, as shown in FIG. 7, the processor 710, the memory 720 and the communication interface 730 are connected to each other through a bus 740. The bus 740 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, only one thick line is shown in FIG. 7, but it does not mean that there is only one bus or only one type of bus.

[0248] In the embodiments of the present application, the processor can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and can implement or execute the methods, steps and logic block diagrams of the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method of the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0249] In the embodiments of the present application, the memory can be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), and can also be a volatile memory, such as a random-access memory (RAM). The memory can be any other medium capable of carrying or storing desired program codes in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, for storing program instructions and / or data.

[0250] In a possible implementation, the communication apparatus 700 can be applied to a terminal device, and specifically, the communication apparatus 700 can be a terminal device or an apparatus capable of supporting a terminal device and realizing the functions of the terminal device in any of the above examples. The memory 720 stores computer programs (or instructions) and / or data for realizing the functions of the terminal device in any of the above examples. The processor 710 can execute the computer programs or instructions stored in the memory 720 to complete the method performed by the terminal device in any of the above examples. When the communication apparatus is applied to a terminal device, the communication interface in the communication apparatus 700 can be used to interact with a network device, send information to the network device, or receive information from the network device.

[0251] In another possible implementation, the communication apparatus 700 can be applied to a network device, and specifically, the communication apparatus 700 can be a network device or an apparatus capable of supporting a network device and realizing the functions of the network device in any of the above examples. The memory 720 stores computer programs (or instructions) and / or data for realizing the functions of the network device in any of the above examples. The processor 710 can execute the computer programs or instructions stored in the memory 720 to complete the method performed by the network device in any of the above examples. When the communication apparatus is applied to a network device, the communication interface in the communication apparatus 700 can be used to interact with a terminal device, send information to the terminal device, or receive information from the terminal device.

[0252] Since the communication apparatus 700 provided in the present example can be applied to a network device to complete the method performed by the network device, or applied to a terminal device to complete the method performed by the terminal device, the technical effects that can be achieved thereby can refer to the above method examples, which will not be described herein again.

[0253] Based on the same technical concept, as shown in FIG. 8, the embodiment of the present application further provides a communication device 1000. The device 1000 can be applied to a terminal device or a network device, for example, and can be used to implement the method in the embodiment shown in FIG. 5. The device 1000 logically includes multiple parts, such as a processor 1001, a memory 1002, and a signal transceiver 1003. The memory 1002 can be used to store a computer program (which can also be referred to as code or instructions). The signal transceiver 1003 is used to implement the communication and signaling interaction of the network device and the terminal device, signal amplification, etc. The signal transceiver 1003 includes a transmitter 10031, a receiver 10032, and an antenna 10033. In the antenna 10033, one box represents one digital channel, F in the box is a digital precoding weight, and one phase shifter (circle with diagonal arrow) represents an analog channel connected to one array element or multiple array elements, i.e., in practice, one phase shifter can control multiple array elements, or the phase shifter and the array element are cross-connected.

[0254] When the communication device is applied to a terminal device, the processor is mainly used to process communication protocols and communication data, control the terminal device, execute software programs, process data of the software programs, etc. The memory is mainly used to store software programs and data. The signal transceiver is mainly used for conversion between baseband signals and radio frequency signals and processing of radio frequency signals. The antenna is mainly used to transceive radio frequency signals in the form of electromagnetic waves.

[0255] When data needs to be sent, the processor performs baseband processing on the data to be sent, and outputs the baseband signal to the signal transceiver. The signal transceiver performs radio frequency processing on the baseband signal, and transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the signal transceiver receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. For ease of illustration, only one memory, one processor, and one transceiver are shown in FIG. 8. In actual terminal device products, there can be one or more processors and one or more memories. The memory can also be referred to as a storage medium or a storage device, etc. The memory can be independent of the processor or integrated with the processor. The embodiment of the present application does not limit this.

[0256] Optionally, the processor can also be referred to as a processing unit, a processing board, a processing module, a processing device, etc. The signal transceiver can also be referred to as a transceiver, a transceiver device, a transceiver circuit, a transceiver module, etc. The transmitter can also be referred to as a sender, a transmission module, or a transmission circuit, etc. The receiver can also be referred to as a receiver, a receiving module, or a receiving circuit, etc.

[0257] The embodiment of the present application further provides a communication system, comprising the terminal device and the network device in the above embodiment. The terminal device is configured to perform all or part of the steps in the embodiment shown in FIG. 5. The network device is configured to perform all or part of the steps in the embodiment shown in FIG. 5.

[0258] The technical solutions provided by the embodiments of the present application can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When realized by software, the technical solutions can be realized in the form of a computer program product, in whole or in part. The computer program product comprises one or more computer instructions. When loaded and executed by a computer, the computer instructions produce the processes or functions described in the embodiments of the present application, in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a terminal device, a network device or other programmable apparatus. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server or data center to another via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. containing one or more available media. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a digital video disc (DVD)), or a semiconductor medium, etc.

[0259] In the embodiments of the present application, each example can refer to each other without logical contradiction, for example, the methods and / or terms of the method embodiments can refer to each other, for example, the functions and / or terms of the device embodiments can refer to each other, for example, the functions and / or terms of the device examples and the method examples can refer to each other.

[0260] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the embodiments of the present application and their equivalent technologies, the embodiments of the present application also intend to include these modifications and variations.

Claims

1. A communication method characterized by comprising: The application is applied to a terminal device, comprising: receiving first configuration information, the first configuration information is used for configuring reference signal resources corresponding to P port groups, each of the P port groups comprises a plurality of antenna ports, and P is a positive integer; sending precoding matrix indication (PMI) information, the PMI information is determined according to a channel measurement result of the reference signal resources, the PMI information indicates a first parameter and / or a parameter combination corresponding to one of the P port groups, the first parameter indicates amplitude and / or phase coefficients corresponding to the P port groups, and the PMI information is used for determining a precoding matrix corresponding to the P port groups; wherein P is an integer greater than 1.

2. A communication method characterized by comprising: The application is applied to a network device, comprising: sending first configuration information, the first configuration information is used for configuring reference signal resources corresponding to P port groups, each of the P port groups comprises a plurality of antenna ports, and P is a positive integer; receiving precoding matrix indication (PMI) information, the PMI information is determined according to a channel measurement result of the reference signal resources, the PMI information indicates a first parameter and / or a parameter combination corresponding to one of the P port groups, the first parameter indicates amplitude and / or phase coefficients corresponding to the P port groups, and the PMI information is used for determining a precoding matrix corresponding to the P port groups; wherein P is an integer greater than 1.

3. The method of claim 1 or 2, wherein, The P port groups include N g,1 port groups in a first dimension and N g,2 port groups in a second dimension; each of the P port groups includes N1 antenna ports in the first dimension and N2 antenna ports in the second dimension; wherein the N g,1 , the N g,2 , the N1 and the N2 are positive integers.

4. The method of claim 3, wherein, The first configuration information includes the N g,1 , the N g,2 , and indication information of a value of at least one of the N1 and the N2.

5. The method of claim 4, wherein, The first parameter W p corresponding to the kth column in the K columns of the discrete Fourier transform DFT matrix in the frequency domain, the first parameter W p has a dimension of (N g,1 N g,2 × K), w p,k corresponding to the kth column in the K columns, and the w p,k satisfies the following formula: wherein k1 x N g,2 k2 x O4 + c k ; wherein the c k indicating the w p,k an index in the precoding matrix; the O3 and the O4 are preconfigured or indicated in the first configuration information; the K is a positive integer, and the k is an integer from 1 to K.

6. The method of claim 5, wherein, Further comprising: receiving information used for indicating a value of K; wherein the value of K is less than or equal to a spatial domain basis number of the precoding matrix.

7. The method according to any one of claims 1 to 6, wherein The first parameter corresponds to W p The parameter combination corresponding to one port group in the P port groups comprises a second parameter W1 and a third parameter W2; and the precoding matrix W satisfies at least one of the following formulas: Or, or 8. The method of claim 7, wherein, the second parameter W1 corresponds to 1 column or L1 columns in a unit matrix, and the second parameter W2 corresponds to 1 column or L2 columns in a single frequency domain discrete Fourier transform (DFT) matrix; or, the second parameter W1 corresponds to 1 column or L1 columns in a DFT matrix, and the second parameter W2 corresponds to 1 column or L2 columns in a unit matrix; wherein the values of L1 and L2 are determined based on the spatial domain basis number of the precoding matrix.

9. The method according to any one of claims 1 to 6, wherein, The first parameter corresponds to W p The parameter combination corresponding to one port group in the P port groups includes a second parameter W1, a fourth parameter and a fifth parameter The precoding matrix W satisfies at least one of the following formulas: Or, or 10. The method of claim 9, wherein, The second parameter W1 corresponds to one column or L1 columns in an identity matrix, and the fourth parameter corresponds to one column or L2 columns in a DFT matrix; or, the second parameter W1 corresponds to one column or L1 columns in a DFT matrix, and the fourth parameter corresponds to one column or L2 columns in an identity matrix; wherein the values of L1 and L2 are determined based on the number of spatial bases of the precoding matrix.

11. The method of claim 7 or 9, wherein, The second parameter W1 satisfies the following formula: wherein W'1 is a frequency domain discrete Fourier transform (DFT) matrix, and W''1 is a unit matrix; or, W'1 is a unit matrix, and W''1 is a DFT matrix.

12. The method of any one of claims 1-4, wherein, The precoding matrix W satisfies the following equation: The first parameter includes the I G and the The I G is the identity matrix, and the indicate phase combining coefficients between different port groups and same beam, the is a diagonal matrix or an identity matrix; a parameter combination corresponding to one of the P port groups comprises the W1, the and said 13. A communications device, characterized by The application comprises a module for executing the method of any one of claims 1 and 3-12; or, a module for executing the method of any one of claims 2-12.

14. A communication system, characterized by The application comprises a communication device for executing the method of any one of claims 1 and 3-12; and, a communication device for executing the method of any one of claims 2-12.

15. A communications device, characterized by comprising: a processor coupled to the memory, the processor being configured to invoke a computer program or instructions in the memory to execute the method of any one of claims 1-12.

16. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer programs or instructions, when the instructions run on a computer, the computer executes the method of any one of claims 1-12.

17. A computer program product, characterized in that, comprising computer programs or instructions, which, when executed on a computer, cause the computer to perform the method of any one of claims 1-12.

Images