Communication methods, and apparatus

Abstract

Provided in the present application are communication methods, and an apparatus, which can reduce the feedback overhead of precoding matrix indicators (PMIs). A method comprises: a terminal device receiving first configuration information, and sending precoding matrix indicator (PMI) information, wherein the first configuration information is used for configuring reference signal resources corresponding to M ports, M being a positive integer, and the PMI information is determined on the basis of a channel measurement result of the reference signal resources, the PMI information indicates indexes of N ports among the M ports in a first polarization, N is a positive integer, and the PMI information is used for determining a precoding matrix corresponding to 2N ports.

Description

A communication method and apparatus

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411759577.0, filed on November 29, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0004] Multiple-input multiple-output (MIMO) technology, as a key technology in wireless communication, can be used to meet the requirements of high-speed transmission. Through the process of channel measurement (or channel estimation), network devices can use the channel information obtained from the channel measurement process to calculate the precoding information between the network device and the terminal device. Subsequently, the network device and the terminal device can use this precoding information to achieve MIMO communication.

[0005] Taking the downlink channel measurement process based on downlink reference signals implemented by network devices as an example, the network device sends resource configuration information and reported configuration information to the terminal device. Resource configuration information is related to the measurement resources. The network device sends downlink signals (e.g., downlink reference signals) on the resources configured in the resource configuration information. The terminal device can measure the downlink signals to determine the quality of each resource. Reported configuration information refers to the information related to the measurement results. This reported configuration information includes codebook configuration information related to the codebook. The terminal device performs measurements and feedback based on this codebook configuration information. Currently, codebook configuration types typically use discrete Fourier transform (DFT) codebooks, resulting in high computational complexity and significant feedback overhead for the terminal device. Summary of the Invention

[0006] This application provides a communication method and apparatus that can reduce the computational complexity and feedback overhead of terminal devices.

[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 M ports, wherein M is a positive integer; and sending precoding matrix indication (PMI) information, the PMI information being determined based on channel measurement results of the reference signal resources, the PMI information indicating the indices of N ports on a first polarization among the M ports, wherein N is a positive integer, and the PMI information being used to determine the precoding matrix corresponding to 2N ports.

[0008] The above design is applied to the port selection codebook. The terminal device indicates the port index for port selection through PMI information, which can reduce the computational complexity and feedback overhead of the terminal device.

[0009] Secondly, this application provides a communication method applied to a network device, comprising: sending first configuration information, the first configuration information being used to configure reference signal resources corresponding to M ports, wherein M is a positive integer; receiving precoding matrix indication (PMI) information, the PMI information being determined based on channel measurement results of the reference signal resources, the PMI information indicating the indices of N ports on a first polarization among the M ports, wherein N is a positive integer, and the PMI information being used to determine the precoding matrix corresponding to 2N ports.

[0010] In one possible design of the first or second aspect, the PMI information includes an index of each of the N ports. With this design, the network device can directly obtain the N port indices from the PMI information, which helps improve the efficiency of determining the precoding matrix.

[0011] In one possible design of the first or second aspect, the indices of the N ports are consecutive, and the PMI information includes the index of the first port among the N ports, or the PMI information includes the index of the last port among the N ports. Such a design derives multiple consecutive port indices based on a single port index indication, which can further reduce feedback overhead.

[0012] In one possible design of the first or second aspect, the first configuration information further includes a first parameter X1 and / or a second parameter X2, wherein the first parameter X1 indicates the number of ports in each of the K port groups in the first dimension, and the second parameter X2 indicates the number of ports in each of the K port groups in the second dimension, wherein the K port groups are determined based on all ports of the M ports in the first polarization, the first parameter X1 and / or the second parameter X2, wherein K is a positive integer less than M, X1 is a positive integer, and X2 is a positive integer. Optionally,

[0013] Based on this design, in one possible implementation, the PMI information includes the index of one of the K port groups, and the index of each of the N ports within the port group. The index of one of the N ports includes a first index of the port in a first dimension and a second index of the port in a second dimension. The first index is an integer less than or equal to X1, and the second index is an integer less than or equal to X2.

[0014] Based on this design, in another possible implementation, the PMI information includes the index of one of the K port groups, the first index of the first port in the first dimension and the second index in the second dimension of the N ports in the port group, the first index offset of every two ports in the first dimension, and the second index offset of every two ports in the second dimension; wherein the value of the first index is an integer less than or equal to X1, and the value of the second index is an integer less than or equal to X2.

[0015] Based on this design, in another possible implementation, the PMI information includes the index of one port group among the K port groups, a first index of the first port among the N ports in the port group in a first dimension and a second index in a second dimension, N-1 first index offsets, and N-1 second index offsets; wherein, one of the N-1 first index offsets indicates the first index offset of one port among the N-1 ports relative to the first port in the first dimension, and one of the N-1 second index offsets indicates the index offset of one port among the N-1 ports relative to the first port in the second dimension. The N-1 ports include all ports among the N ports except the first port, the first index is an integer less than or equal to X1, and the second index is an integer less than or equal to X2.

[0016] The above design uses a two-dimensional index to indicate the port in the PMI information, which can reduce the indication overhead.

[0017] In one possible design of the first or second aspect, the value of N is determined based on the number of layers corresponding to the precoding matrix. Optionally, the terminal device can indicate the number of layers corresponding to the precoding matrix to the network device via a rank indicator RI.

[0018] In one possible design of the first or second aspect, the precoding matrix is ​​related to one or more of the following: the indices of the N ports on the aforementioned first polarization, the number of ports M, the rank indicator RI (or number of layers), and the phase coefficients between polarizations. For example, the phase coefficients between polarizations can be based on... Sure, The precoding matrix is ​​related to the phase coefficients between polarizations, which can also be understood as the precoding matrix being related to the value of n. Optionally, the terminal device can indicate the value of n in the PMI information.

[0019] The following examples illustrate the port selection design and precoding matrix construction for different layer numbers.

[0020] In one possible design of the first or second aspect, the number of layers corresponding to the precoding matrix is ​​v, the value of N is less than or equal to v, and the precoding matrix W (v) The following relationship must be satisfied:

[0021] Among them, v 1 ...v v Each indicates a column vector determined by the index of one of the N ports on the first polarization; Indicates the phase coefficients between v polarizations, Based on Sure. The value of n can be one of 0, 1, 2 or 3.

[0022] When N equals v, there are v column vectors (i.e., v... 1 ...v v All of them are different, and the port indices corresponding to the v column vectors on the first polarization are all different. The v column vectors correspond one-to-one with the indices of the N ports on the first polarization. The value of can be any When N is less than v, there are v column vectors (i.e., v... 1 ...v v In the first polarization, at least two column vectors are different; at least two of the v column vectors correspond to the same port index; among the N port indices on the first polarization, there exists at least one port index paired with multiple column vector pairs; the phase coefficients between polarizations corresponding to the same column vectors are different, for example, v 1 With v 3 When they are the same, and Different, such as

[0023] Taking v=4 as an example, the precoding matrix W (4) The following relationship must be satisfied:

[0024] Wherein, the v 1 The v 2 The v 3 and the v 4 Each indicates a column vector determined based on the index of one of the N ports; The The and stated Based on Definitely. The value of n is either 0 or 1. In one possible implementation, when N is 2, the value of v is... 1 With the v 3 Similarly, the v 2 With the v 4 The same, the With the For the The With the for

[0025] When N ports are indicated using a one-dimensional index in the PMI information, the precoding matrix W... (4) It can be transformed into the following relationship:

[0026] in, This represents the codebook (or precoding matrix) and p, p when the layer number v is 4. 1 It is related to n. p indicates the index of the first port out of N ports on the first polarization, p 1 Indicates the index of the second port out of N ports in the first polarization. n indicates n in P CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The PMI information carries indication information that can be used to determine the values ​​of p and n. For example, the terminal device indicates the value of p through a first indication information i1 and the value of n through a second indication information i2 in the PMI information. Accordingly, the network device can determine the value of p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 The value of .

[0027] When N ports are indicated using a two-dimensional index in the PMI information, the precoding matrix W... (4) It can be transformed into the following relationship:

[0028] in, This represents the precoding matrix and c,a,a when the number of layers v is 4. 1 ,b,b 1 Related to n. Where c indicates the index of the port group to which the selected port belongs, a indicates the first index of the first port in the first dimension of the first polarization among N ports, and b indicates the second index of the first port in the second dimension of the first polarization among N ports; a 1 Indicates the first index of the second port in the first dimension of the first polarization, b 1 Indicates the second index of the second port in the second dimension of the first polarization among N ports. n indicates n in P CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The value of .

[0029] Thirdly, the communication device can be a terminal device, or a device, module, or chip within the terminal device, or a device compatible with the terminal device. In one design, the communication device may include modules corresponding to the methods / operations / steps / actions described in the first aspect. These modules can be hardware circuits, software, or a combination of hardware circuits and software. In one design, the communication device may include a processing module and a communication module, the communication module including a transmitting unit and a receiving unit. Optionally, the communication module can also be described as a transceiver module or transceiver unit, and the processing module can also be described as a processing unit.

[0030] The communication module is used to receive first configuration information, which is used to configure reference signal resources corresponding to M ports, where M is a positive integer;

[0031] The processing module is used to send precoding matrix indication (PMI) information through the communication module. The PMI information is determined based on the channel measurement results of the reference signal resource. The PMI information indicates the index of N ports on the first polarization among the M ports, where N is a positive integer. The PMI information is used to determine the precoding matrix corresponding to the 2N ports.

[0032] The above design is applied to the port selection codebook. The terminal device indicates the port index for port selection through PMI information, which can reduce the computational complexity and feedback overhead of the terminal device.

[0033] Fourthly, the communication device can be a network device, or a device, module, or chip within a network device, or a device compatible with a network device. In one design, the communication device may include modules corresponding to the methods / operations / steps / actions described in the second aspect. These modules can be hardware circuits, software, or a combination of hardware circuits and software. In one design, the communication device may include a processing module and a communication module, the communication module including a transmitting unit and a receiving unit. Optionally, the communication module can also be described as a transceiver module or transceiver unit, and the processing module can also be described as a processing unit.

[0034] The processing module is used to send first configuration information through the communication module. The first configuration information is used to configure reference signal resources corresponding to M ports, where M is a positive integer.

[0035] The communication module is also used to receive precoding matrix indication (PMI) information, which is determined based on channel measurement results of the reference signal resource. The PMI information indicates the indices of N ports on the first polarization among the M ports, where N is a positive integer. The PMI information is used to determine the precoding matrix corresponding to the 2N ports.

[0036] In one possible design of the third or fourth aspect, the PMI information includes an index of each of the N ports. With this design, the network device can directly obtain the N port indices from the PMI information, which helps improve the efficiency of determining the precoding matrix.

[0037] In one possible design of the third or fourth aspect, the indices of the N ports are consecutive, and the PMI information includes the index of the first port among the N ports, or the PMI information includes the index of the last port among the N ports. Such a design derives multiple consecutive port indices based on a single port index indication, which can further reduce feedback overhead.

[0038] In one possible design of the third or fourth aspect, the first configuration information further includes a first parameter X1 and / or a second parameter X2, wherein the first parameter X1 indicates the number of ports in each of the K port groups in the first dimension, and the second parameter X2 indicates the number of ports in each of the K port groups in the second dimension, wherein the K port groups are determined based on all ports of the M ports in the first polarization, the first parameter X1 and / or the second parameter X2, wherein K is a positive integer less than M, X1 is a positive integer, and X2 is a positive integer. Optionally,

[0039] Based on this design, in one possible implementation, the PMI information includes the index of one of the K port groups, and the index of each of the N ports within the port group. The index of one of the N ports includes a first index of the port in a first dimension and a second index of the port in a second dimension. The first index is an integer less than or equal to X1, and the second index is an integer less than or equal to X2.

[0040] Based on this design, in another possible implementation, the PMI information includes the index of one of the K port groups, the first index of the first port in the first dimension and the second index in the second dimension of the N ports in the port group, the first index offset of every two ports in the first dimension, and the second index offset of every two ports in the second dimension; wherein the value of the first index is an integer less than or equal to X1, and the value of the second index is an integer less than or equal to X2.

[0041] Based on this design, in another possible implementation, the PMI information includes the index of one port group among the K port groups, a first index of the first port among the N ports in the port group in a first dimension and a second index in a second dimension, N-1 first index offsets, and N-1 second index offsets; wherein, one of the N-1 first index offsets indicates the first index offset of one port among the N-1 ports relative to the first port in the first dimension, and one of the N-1 second index offsets indicates the index offset of one port among the N-1 ports relative to the first port in the second dimension. The N-1 ports include all ports among the N ports except the first port, the first index is an integer less than or equal to X1, and the second index is an integer less than or equal to X2.

[0042] The above design uses a two-dimensional index to indicate the port in the PMI information, which can reduce the indication overhead.

[0043] In one possible design of the third or fourth aspect, the value of N is determined based on the number of layers corresponding to the precoding matrix. Optionally, the terminal device can indicate the number of layers corresponding to the precoding matrix to the network device via a rank indicator RI.

[0044] In one possible design of the third or fourth aspect, the precoding matrix is ​​related to one or more of the following: the indices of the N ports on the first polarization, the number of ports M, the rank indicator RI (or the number of layers), and the phase coefficients between polarizations. For example, the phase coefficients between polarizations can be based on... Sure, The precoding matrix is ​​related to the phase coefficients between polarizations, which can also be understood as the precoding matrix being related to the value of n. Optionally, the terminal device can indicate the value of n in the PMI information.

[0045] The following examples illustrate the port selection design and precoding matrix construction for different layer numbers.

[0046] In one possible design of the third or fourth aspect, the number of layers corresponding to the precoding matrix is ​​v, the value of N is less than or equal to v, and the precoding matrix W (v) The following relationship must be satisfied:

[0047] Among them, v 1 ...v v Each indicates a column vector determined by the index of one of the N ports on the first polarization; Indicates the phase coefficients between v polarizations, Based on Sure. The value of n can be one of 0, 1, 2 or 3.

[0048] When N equals v, there are v column vectors (i.e., v... 1 ...v v All of them are different, and the port indices corresponding to the v column vectors on the first polarization are all different. The v column vectors correspond one-to-one with the indices of the N ports on the first polarization. The value of can be any When N is less than v, there are v column vectors (i.e., v... 1 ...v vIn the first polarization, at least two column vectors are different; at least two of the v column vectors correspond to the same port index; among the N port indices on the first polarization, there exists at least one port index paired with multiple column vector pairs; the phase coefficients between polarizations corresponding to the same column vectors are different, for example, v 1 With v 3 When they are the same, and Different, such as

[0049] Taking v=4 as an example, the precoding matrix W (4) The following relationship must be satisfied:

[0050] Wherein, the v 1 The v 2 The v 3 and the v 4 Each indicates a column vector determined based on the index of one of the N ports; The The and stated Based on Definitely. The value of n is either 0 or 1. In one possible implementation, when N is 2, the value of v is... 1 With the v 3 Similarly, the v 2 With the v 4 The same, the With the For the The With the for

[0051] When N ports are indicated using a one-dimensional index in the PMI information, the precoding matrix W... (4) It can be transformed into the following relationship:

[0052] in, This represents the codebook (or precoding matrix) and p, p when the layer number v is 4. 1 It is related to n. p indicates the index of the first port out of N ports on the first polarization, p 1 Indicates the index of the second port out of N ports in the first polarization. n indicates n in P CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The PMI information carries indication information that can be used to determine the values ​​of p and n. For example, the terminal device indicates the value of p through a first indication information i1 and the value of n through a second indication information i2 in the PMI information. Accordingly, the network device can determine the value of p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 The value of .

[0053] When N ports are indicated using a two-dimensional index in the PMI information, the precoding matrix W... (4) It can be transformed into the following relationship:

[0054] in, This represents the precoding matrix and c,a,a when the number of layers v is 4. 1 ,b,b 1 Related to n. Where c indicates the index of the port group to which the selected port belongs, a indicates the first index of the first port in the first dimension of the first polarization among N ports, and b indicates the second index of the first port in the second dimension of the first polarization among N ports; a 1 Indicates the first index of the second port in the first dimension of the first polarization, b 1 Indicates the second index of the second port in the second dimension of the first polarization among N ports. n indicates n in P CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The value of .

[0055] Fifthly, this application provides a communication device including at least one processor and a memory; the memory is used to store computer programs or instructions, and when the device is running, the at least one processor executes the computer programs or instructions to cause the communication device to perform the methods as described in the first aspect or embodiments of the first aspect above, or to perform the methods as described in the second aspect or embodiments of the second aspect above.

[0056] In a sixth aspect, this 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 methods of the first aspect or embodiments thereof, or to perform the methods of the second aspect or embodiments thereof.

[0057] In a seventh aspect, this application also provides a computer-readable storage medium storing computer-readable instructions that, when executed on a computer, cause the computer to perform a method as described in the first aspect or any possible design of the first aspect, or to perform a method as described in the second aspect or any possible design of the second aspect.

[0058] Eighthly, this application provides a computer program product including instructions, comprising a computer program or instructions that, when run on a computer, cause the computer to perform the methods of the first aspect or embodiments thereof, or to perform the methods of the second aspect or embodiments thereof.

[0059] Ninthly, this application provides a chip system including a processor and potentially a memory, for implementing the methods described in the first aspect or any possible design of the first aspect, or performing the methods described in the second aspect or any possible design of the second aspect. The chip system may be composed of chips or may include chips and other discrete devices.

[0060] In a tenth aspect, this application provides a communication system comprising a terminal device and a satellite, the communication system being configured to perform the method described in the first aspect or any possible design of the first aspect, or to perform the method described in the second aspect or any possible design of the second aspect.

[0061] For the technical effects that can be achieved in aspects five through ten above, please refer to the description of the technical effects that can be achieved in aspect one above or the corresponding possible design scheme in aspect one, and this application will not repeat them here. Attached Figure Description

[0062] Figure 1 is a schematic diagram of the architecture of a wireless communication system;

[0063] Figure 2A is a schematic diagram of the structure of a network device;

[0064] Figure 2B is a schematic diagram of the logical function division of a network element;

[0065] Figure 3A is one of the structural schematic diagrams of beamforming provided in the embodiments of this application;

[0066] Figure 3B is one of the structural schematic diagrams of beamforming provided in the embodiments of this application;

[0067] Figure 3C is one of the structural schematic diagrams of beamforming provided in the embodiments of this application;

[0068] Figure 4 is a schematic diagram of a beam distribution provided in an embodiment of this application;

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

[0070] Figure 6 is a schematic diagram of a port distribution provided in an embodiment of this application;

[0071] Figures 7A to 7D are schematic diagrams illustrating the division of several port groups provided in the embodiments of this application;

[0072] Figure 8 is one of the schematic diagrams of the distribution of port indexes provided in the embodiments of this application;

[0073] Figure 9 is one of the schematic diagrams showing the distribution of port indexes provided in the embodiments of this application;

[0074] Figure 10A is one of the schematic diagrams of port selection provided in the embodiments of this application;

[0075] Figure 10B is one of the schematic diagrams of port selection provided in the embodiments of this application;

[0076] Figure 11A is one of the schematic diagrams of port selection provided in the embodiments of this application;

[0077] Figure 11B is one of the schematic diagrams of port selection provided in the embodiments of this application;

[0078] Figure 12 is a schematic diagram of the structure of a communication device in an embodiment of this application;

[0079] Figure 13 is one of the structural schematic diagrams of the communication device in the embodiments of this application. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0081] The at least one item mentioned in the embodiments of this application refers to one or more items. Multiple items refers to two or more items. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, it should be understood that although the terms "first," "second," etc., may be used to describe objects in the embodiments of this application, these objects should not be limited to these terms. These terms are only used to distinguish the objects from each other.

[0082] The terms "comprising" and "having," and any variations thereof, used in the following description of embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. It should be noted that in embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any method or design described as "exemplary" or "for example" in embodiments of this application should not be construed as preferred or advantageous over other methods or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0083] The technology provided in this application can be applied to various communication systems, such as Universal Mobile Telecommunications System (UMTS), Wireless Local Area Network (WLAN), Wireless Fidelity (Wi-Fi) system, 4th generation (4G) mobile communication system such as Long Term Evolution (LTE) system, 5th generation (5G) mobile communication system such as New Radio (NR) system, and future communication systems, etc.

[0084] This application will present various aspects, embodiments, or features relating to systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

[0085] Furthermore, in the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as an "example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "example" is intended to present concepts in a concrete manner. In the embodiments of this application, "of," "corresponding, relevant," and "corresponding" may sometimes be used interchangeably, and it should be noted that their intended meanings are consistent unless their distinction is emphasized.

[0086] In a communication system, a network element can send signals to or receive signals from another network element. These signals can include information or data. A network element can also be referred to as an entity, network entity, device, communication equipment, communication module, node, communication node, etc. This application describes the concept of a network element. For example, a communication system can include at least one terminal device and at least one network device. The signal-transmitting network element can be a network device, and the signal-receiving network element can be a terminal device; or, the signal-transmitting network element can be a terminal device, and the signal-receiving network element can be a network device. Furthermore, it is understood that if the communication system includes multiple terminal devices, these terminal devices can also exchange signals; that is, both the signal-transmitting network element and the signal-receiving network element can be terminal devices.

[0087] Figure 1 illustrates an exemplary architecture diagram of a communication system 10 applicable to an embodiment of this application. As shown in Figure 1, the communication system includes a radio access network (RAN) 100 and a core network 200. Optionally, the communication system 10 may also include an Internet 300. The RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is wirelessly connected to the RAN node 110, and the RAN node 110 is wirelessly or wiredly connected to the core network 200. The core network equipment in core network 200 and the RAN node 110 in RAN 100 can be independent physical devices, or they can be the same physical device that integrates the logical functions of the core network equipment and the logical functions of the RAN node. Terminals can be interconnected with each other, and RAN nodes can be interconnected with each other, via wired or wireless means.

[0088] RAN100 can be an evolved universal terrestrial radio access (E-UTRA) system, an NR system, or a future radio access system as defined in the 3rd generation partnership project (3GPP). RAN100 can also include two or more of the above-mentioned different radio access systems. RAN100 can also be an open RAN (O-RAN).

[0089] The network device involved in this application embodiment can be a RAN node. A RAN node, also known as a radio access network device, RAN entity, or access node, is used to help terminals access a communication system wirelessly. In one application scenario, a 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. A RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or an indoor station (as shown in Figure 1, 110b), or a relay node or donor node.

[0090] Terminal equipment can be any device or module that accesses the aforementioned communication system and possesses corresponding communication functions. Terminal equipment can also be referred to as user equipment (UE), terminal, user device, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication equipment, user agent, or user device. Terminal equipment typically contains communication modules, circuits, or chips that perform the corresponding communication functions. It may also be configured with program instructions for performing these functions.

[0091] For example, the terminal device in the embodiments of this application may be a mobile phone, a personal digital assistant (PDA) computer, a laptop computer, a tablet computer, a drone, a computer with wireless transceiver capabilities, 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 care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home (e.g., game consoles, smart TVs, smart speakers, smart refrigerators, and fitness equipment), a transportation vehicle with wireless communication capabilities, a communication module, or a roadside unit (RSU) with terminal functionality. The embodiments of this application do not limit the specific technology or device form used in the terminal device.

[0092] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0093] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0094] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0095] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0096] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. In order to communicate with the base station, the terminal needs to establish a radio connection with a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

[0097] Communication between access network devices and terminal devices can follow a specific protocol layer structure. For example, this protocol layer structure may include a control plane protocol layer structure and a user plane protocol layer structure. For instance, the control plane protocol layer structure may include at least one of the following: radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, media / medium access control (MAC) layer, or physical (PHY) layer, etc. Similarly, the user plane protocol layer structure may include at least one of the following: service data adaptation protocol (SDAP) layer, PDCP layer, RLC layer, MAC layer, or physical layer, etc.

[0098] Figure 2A is a schematic diagram of the network device structure used in an embodiment of this application. The RAN node includes one or more centralized units (CUs), one or more distributed units (DUs), and one or more radio units (RUs). As an example, only one CU, DU, and RU are shown in Figure 2A. The CU performs the functions of the radio resource control protocol and packet data aggregation layer protocol (PDCP) of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The DU performs the functions of the radio link control layer (RLC) and medium access control layer (MAC) of the RAN, and can also perform some or all of the physical layer functions. For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications. The RU can be used to implement the radio frequency signal transmission and reception functions. The CU and DU can be two independent units, or they can be integrated into the same RAN node in the baseband unit (BBU). The RU can be included in radio frequency equipment, such as in a remote radio unit (RRU) or an active antenna unit (AAU).

[0099] Figure 2A illustrates an example where the CU and DU are integrated within the BBU. It also shows that the BBU in the RAN communicates with the core network via a backhaul link, the CU and DU within the BBU communicate via a midhaul link, and the BBU communicates with at least one RU via a fronthaul link. The BBU and RU may or may not be co-located. The RF unit RU in the RAN communicates with at least one UE via an air interface.

[0100] Optionally, the CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane. As illustrated in Figure 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 CU's control plane functions. The CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements in the core network can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. The AMF network element is responsible for mobility management in the mobile network, such as location updates for terminal devices, network registration for terminal devices, and handover of terminal devices. 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 CU's user plane functions. The CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements in the core network, such as the user plane function (UPF) in a 5G system, are responsible for data forwarding and receiving in terminal devices. The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0101] In some examples, a DU is a logical node that carries the Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, Higher Physical Layer (PHY) layer, and other functions. In some examples, a DU can control at least one RU. The DU connects to the RU through interfaces, which can be fronthaul interfaces. In some examples, the Higher PHY layer includes the PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0102] In some examples, the RU is a logical node carrying both lower physical layer (PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP transmission reception point (TRP) or remote radio head (RRH) or other similar entity. In some examples, the Low-PHY includes PHY processing functions such as Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more UEs via a radio link.

[0103] The DU and RU can be co-located or not. The DU and RU exchange control plane and user plane information via a lower-layer split-control, user, and synchronization (LLS-CUS) interface through a fronthaul link. LLS-CUS may include LLS-C and LLS-U interfaces that provide the control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and RU. The DU and RU exchange management information via an LLS-M interface on the fronthaul link; the management plane (M-Plane) refers to non-real-time management operations between the DU and RU.

[0104] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0105] In different systems, RAN nodes may have different names. For example, in an O-RAN system, CU can be called an open CU (O-CU), DU can be called an open DU (O-DU), and RU can be called an open RU (O-RU). The CU-control panel (CU-CP) can also be called an open CU-CP (O-CU-CP), and the CU-user panel (CU-UP) can also be called an open CU-UP (O-CU-UP). The RAN nodes in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. For example, a RAN node can be a server loaded with the corresponding software modules. The embodiments of this application do not limit the specific technology or device form used in the RAN nodes.

[0106] The relevant terms used in the embodiments of this application will be explained below. It should be noted that these explanations are for the purpose of making the embodiments of this application easier to understand, and should not be regarded as a limitation on the scope of protection claimed by this application.

[0107] (1) Reference signal (RS).

[0108] Reference signals, also known as pilot signals, are essential in communication systems for transmitting and receiving data, obtaining system synchronization and feedback channel information, and estimating the uplink or downlink channel. Channel estimation refers to the process of reconstructing or recovering the received signal to compensate for signal distortion caused by channel fading and noise fading. It uses reference signals known to the transmitter and receiver to track the time and frequency domain changes of the channel. These reference signals, distributed across different resource elements (REs) in the time-frequency two-dimensional space within orthogonal frequency division multiplexing (OFDM) symbols, have known amplitudes and phases.

[0109] At the physical layer, uplink communication can include the transmission of uplink physical channels and uplink signals. Uplink physical channels include the random access channel (PRACH), physical uplink control channel (PUCCH), and physical uplink shared channel (PUSCH), while uplink signals include the sounding reference signal (SRS), the PUCCH de-modulation reference signal (PUCCH-DMRS), the PUSCH demodulation reference signal (PUSCH-DMRS), the phase tracking reference signal (PTRS), and the uplink positioning reference signal (RS), among others.

[0110] At the physical layer, downlink communication can include the transmission of downlink physical channels and downlink signals. Downlink physical channels include the physical broadcast channel (PBCH), physical downlink control channel (PDCCH), and physical downlink shared channel (PDSCH), etc. Downlink signals include the primary synchronization signal (PSS) / secondary synchronization signal (SSS), physical downlink control channel demodulation reference signal (PDCCH-DMRS), physical downlink shared channel demodulation reference signal (PDSCH-DMRS), PTRS, channel state information reference signal (CSI-RS), cell reference signal (CRS), tracking reference signal (TRS), and positioning reference signal (RS), etc.

[0111] (2) Resources.

[0112] In this embodiment of the application, the network device can configure a resource set / or resources for the terminal device.

[0113] The resource set may include at least one of the following: 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. Here, CSI refers to channel state information (CSI).

[0114] In this application embodiment, a reference signal can correspond to a resource, and a reference signal can occupy a resource. A resource can be called a reference signal resource. The resources in this application embodiment can include frequency domain resources and / or time domain resources, etc. Resources can also include at least one of the following: CSI-SSB resources, CSI-IM resources, NZP-CSI-RS resources, ZP-CSI-RS resources, SRS resources, demodulation deference signal (DMRS) resources, PTRS resources, CRS resources, or TRS resources. In this application embodiment, the resource is described as a channel state information reference signal (CSI-RS) resource. CSI-RS resources can also be written as CSIRS resources in this document, or CSI-RS resources can be replaced with other resources. CSI-RS resources can also be replaced with resources described as occupied by CSI-RS, resources corresponding to CSI-RS, or resources replaced by CSI-RS.

[0115] (3) Beamforming.

[0116] A beam is a communication resource. Beams can be wide, narrow, or other types. The technology used to form beams is called beamforming. Beamforming refers to adjusting the amplitude and / or phase of a signal so that the radiated signal through an antenna array has a certain directionality, enabling higher antenna array gain. The main lobe of the antenna array's radiation pattern can be called the beam.

[0117] In beamforming technology, the amplitude and / or phase of a signal are adjusted after being filtered by a spatial domain transmission filter. Different spatial domain transmission filters using different spatial filtering parameters can achieve beams in different directions. In the embodiments of this application, the spatial filtering parameters can be replaced by beams, or the spatial filtering parameters can be replaced by spatial domain transmission filters. Spatial domain transmission filters can also be called spatial filters.

[0118] Specifically, beamforming technology includes digital beamforming (DBF), analog beamforming (ABF), and hybrid digital-analog beamforming (hybrid beamforming). Hybrid beamforming (HBF) technology. DBF technology has multiple digital processing channels. Each digital processing channel adjusts the phase (or amplitude and phase) of the signal in the digital domain, making the radiated signal through the antenna directional. Therefore, for DBF technology, the function of the aforementioned spatial transmission filter can be achieved through multiple digital processing channels. ABF technology can transmit signals simultaneously using an antenna array composed of multiple antenna elements. Each antenna element corresponds to a phase shifter. By adjusting the phase of the phase shifter corresponding to each antenna element, the radiated signal through the antenna array is made directional. Therefore, for ABF technology, the function of the aforementioned spatial transmission filter can be achieved through multiple phase shifters corresponding to multiple antenna elements in the antenna array. HBF technology is a combination of ABF and DBF technologies, possessing both multiple digital processing channels and multiple analog phase shifters. Therefore, for hybrid beamforming technology, the function of the aforementioned spatial transmission filter can be achieved through multiple phase shifters corresponding to multiple antenna elements in the antenna array and multiple digital processing channels. However, this application is not limited to this; the aforementioned spatial transmission filter can also be implemented using other technologies.

[0119] The following description, using a network device as a base station as an example and in conjunction with the implementation details shown in Figures 3A to 3C, illustrates the beamforming process. Generally, in higher frequency communication systems, base stations (and some frequency band terminals) typically use large-scale array antennas (e.g., antennas with 500 to over 1000 elements) to compensate for path loss caused by higher frequency bands and improve coverage. From the perspective of base station implementation, even with large arrays, different frequency bands and array sizes use different array weighting methods (i.e., different beamforming methods). Based on the beamforming implementation scheme, they can be roughly divided into the following three categories.

[0120] One implementation is digital beamforming (DBF), whose basic structure is shown in Figure 3A. Each of the multiple transmit / receive channels connects to a subarray. Each transmit / receive channel is represented as a digital-to-analog converter (DAC), and a subarray consists of multiple elements, which can be understood as antenna elements. Each transmit / receive channel corresponds to one antenna port, which is represented as a digital port. This structure is typical for low-frequency massive MIMO. Because each antenna signal is directly converted to the digital domain, subsequent array weighting is performed in the digital domain, hence the name digital beamforming. Digital domain signal processing offers the highest degree of freedom and can support very complex signal processing methods; therefore, DBF architecture offers the best performance for the same array size. On the other hand, digital-to-analog converters (DACs) and analog-to-digital converters (ADCs) have high power consumption and cost (especially under high bandwidth conditions).

[0121] Another implementation is analog beamforming (ABF), whose structure is shown in Figure 3B. One transmit / receive channel connects to one subarray. One transmit / receive channel represents a digital-to-analog converter (DAC). One subarray includes multiple phase shifters and multiple elements, which can be understood as antenna elements. Each transmit / receive channel corresponds to one antenna port, which is represented as a digital port. Compared to DBF, the entire ABF array corresponds to only one DAC, so the biggest advantage of the ABF architecture is its low cost and power consumption. However, ABF also has significant bottlenecks. The phase shifter settings in the analog domain determine the beam direction after beamforming. Since the signals are directly combined in the analog domain, unlike DBF which utilizes digital signal processing for weighting, ABF requires pre-configuring the phase shifter settings (pointing the analog beam to the target terminal) during transmission and reception. This process needs to be completed through beam scanning during the link establishment phase, introducing additional latency. Generally, once the analog beam is blocked or moves, causing misalignment, the system's link quality will rapidly degrade or even terminate. Therefore, the communication reliability of ABF is not as good as that of DBF.

[0122] Another implementation is hybrid beamforming (HBF), the structure of which is shown in Figure 3C. Each of the multiple transmit / receive channels is connected to a subarray. Each transmit / receive channel is represented as a digital-to-analog converter (DAC). A subarray includes multiple phase shifters and multiple elements, which can be understood as antenna elements. Each transmit / receive channel corresponds to one antenna port, which is represented as a digital port.

[0123] On the one hand, the HBF has a certain number of digital ports to support digital beamforming, and on the other hand, each digital port drives an ABF subarray. Compared with ABF, for the same array size, each digital channel drives a smaller analog subarray (4 in Figure 3C and 6 in Figure 3B), thus resulting in a wider beam, better reliability, and lower beam scanning overhead. Generally, the ratio of HBF digital ports to analog phase shifters varies depending on different frequencies and system design requirements. For example, in high-frequency bands, the number of digital ports is very small (4-16), and the number of analog phase shifters corresponding to a single digital channel is relatively large (16-32), which is closer to ABF. In low-frequency bands, the number of digital ports is large (32-128), and the number of analog phase shifters per digital channel is smaller (e.g., 2-10).

[0124] Generally, both HBF and ABF architectures have analog beams. When the beam is aligned with the communication target, signal quality is improved. The direction of the analog beam (determined by beam weights) needs to be configured before transmission and reception. During signal transmission / reception, digital components (such as digital channels, RF units, or antenna ports) can digitally weight the signal. j , here w j This can be understood as sub-band level digital weighting. Optionally, multiple sub-bands (or frequency bands) may use the same weight; or different sub-bands may use different weights, for example, the weight of sub-band f is denoted as w. j (f) Simulations (such as analog channels, analog phase shifters) can only perform analog weighting. i The w i This can be understood as full-band analog weighting, meaning the same weight w is shared across the entire frequency band. i By combining digital and analog weighting, a beamforming effect is created that focuses the beam in a specific direction in space.

[0125] (4) Antenna Port and Port Group

[0126] An antenna port, often simply called a port, can be understood as a virtual transmitting antenna identified by the receiving end, or a spatially distinguishable virtual transmitting antenna. Each virtual antenna can be pre-configured with one antenna port. Each virtual antenna can be a weighted combination of multiple physical antennas. One or more antenna ports can correspond to a reference signal; therefore, each antenna port can be called a port for a reference signal, such as a CSI-RS port, DMRS port, or SRS port. In the embodiments provided in this application, one antenna port can also be used to transmit multiple reference signals. For example, multiple reference signals can be transmitted through this antenna port using frequency division or time division.

[0127] In this context, an antenna port is a logical concept, and one antenna port generally corresponds to one physical antenna. An antenna port is typically associated with a reference signal, and its meaning can be understood as a transmit / receive interface on the channel through which the reference signal passes. For low frequencies, one antenna port may correspond to one or more antenna elements that jointly transmit the reference signal; the receiver can treat them as a whole without distinguishing between individual antenna elements. For high-frequency systems, an antenna port may correspond to a beam; similarly, the receiver only needs to treat this beam as an interface and does not need to distinguish between individual antenna elements.

[0128] In protocols, antenna ports are typically characterized by "antenna port" or "port," but they can also be characterized by resources (such as CSI-RS resources, SRS resources, DMRS resources, PTRS resources, CRS resources, TRS resources, synchronization signal block (SSB) resources, etc.) or resource groups. In other words, the identifier for an antenna port in this application can be replaced with the identifiers mentioned above; for example, an antenna port can be replaced with an identifier for a resource, a pilot resource, or a reference signal resource.

[0129] In one possible design, multiple antenna ports of the network device can be grouped to form multiple port groups. In another possible design, one reference signal resource (such as a CSI-RS resource) corresponds to one port group, or multiple reference signal resources can each correspond to multiple port groups. In yet another possible design, multiple reference signal resources correspond to one port group. Each port group corresponds to at least one antenna port. Optionally, if a port group corresponds to one analog beam, the multiple antenna ports included in the same port group can be multiple antenna ports corresponding to the same analog beam; or, if a port group corresponds to multiple analog beams, the multiple antenna ports included in the same port group can be antenna ports corresponding to multiple analog beams. Optionally, in the HBF architecture, the port group can also be described as a digital-to-analog port group.

[0130] The concept of a port group can also be replaced with 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 collection, etc., and this application embodiment does not impose any limitations. In this application embodiment, a port group can also be replaced with "port #A to port #B". Port #A and port #B can be understood as examples of port indices. The antenna ports indicated by ports #A to #B can be understood as antenna ports indexed from #A to #B, and these antenna port indices are consecutive. In this application embodiment, a port set can also be replaced with the index of each antenna port included in the port set. In this case, the antenna ports included in the port set can be consecutive antenna ports or non-consecutive antenna ports.

[0131] (5) Precoding and codebook.

[0132] In communication systems, multiple-input multiple-output (MIMO) technology can be used to increase system capacity and improve throughput. 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 noise. In communication systems with multiple antennas, signals from multiple transmitting antennas can be superimposed on any one receiving antenna. Therefore, the method of transmitting signals at the transmitting end affects system performance, and recovering 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, while also reducing the complexity of eliminating inter-channel interference in the receiver. In this case, precoding is expressed as y = H × W × x + n, where W is the precoding matrix (or vector, or precoder). To simplify implementation, W can be selected from a predefined set of matrices (or vectors), called the codebook. The above signal transmission method is also called a codebook-based transmission method. If the sending end can obtain all the information of H, then W can be obtained by the sending end itself. This signal transmission method is also known as the non-codebook (NCB) transmission method.

[0133] (6) Precoding matrix indicator (PMI) information.

[0134] PMI information can be used to determine the precoding matrix. The precoding matrix can be, for example, a precoding matrix determined by the terminal device based on the channel matrix of a single frequency domain unit. This 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 methods used by the terminal device to determine the precoding matrix are not limited to those described above; specific implementation methods can be found in the protocol, and for the sake of brevity, they will not be listed here.

[0135] For example, the precoding matrix can be obtained by performing singular value decomposition (SVD) on the channel matrix or its covariance matrix, or by performing eigenvalue decomposition (EVD) on the covariance matrix of the channel matrix. It should be understood that the methods for determining the precoding matrix listed above are merely examples and should not constitute any limitation on this application.

[0136] It is understood that, according to the method provided in this application, the network device can determine the CSI RS port, the frequency domain discrete Fourier transform (DFT) vector, and the combining coefficients of the space-frequency vector for constructing the precoding vector based on feedback from the terminal device, thereby determining the precoding matrix corresponding to each frequency domain unit. This precoding matrix can be directly used for downlink data transmission; alternatively, it can be processed using beamforming methods, such as zero forcing (ZF), regularized zero-forcing (RZF), minimum mean-squared error (MMSE), and signal-to-leakage-and-noise ratio (SLNR), to obtain the final precoding matrix for downlink data transmission. This application does not limit this. Unless otherwise specified, the precoding matrix mentioned below refers to the precoding matrix determined based on the method provided in this application.

[0137] It is understandable that the precoding matrix determined by the terminal device can be interpreted 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 can recover the precoding matrix based on the PMI. It is understandable 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.

[0138] In downlink channel measurement, the higher the approximation between the precoding matrix determined by the network device based on the PMI and the precoding matrix determined by the terminal device, the better the precoding matrix determined by the network device for data transmission can be adapted to the channel state, thus improving the signal reception quality.

[0139] (7) Precoding and codebook

[0140] In MIMO systems, the mathematical expression for communication is y = H × x + n, where y is the received signal, H is the MIMO channel, x is the transmitted signal, and n is noise. In communication systems with multiple antennas, signals from multiple transmit antennas can be superimposed on any one receive antenna. Therefore, the method of transmitting signals at the transmitter affects system performance, and recovering the transmitted signal at the receiver is often complex. In this context, precoding is used to reduce system overhead and maximize the system capacity of MIMO, while also reducing the complexity of eliminating inter-channel interference in the receiver. In this case, the mathematical expression is y = H × W × x + n, where W is the precoding matrix (or vector). To simplify implementation complexity, W can be selected from a predefined set of matrices (or vectors), called the codebook. This method is also known as the codebook-based transmission method.

[0141] The codebook includes a codebook index and a precoding matrix. The corresponding precoding matrix can be determined based on the PMI feedback from the CSI. In type I codebook feedback, the PMI can specifically include feedback on precoding matrices for different transport layers and subbands. The precoding matrix to be fed back for one transport layer and one subband can be represented as W: W = W1 × W2, where the dimension of W is P. CSI-RS ×N3, W1 is a wideband precoding matrix with dimension P. CSI-RS ×v, W2 is the subband precoding matrix with dimensions v×N3. P CSI-RS N3 indicates the number of CSI-RS ports, N3 indicates the number of sub-bands or PMIs, and v indicates the number of layers (or streams).

[0142] When the number of CSI-RS ports is less than or equal to 2, the codebook feedback parameters (including codebook index and number of layers) are as follows:

[0143] Table 1

[0144] When the number of CSI-RS ports is greater than 2, the number of precoding matrices, i.e. the number of weights, in the codebook will increase geometrically with the number of CSI-RS ports and layers. Therefore, the codebook is no longer suitable to be listed in the form of enumeration. Instead, it is generated according to certain rules based on the relevant parameter configuration. In other words, the codebook can be determined based on the relevant parameter configuration.

[0145] Taking a type I codebook as an example, when codebookmode=1, the codebook can be determined according to the following three steps: 1. Determine the spatial beam set, that is, the set of all values ​​in a codebook; 2. Select the wideband beam group, that is, determine the wideband precoding matrix W1; 3. Beam selection and phase quantization adjustment, that is, determine the subband precoding matrix W2.

[0146] The spatial beam set is determined by the parameter configuration in Table 2:

[0147] Table 2

[0148] In Table 2, N1 represents the number of logical antenna ports in a certain direction of the same polarization, generally referring to the horizontal direction; N2 represents the number of logical antenna ports in another direction of the same polarization, generally referring to the vertical direction; O1 represents the oversampling factor of the Discrete Fourier Transform (DFT) in the direction of N1 (horizontal direction); O2 represents the oversampling factor of the DFT in the direction of N2 (vertical direction).

[0149] As shown in Table 2, with P CSI-RS Taking 16 as an example, for the same level of logical antenna ports, the possible combinations in the horizontal and vertical directions are only (4, 2) and (8, 1) as shown in the table above. When N1 is 4 and N2 is 2, it means that during beamforming, a total of N1×N2 weight vectors with a horizontal dimension of 4 and a vertical dimension of 2 can be formed. These weight vectors are orthogonal to each other, meaning that the beams formed by weighting these weight vectors do not interfere with each other.

[0150] The physical significance of O1 and O2 lies in the fact that DFT oversampling increases the number of weight vectors in the horizontal and vertical directions, thus generating more weight vectors. The values ​​of O1 and O2 also determine the beam density in the horizontal and vertical directions when the antenna configuration is fixed, i.e., when N1 and N2 are determined. The larger the values ​​of O1 and O2, the smaller the beam step size and the higher the accuracy during beam scanning. However, the trade-off is that the weight vectors are no longer orthogonal, meaning that there is interference between the beams formed after weighting these weight vectors.

[0151] Figure 4 is a schematic diagram of a spatial beam index with 16 CSI-RS ports. As shown in Figure 4, (N1, N2) takes the value (4, 2), so the formed spatial beam has a horizontal dimension of 4 and a vertical dimension of 2. (O1, O2) takes the value (4, 4), and each dot corresponds to a DFT oversampled weight vector. Since beams in different directions can be formed by weighting with different weight vectors, each dot in Figure 4 corresponds to a different DFT beam. Among them, the weight vectors corresponding to the black dots are orthogonal to each other, that is, the DFT beams corresponding to the black dots do not interfere with each other; while the weight vectors corresponding to the black dots and the shaded dots are no longer orthogonal, that is, there is some interference between the DFT beams corresponding to the black dots and the shaded dots.

[0152] As shown in Figure 4, the oversampled DFT beam index can be determined based on the position of each dot in the horizontal and vertical directions. 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 dot marked "1" in the spatial beams shown in Figure 4.

[0153] The broadband precoding matrix W1 is formed by oversampling the DFT matrix, that is, the DFT matrix is ​​oversampled in space to obtain the beamforming weights of the required precision. The weight vectors of the l-th and m-th beams corresponding to the horizontal and vertical directions satisfy the following expression:

[0154] Among them, v l Let l be the weight vector in the horizontal direction, and its length is N1. The number of weight vectors in the horizontal direction is determined by the number of values ​​that l can take; that is, l also represents the weights chosen in the horizontal direction.

[0155] u m Let m be the weight vector in the vertical direction, and its length is N². The number of vectors in the vertical direction is determined by the number of possible values ​​for m, meaning that m also represents the weights chosen in the vertical direction.

[0156] After confirming the weight sets in the horizontal and vertical directions, the selected weight set is determined. (This is achieved through v...) l and u m The Kronecker product represents only the weighting result for one set of polarized antennas. Typically, the other set of polarized antennas will have a certain phase deviation, determined by W2. Therefore, the final expression of W1 is v. l and u m The form of the second sub-block diagonal matrix in the Kronecker product.

[0157] The weight vector of the (l, m)th beam satisfies the following expression (3):

[0158] Based on the above expression, by calculating all possible values ​​of l and m, the beam corresponding to W1 can be determined. The beam corresponding to W1 may fall into two categories:

[0159] (1) Multiple oversampled DFT beams, and no two beams are orthogonal to each other, with the whole structure revolving around v. l,m express;

[0160] (2) Multiple orthogonal DFT beams, through v l,m v l′,m′ v l″,m″ ...to distinguish between multiple beams.

[0161] Accordingly, W1 satisfies the following expression (4):

[0162] Among them, P CSI-RS This indicates the number of CSI-RS ports, and v represents the number of layers (or streams). This represents the power normalization coefficient, which ensures that the total power at the antenna ports remains constant before and after beamforming weighting. The number of ports in CSI-RS is the same as the number of rows in the wideband precoding matrix W1, and is v l,m Double the number of rows; the non-zero diagonal block in the top left corner of W1, i.e., v l,m v l′,m′ In the column vector group formed by ..., each column represents the beam in a specific direction of the same polarized antenna.

[0163] When the number of CSI-RS ports is greater than 2, the PMI index includes a wideband indicator i1 and a subband indicator i2. The wideband indicator i1 is a composite index, and its basic definition is as follows:

[0164] Among them, i 1,1 This is the first DFT beam (or spatial basis, or IDFT beam) fed back by the terminal device. IDFT refers to the inverse discrete fourier transform (IDFT). The corresponding horizontal coordinate position in the spatial beam index diagram shown in Figure 4 is equivalent to the aforementioned horizontal index l;i 1,2 The vertical coordinate position of the DFT beam (or spatial basis, or IDFT beam) in the spatial beam index diagram shown in Figure 4 is equivalent to the aforementioned vertical index m; i 1,3 i is the offset of another DFT beam fed back by the terminal device relative to the first DFT beam.1,3 Includes horizontal and vertical offsets; v represents the number of layers.

[0165] When the number of layers v is 2, i 1,3 The offsets in the horizontal and vertical directions can be selected according to Table 3.

[0166] Table 3

[0167] In Table 3, the value corresponding to k1 is the horizontal offset of the other DFT beam relative to the first DFT beam, and the value corresponding to k2 is the vertical offset of the other DFT beam relative to the first DFT beam.

[0168] 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 and vertical directions can be selected according to Table 4.

[0169] Table 4

[0170] Understandably, for each CSI-RS resource, the terminal device needs to determine the autocorrelation covariance matrix R of its corresponding frequency domain channel coefficients. hh Select DFT beams (or spatial basis, or IDFT beams) from the set of spatial beams to determine the broadband precoding matrix W1.

[0171] The subband precoding matrix W2 is used to perform phase difference quantization and adjustment on the weights of another set of polarized antennas. The subband indicator i2 fed back by the terminal device corresponds to W2. With codebookmode=1, when the layer number v is 1, the PMI content fed back by the terminal device to the network device is shown in Table 5:

[0172] Table 5

[0173] in, That is, the precoding matrix determined based on the wideband precoding matrix W1 and the subband precoding matrix W2 when the layer number v is 1. Specifically, P CSI-RS The number of CSI-RS ports, based on the i1 contained in the terminal device feedback. 1,1 and i 1,2 The horizontal index l and vertical index m of the DFT beam in the spatial beam index diagram can be determined, thereby determining the weight vector of the (l, m)th beam. n represents the value corresponding to i2 fed back by the terminal device.

[0174] With codebookmode=1, when the layer number v is 2, the PMI content fed back by the terminal device to the network device is shown in Table 6:

[0175] Table 6

[0176] in, That is, the precoding matrix determined based on the wideband precoding matrix W1 and the subband precoding matrix W2 when the number of layers v is 2. k1 and k2 are i in Table 2. 1,3 Includes offsets in the horizontal and vertical directions, v l′,m′ Used to indicate a distinction from v l,m The orthogonal DFT beams are used, and the other parameters are the same as those in Table 4, so they will not be repeated here.

[0177] With 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 shown in Table 7:

[0178] Table 7

[0179] in, That is, when the number of layers v is 3 and the number of CSI-RS ports is less than 16, the precoding matrix is ​​determined based on the wideband precoding matrix W1 and the subband precoding matrix W2. k1 and k2 are i in Table 4. 1,3 The parameters include the horizontal and vertical offsets, and the remaining parameters are the same as those in Tables 4 and 5, so they will not be repeated here.

[0180] 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.

[0181] 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, PCSI-RS All elements except the m-th element are 0.

[0182] As described above, the current PMI uses a Type 1 DFT codebook. Terminals reporting PMI include DFT-related parameters, resulting in high computational complexity and significant feedback overhead. Therefore, this application provides a port selection (PS) method for Type 1 codebook feedback, which reduces computational complexity and feedback overhead.

[0183] Based on this, this application provides a communication method, as illustrated in Figure 5. The method mainly includes the following steps.

[0184] S501, the network device sends the first configuration information to the terminal device.

[0185] The first configuration information is used to configure reference signal resources corresponding to M ports, where M is a positive integer. The M ports may correspond to one or more reference signal resources, and this application embodiment does not limit this. The ports described in this application embodiment can also be replaced with antenna ports or reference signal ports (e.g., CSI-RS ports). Accordingly, the terminal device can detect the reference signal (e.g., CSI-RS) sent by the network device on the reference signal resources to obtain channel measurement results. These channel measurement results include the channel measurement results corresponding to each of the M ports. For example, the channel measurement results may be reference signal received quality (RSRQ), reference signal received power (RSRP), interference-plus-noise ratio (SINR), signal-to-noise ratio (SNR), or other information, such as layer 1 reference signal received power (L1-RSRP) or layer 1 interference-plus-noise ratio (L1-SINR).

[0186] In one possible design, the M ports represent a subset of the network device's total antenna ports. The network device can perform port selection (or port dimensionality reduction) according to predefined rules. For example, it can select the top M ports with better channel measurement results from all antenna ports, or sort them by index from smallest to largest, or by index from largest to smallest. Taking channel measurement results as an example of reference signal reception quality, the network device can use the reference signal reception quality obtained by measuring historically transmitted reference signals (such as sounding reference signals, SRS) from the terminal device to sort all antenna ports by reference signal reception quality from highest to lowest, thus determining the top M antenna ports with the highest reference signal reception quality. For example, the total number of antenna ports can be 128, 256, or 512, then M ∈ {4, 8, 12, 16, 24, 32, 64, 72, 96, 128, 256, 512}. In another possible design, the M ports represent all antenna ports of the network device (e.g., 128, 256, or 512). The terminal device can measure the reference signal transmitted by the network device based on the reference signal resources corresponding to the M ports to obtain the channel measurement results for all antenna ports. Taking a reference signal resource that supports a maximum of 32 ports as an example, when M is less than or equal to 32, the number of reference signal resources corresponding to the aforementioned M ports is one; when M is greater than 32, the number of reference signal resources corresponding to the aforementioned M ports is multiple.

[0187] The M ports include ports on dual polarization; for example, the M ports can be divided into ports on the first polarization. On each port and second polarization M ports. Alternatively, it can be described as: M ports including... Group dual-polarized ports, Each dual-polarization port group includes M ports: one port on the first polarization and one port on the second polarization. According to the horizontal and vertical distribution of the antenna ports, the ports on a single polarization... The ports are divided into M1 ports in the first dimension and M2 ports in the second dimension. Both M1 and M2 are positive integers. The first dimension is the horizontal dimension, and the second dimension is the vertical dimension; or, the first dimension is the vertical dimension, and the second dimension is the horizontal dimension. Optionally, the network device may also include the values ​​of M1 and M2 in the first configuration information to indicate to the terminal device the distribution of the M ports in the two dimensions. Table 8 below illustrates examples of possible values ​​for M1 and M2.

[0188] Table 8

[0189] As an example, with M=128, the antenna port on a single polarization For example, Figure 6 also illustrates the two-dimensional distribution of 64 ports, that is, the number of ports in the horizontal dimension M1 = 16 and the number of ports in the vertical dimension M2 = 4.

[0190] Optionally, the network device can also group the M ports, such as configuring K port groups based on the M ports on a single polarization (first polarization or second polarization) using first configuration information. The aforementioned N ports can be included in one of the K port groups, and different port groups include different ports. For example, on a single polarization... The ports are divided into K port groups, with K1 port groups in the first dimension and K2 port groups in the second dimension, where K = K1 × K2. The first configuration information may include a first parameter X1 and a second parameter X2; or, when X1 takes a default value (e.g., 1), the first configuration information may only include the second parameter X2; or, when X2 takes a default value (e.g., 1), the first configuration information may only include the first parameter X1. The first parameter X1 indicates the number of ports in each of the K port groups in the first dimension, and the second parameter X2 indicates the number of ports in each of the K port groups in the second dimension; or it can be understood that each of the K port groups includes... The ports are X1 ports in the first dimension, and the... There are X2 ports in the second dimension. Here, K is a positive integer less than M, X1 is a positive integer (e.g., X1 less than M1), and X2 is a positive integer (e.g., X2 less than M2). Optionally, the values ​​of X1 and X2 can also satisfy: X1 equals M1, X2 is less than M2; or, X1 is less than M1, X2 equals M2.

[0191] Accordingly, for the terminal device, the terminal device can, based on the first parameter X1, the second parameter X2, and all ports of M ports on a single polarization (such as the first polarization or the second polarization), (1 port), determine K port groups.

[0192] Alternatively, when dividing M ports into K port groups, the number of reference signal resources corresponding to the M ports can be defined as K, with a one-to-one correspondence between the K port groups and the K reference signal resources. In this case, a port group can also be understood as a port on a single polarization corresponding to a reference signal resource sent by the network device. Or, multiple reference signal resources can be configured for a port group, that is, the number of reference signal resources corresponding to the M ports is greater than K. For example, when S reference signal resources are configured for a port group, the number of reference signal resources corresponding to the M ports is (K×S).

[0193] The port group in this embodiment can also be described as a port region, port set, or other names. As an example, Table 9 below also illustrates some possible values ​​for X1 and X2.

[0194] Table 9

[0195] Taking M=128 and K=4 as an example, the number of ports in a single polarization is 64 out of 128 ports. Based on these 64 ports, four port groups are formed. Each port group includes 8 ports in the first dimension and 2 ports in the second dimension. As shown in Figure 7A, the positions of the ports within each of the K port groups can be continuous. As shown in Figures 7B, 7C, and 7D, the positions of the ports within each of the K port groups can also be non-contiguous.

[0196] In one possible design, the first configuration information may also include index indicators for K port groups. Taking K=4 as an example, Table 10 below illustrates one port group index configuration, where the index indicator occupies 2 bits and can be used to indicate the index of port groups 0 to 3.

[0197] Table 10

[0198] In another possible design, the first configuration information can directly include the index of each port group in the K port groups, or the first configuration information can include the index of the first port group in the K port groups and the value of K, or the first configuration information can include the index of the last port group in the K port groups and the value of K, or the first configuration information can include The index of the last port group in each port group and the value of K.

[0199] It is understood that the method by which the network device provides grouping instructions for the M ports through the first configuration information can also be replaced by the terminal device configuring and reporting the grouping instructions for the M ports itself, or it can be replaced by a port grouping method predefined by the protocol. This application embodiment does not limit this.

[0200] Optionally, the network device can determine the aforementioned first configuration information based on the capability information reported by the terminal device. For example, if the capability information reported by the terminal device indicates the number of ports supported by the terminal device, the network device can determine the value of M based on this capability information. Alternatively, if the capability information reported by the terminal device indicates that the terminal device supports a port selection codebook, the network device can send the aforementioned first configuration information to the terminal device based on this capability information.

[0201] Optionally, the network device can send the first configuration information described in the above example via PDCCH or PDSCH. For example, the first configuration information can be carried in RRC signaling, MAC control element (MAC-CE), or downlink control information (DCI); or it can be understood that the first configuration information can be RRC signaling, MAC-CE, or DCI.

[0202] S502, the terminal device sends PMI information to the network device based on the channel measurement results of the reference signal resources.

[0203] The PMI information is determined based on channel measurement results of the reference signal resources. For example, based on the channel measurement results of the reference signal resources, the terminal device selects N ports from M ports that are on a single polarization (such as the first polarization or the second polarization). Then, the PMI information indicates the index of the N ports on a single polarization (such as the first polarization or the second polarization) from the aforementioned M ports. This PMI information can be used to determine the precoding matrix corresponding to 2N ports. The 2N ports include N ports on the first polarization and N ports on the second polarization, or it can be understood that the 2N ports correspond to N sets of dual-polarization ports, and each set of dual-polarization ports corresponds to one port on the first polarization and one port on the second polarization of the 2N ports.

[0204] Optionally, the terminal device can send the above PMI information via PUCCH or PUSCH. For example, the PMI information can be carried in uplink control information (UCI).

[0205] With M = 32, the number of ports on a single polarization For example, the port index range of M ports on a single polarization is 0 to 15, which means the index range of N ports is also 0 to 15. Figure 8 illustrates several index distribution methods for 16 ports on a single polarization. Taking M as 128, the number of ports on a single polarization... For example, the port index range of M ports on a single polarization is 0 to 63, which means the index range of N ports is also 0 to 63. Figure 9 illustrates several index distribution methods for 64 ports on a single polarization. It can be understood that the indexes in a column shown in Figure 9(b) can be distributed in an increasing order from bottom to top, such as the first column being 0 to 3 from bottom to top; or distributed in an increasing order from top to bottom, such as the first column being 0 to 3 from top to bottom.

[0206] The precoding matrix can be used for downlink data transmission. The value of N is related to the transmission layer number v, and N is less than or equal to v. For example, the value of N can be determined in the following ways: the protocol predefines the values ​​of N corresponding to different values ​​of v; or, the network device indicates the value of N to the terminal device; or, the terminal device determines the value of N based on the value of v according to the criterion that N is less than or equal to v, and indicates the value of N to the network device in the PMI information. This embodiment of the application does not limit this. Optionally, the terminal device can also indicate the layer number v to the network device through a rank indication (RI).

[0207] Understandably, the codebook parameters used to construct the precoding matrix (i.e., the port selection codebook) are related to one or more of the following: the number of measured ports, port selection information, the number of layers, and the phase coefficients between polarizations. The port selection information includes port indices on a single polarization, or indices of port groups on a single polarization and port indices within port groups. Optionally, the port indices within port groups can be one-dimensional or two-dimensional indices. For ease of understanding, some possible codebook designs are described below.

[0208] For port selection reporting in M ​​ports, with a layer number of v, the precoding matrix (codebook) of type I satisfies the following relationship (1):

[0209] Where M represents the number of ports, and when the reference signal sent by the network device is CSI-RS, M can also be replaced by P. CSI-RS However, the embodiments in this application do not limit this.

[0210] v 1 ...v v Each indicates a column vector (or identity matrix, or unit vector) determined by the index of one of N ports on a single polarization, i.e., v 1 ...v v It refers to v column vectors, where one of the v column vectors is a column vector v. iThe index of one of the N ports, where i is a positive integer less than or equal to v. Optionally, if N is less than v, some column vectors in the v column vectors have the same port index on a single polarization, and some column vectors in the v column vectors are the same; or if N is equal to v, different column vectors in the v column vectors have different port indices on a single polarization, and all v column vectors are different.

[0211] It is understood that the term "relation" in relation (1) above can also be replaced by a name such as a relational formula or expression. The embodiments of this application are described below using a relation as an example, but this is not a limitation. The first row of elements in relation (1) above corresponds to the first polarization direction, and the second row of elements in relation (1) above corresponds to the second polarization direction. For example, v in the first row... 1 The index of one port out of N ports corresponding to M ports in the first polarization, v in the second row 1 The index of one of the N ports corresponding to M ports on the second polarization.

[0212] Indicates v phase coefficients, such as phase coefficients between polarizations. Any one of the v phase coefficients. It can be based on Specifically, i is a positive integer less than or equal to v. In one possible design, The value of n can be one of 0, 1, 2, or 3. The value of n can be predefined, or the network device can indicate the value of n to the terminal device, or the terminal device can determine n based on channel measurement results and indicate the value of n in the PMI information. This application embodiment does not limit this. In another possible design, n is an integer, m is a positive integer, n / m is less than 2, and the values ​​of n and m can be predefined, or the network device can indicate the values ​​of n and m to the terminal device, or the terminal device can indicate the values ​​of n and m in the PMI information. This application embodiment does not limit this. For example, when m is 3, the value of n is one of 0, 1, 2, 3, 4, and 5; when m is 4, the value of n is one of 0, 1, 2, 3, 4, 5, 6, and 7. In a first possible design, the PMI information indicating the port index can use a one-dimensional index. For example, the PMI information includes the index of each of the N ports on a single polarization. Furthermore, if the indices of the N ports are consecutive, the PMI information can include one of the following indices: the index of the first port among the N ports, the index of the last port among the N ports, the index of the [missing index] among the N ports... Index of each port.

[0213] Accordingly, after receiving the PMI information, the network device can determine the indices of N ports on a single polarization based on the indices included in the PMI information, and then determine v based on the indices of the N ports on a single polarization. 1 ...v v .

[0214] In the second possible design, corresponding to the two-dimensional distribution of M ports in the first and second dimensions, the PMI information indicating the port index can use a two-dimensional index. For example, the PMI information includes a two-dimensional index of each of the N ports, and the two-dimensional index of one of the N ports includes a first index of that port in the first dimension and a second index of that port in the second dimension. Alternatively, when N is greater than 1, the PMI information includes the first index of the first port in the first dimension, the second index of the first port in the second dimension, the first index offset of every two ports in the first dimension, and the second index offset of every two ports in the second dimension. Based on the fact that the M ports include M1 ports in the first dimension and M2 ports in the second dimension, it can be understood that in this design, the first index of the PMI includes integers less than or equal to M1. For example, when the index starts numbering from 0, the value range of the first index is 0 to M1-1; for example, when the index starts numbering from 1, the value range of the first index is 1 to M1. Similarly, in this design, the value of the second index included in PMI is an integer less than or equal to M2. For example, when the index starts numbering from 0, the value range of the second index is 0 to M2-1; for example, when the index starts numbering from 1, the value range of the second index is 1 to M2.

[0215] Accordingly, after receiving the PMI information, the network device can determine the two-dimensional index of each of the N ports based on the two-dimensional index included in the PMI information. Then, the network device first maps the two-dimensional index of each of the N ports to the index of the N ports on a single polarization, and finally determines v based on the index of the N ports on the single polarization. 1 ...v v For example, as illustrated in Figure 8(a), assuming the first dimension corresponds to the horizontal dimension, the first index on the first dimension is 0 to 7 from left to right; the second dimension corresponds to the vertical dimension, the second index on the second dimension is 0 to 1 from bottom to top. When the two-dimensional index carried in the PMI information indicates that the first index is 4 and the second index is 1, the network device can determine that the index of the port mapped on a single polarity is 4.

[0216] In the third possible design, where M ports are divided into K port groups on a single polarization, N ports can be included in one of the K port groups. For example, a terminal device can determine its service area covered by one of the K port groups through the network device based on its location. The terminal device can then select a port within that port group, and the PMI information will contain the index of the N ports in that port group, as well as the index of at least one of the N ports within that port group.

[0217] The PMI information indicating port index can adopt a one-dimensional index method. The implementation method can refer to the first possible design understanding mentioned above, and this application embodiment will not elaborate on this. Based on the fact that a port group includes X1 ports in the first dimension and X2 ports in the second dimension, it can be understood that: the port index included in the PMI in this design is an integer less than or equal to (X1×X2). For example, when the index starts numbering from 0, the value range of the port index is 0 to (X1×X2)-1; and when the index starts numbering from 1, the value range of the port index is 1 to (X1×X2).

[0218] The PMI information indicating port index can adopt a two-dimensional index method. The implementation method can refer to the second possible design understanding described above, and this application embodiment will not elaborate further. Based on a port group including X1 ports in the first dimension and X2 ports in the second dimension, it can be understood that: in this design, the first index of the PMI includes integers less than or equal to X1. For example, when the index starts numbering from 0, the value range of the first index is 0 to X1-1; for example, when the index starts numbering from 1, the value range of the first index is 1 to X1. Similarly, in this design, the second index of the PMI includes integers less than or equal to X2. For example, when the index starts numbering from 0, the value range of the second index is 0 to X2-1; for example, when the index starts numbering from 1, the value range of the second index is 1 to X2.

[0219] Accordingly, after receiving the PMI information, the network device can determine the index of each of the N ports within the port group based on the port group index and the port index included in the PMI information. Then, the network device first maps the index of each of the N ports within the port group to the index of the N ports on a single polarization. Finally, it determines v based on the index of the N ports on the single polarization. 1 ...v v .

[0220] Optionally, the PMI information can be defined to include the index (c) of the port group and the first index a of a port within the port group. * Second index b * The network device follows the c and a instructions in the PMI information.* and b * This allows you to determine the port's index on a single polarization. For example, a network device can determine its port's index on a single polarization using the following method. Alternatively, the network device can use the c and a parameters indicated in the PMI information. * and b * We can first determine the first index a and the second index b of the port in single polarization as follows: Then, the network device determines the index of the port on a single polarization based on the values ​​of a and b.

[0221] Taking port group 0 in Figure 7A and (b) in Figure 9 as examples, there are 8 ports in the first dimension and 2 ports in the second dimension within a port group, i.e., X1 = 8, X2 = 2. Assuming the first dimension corresponds to the horizontal dimension, the first index in the first dimension within a port group ranges from 0 to 7 from left to right; the second dimension corresponds to the vertical dimension, and the second index in the second dimension within a port group ranges from 0 to 1 from bottom to top. When the port group index (c) carried in the PMI information is 0, and the two-dimensional index (a) of a port within the port group... * b * ) indicates the first index (a * The second index (b) is 4. * When ) is 1, the network device can determine that the index of the port mapped on a single polarity is 17.

[0222] To facilitate understanding, the implementation of the above relationship (1) will be explained in detail below, taking v = 1 to 8 as examples respectively.

[0223] Example (1), v = 1, one implementation of relation (1) can be understood by referring to the following relation (2).

[0224] Where, when v = 1, N = 1, Where n / m is less than 2, for example, when m is 2, the value of n is one of 0, 1, 2 or 3; when m is 3, the value of n is one of 0, 1, 2, 3, 4 or 5. Subsequent examples will be illustrated with m being 2.

[0225] In one possible design, the index of the PMI information indication port adopts a one-dimensional index method, and the above relationship (2) can be specifically represented as the following relationship (2-1):

[0226] in, This indicates that the codebook (or precoding matrix) at layer number v = 1 is related to p and n. p indicates the index of a port on a single polarization, and n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the above The PMI information carries indication information that can be used to determine the values ​​of p and n. For example, the terminal device indicates the value of p through the first indication information i1 and the value of n through the second indication information i2 in the PMI information.

[0227] As shown in Figure 10A, the total number of ports P CSI-RS =32, the number of ports on a single polarization is 16, and the one-dimensional index range of the ports on a single polarization is 0 to 15. Assuming the terminal device selects the port with index 8 out of the 16 ports on a single polarization based on channel measurements of the reference signal resources, the terminal device can use 4 bits to report i1 in the PMI information to indicate the index 8 of that port. Therefore, the network device can determine that p is 8, and the column vector v in the precoding matrix... p =[0000000010000000] T And determine that the port selected via the terminal device port is the port with index 8 on a single polarization, corresponding to the port with index 8 and the port with index 24 among the 32 ports (index range 0 to 31).

[0228] In another possible design, the PMI indicator port index adopts a two-dimensional index method, and the above relationship (2) can be specifically expressed as the following relationship (2-2):

[0229] in, This indicates that the codebook (or precoding matrix) at layer number v = 1 is related to c, a, b, and n. Here, c indicates the index of the port group to which the selected port belongs, a indicates the first index of a port in the first dimension on a single polarization, b indicates the second index of a port in the second dimension on a single polarization, and n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the above The PMI information carries indication information that can be used to determine the values ​​of c, a, b, and n. For example, the terminal device indicates the value of n in the PMI information through the second indication information i2, and through the third indication information i... 1,1 Indicates that a is mapped to a within port group c. * The value is determined by the fourth indicator information i.1,2 Indicates that b is mapped within port group c. * The value of , and the value of c indicated by the fifth instruction information i3.

[0230] As shown in Figure 10B, the total number of ports P CSI-RS =128, the number of ports on a single polarization is 64, M1=16, M2=4; X1=8, X2=2, K=4, K1=2, K2=2. The index c of the port group ranges from 0 to 3. Within a single port group, the first index on the first dimension, from left to right, is 0 to X1-1 (i.e., 0 to 7), and the second index on the second dimension, from bottom to top, is 0 to X2-1 (i.e., 0 to 1). Assume that the terminal device selects a port group with index c=1 on a single polarization based on the channel measurement results of the reference signal resources, and the first index (a) within the port group... * ) is 4, second index (b) * If the port is 1, the terminal device can use 2 bits to report i2 in the PMI information to indicate the port group with index 1, and use 3 bits to report i 1,1 To indicate the first index (a) of the port within the port group * =4) and using 1 bit to report i 1,2 To indicate the second index (b) of the port within the port group * =1). Corresponding to the distribution of M ports in the first and second dimensions, taking the case in Figure 9(b) where each column index increases from bottom to top as an example, the network device, according to c, a indicated in the PMI information... * and b * The index of the port corresponding to a single polarization can be determined. Alternatively, the network device can use the c and a parameters indicated in the PMI information. * and b * We can first determine the first index a and the second index b of the port in single polarization as follows: Furthermore, based on the values ​​of a and b, the network device determines that the port index mapped to a single polarization is 19.

[0231] Based on the above example, the network device can determine that the port selection corresponds to port 19 on a single polarization, and then the column vector v in the precoding matrix... a,b The length of this column vector is 64, and the non-zero elements in this column vector include element 19, while all other elements are zero. a,b Represented as v a,b =[0000000000000000001000000000000000000000000000000000000000000000] T.

[0232] Example (2), v = 2, one implementation of relation (1) can be understood by referring to the following relation (3).

[0233] In one possible design, when v = 2, N = 1, that is, v 1 =v 2 ; For example The value of n can be one of 0, 1, 2, or 3. 1 The relevant design content can be understood by referring to the description in Example (1), and will not be repeated in the embodiments of this application.

[0234] When the index of the PMI information indication port adopts a one-dimensional indexing method, the above relationship (3) can be specifically expressed as the following formula (3-1):

[0235] in, This indicates that the codebook (or precoding matrix) at layer number v = 2 is related to p and n. p indicates the index of a port on a single polarization, and n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 and v 2 The value of , Corresponding to the above The value of , Corresponding to the above The PMI information carries indication information that can be used to determine the values ​​of p and n. For example, the network device indicates the value of p through the first indication information i1 and the value of n through the second indication information i2 in the PMI information.

[0236] When the PMI indicator port index uses a two-dimensional indexing method, the above relationship (3) can be specifically represented as the following relationship (3-2):

[0237] in, This indicates that the codebook (or precoding matrix) for layer number v = 2 is related to c, a, b, and n. Here, c indicates the index of the port group to which the selected port belongs, a indicates the first index of a port in the first dimension on a single polarization, b indicates the second index of a port in the second dimension on a single polarization, and n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v a,bCorresponding to the aforementioned v 1 and v 2 The value of , Corresponding to the above The value of , Corresponding to the above The PMI information carries indication information that can be used to determine the values ​​of c, a, b, and n. For example, a network device indicates the value of n in the PMI information through the second indication information i2, and through the third indication information i... 1,1 Indicates that a is mapped to a within port group c. * The value is determined by the fourth indicator information i. 1,2 Indicates that b is mapped within port group c. * The value of , and the value of c indicated by the fifth instruction information i3.

[0238] In another possible design, when v = 2, N = 2, and in relation (3) v 1 ≠v 2 ; For example The value of n can be one of 0, 1, 2, or 3. When the PMI information indicates the index of each of the N ports, v 1 v 2 The relevant design details can be understood by referring to the description in Example (1), and will not be repeated in the embodiments of this application.

[0239] When a one-dimensional index is used in PMI information to indicate the index of the first port among N consecutive ports, v 1 and v 2 The corresponding port indices on a single polarization are continuous, and the above relationship (3) can be specifically expressed as the following formula (3-3):

[0240] in, This represents the codebook (or precoding matrix) and p, p when the layer number v is 2. 1 It is related to n. p indicates the index of the first port out of N ports on a single polarization, p 1 Indicates the index of the second port out of N ports on a single polarization. n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The PMI information carries indication information that can be used to determine the values ​​of p and n. For example, the terminal device indicates the value of p through a first indication information i1 and the value of n through a second indication information i2 in the PMI information. Accordingly, the network device can determine the value of p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 The value of .

[0241] As shown in Figure 11A, v p The corresponding port index on a single polarization is p=8, and the network device can determine the element v in the precoding matrix. p =[0000000010000000] T Furthermore, network devices can determine... The corresponding port index on a single polarization is p 1 =9, network devices can determine the elements in the precoding matrix.

[0242] The PMI information uses a two-dimensional index to indicate the index of each of the N ports, or uses a two-dimensional index to indicate the index of the first port in the N ports within the port group (the first index a). * Second index b * When the first index offset (ε) in the first dimension and the second index offset (ζ) in the second dimension are given, the above relationship (3) can be specifically expressed as the following relationship (3-4):

[0243] in, This represents the codebook (or precoding matrix) and c,a,a when the layer number v is 2. 1 ,b,b 1 The value is related to n. Here, c indicates the index of the port group to which the selected port belongs, a indicates the first index of the first port in the first dimension of a single polarization, and b indicates the second index of the first port in the first dimension of a single polarization; a 1 Indicates the first index of the second port out of N ports in the first dimension on a single polarization, b 1 Indicates the second index of the second port in a single polarization of N ports, representing the second dimension. n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the above and The value of .

[0244] The PMI information carries information that can be used to determine c, a, and a. 1 ,b,b 1 The information indicating the value of n.

[0245] For example, the terminal device indicates the value of n in the PMI information through the second indication information i2, and through the third indication information i 1,1,0 The instruction indicates that the 'a' corresponding to the first port is mapped to the 'a' in port group c. * The value is determined by the fourth indicator information i. 1,2,0 The instruction indicates that the b corresponding to the first port is mapped to b in port group c. * The value of c is determined by the fifth instruction information i3, and the value of c is determined by the sixth instruction information i. 1,3 Indicates the values ​​of ε and ζ. Optionally, this can be expressed in the PMI information via the sixth indicator information i. 1,3 The values ​​of ε and ζ can also be replaced by: using the sixth indicator information i 1,3 Indicates the value of ε and the seventh indication information i 1,4 This indicates the value of ζ. It can be understood that the value of ε is less than X1, and the value of ζ is less than X2.

[0246] As shown in Figure 11B, the total number of ports P CSI-RS =128, the number of ports on a single polarization is 64, M1=16, M2=4, X1=8, X2=2, K=4, K1=2, K2=2. The index c of the K port groups ranges from 0 to 3. The first index on the first dimension, from left to right, is 0 to X1-1 (i.e., 0 to 7), and the second index on the second dimension, from bottom to top, is 0 to X2-1 (i.e., 0 to 1). Assume that the terminal device selects the port group with index 1 on a single polarization based on the channel measurement results of the reference signal resources, and the first index (a) within the port group... * ) is 4, second index (b) * The port with a value of 1, and the first index (a) within the port group. *1 ) is 5, second index (b) *1 If the port number is 0, the terminal device can use 2 bits to indicate the port group with index 1 and 3 bits to indicate the first index (a) of the first port in the PMI information. * =4), 1 bit indicates the second index of the port (b * =1), 3 bits indicate the first index offset (ε=a) *1 -a * =1), and 1 bit indicating the second index offset (ζ=b) *1 -b *=-1).

[0247] For example, taking X1 = 8 and X2 = 2 as an example, Table 11 below illustrates some possible values ​​of (ε, ζ). In the PMI information, i 1,3 Report an index of a value of (ε, ζ) to indicate the values ​​of ε and ζ.

[0248] Table 11

[0249] It is understood that Table 11 is only an example of possible values ​​for (ε, ζ). In actual applications, the values ​​of (ε, ζ) may include one or more rows in Table 11, or may include other values. This application embodiment does not limit this. Corresponding to the distribution of M ports in the first and second dimensions, taking the case in Figure 9(b) where each column index increases from bottom to top as an example: In one possible implementation, the network device determines the value based on c, a... * and b * The index of the first port on a single polarization can be determined. And according to c and a indicated in the PMI information * b * ε and ζ, determine a *1 =5, b *1 =0, thus determining the index of the second port on a single polarization. In another possible implementation, the network device determines the information based on c, a as indicated in the PMI information. * and b * We can first determine the first index a and the second index b of the first port in single polarization as follows: Furthermore, based on the values ​​of a and b, the network device determines the port index mapped to a single polarization to be 19. Similarly, the network device determines the port index based on c and a as indicated in the PMI information. * b * ε and ζ, we can first determine a *1 =5, b *1 =0, thus determining the first index a of the second port in single polarization. 1 Second index b 1 They are respectively: b 1 =b *1 +(c mod K2)×X2=2; Furthermore, the network device according to a 1 and b 1 The value of determines that the port index mapped to a single polarization is 22.

[0250] Based on the above example, if the network device can determine that the port selection corresponds to port 19 and port 22 on a single polarization, then the column vector v in the precoding matrix... a,b The length of this column vector is 64, and the non-zero elements in this column vector include element 19. All other elements are zero, denoted as v. a,b =[0000000000000000001000000000000000000000000000000000000000000000] T Column vectors in the precoding matrix A column vector of length 64, wherein the only non-zero element in the column vector is 22, is represented as

[0251] For example, the terminal device indicates the value of n in the PMI information through the second indication information i2; through i 1,1,0 The instruction indicates that the 'a' corresponding to the first port is mapped to the 'a' in port group c. * The value of i is determined by i. 1,2,0 The instruction indicates that the b corresponding to the first port is mapped to b in port group c. * The value of i; through i 1,1,1 Indicates the a corresponding to the second port 1 a mapped within port group c *1 The value of i is determined by i. 1,2,1 Indicates the b corresponding to the second port 1 b mapped within port group c *1 The value of ; and the value of c indicated by i3. Accordingly, the network device can determine the value of based on n, a * b * a *1 b *1 c, determine the index of the two ports mapped to a single polarization. The specific method can be understood by referring to the previous example. This application embodiment will not elaborate on this.

[0252] Example (3), v = 3, one implementation of relation (1) can be understood by referring to the following relation (4).

[0253] In one possible design, when v = 3, N < 3. Taking N = 2 as an example, v 1 v 2 v 3 Any two column vectors in the same array are identical. Any two coefficients in v are the same. For example, v 1 =v 3 v 1≠v 2 ; For example The value of n can be one of 0, 1, 2, or 3. 1 and v 3 The relevant design details can be found in Example (1) or Example (2) as described in v. 1 understand.

[0254] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (4) can be specifically represented as the following relationship (4-1):

[0255] The relevant parameters or column vectors in the above relationship (4-1) can be understood by referring to the description in relationship (3-3), and will not be repeated in this embodiment.

[0256] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (4) can be specifically represented as the following relationship (4-2):

[0257] The relevant parameters or column vectors in the above relationship (4-2) can be understood by referring to the description in relationship (3-4), and will not be repeated in this embodiment.

[0258] In another possible design, when v = 3, N = 3, v 1 ≠v 2 ≠v 3 , For example The value of n can be one of 0, 1, 2, or 3. 1 The relevant design details can be found in Example (1) or Example (2) respectively. 1 It is understood that the embodiments in this application will not be described in detail.

[0259] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (4) can be specifically represented as the following relationship (4-3):

[0260] in, This represents the codebook (or precoding matrix) and p, p when the layer number v is 3. 1 p 2 It is related to n. p indicates the index of the first port out of N ports on a single polarization, p 1 p indicates the index of the second port out of N ports on a single polarization. 2 Indicates the index of the 3rd port out of N ports on a single polarization. n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the aforementioned v 3 The value of . Corresponding to the above and The values ​​of p and p are carried in the PMI information and can be used to determine p, p. 1 p 2 The information indicates the value of p, such as how a terminal device indicates the value of p through first indication information i1 and the value of n through second indication information i2 in the PMI information. Accordingly, the network device can determine the value of p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 p corresponding to the third port 2 .

[0261] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (4) can be specifically represented as the following relationship (4-4):

[0262] in, This represents the codebook (or precoding matrix) and c,a,a when the layer number v is 3. 1 ,a 2 ,b,b 1 ,b 2 The value is related to n. Here, c indicates the index of the port group to which the selected port belongs, a indicates the first index of the first port in the first dimension of a single polarization, and b indicates the second index of the first port in the first dimension of a single polarization; a 1 Indicates the first index of the second port out of N ports in the first dimension on a single polarization, b 1 The second index of the second port out of N ports in a single polarization; a 2 Indicates the first index of the third port out of N ports in the first dimension on a single polarization, b 2 Indicates the second index of the second dimension of the third port out of N ports on a single polarization. n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2The value of , Corresponding to the aforementioned v 3 The value of . Corresponding to the above and The value of .

[0263] The PMI information carries information that can be used to determine c, a, and a. 1 ,a 2 ,b,b 1 ,b 2 The information indicating the value of n.

[0264] For example, in PMI information, network devices indicate the value of n through the second indication information i2, and through the third indication information i 1,1 Indicates that a is mapped to a within port group c. * The value is determined by the fourth indicator information i. 1,2 Indicates that b is mapped within port group c. * The value of c is determined by the fifth instruction information i3, and the value of c is determined by the sixth instruction information i. 1,3 Indicates the values ​​of ε and ζ.

[0265] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε, the second port is mapped to b within port group c. *1 The value of is b *1 =b * +ζ; The third port is mapped to a within port group c. *2 The value of is a *2 =a * +2×ε, the third port is mapped to b within port group c. *2 The value of is b *2 =b * +2×ζ.

[0266] For example, network devices use i2 to indicate the value of n in PMI information, and use i... 1,1 Indicates that a is mapped to a within port group c. * The value of i is determined by i. 1,2 Indicates that b is mapped within port group c. * The value of is determined by i3 indicating the value of c, and by i 1,3,0 Indicator ε 0 and ζ 0 The value of i, and through i 1,3,1 Indicator ε 1 and ζ 1 The value of i. In one possible implementation, i 1,3,0 Including ε0 and ζ 0 The value of i 1,3,1 Including ε 1 and ζ 1 The values ​​of ε and ζ are taken. In another possible implementation, the range of values ​​for ε and ζ is predefined or configured by the network device, as shown in Table 11, where multiple values ​​of (ε, ζ) are given. 1,3,0 The index includes the first value in (ε, ζ) to indicate ε. 0 and ζ 0 The value of is the first value; i 1,3,1 The index includes the second value in (ε, ζ) to indicate ε. 1 and ζ 1 The value is the second value.

[0267] Optionally, (ε) can also be predefined. 0 , ζ 0 ) and (ε 1 , ζ 1 The range of values ​​for ε is shown in Table 12 below, taking the first dimension within the port group as an example where X1 = 8 and X2 = 2. 0 , ζ 0 ) and (ε 1 , ζ 1 Some possible values ​​for ). Network devices only use i in PMI information. 1,3 Indication (ε) 0 , ζ 0 ) and (ε 1 , ζ 1 The index (or composite index) corresponding to ).

[0268] Table 12

[0269] Understandably, Table 12 is only used as (ε) 0 , ζ 0 ) and (ε 1 , ζ 1 Possible values ​​for ε, in practical applications 0 , ζ 0 ) and (ε 1 , ζ 1 The value of ) may include one or more rows in Table 12, or may include other values, which are not limited in this application embodiment.

[0270] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε 0 The second port is mapped to port b within port group c. *1The value of is b *1 =b * +ζ 0 The third port is mapped to port a within port group c. *2 The value of is a *2 =a * +ε 1 The second port is mapped to port b within port group c. *2 The value of is b *2 =b * +ζ 1 .

[0271] For example, the terminal device indicates the value of n in the PMI information through the second indication information i2; through i 1,1,0 The instruction indicates that the 'a' corresponding to the first port is mapped to the 'a' in port group c. * The value of i is determined by i. 1,2,0 The instruction indicates that the b corresponding to the first port is mapped to b in port group c. * The value of i; through i 1,1,1 Indicates the a corresponding to the second port 1 a mapped within port group c *1 The value of i is determined by i. 1,2,1 Indicates the b corresponding to the second port 1 b mapped within port group c *1 The value of i; through i 1,1,2 Indicates the a corresponding to the 3rd port 2 a mapped within port group c *2 The value of i is determined by i. 1,2,2 Indicates the b corresponding to the 3rd port 2 b mapped within port group c *2 The value of ; and the value of c indicated by i3. Accordingly, the network device can determine the value of based on n, a * b * a *1 b *1 a *2 b *2 c, determine the index of the three ports mapped to a single polarization. The specific method can be understood by referring to the previous example. This application embodiment will not elaborate on this.

[0272] Example (4), v = 4, one implementation of relation (1) can be understood by referring to the following relation (5).

[0273] In one possible design, when v = 4, N < 4. Taking N = 2 as an example, v1, v2, v3, and v4 are divided into two groups, each group consisting of two column vectors. The two column vectors within the same group are identical, but the polarization phase coefficients corresponding to the two column vectors within the same group are different. For example, v1 =v 3 , For example The value of n can be one of 0, 1, 2, or 3. 1 and v 3 The relevant design details can be found in Example (1) or Example (2) as described in v. 1 Understanding, v 2 and v 4 The relevant design details can be found in relation (3-3) described by v. p1 Or as described in (3-4) It is understood that the embodiments in this application will not be described in detail.

[0274] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-1):

[0275] The relevant parameters or column vectors in the above relation (5-1) can be understood by referring to the description in relation (3-3), and will not be repeated in this embodiment.

[0276] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-2):

[0277] The relevant parameters or column vectors in the above relationship (5-2) can be understood by referring to the description in relationship (3-4), and will not be repeated in this embodiment.

[0278] Taking v=4 and N=3 as an example, among v1, v2, v3, and v4, only two column vectors are identical, and the polarization phase coefficients corresponding to these two column vectors are different. For example, v 1 =v 4 , v 1 ≠v 2 ≠v 3 ; For example The value of n can be one of 0, 1, 2, or 3. 1 The relevant design details can be found in Example (1) or Example (2) as described in v. 1 It is understood that the embodiments in this application will not be described in detail.

[0279] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-3):

[0280] The relevant parameters or column vectors in the above relationship (5-3) can be understood by referring to the description in relationship (4-3), and will not be repeated in this embodiment.

[0281] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-4):

[0282] The relevant parameters or column vectors in the above relationship (5-4) can be understood by referring to the description in relationship (4-4), and will not be repeated in this embodiment.

[0283] In another possible design, when v = 4, N = 4, for example, v 1 ≠v 2 ≠v 3 ≠v 4 , For example The value of n can be one of 0, 1, 2, or 3. 1 The relevant design details can be found in Example (1) or Example (2) respectively. 1 It is understood that the embodiments in this application will not be described in detail.

[0284] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-5):

[0285] in, This represents the codebook (or precoding matrix) and p,p when the layer number v is 4. 1 ,p 2 ,p 3 The value of p is related to n. p indicates the index of the first port out of N ports on a single polarization. 1 p indicates the index of the second port out of N ports on a single polarization. 2 Indicates the index of the 3rd port out of N ports on a single polarization, p 3 Indicates the index of the 4th port out of N ports on a single polarization. n indicates... In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v p Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the aforementioned v 3 The value of , Corresponding to the aforementioned v 4The value of . Corresponding to the above and The values ​​of p and p are carried in the PMI information and can be used to determine p. 1 ,p 2 ,p 3 The indication information for the value of n, for example, in the PMI information, the terminal device indicates the value of p through the first indication information i1 and the value of n through the second indication information i2. Accordingly, the network device can determine the p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 The third port corresponds to p 2 and the p corresponding to the 4th port 3 .

[0286] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (5) can be specifically represented as the following relationship (5-6):

[0287] in, This represents the codebook (or precoding matrix) and c,a,a when the layer number v is 4. 1 ,a 2 ,a 3 ,b,b 1 ,b 2 ,b 3 The value is related to n. Here, c indicates the index of the port group to which the selected port belongs, a indicates the first index of the first port in the first dimension of a single polarization, and b indicates the second index of the first port in the first dimension of a single polarization; a 1 Indicates the first index of the second port out of N ports in the first dimension on a single polarization, b 1 The second index of the second port out of N ports in a single polarization; a 2 Indicates the first index of the third port out of N ports in the first dimension on a single polarization, b 2 The second index of the second dimension of the third port out of N ports on a single polarization; a 3 Indicates the first index of the fourth port out of N ports in the first dimension on a single polarization, b 3 Indicates the second index of the second dimension of the fourth port out of N ports on a single polarization. n indicates In the context of n, the value of n can be one of 0, 1, 2, or 3. CSI-RS Corresponding to the aforementioned values ​​of M, v a,b Corresponding to the aforementioned v 1 The value of , Corresponding to the aforementioned v 2 The value of , Corresponding to the aforementioned v 3 The value of , Corresponding to the aforementioned v 4 The value of . Corresponding to the above and The value of .

[0288] The PMI information carries information that can be used to determine c, a, and a. 1 ,a 2 ,a 3 ,b,b 1 ,b 2 ,b 3 The information indicating the value of n.

[0289] For example, in PMI information, network devices indicate the value of n through the second indication information i2, and through the third indication information i 1,1 Indicates that a is mapped to a within port group c. * The value is determined by the fourth indicator information i. 1,2 Indicates that b is mapped within port group c. * The value of c is determined by the fifth instruction information i3, and the value of c is determined by the sixth instruction information i. 1,3 Indicates the values ​​of ε and ζ.

[0290] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε, the second port is mapped to b within port group c. *1 The value of is b *1 =b * +ζ; The third port is mapped to a within port group c. *2 The value of is a *2 =a * +2×ε, the third port is mapped to b within port group c. *2 The value of is b *2 =b * +2×ζ; The fourth port is mapped to a within port group c. *3 The value of is a *3 =a * +3×ε, the fourth port is mapped to b within port group c. *3 The value of is b *3 =b * +3×ζ.

[0291] For example, network devices use i2 to indicate the value of n in PMI information, and use i... 1,1Indicates that a is mapped to a within port group c. * The value of i is determined by i. 1,2 Indicates that b is mapped within port group c. * The value of is determined by i3 indicating the value of c, and by i 1,3,0 Indicator ε 0 and ζ 0 The value of i is determined by i. 1,3,1 Indicator ε 1 and ζ 1 The value of , and through i 1,3,2 Indicator ε 2 and ζ 2 The value of i. In one possible implementation, i 1,3,0 Including ε 0 and ζ 0 The value of i 1,3,1 Including ε 1 and ζ 1 The value of i 1,3,2 Including ε 2 and ζ 2 The values ​​of ε and ζ are taken. In another possible implementation, the range of values ​​for ε and ζ is predefined or configured by the network device, as shown in Table 11, where multiple values ​​of (ε, ζ) are given. 1,3,0 The index includes the first value in (ε, ζ) to indicate ε. 0 and ζ 0 The value of is the first value; i 1,3,1 The index includes the second value in (ε, ζ) to indicate ε. 1 and ζ 1 The value of i is the second value; 1,3,1 The index includes the third value in (ε, ζ) to indicate ε. 2 and ζ 2 The value is the third value.

[0292] Optionally, (ε) can also be predefined. 0 , ζ 0 ), (ε 1 , ζ 1 ) and (ε 2 , ζ 2 The range of values ​​for ε is shown in Table 13 below, taking the first dimension within the port group as an example where X1 = 8 and X2 = 2. 0 , ζ 0 ), (ε 1 , ζ 1 ) and (ε 2 , ζ 2 Some possible values ​​for ). Network devices only use i in PMI information. 1,3 Indication (ε) 0 , ζ 0), (ε 1 , ζ 1 ) and (ε 2 , ζ 2 The index (or composite index) corresponding to ).

[0293] Table 13

[0294] Understandably, Table 13 is only used as (ε) 0 , ζ 0 ), (ε 1 , ζ 1 ) and (ε 2 , ζ 2 Possible values ​​for ε, in practical applications 0 , ζ 0 ), (ε 1 , ζ 1 ) and (ε 2 , ζ 2 The value of ) may include one or more rows in Table 13, or may include other values, which are not limited in this embodiment.

[0295] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε 0 The second port is mapped to port b within port group c. *1 The value of is b *1 =b * +ζ 0 The third port is mapped to port a within port group c. *2 The value of is a *2 =a * +ε 1 The third port is mapped to port b within port group c. *2 The value of is b *2 =b * +ζ 1 The fourth port is mapped to port a within port group c. *3 The value of is a *3 =a * +ε 2 The fourth port is mapped to port b within port group c. *3 The value of is b *3 =b * +ζ 2 .

[0296] For example, the terminal device indicates the value of n in the PMI information through the second indication information i2; through i 1,1,0The instruction indicates that the 'a' corresponding to the first port is mapped to the 'a' in port group c. * The value of i is determined by i. 1,2,0 The instruction indicates that the b corresponding to the first port is mapped to b in port group c. * The value of i; through i 1,1,1 Indicates the a corresponding to the second port 1 a mapped within port group c *1 The value of i is determined by i. 1,2,1 Indicates the b corresponding to the second port 1 b mapped within port group c *1 The value of i; through i 1,1,2 Indicates the a corresponding to the 3rd port 2 a mapped within port group c *2 The value of i is determined by i. 1,2,2 Indicates the b corresponding to the 3rd port 2 b mapped within port group c *2 The value of i; through i 1,1,3 Indicates the a corresponding to the 4th port 3 a mapped within port group c *3 The value of i is determined by i. 1,2,3 Indicates the b corresponding to the 4th port 3 b mapped within port group c *3 The value of ; and the value of c indicated by i3. Accordingly, the network device can determine the value of based on n, a * b * a *1 b *1 a *2 b *2 a *3 b *3 c, determine the index of the four ports mapped to a single polarization. The specific method can be understood by referring to the previous example. This application embodiment will not elaborate on this.

[0297] Example (5), v = 5, one implementation of relation (1) can be understood by referring to the following relation (6).

[0298] In one possible design, when v = 5, N < 5. Taking N = 3 as an example, v1, v2, v3, v4, and v5 are divided into three groups. The first two groups each contain two column vectors; the two column vectors within the same group are identical, but their polarization phase coefficients are different. The last group contains one column vector. For example, v 1 =v 4 , v 2 =v 5 , v1 ≠v 2 ≠v 3 ; For example The value of n can be one of 0, 1, 2, or 3. 1 v 4 The relevant design details can be found in Example (1) or Example (2) as described in v. 1 It is understood that the embodiments in this application will not be described in detail.

[0299] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-1):

[0300] The relevant parameters or column vectors in the above relation (6-1) can be understood by referring to the description in relation (4-3), and will not be repeated in this embodiment.

[0301] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-2):

[0302] The relevant parameters or column vectors in the above relationship (6-2) can be understood by referring to the description in relationship (4-4), and will not be repeated in this embodiment.

[0303] Taking N=4 as an example, v1, v2, v3, v4, and v5 have only two identical column vectors, and the polarization phase coefficients corresponding to these two column vectors are different. For example, v 1 =v 5 , v 2 =v 5 , v 1 ≠v 2 ≠v 3 ≠v 4 ; For example The value of n can be one of 0, 1, 2, or 3. 1 v 5 The relevant design details can be found in Example (1) or Example (2) as described in v. 1 It is understood that the embodiments in this application will not be described in detail.

[0304] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-3):

[0305] The relevant parameters or column vectors in the above relationship (6-3) can be understood by referring to the description in relationship (5-5), and will not be repeated in this embodiment.

[0306] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-4):

[0307] The relevant parameters or column vectors in the above relationship (6-4) can be understood by referring to the description in relationship (5-6), and will not be repeated in this embodiment.

[0308] In another possible design, when v = 5, N = 5, for example, v 1 ≠v 2 ≠v 3 ≠v 4 ≠v 5 , For example The value of n can be one of 0, 1, 2, or 3. 1 The relevant design details can be found in Example (1) or Example (2) respectively. 1 It is understood that the embodiments in this application will not be described in detail.

[0309] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-5):

[0310] in, This represents the codebook (or precoding matrix) and p,p when the layer number v is 5. 1 ,p 2 ,p 3 ,p 4 Related to n. Where p, p 1 ,p 2 ,p 3 ,n, P CSI-RS You can refer to the description of relation (5-5) to understand p 4 Indicates the index of the 5th port out of N ports on a single polarization. The PMI information carries information that can be used to determine p,p 1 ,p 2 ,p 3 ,p 4The indication information for the value of n, for example, in the PMI information, the terminal device indicates the value of p through the first indication information i1 and the value of n through the second indication information i2. Accordingly, the network device can determine the p corresponding to the second port among the N ports based on the rule of consecutive N port indices and i1. 1 The third port corresponds to p 2 The fourth port corresponds to p 3 , and p corresponding to the 5th port 4 .

[0311] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (6) can be specifically represented as the following relationship (6-6):

[0312] in, This represents the codebook (or precoding matrix) and c,a,a when the layer number v is 5. 1 ,a 2 ,a 3 ,a 4 ,b,b 1 ,b 2 ,b 3 ,b 4 Related to n. Where c, a, a 1 ,a 2 ,a 3 ,b,b 1 ,b 2 ,b 3 ,n,P CSI-RS You can refer to the description of relationship (5-6) to understand, a 4 Indicates the first index of the 5th port out of N ports in the first dimension on a single polarization, b 4 The second index indicates the second dimension of the 5th port out of N ports on a single polarization.

[0313] The PMI information carries information that can be used to determine c, a, and a. 1 ,a 2 ,a 3 ,a 4 ,b,b 1 ,b 2 ,b 3 ,b 4 The information indicating the value of n.

[0314] For example, in PMI information, network devices indicate the value of n through the second indication information i2, and through the third indication information i 1,1 Indicates that a is mapped to a within port group c. * The value is determined by the fourth indicator information i. 1,2Indicates that b is mapped within port group c. * The value of c is determined by the fifth instruction information i3, and the value of c is determined by the sixth instruction information i. 1,3 Indicates the values ​​of ε and ζ.

[0315] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε, the second port is mapped to b within port group c. *1 The value of is b *1 =b * +ζ; The third port is mapped to a within port group c. *2 The value of is a *2 =a * +2×ε, the second port is mapped to b within port group c. *2 The value of is b *2 =b * +2×ζ; The fourth port is mapped to a within port group c. *3 The value of is a *3 =a * +3×ε, the fourth port is mapped to b within port group c. *3 The value of is b *3 =b * +3×ζ; The 5th port is mapped to a within port group c. *4 The value of is a *4 =a * +4×ε, the 5th port is mapped to b within port group c. *4 The value of is b *4 =b * +4×ζ.

[0316] For example, network devices use i2 to indicate the value of n in PMI information, and use i... 1,1 Indicates that a is mapped to a within port group c. * The value of i is determined by i. 1,2 Indicates that b is mapped within port group c. * The value of is determined by i3 indicating the value of c, and by i 1,3,0 Indicator ε 0 and ζ 0 The value of i is determined by i. 1,3,1 Indicator ε 1 and ζ 1 The value of i is determined by i. 1,3,2 Indicator ε 2 and ζ 2 The value of , and through i 1,3,3 Indicator ε 3 and ζ 3The value of i. In one possible implementation, i 1,3,0 Including ε 0 and ζ 0 The value of i 1,3,1 Including ε 1 and ζ 1 The value of i 1,3,2 Including ε 2 and ζ 2 The value of i 1,3,3 Including ε 3 and ζ 3 The values ​​of ε and ζ are taken. In another possible implementation, the range of values ​​for ε and ζ is predefined or configured by the network device, as shown in Table 11, where multiple values ​​of (ε, ζ) are given. 1,3,0 The index includes the first value in (ε, ζ) to indicate ε. 0 and ζ 0 The value of is the first value; i 1,3,1 The index includes the second value in (ε, ζ) to indicate ε. 1 and ζ 1 The value of i is the second value; 1,3,1 The index includes the third value in (ε, ζ) to indicate ε. 2 and ζ 2 The value of is the third value; i 1,3,2 The index includes the fourth value in (ε, ζ) to indicate ε. 3 and ζ 3 The value is the fourth value.

[0317] Optionally, (ε) can also be predefined. 0 , ζ 0 ), (ε 1 , ζ 1 ), (ε 2 , ζ 2 ) and (ε 3 , ζ 3 The range of values ​​for ε is shown in Table 14 below, taking the first dimension within the port group as an example where X1 = 8 and X2 = 2. 0 , ζ 0 ), (ε 1 , ζ 1 ), (ε 2 , ζ 2 ) and (ε 3 , ζ 3 Some possible values ​​for ). Network devices only use i in PMI information. 1,3 Indication (ε) 0 , ζ 0 ), (ε 1 , ζ 1 ), (ε 2 , ζ2 ) and (ε 3 , ζ 3 The index (or composite index) corresponding to ).

[0318] Table 14

[0319] Understandably, Table 14 is only used as (ε) 0 , ζ 0 ), (ε 1 , ζ 1 ), (ε 2 , ζ 2 ) and (ε 3 , ζ 3 Possible values ​​for ε, in practical applications 0 , ζ 0 ), (ε 1 , ζ 1 ), (ε 2 , ζ 2 ) and (ε 3 , ζ 3 The value of ) may include one or more rows in Table 14, or may include other values, which are not limited in this application embodiment.

[0320] Accordingly, the network device can determine that the second port is mapped to port a within port group c. *1 The value of is a *1 =a * +ε 0 The second port is mapped to port b within port group c. *1 The value of is b *1 =b * +ζ 0 The third port is mapped to port a within port group c. *2 The value of is a *2 =a * +ε 1 The third port is mapped to port b within port group c. *2 The value of is b *2 =b * +ζ 1 The fourth port is mapped to port a within port group c. *3 The value of is a *3 =a * +ε 2 The fourth port is mapped to port b within port group c. *3 The value of is b *3 =b * +ζ 2 The 5th port is mapped to port a within port group c. *4 The value of is a *4=a * +ε 3 The 5th port is mapped to port b within port group c. *4 The value of is b *4 =b * +ζ 3 .

[0321] For example, the terminal device indicates the value of n in the PMI information through the second indication information i2; through i 1,1,0 The instruction indicates that the 'a' corresponding to the first port is mapped to the 'a' in port group c. * The value of i is determined by i. 1,2,0 The instruction indicates that the b corresponding to the first port is mapped to b in port group c. * The value of i; through i 1,1,1 Indicates the a corresponding to the second port 1 a mapped within port group c *1 The value of i is determined by i. 1,2,1 Indicates the b corresponding to the second port 1 b mapped within port group c *1 The value of i; through i 1,1,2 Indicates the a corresponding to the 3rd port 2 a mapped within port group c *2 The value of i is determined by i. 1,2,2 Indicates the b corresponding to the 3rd port 2 b mapped within port group c *2 The value of i; through i 1,1,3 Indicates the a corresponding to the 4th port 3 a mapped within port group c *3 The value of i is determined by i. 1,2,3 Indicates the b corresponding to the 4th port 3 b mapped within port group c *3 The value of i; through i 1,1,4 Indicates the a corresponding to the 5th port 4 a mapped within port group c *4 The value of i is determined by i. 1,2,4 Indicates the b corresponding to the 5th port 4 b mapped within port group c *4 The value of ; and the value of c indicated by i3. Accordingly, the network device can determine the value of based on n, a * b * a *1 b *1 a *2 b *2 a *3 b *3 a *4 b *4c, determine the index of the five ports mapped to a single polarization. The specific method can be understood by referring to the example above. This application will not elaborate on this in the embodiment.

[0322] Example (6), v = 6, one implementation of relation (1) can be understood by referring to the following relation (7).

[0323] In the first possible design, N < 6. Taking N = 3 as an example, v1 to v6 are divided into three groups. Each group includes two column vectors. The two column vectors within the same group are identical, but the polarization phase coefficients corresponding to the two column vectors within the same group are different. For example, v 1 =v 4 v 2 =v 5 v 3 =v 6 ,

[0324] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (7) can be specifically represented as the following relationship (7-1):

[0325] The relevant parameters or column vectors in the above relationship (7-1) can be understood by referring to the description in relationship (4-3), and will not be repeated in this embodiment.

[0326] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (7) can be specifically represented as the following relationship (7-2):

[0327] The relevant parameters or column vectors in the above relationship (7-2) can be understood by referring to the description in relationship (4-4), and will not be repeated in this embodiment.

[0328] In the second possible design, N < 6; taking N = 4 as an example, v 1 =v 5 v 2 =v 6 ,

[0329] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (7) can be specifically represented as the following relationship (7-3):

[0330] The relevant parameters or column vectors in the above relationship (7-3) can be understood by referring to the description in relationship (5-5), and will not be repeated in this embodiment.

[0331] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (7) can be specifically represented as the following relationship (7-4):

[0332] The relevant parameters or column vectors in the above relationship (7-4) can be understood by referring to the description in relationship (5-6), and will not be repeated in this embodiment.

[0333] Similarly, when v = 6, N = 5, and among v1 to v6, only two column vectors are identical, and the polarization phase coefficients corresponding to these two column vectors are different. For example, v 1 =v 6 , The corresponding formulas can be further understood by referring to the foregoing examples; this application will not elaborate on them in the embodiments. When v = 6, v1 to v6 are all different. The corresponding formulas can be further understood by referring to the foregoing examples, and will not be elaborated upon in the embodiments of this application.

[0334] Example (7), v = 7, one implementation of relation (1) can be understood by referring to relation (8) below.

[0335] In the first possible design, N < 7. Taking N = 4 as an example, v1 to v7 are divided into four groups. The first three groups each include two column vectors. The two column vectors within the same group are identical, but the polarization phase coefficients corresponding to the two column vectors within the same group are different. The last group includes one column vector. For example, v 1 =v 5 v 2 =v 6 v 3 =v 7 ,

[0336] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (8) can be specifically represented as the following relationship (8-1):

[0337] The relevant parameters or column vectors in the above relation (8-1) can be understood by referring to the description in relation (5-5), and will not be repeated in this embodiment.

[0338] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (8) can be specifically represented as the following relationship (8-2):

[0339] The relevant parameters or column vectors in the above relationship (8-2) can be understood by referring to the description in relationship (5-6), and will not be repeated in this embodiment.

[0340] Similarly, when v=7 and N=5, v1 to v7 are divided into five groups. The first two groups each contain two column vectors; the two column vectors within the same group are identical, but their corresponding polarization phase coefficients are different. The remaining three groups each contain one column vector. For example, v 1 =v 6 v 2 =v 7 v 1 ≠v 2 ≠v 3 ≠v 4 ≠v 5 , The corresponding formulas can be further understood by referring to the foregoing examples; this application will not elaborate on them further. When v = 7 and N = 6, only two column vectors among v1 to v7 are identical, and the polarization phase coefficients corresponding to these two column vectors are different. For example, v 1 =v 7 v 1 ≠v 2 ≠v 3 ≠v 4 ≠v 5 ≠v 6 , The corresponding formulas can be further understood by referring to the foregoing examples; this application's embodiments will not elaborate on them. When v=7 and N=7, v1 to v7 are all different. The corresponding formulas can be further understood by referring to the foregoing examples, and will not be elaborated upon in the embodiments of this application.

[0341] Example (8), v = 8, one implementation of relation (1) can be understood by referring to the following relation (9).

[0342] In the first possible design, N < 8. Taking N = 4 as an example, v1 to v7 are divided into four groups. Each group includes two column vectors. The two column vectors within the same group are identical, but the polarization phase coefficients corresponding to the two column vectors within the same group are different. For example, v 1 =v 5 v 2 =v 6 v 3 =v 7 v 4 =v 8 ,

[0343] When the PMI information uses a one-dimensional index to indicate N ports, the above relationship (9) can be specifically represented as the following relationship (9-1):

[0344] The relevant parameters or column vectors in the above relation (9-1) can be understood by referring to the description in relation (5-5), and will not be repeated in this embodiment.

[0345] When the PMI information uses a two-dimensional index to indicate N ports, the above relationship (9) can be specifically represented as the following relationship (9-2):

[0346] The relevant parameters or column vectors in the above relation (9-2) can be understood by referring to the description in relation (5-6), and will not be repeated in this embodiment.

[0347] Similarly, when v=8 and N=5, v1 to v8 are divided into five groups. The first three groups each contain two column vectors; the two column vectors within the same group are identical, but their polarization phase coefficients are different. The remaining two groups each contain one column vector. For example, v 1 =v 6 v 2 =v 7 v 3 =v 8 v 1 ≠v 2 ≠v 3 ≠v 4 ≠v 5 , The corresponding formulas can be further understood by referring to the foregoing examples, and will not be elaborated upon in this embodiment. When v=8 and N=6, v1 to v8 are divided into six groups. The first two groups each include two column vectors. The two column vectors within the same group are identical, and the polarization phase coefficients corresponding to the two column vectors within the same group are different. The remaining two groups each include one column vector. For example, v 1 =v 7 v 2 =v 8 v 1 ≠v 2 ≠v 3 ≠v 4 ≠v 5 ≠v 6 , The corresponding formulas can be further understood by referring to the foregoing examples; this application will not elaborate on them further. When v = 8 and N = 7, only two column vectors among v1 to v8 are identical, and the polarization phase coefficients corresponding to these two column vectors are different. For example, v 1 =v 8 v 1 ≠v 2 ≠v 3 ≠v4 ≠v 5 ≠v 6 ≠v 7 , The corresponding formulas can be further understood by referring to the foregoing examples; this application's embodiments will not elaborate on them. When v=8 and N=8, v1 to v7 are all different. The corresponding formulas can be further understood by referring to the foregoing examples, and will not be elaborated upon in the embodiments of this application.

[0348] When applying the methods provided in the embodiments of this application, some or all of the steps can be executed, or they can be combined with other schemes or steps. The embodiments of this application do not limit this.

[0349] Based on the same technical concept, as illustrated in Figure 12, this application embodiment also provides a communication device 1200. For example, the communication device 1200 may be a chip or a chip system. Optionally, in this application embodiment, the chip system may be composed of chips, or may include chips and other discrete devices.

[0350] The communication device 1200 can be used to implement the function of any network element in the communication system described in the foregoing examples. The communication device 1200 may include at least one processor 1210. Optionally, the processor 1210 is coupled to a memory, which may be located within the device; or the memory may be integrated with the processor; or the memory may be located outside the device. For example, the communication device 1200 may also include at least one memory 1220. The memory 1220 stores the computer programs, computer programs or instructions, and / or data necessary for implementing any of the above examples; the processor 1210 may execute the computer programs or instructions stored in the memory 1220 to complete the methods in any of the above examples.

[0351] The communication device 1200 may also include a communication interface 1230, through which the communication device 1200 can interact with other devices. For example, the communication interface 1230 may be a transceiver, circuit, bus, module, pin, or other type of communication interface. When the communication device 1200 is a chip-based device or circuit, the communication interface 1230 may also be an input / output circuit, capable of inputting information (or receiving information) and outputting information (or sending information). The processor may be an integrated processor, microprocessor, integrated circuit, or logic circuit, and the processor can determine the output information based on the input information.

[0352] The coupling in this embodiment is an indirect coupling or communication connection between devices, units, or modules, which can be electrical, mechanical, or other forms, used for information exchange between devices, units, or modules. The processor 1210 may operate in conjunction with the memory 1220 and the communication interface 1230. This embodiment does not limit the specific connection medium between the processor 1210, the memory 1220, and the communication interface 1230.

[0353] Optionally, referring to Figure 12, the processor 1210, the memory 1220, and the communication interface 1230 are interconnected via a bus 1240. The bus 1240 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 ease of illustration, only one thick line is used in Figure 12, but this does not indicate that there is only one bus or one type of bus.

[0354] In the embodiments of this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams of the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0355] In the embodiments of this application, the memory can be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it can be volatile memory, such as random-access memory (RAM). Memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures, and accessible by a computer, but is not limited thereto. The memory in the embodiments of this application can also be a circuit or any other device capable of implementing storage functions, used to store program instructions and / or data.

[0356] In one possible implementation, the communication device 1200 can be applied to a terminal device. Specifically, the communication device 1200 can be a terminal device or a device capable of supporting the terminal device and implementing the functions of the terminal device in any of the examples mentioned above. The memory 1220 stores computer programs (or instructions) and / or data that implement the functions of the terminal device in any of the examples mentioned above. The processor 1210 can execute the computer programs or instructions stored in the memory 1220 to complete the methods executed by the terminal device in any of the examples mentioned above. When the communication device is applied to a terminal device, the communication interface in the communication device 1200 can be used to interact with network devices, sending information to or receiving information from network devices.

[0357] In another possible implementation, the communication device 1200 can be applied to a network device. Specifically, the communication device 1200 can be a network device or a device capable of supporting a network device and implementing the functions of the network device in any of the examples mentioned above. The memory 1220 stores computer programs (or instructions) and / or data that implement the functions of the network device in any of the examples mentioned above. The processor 1210 can execute the computer programs or instructions stored in the memory 1220 to complete the methods performed by the network device in any of the examples mentioned above. When the communication device is applied to a network device, the communication interface in the communication device 1200 can be used to interact with a terminal device, sending information to the terminal device or receiving information from the terminal device.

[0358] Since the communication device 1200 provided in this example can be applied to a network device to complete the method executed on the network device side, or applied to a terminal device to complete the method executed on the terminal device side, the technical effects it can achieve can be referred to the above method example, and will not be repeated here.

[0359] Based on the same technical concept, as illustrated in Figure 13, this application also provides a communication device 1000. This communication device 1000 can be applied to terminal devices or network devices, and can be used to implement the method shown in the embodiment of Figure 5. The device 1000 logically includes multiple parts, such as a processor 1001, a memory 1002, and a signal transceiver unit 1003. The memory 1002 can be used to store computer programs (also called code or instructions). The signal transceiver unit 1003 is used to implement communication and signaling interaction between the network device and the terminal device, signal amplification, etc. The signal transceiver unit 1003 includes a transmitter 10031, a receiver 10032, and an antenna 10033. In the antenna 10033, a box represents a digital channel, F in the box is the digital precoding weight, and a phase shifter (circle with a slanted arrow) represents an analog channel, connecting one or more arrays. That is, in practice, one phase shifter can control multiple arrays, or the phase shifter and arrays can be cross-connected.

[0360] When this communication device is used in a terminal device, the processor is mainly used to process communication protocols and data, control the terminal device, execute software programs, and process data from those programs. The memory is mainly used to store software programs and data. The signal transceiver unit is mainly used for converting baseband signals to radio frequency signals and processing radio frequency signals. The antenna is mainly used for transmitting and receiving radio frequency signals in the form of electromagnetic waves.

[0361] When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs a baseband signal to the signal transceiver unit. The signal transceiver unit then performs radio frequency (RF) processing on the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the signal transceiver unit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal back into data and processes the data. For ease of explanation, Figure 13 only shows one memory, processor, and transceiver. In actual terminal device products, there may be one or more processors and one or more memories. The memory can also be called a storage medium or storage device, etc. The memory can be set up independently of the processor or integrated with the processor; this application embodiment does not limit this.

[0362] Optionally, a processor can also be called a processing unit, processing board, processing module, processing device, etc.; a signal transceiver unit can also be called a transceiver, transceiver, transceiver device, transceiver circuit, transceiver module, etc. A transmitter can sometimes be called a transmitter module or transmitting circuit, etc. A receiver can sometimes be called a receiver module or receiving circuit, etc.

[0363] This application also provides a communication system, which includes the terminal device and network device described in the above embodiments. The terminal device is used to perform all or part of the steps in the embodiments shown in FIG. 5. The network device is used to perform all or part of the steps in the embodiments shown in FIG. 5.

[0364] The technical solutions provided in this application can be implemented, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a terminal device, a network device, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media, etc.

[0365] In the embodiments of this application, examples can be referenced to each other without logical contradictions. For example, methods and / or terms between method embodiments can be referenced to each other, functions and / or terms between device embodiments can be referenced to each other, and functions and / or terms between device examples and method examples can be referenced to each other.

[0366] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of the embodiments of this application and their equivalents, the embodiments of this application are also intended to include these modifications and variations.

Claims

1. A communication method, characterized in that, Applied to terminal devices, including: Receive first configuration information, which is used to configure reference signal resources corresponding to M ports, where M is a positive integer; The PMI information, which is determined based on the channel measurement results of the reference signal resource, is sent to indicate the indices of N ports on the first polarization out of the M ports, where N is a positive integer. The PMI information is used to determine the precoding matrix corresponding to the 2N ports.

2. A communication method, characterized in that, Applied to network devices, including: Send first configuration information, which is used to configure reference signal resources corresponding to M ports, where M is a positive integer; The system receives precoding matrix indication (PMI) information, which is determined based on channel measurement results of the reference signal resource. The PMI information indicates the indices of N ports on the first polarization out of the M ports, where N is a positive integer. The PMI information is used to determine the precoding matrix corresponding to the 2N ports.

3. The method as described in claim 1 or 2, characterized in that, The PMI information includes the index of each of the N ports.

4. The method as described in claim 1 or 2, characterized in that, The indices of the N ports are consecutive, and the PMI information includes the index of the first port among the N ports, or the PMI information includes the index of the last port among the N ports.

5. The method as described in claim 1 or 2, characterized in that, The first configuration information further includes a first parameter X1 and / or a second parameter X2. The first parameter X1 indicates the number of ports in each of the K port groups in the first dimension, and the second parameter X2 indicates the number of ports in each of the K port groups in the second dimension. The K port groups are determined based on all ports of the M ports in the first polarization, the first parameter X1 and / or the second parameter X2, where K is a positive integer less than M, X1 is a positive integer, and X2 is a positive integer.

6. The method as described in claim 5, characterized in that, The PMI information includes the index of one of the K port groups, and the index of each of the N ports in the port group. The index of one of the N ports includes a first index of the port in a first dimension and a second index of the port in a second dimension. The first index is an integer less than or equal to X1, and the second index is an integer less than or equal to X2.

7. The method as described in claim 5, characterized in that, The PMI information includes the index of one port group among the K port groups, the first index of the first port in the first dimension and the second index in the second dimension of the N ports in the port group, the first index offset of every two ports in the first dimension, and the second index offset of every two ports in the second dimension; wherein the value of the first index is an integer less than or equal to X1, and the value of the second index is an integer less than or equal to X2.

8. The method according to any one of claims 1-7, characterized in that, The value of N is determined based on the number of layers corresponding to the precoding matrix.

9. The method according to any one of claims 1-8, characterized in that, The precoding matrix corresponds to a layer number of 4, and the value of N is less than or equal to 4. The precoding matrix W (4) The following relationship must be satisfied: Wherein, the v 1 The v 2 The v 3 and the v 4 Each indicates a column vector determined based on the index of one of the N ports; The The Japanese Based on Definitely. The value of n is either 0 or 1.

10. The method as described in claim 9, characterized in that, The N is 2, the v 1 With the v 3 Similarly, the v 2 With the v 4 The same, the With the For the The With the for 11. The method as described in claim 9 or 10, characterized in that, The PMI information also indicates the value of n.

12. A communication device, characterized in that, Includes modules for performing the method as described in any one of claims 1 and 3-11.

13. A communication device, characterized in that, Includes a module for performing the method as described in any one of claims 2-11.

14. A communication system, characterized in that, It includes a communication device for performing the method as described in any one of claims 1 and 3-11, and a communication device for performing the method as described in any one of claims 2-11.

15. A communication device, characterized in that, include: A processor coupled to a memory, the processor being configured to invoke a computer program or instructions in the memory to perform the method as described in any one of claims 1-11.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-11.

17. A computer program product, characterized in that, It includes a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-11.

Images