Precoding matrix indication method and related apparatus

Abstract

Disclosed in the embodiments of the present application are a precoding matrix indication method and a related apparatus. The method comprises: by means of using first information and second information, a terminal device feeds back to a network device a plurality of beam sets and a plurality of beams in the plurality of beam sets, so as to ensure that the plurality of beams indicated by the terminal device precisely correspond to a plurality of wireless propagation paths between the terminal device and the network device, thereby effectively improving precision of a precoding matrix indicator. While keeping communication overhead occupied by the precoding matrix indicator unchanged, the present application improves matching precision between beams indicated by precoding matrix indicators and wireless propagation paths in actual communication environments, thereby effectively improving communication quality between terminal devices and network devices.

Description

A precoding matrix indication method and related apparatus

[0001] This application claims priority to Chinese Patent Application No. CN202510041838.3, filed with the State Intellectual Property Office of China on January 9, 2025, entitled "A Precoding Matrix Indication Method and Related Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

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

[0003] In communication systems, communication devices transmit data by transmitting wireless signals. Taking the transmission of data from a network device to a terminal device as an example, the network device performs beamforming on the data stream to enhance the directionality of the wireless signal carrying the data stream, thereby improving the terminal device's ability to receive the wireless signal and increasing the spectral efficiency and data throughput of the communication system. There may be multiple wireless propagation paths from the network device to the terminal device. To ensure that the wireless signal transmitted by the network device can be accurately focused on the location of the terminal device, the terminal device needs to feed back a precoding matrix indicator (PMI) to the network device. This allows the network device to determine the corresponding beam base based on the PMI. The beam base corresponds to a specific spatial direction; in other words, the beam base determines the shape and direction of the beam, which the network device can use for beamforming. The beam base can also be called the spatial basis or the beam.

[0004] Taking the example of multiple wireless propagation paths between network devices and terminal devices, each transmission path has a directional angle or path angle relative to the network device. In order for the precoding matrix to accurately correspond to the wireless propagation path, the number of beams included in the precoding matrix needs to be equal to the number of wireless propagation paths, and the direction of the beams needs to correspond to the path angle of the wireless propagation path.

[0005] Because the beams in orthogonal beam groups are not orthogonal, energy leakage exists between multiple beams in different orthogonal beam groups. If the multiple beams that the terminal device needs to feed back are not in the same beam group, the terminal device can only feed back multiple beams from the beam group with the least energy loss. Since the multiple beams that the terminal device needs to feed back are not completely consistent with the multiple beams that the terminal device actually feeds back, the precoding matrix determined by the network device based on the multiple beams fed back by the terminal device does not completely correspond to the wireless propagation path between the network device and the terminal device. When the network device sends wireless signals to the terminal device based on this precoding matrix, it will affect the communication quality of the wireless signal, reduce the spectral efficiency and data throughput of the communication system.

[0006] In summary, current terminal devices suffer from low feedback accuracy of the feedback beam. Summary of the Invention

[0007] This application discloses a precoding matrix indication method, which can improve the beam accuracy fed back by the precoding matrix indication while keeping the communication overhead occupied by the precoding matrix indication unchanged, thereby effectively improving the communication quality between the terminal device and the network device.

[0008] In a first aspect, embodiments of this application propose a precoding matrix indication method, which is applied to a first communication device.

[0009] The first communication device is applied to the terminal side, such as a terminal or a communication module within a terminal, or a circuit or chip (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) within a terminal responsible for communication functions. For example, the first communication device can be a terminal device, a device or apparatus with a chip, or a device or apparatus with integrated circuits, or a chip, chip system, functional module, control unit, circuit, processor, or integrated circuit that can be applied to the aforementioned device or apparatus; specific applications are not limited in this application.

[0010] The method includes: receiving a reference signal; determining a precoding matrix indicator (PMI) based on the reference signal, wherein the PMI includes first information and second information, wherein the first information indicates G beam sets, where G is an integer greater than 1, any one of the G beam sets includes multiple mutually orthogonal beams, and the second information indicates L beams in the G beam sets, where L beams are used to determine the precoding matrix, and L is an integer greater than 1; and transmitting the PMI.

[0011] In one possible implementation, the second information indicates L beams in a set of G beams, including: the second information indicates L beams that belong to a set of G beams.

[0012] In one possible implementation, the L beams belong to a set of G beams, including: the L beams belong to at least one of the sets of G beams.

[0013] In another possible implementation, the L beams belong to a set of G beams, including: the L beams belong to at least two of the G beam sets.

[0014] It should be noted that the beam set in the embodiments of this application refers to an orthogonal beam set or an oversampled frequency domain discrete Fourier transform (DFT) beam set.

[0015] Optionally, the second information indicating L beams in the G beam sets can be replaced with: the second information indicating that each beam set in the G beam sets includes L beams. In this case, the PMI fed back by the first communication device indicates a total of G×L beams. Optionally, the fourth information received by the first communication device is used to configure the number of beams to be fed back by the first communication device to be G×L, or the fourth information is used to configure the number of beams to be fed back in each of the G beam sets to be fed back by the first communication device to be L. G×L means G multiplied by L.

[0016] It is understood that the first information and the second information can also be carried in different signaling, and the embodiments of this application do not limit this.

[0017] In the above technical solution, the first communication device uses first information and second information to feed back multiple beam sets and multiple beams within those beam sets to the second communication device. This ensures that the L beams indicated by the first communication device accurately correspond to the L wireless propagation paths between the first and second communication devices, effectively improving the accuracy of the precoding matrix indication. While maintaining the communication overhead of the precoding matrix indication unchanged, the matching accuracy between the beams indicated by the precoding matrix and the wireless propagation paths in the actual communication environment can be improved, effectively enhancing the communication quality between the first and second communication devices.

[0018] In conjunction with the first aspect, in one possible implementation of the first aspect, the first communication device determines the precoding matrix indication (PMI) based on a reference signal, including: First, the first communication device performs channel measurement based on the reference signal to determine channel state information. Then, the first communication device determines L beams based on the channel state information. For example, the first communication device determines L wireless transmission paths of the channel between the first communication device and the second communication device based on the channel state information. Based on the path angles corresponding to the L wireless transmission paths, the first communication device finds L beams in a set of X beams that can characterize the L wireless transmission paths. The beam directions of the L beams need to correspond to the path angles of the L wireless transmission paths, where X is an integer greater than or equal to G, and X is less than or equal to O1O2, where O1 is the oversampling factor of the antenna port of the first communication device in the horizontal dimension, and O2 is the oversampling factor of the antenna port of the first communication device in the vertical dimension. Finally, the first communication device determines first information included in the precoding matrix indication based on the set of G beams containing the L beams, and the first communication device determines second information included in the precoding matrix indication based on the L beams.

[0019] It should be noted that in the embodiments of this application, O1O2 refers to O1 multiplied by O2, or O1×O2; similarly, N1N2 refers to N1 multiplied by N2, or N1×N2.

[0020] In one example, the first communication device employs a first algorithm to determine G beam sets from X beam sets, where X is an integer greater than or equal to G. The first algorithm includes any one of the following: least absolute shrinkage and selection operator (Lasso), orthogonal matching pursuit (OMP), iterative soft thresholding algorithm (ISTA), or approximate message passing (AMP).

[0021] In conjunction with the first aspect, in one possible implementation of the first aspect, the method further includes: the first communication device receiving third information from the second communication device, the third information being used to configure the number G of beam sets to be fed back by the first communication device.

[0022] In the above technical solution, the number G of beam sets that the first communication device needs to feed back is configured by the second communication device. It is understood that the number G of beam sets can also be pre-configured in the first communication device or predefined by the protocol, and this application embodiment does not limit this.

[0023] In one possible implementation, the third information is carried within configuration information, which is used to configure the resources of the reference signal.

[0024] For example, the third information is carried in the configuration information, including the Radio Resource Control Report (RRC) reportconfig information.

[0025] In conjunction with the first aspect, in one possible implementation of the first aspect, the method further includes: the first communication device receiving fourth information from the second communication device, the fourth information being used to configure the number L of beams to be fed back by the first communication device.

[0026] In conjunction with the first aspect, in one possible implementation of the first aspect, the method further includes: the first communication device receiving fourth information from the second communication device, the fourth information being used to configure the number L of beams L to be fed back from the g-th beam set among the G beam sets to be fed back by the first communication device. g Wherein, the number of beams requiring feedback in the g-th beam set out of the G beam sets is L. g , g∈{1,···,G}, L g L is an integer greater than or equal to 0. g The relationship between L and L satisfies:

[0027] In other words, the fourth information is used to configure the number of beams that need to be fed back for each of the G beam sets to be fed back by the first communication device.

[0028] In one example, the fourth information is used to configure the number of beams to be fed back in each of the three beam sets to be fed back by the first communication device to be 3, that is, the fourth information is used to configure the number of beams to be fed back by the first communication device to be 9.

[0029] In another example, the fourth information is used to configure the number of beams that need to be fed back in the first beam set of the three beam sets to be fed back by the first communication device to be 3, the number of beams that need to be fed back in the second beam set of the three beam sets to be 2, and the number of beams that need to be fed back in the third beam set of the three beam sets to be 1.

[0030] It is understood that the number of beams that need to be fed back in each of the L or G beam sets can also be pre-configured in the first communication device or predefined by the protocol, and this application embodiment does not limit this.

[0031] In one possible implementation, the fourth piece of information is the numberOfBeams parameter information, which is carried in the configuration information and used to configure the resources of the reference signal.

[0032] In conjunction with the first aspect, in one possible implementation of the first aspect, the first information belongs to the parameter i included in the PMI. 1,1 , where parameter i 1,1 This is used to indicate the set of beams where the L beams fed back by the first communication device are located.

[0033] In conjunction with the first aspect, in one possible implementation of the first aspect, the first information includes: [q 1,1 ,q 1,2 ,···,q g,1 ,q g,2 ,···,q G,1 ,q G,2 ], where parameter q g,1 and parameter q g,2 Indicates the g-th beam set in a set of G beam sets, with parameter q g,1 ∈{0,1,…,O1-1}, parameter q g,2 ∈{0,1,…,O2-1}, where O1 is the oversampling factor of the antenna port of the first communication device in the horizontal dimension, and O2 is the oversampling factor of the antenna port of the first communication device in the vertical dimension.

[0034] In conjunction with the first aspect, in one possible implementation of the first aspect, the second information belongs to parameter i. 1,2 , parameter i 1,2 Used to indicate the position of L beams within the beam set containing L beams.

[0035] In conjunction with the first aspect, in one possible implementation of the first aspect, the second information includes: [i 1,2,1 ,…,i 1,2,g ,…,i 1,2,G ], where parameter i 1,2,g Indicates the beam to be fed back from the g-th beam set in a set of G beam sets. L g Let N1 be the number of beams to be fed back in the g-th beam set out of G beam sets, N2 be the number of horizontal ports in the reference signal port group, and g ∈ {1, ..., G}. The reference signal port group corresponds to the reference signal.

[0036] Here, the reference signal port group corresponds to the reference signal, specifically referring to the first communication device receiving and measuring the reference signal according to the reference signal port group. If the reference signal is CSI-RS, then the reference signal port group corresponding to the reference signal is the CSI-RS port group.

[0037] Furthermore, the relationship between the reference signal port group and the beam set is as follows: The terminal device receives the corresponding CSI-RS based on the CSI-RS port group and measures the channel information. Then, based on this channel information, it determines the L beams that need to be fed back and the beam set in which these L beams belong. Since the number of horizontal ports in the CSI-RS port group is N1 and the number of vertical ports in the CSI-RS port group is N2, the horizontal dimension of the CSI-RS port group and the beam set are the same, and the vertical dimension of the CSI-RS port group is the same. The number of beams included in a beam set can also be understood as the number of ports included in a CSI-RS port group (P). CSI-RS That is, N1N2=P CSI-RS Therefore, the reference signal port group can also be referred to as the beam set.

[0038] In conjunction with the first aspect, in one possible implementation of the first aspect, the second information indicates L vectors, and the L vectors correspond to L beams.

[0039] In one example, the L vectors are L vectors combined from a codebook.

[0040] Secondly, embodiments of this application propose a precoding matrix indication method, which is applied to a second communication device.

[0041] The second communication device may be a network device, a device or apparatus with a chip, a device or apparatus with integrated circuits, or a chip, chip system, module, control unit, circuit, or processor applicable to the aforementioned device or apparatus, or at least one of a central unit (CU) or a distributed unit (DU), the specific of which is not limited in this application.

[0042] The method includes: transmitting a reference signal; receiving a precoding matrix indication (PMI) corresponding to the reference signal, wherein the PMI includes first information and second information, the first information indicating G beam sets, where G is an integer greater than 1, any one of the G beam sets includes multiple mutually orthogonal beams, the second information indicating L beams in the G beam sets, the L beams being used to determine the precoding matrix, where L is an integer greater than 1; determining the precoding matrix based on the PMI, the precoding matrix being used for precoding processing of data transmitted from the second communication device to the first communication device.

[0043] In one example, using a Type II codebook, any column of the precoding matrix used by the second communication device can be represented as:

[0044] In this application, the first row within the brackets "[]" corresponds to the precoding vector for the first polarization direction, and the second row within the brackets "[]" corresponds to the precoding vector for the second polarization direction. It should be understood that the polarization direction in this application refers to the direction of the electric field vector of the electromagnetic wave radiated by the antenna in space. β is the power adjustment coefficient. The amplitude coefficient, This represents the phase coefficient at the antenna port. Let be the i-th spatial basis (or the i-th vector), i∈{0,1,...,L-1}. The L vectors (i.e., the L spatial basis) formed by the codebook combination in the above formula can be determined based on the parameters (indices) included in the PMI. In other words, the second communication device determines L beams based on the first and second information included in the PMI. Then, the second communication device determines the corresponding L vectors based on these L beams. Finally, the second communication device determines the corresponding precoding matrix based on these L vectors.

[0045] In the above technical solution, the first communication device uses first information and second information to feed back multiple beam sets and multiple beams within those beam sets to the second communication device. This ensures that the L beams indicated by the first communication device accurately correspond to the L wireless propagation paths between the first and second communication devices, effectively improving the accuracy of the precoding matrix indication. While maintaining the communication overhead of the precoding matrix indication unchanged, the matching accuracy between the beams indicated by the precoding matrix and the wireless propagation paths in the actual communication environment can be improved, effectively enhancing the communication quality between the first and second communication devices.

[0046] The second aspect provides some possible implementation methods and beneficial effects that can be referred to in the first aspect, and will not be repeated here.

[0047] Thirdly, embodiments of this application propose a communication system, comprising: a first communication device and a second communication device. The communication system includes: the second communication device transmitting a reference signal to the first communication device; the first communication device receiving the reference signal; the first communication device performing channel measurement based on the reference signal to determine first information and second information, wherein the first information indicates G beam sets, where G is an integer greater than 1, and any one of the G beam sets includes multiple mutually orthogonal beams; the second information indicates L beams in the G beam sets, where L is an integer greater than 1, and the L beams are used to determine a precoding matrix; the first communication device transmitting the PMI to the second communication device; the second communication device determining the precoding matrix based on the PMI; and the second communication device transmitting data to the first communication device, the data being precoded by the precoding matrix.

[0048] In conjunction with the third aspect, in one possible implementation of the third aspect, the communication system performs the methods shown in the first and / or second aspects described above, which will not be elaborated here.

[0049] Fourthly, this application provides a communication device, which is a first communication device. The device includes a transceiver module and a processing module. The components of the communication device can also be used to execute the steps performed in various possible implementations of the first aspect and achieve the corresponding technical effects. For details, please refer to the first aspect, which will not be repeated here.

[0050] Fifthly, this application provides a communication device, which is a second communication device. The communication device includes a transceiver module and a processing module. The constituent modules of the communication device can also be used to execute the steps performed in various possible implementations of the second aspect and achieve the corresponding technical effects. For details, please refer to the second aspect, which will not be repeated here.

[0051] Sixthly, this application provides a communication device comprising one or more processors. The one or more processors are capable of executing the computer program or instructions, which, when executed, cause the communication device to implement the methods in any possible design or implementation of the first aspect described above.

[0052] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0053] In one possible design, the communication device may further include a memory. The memory is used to store part or all of the computer programs or instructions necessary to implement the functions described in the first aspect above.

[0054] The aforementioned communication device may be a terminal, or a communication module in a terminal, or a chip in a terminal that is responsible for communication functions, such as a modem chip (also known as a baseband chip), or a system-on-a-chip (SoC) containing a modem module, or a chip or a system-in-package (SIP) chip.

[0055] In a seventh aspect, this application provides a communication device including at least one logic circuit and an input / output interface; the logic circuit is configured to perform the method described in any possible implementation of any of the preceding first aspects.

[0056] In an eighth aspect, this application provides a communication device comprising one or more processors. The one or more processors are capable of executing the computer program or instructions, which, when executed, cause the communication device to implement the methods in any possible design or implementation of the second aspect described above.

[0057] In one possible design, the communication device may further include an interface circuit, through which the processor communicates with other devices or components.

[0058] In one possible design, the communication device may further include a memory. The memory is used to store part or all of the computer programs or instructions necessary to implement the functions described in the second aspect above.

[0059] In a ninth aspect, this application provides a communication device including at least one logic circuit and an input / output interface; the logic circuit is configured to perform the method described in any possible implementation of any of the preceding second aspects.

[0060] In a tenth aspect, this application provides a communication system that includes the aforementioned network equipment and / or terminal equipment.

[0061] Eleventhly, this application provides a computer-readable storage medium for storing a computer program or instructions that, when executed by a processor, perform the method as described in any possible implementation of the first and / or second aspects above.

[0062] In a twelfth aspect, this application provides a computer program product (or computer program) that, when executed by a processor, allows the processor to perform the method described in any possible implementation of either the first aspect or the second aspect.

[0063] In a thirteenth aspect, this application provides a chip or chip system including at least one processor for supporting a communication device in implementing the method described in any possible implementation of any of the first and / or second aspects described above.

[0064] In one possible design, the chip or chip system may further include a memory for storing program instructions and data necessary for the communication device. The chip system may be composed of chips or may include chips and other discrete devices. Optionally, the chip system may also include interface circuitry that provides program instructions and / or data to the at least one processor.

[0065] The technical effects of any of the design methods in aspects three through thirteen can be found in the technical effects of the different design methods in aspects one through two above, and will not be repeated here. Attached Figure Description

[0066] Figure 1 is a schematic diagram of the architecture of the communication system 100 used in the embodiments of this application;

[0067] Figure 2 is a schematic diagram of measuring the downlink channel;

[0068] Figure 3 is a schematic diagram of a spatial basis combination;

[0069] Figure 4 is a schematic diagram of the spatial basis combination;

[0070] Figure 5 is a schematic diagram of multiple beam sets supported by the terminal device;

[0071] Figure 6 is a schematic diagram of beam feedback of the terminal device in an embodiment of this application;

[0072] Figure 7a is a stem-and-leaf diagram of different beam sets in the embodiments of this application;

[0073] Figures 7b and 7d are schematic diagrams of the energy distribution of each beam in the beam set;

[0074] Figure 8 is a schematic diagram of a communication scenario in an embodiment of this application;

[0075] Figure 9 is a flowchart illustrating one embodiment of the precoding matrix indication method in this application.

[0076] Figures 10 and 11 are schematic diagrams of an application scenario according to an embodiment of this application;

[0077] Figure 12 is a structural schematic diagram of a communication device according to an embodiment of this application;

[0078] Figure 13 is another structural schematic diagram of the communication device according to an embodiment of this application;

[0079] Figure 14 is another structural schematic diagram of the communication device according to an embodiment of this application. Detailed Implementation

[0080] First, some terms used in the embodiments of this application will be explained to facilitate understanding by those skilled in the art.

[0081] (1) Configuration and Pre-configuration: In this application, both configuration and pre-configuration are used. Configuration refers to the access network device sending configuration information or parameter values ​​of some parameters to the terminal device through messages or signaling, so that the terminal device can determine the communication parameters or resources during transmission based on these values ​​or information. Pre-configuration corresponds to configuration and refers to the alignment of information or parameter values ​​between the terminal and the access network device without using messages or signaling. Instead, it uses parameter information or parameter values ​​that the access network device and the terminal device have negotiated in advance. These parameters can also be parameter information or parameter values ​​used by the access network device or the terminal device as specified by standard protocols, or parameter information or parameter values ​​that are pre-stored in the access network device or the terminal device. This application does not limit this. Furthermore, these values ​​and parameters can be changed or updated.

[0082] (2) The terms "system" and "network" in the embodiments of this application can be used interchangeably. "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, sequence, priority or importance of multiple objects.

[0083] References to "one embodiment" or "some embodiments" as described in this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0084] In the description of this application, unless otherwise specified, " / " means "or". For example, A / B can mean A or B. The "and / or" in this article is merely an association relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single item or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a and b and c. Here, a, b, and c can be single or multiple.

[0085] (3) In the embodiments of this application, "send" and "receive" represent the direction of signal transmission. For example, "send information to the terminal" can be understood as the destination of this information is the terminal device, which can include directly sending through the air interface, and also include indirectly sending through the air interface by other units or modules. "Receive information from the network device" can be understood as the source of this information is the network device, which can include directly receiving from the network device through the air interface, and can also include indirectly receiving from the network device through the air interface from other units or modules. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface.

[0086] In other words, sending and receiving can be carried out between devices, for example, between a network device and a terminal device, or can be carried out within a device, for example, sending or receiving between components within a device, between modules, between chips, between software modules or hardware modules through a bus, wiring or interface.

[0087] It can be understood that the information may be subjected to corresponding processing, such as encoding, modulation, etc. between the source end and the destination end of the information transmission, but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0088] (4) In the embodiments of the present application, "indication" may include direct indication and indirect indication, and may also include explicit indication and implicit indication. The information indicated by a certain piece of information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated. For example, but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated, etc. It is also possible to indirectly indicate the information to be indicated by indicating other information, where there is an association relationship between the other information and the information to be indicated; it is also possible to only indicate a part of the information to be indicated, while the other parts of the information to be indicated are known or pre-agreed. For example, the arrangement order of each piece of information pre-agreed (such as protocol pre-definition) can be used to indicate specific information, so as to reduce the indication overhead. The present application does not limit the specific manner of indication. It can be understood that for the sender of the indication information, the indication information can be used to indicate the information to be indicated, and for the receiver of the indication information, the indication information can be used to determine the information to be indicated.

[0089] The information to be indicated can be sent as a whole, or can be divided into multiple sub-information and sent separately, and the sending periods and / or sending times of these sub-information can be the same or different. The present application does not limit the specific sending method. Among them, the sending periods and / or sending times of these sub-information can be pre-defined, such as pre-defined according to the protocol, or can be configured by the transmitting device by sending configuration information to the receiving device. Among them, the configuration information can, for example, but not limited to, include one or at least a combination of two of radio resource control (RRC) signaling, media access control (MAC) layer (or medium access control (MAC) layer) signaling, and physical layer signaling. Among them, MAC layer signaling, for example, includes MAC control element (CE); physical layer signaling, for example, includes downlink control information (DCI).

[0090] (5) Reference signal (RS), also known as pilot signal. In communication systems, estimating the uplink or downlink channel is essential for transmitting and receiving data, obtaining system synchronization and feedback channel information. 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 are distributed across different resource elements (REs) in the time-frequency two-dimensional space within the orthogonal frequency division multiplexing (OFDM) symbols, and have known amplitudes and phases.

[0091] 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), etc. Uplink signals include the channel sounding reference signal (SRS), the physical uplink control channel demodulation reference signal (PUCCH-DMRS), the physical uplink shared channel demodulation reference signal (PUSCH-DMRS), the demodulation reference signal (DMRS), the phase tracking reference signal (PTRS), and the positioning reference signal (SRS or SRS for positioning), etc.

[0092] 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 demodulation reference signal (PDCCH-DMRS), physical downlink shared channel demodulation reference signal (PDSCH-DMRS), demodulation reference signal (DMRS), phase tracking reference signal (PTRS), channel states information reference signal (CSI-RS), cell reference signal (CRS), tracking reference signal (TRS), positioning reference signal (positioning RS), and synchronization signal block (SSB), etc.

[0093] (6) Precoding Techniques: The transmitter, knowing the channel conditions, can process the signal to be transmitted using a precoding matrix that matches the channel, ensuring the precoded signal is compatible with the channel. Therefore, compared to the receiver receiving an un-precoded signal and eliminating inter-channel interference, the complexity of receiving a precoded signal and eliminating inter-channel interference is reduced. Thus, by precoding the signal to be transmitted, the quality of the received signal (e.g., signal-to-interference-plus-noise ratio, SINR) is improved. Precoding techniques also enable transmission between the transmitter and multiple receivers on the same time-frequency resources, achieving multiple-user multiple-input multiple-output (MU-MIMO).

[0094] Optionally, the sending end can be a network device and the receiving end can be a terminal device; or, the sending end can be a terminal device and the receiving end can be a terminal device.

[0095] One implementation employs Multiple Input Multiple Output (MIMO) technology to increase system capacity and improve throughput. The mathematical expression is y = Hx + n, where y is the received signal, H is the channel information of 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 at the receiver. In this case, the mathematical expression is y = HPx + n, where P is the precoding matrix (or vector). To simplify implementation complexity, P can be selected from a predefined set of matrices (or vectors), called the codebook. This method is also known as a codebook-based transmission method. If the sending end can obtain all the information of H, then P can be obtained by the sending end itself. This method is also known as the non-codebook (NCB) sending method.

[0096] It should be understood that the descriptions of precoding techniques are for illustrative purposes only and are not intended to limit the scope of protection of the embodiments of this application. In specific implementations, the transmitting end may also perform precoding in other ways. For example, when channel information (e.g., but not limited to the channel matrix) is unknown, a pre-set precoding matrix or a weighted processing method may be used for precoding. For the sake of brevity, the specific details will not be elaborated upon here.

[0097] (7) Precoding Matrix Indication (PMI): This can be used to indicate 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, and for the sake of brevity, they will not be listed here.

[0098] 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.

[0099] It should be noted that, according to the method provided in this application, the network device can determine the channel state information (CSI) RS port, the frequency domain discrete Fourier transform (DFT) vector, and the space-frequency vector combining coefficients used to construct the precoding vector based on feedback from the terminal device, and then determine 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 used 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.

[0100] 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 Precoding Matrix Indicator (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.

[0101] 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.

[0102] (8) Antenna Port: This can be simply called a port. It can be understood as the transmitting antenna that is identified by the receiving end, or a transmitting antenna that can be distinguished in space. An antenna port can be pre-configured for each virtual antenna. Each virtual antenna can be a weighted combination of multiple physical antennas. Each antenna port can correspond to a reference signal. Therefore, each antenna port can be called a port of a reference signal, such as a CSI-RS port, demodulation reference signal (DMRS), SRS port, etc.

[0103] In this context, an antenna port is a logical concept, and there is generally no direct correspondence between an antenna port and a 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, an 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 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 elements.

[0104] Furthermore, a port group can refer to a group of multiple antenna ports. One approach is to group multiple digital ports of a network device to form multiple port groups. Another approach (especially in hybrid digital-analog beamforming architectures) is that a port group can be multiple digital ports corresponding to the same analog beam, also simply called a port group or digital-analog port group. Alternatively, a port group can be a group of digital ports corresponding to multiple analog beams, also simply called a port group or digital-analog port group. Or, multiple digital ports of the same analog beam can be divided into multiple subsets, each subset being called a port group or digital-analog port group.

[0105] (9) Channel State Information (CSI) Report: In a wireless communication system, this is information reported by the receiving end (e.g., a terminal device) to the transmitting end (e.g., a network device) to describe the channel attributes of the communication link. The CSI report may include, but is not limited to, precoding matrix indicator (PMI), rank indicator (RI), channel quality indicator (CQI), channel state information reference signal (CSI-RS), CSI-RS resource indicator (CRI), and layer indicator (LI). It should be understood that the specific content of the CSI listed above is merely illustrative and should not constitute any limitation on this application. The CSI may include one or more of the information listed above, or other information used to characterize the CSI besides those listed above; this application does not limit this.

[0106] (10) Beams. Beams and beam pair links (BPLs) are introduced into communication systems. A beam is a communication resource. Beams can be divided into transmit beams and receive beams. Beamforming techniques can be beamforming or other technologies. Beamforming includes transmit beamforming and receive beamforming.

[0107] A beam is a communication resource. A beam can be wide, narrow, or other types. The technology used to form a beam can be beamforming or other techniques. Beamforming technology can specifically be digital beamforming, analog beamforming, or hybrid digital / analog beamforming. Different beams can be considered different resources. The same or different information can be transmitted through different beams. Optionally, multiple beams with the same or similar communication characteristics can be considered as a single beam. A beam can include one or more antenna ports for transmitting data channels, control channels, and detection signals. For example, a transmit beam can refer to the signal strength distribution in different directions of space after a signal is transmitted through an antenna, and a receive beam can refer to the signal strength distribution in different directions of space of the wireless signal received from the antenna. It is understood that one or more antenna ports forming a beam can also be considered a set of antenna ports. In protocols, beams can also be represented by spatial filters.

[0108] Transmit beam: The transmitting device sends a signal with a certain beamforming weight, so that the transmitted signal forms a spatially directional beam. In the uplink direction, the transmitting device can be a terminal; in the downlink direction, the transmitting device can be a network device.

[0109] Received beam: The receiving device receives signals with a certain beamforming weight, forming a spatially directional beam. In the uplink direction, the receiving device can be a network device; in the downlink direction, the receiving device can be a terminal.

[0110] Transmit beamforming: When a transmitting device with an antenna array transmits a signal, a specific amplitude and phase are set on each antenna element of the antenna array to give the transmitted signal a certain spatial directivity. That is, the signal power is high in some directions and low in some directions, and the direction with the highest signal power is the direction of the transmitted beam. The antenna array consists of multiple antenna elements, and the specific amplitude and phase added are the beamforming weights.

[0111] Receiver beamforming: When a receiver with an antenna array receives a signal, a specific amplitude and phase are set on each antenna element of the array to make the power gain of the received signal directional. That is, the power gain is high when receiving signals in certain directions, and low when receiving signals in other directions. The direction with the highest power gain is the direction of the received beam. The antenna array consists of multiple antenna elements, and the specific amplitude and phase added are the beamforming weights.

[0112] Optionally, using a certain transmit beam to transmit a signal can be understood as using a certain beamforming weight to transmit a signal.

[0113] Optionally, using a certain receiving beam to receive the signal can be understood as using a certain beamforming weight to receive the signal.

[0114] Generally, different beams can be considered as different resources. The same information or different information can be transmitted using (or through) different beams. Beam pairs are based on the concept of beams. A beam pair typically includes a transmit beam from a transmitting device and a receive beam from a receiving device.

[0115] It should be noted that in the embodiments of this application, the beam can also be replaced with other descriptions, such as: beam basis, spatial basis, spatial weights, spatial parameters, or quantity. The basis refers to basis vectors, which are a special set of vectors in a vector space (called basis vectors) such that any vector in the vector space can be uniquely represented as a linear combination of basis vectors. Similarly, the beam basis is a set of basis vectors that can be used to represent the beam using their linear combination.

[0116] Secondly, the communication system involved in the embodiments of this application is introduced. This application can be applied to long term evolution (LTE) systems, new radio (NR) systems, or future communication systems. The communication system includes at least one of network equipment or terminal equipment.

[0117] Figure 1 is a schematic diagram of the architecture of the communication system 100 used in the embodiments of this application.

[0118] As shown in Figure 1, the communication system includes a wireless access network and a core network. Optionally, the communication system 100 may also include the Internet. The wireless access network may include at least one network device (also understood as an access network device, as shown in Figure 1, 110a and 110b), and at least one terminal (also understood as the terminal device described above, as shown in Figure 1, 120a-120j). Furthermore, the network device (or wireless network device) may 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), a relay node or a donor node, etc. It is understood that all or part of the functions of the network device in this application may also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The embodiments of this application do not limit the specific technology or specific device form adopted by the wireless network device.

[0119] For ease of description, the communication system illustrated in Figure 1 is described using the network device as a base station and the terminal device as a terminal as an example. It is understood that when the communication system includes an integrated access and backhaul (IAB) network, the base station can be an IAB node. Optionally, in the embodiments of this application, the base station and the network device can be interchanged.

[0120] In this application, the base station and the terminal can be fixed or mobile. The base station and the terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted, on water, or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base station and the terminal.

[0121] 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 through 120i, terminal 120i is a base station. However, for base station 110a, 120i is a terminal; that is, 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.

[0122] 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 achieved using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0123] 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.

[0124] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also susceptible to interference from signals from neighboring cells.

[0125] The technical solution of this application can be applied to cellular communication systems related to the 3rd Generation Partnership Project (3GPP). For example, 4th generation (4G) communication systems, 5G communication systems, and communication systems beyond the 5th generation. For example, future communication systems. For example, 4th generation communication systems may include Long Term Evolution (LTE) communication systems. 5th generation communication systems may include New Radio (NR) communication systems. The technical solution of this application can also be applied to Wireless Fidelity (WiFi) systems, communication systems supporting the convergence of multiple wireless technologies, device-to-device (D2D) systems, or vehicle-to-everything (V2X) communication systems.

[0126] The terminal equipment and network equipment involved in this application are described below.

[0127] Terminal equipment, often simply called a terminal, refers to devices or modules that connect to the aforementioned communication systems and possess corresponding communication functions. Terminals typically contain communication modules, circuits, or chips that perform these functions. They are also configured with program instructions for executing these functions. Terminal equipment is also known as user equipment (UE), mobile station (MS), mobile terminal (MT), fixed wireless access (FWA), customer premises equipment (CPE), etc. Terminal equipment includes wireless communication capabilities (providing voice / data connectivity to users). Examples include handheld devices with wireless connectivity, in-vehicle devices, and machine-type communication (MTC) terminals. Currently, terminal devices can include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving (e.g., drones, vehicles), wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes. For example, wireless terminals in self-driving can be drones, helicopters, or airplanes. For example, wireless terminals in vehicle-to-everything (V2X) can be in-vehicle equipment, vehicle-mounted equipment, in-vehicle modules, vehicles, or ships. Wireless terminals in industrial control can be cameras, robots, or robotic arms. Wireless terminals in smart homes can be televisions, air conditioners, robot vacuums, speakers, or set-top boxes. The terminal device can also be a device or module that is connected to the communication system shown above and has corresponding communication functions. The terminal device usually contains a communication module, circuit or chip that performs the corresponding communication function, and the terminal device is also configured with program instructions for performing the corresponding communication function.

[0128] Terminal equipment can be a device or apparatus with a chip, or a device or apparatus with integrated circuitry, or a chip, chip system, module, or control unit in the aforementioned devices or apparatuses; specific details are not limited in this application. In this application, the term "terminal equipment" can refer to the terminal equipment itself, or to the chip, functional module, or integrated circuit within the terminal equipment that performs the methods provided in this application; specific details are not limited in this application. Network equipment is a device deployed in a wireless access network to provide wireless communication functions for terminal equipment. Network equipment can connect terminal equipment to a radio access network (RAN) node of a wireless network, and can also be called access network equipment, RAN entity, access node, or network node, etc.

[0129] Specifically, network equipment can be network equipment for cellular systems related to the 3rd Generation Partnership Project (3GPP). For example, 4G communication systems, 5G communication systems, or future communication systems. Network equipment can also be network equipment in open RAN (O-RAN or ORAN) or cloud radio access network (CRAN). Alternatively, network equipment can also be network equipment in a communication system resulting from the integration of two or more of the above communication systems.

[0130] Network equipment includes, but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved Node B, or home Node B, HNB), base band unit (BBU), access point (AP) in wireless fidelity (WIFI) systems, macro base station, micro base station, wireless relay node, donor node, radio controller in CRAN scenarios, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP), etc., and can also be network equipment in 5G mobile communication systems. For example, next-generation base station (gNB) in NR systems, TRP, TP; or one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G mobile communication system; or, network equipment can also be network nodes constituting a gNB or transmission point. Examples include centralized unit (CU), distributed unit (DU), centralized unit control plane (CU-CP), centralized unit user plane (CU-UP), or radio unit (RU). CUs and DUs can be separate entities or included in the same network element, such as a BBU. RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs). Alternatively, network equipment can be servers, wearable devices, vehicles, or in-vehicle equipment. For example, network equipment in V2X technology can be roadside units (RSUs). It should be understood that the aforementioned TRP can be a device or module located on the network side of the communication system and possessing corresponding communication functions. The TRP typically contains communication modules, circuits, or chips that perform the corresponding communication functions. The TRP can also be configured with program instructions for the corresponding communication functions.

[0131] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (ORAN) system, CU can also be called an open centralized unit (O-CU) or an open CU, DU can also be called an open distributed unit (O-DU), CU-CP can also be called an open centralized unit control plane (O-CU-CP), CU-UP can also be called an open centralized unit user plane (O-CU-UP), and RU can also be called an open radio unit (O-RU). This application does not limit the specific names. Any of the units CU, CU-CP, CU-UP, DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0132] Optionally, for network elements in the ORAN system, each network element can implement the protocol layer functions shown in Table 1 below.

[0133] Table 1

[0134] The architecture of the CU and DU of a network device is described below. A network device includes at least one CU and at least one DU. Optionally, the network device may also include at least one RU.

[0135] The following example uses a network device consisting of a CU and a DU. The CU has some core network functions and can include CU-CP and CU-UP. The CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU may be configured to implement the functions of at least one layer of the Packet Data Convergence Protocol (PDCP) layer and above (e.g., at least one of the RRC or SDAP layers). The DU may be configured to implement the functions of at least one layer of the protocol layer below the PDCP layer (e.g., at least one of the RLC, MAC, or physical (PHY) layers). Alternatively, the CU may be configured to implement the functions of at least one layer of the protocol layer above the PDCP layer (e.g., at least one of the RRC or SDAP layers), and the DU may be configured to implement the functions of at least one layer of the protocol layer below the PDCP layer (e.g., at least one of the RLC, MAC, or PHY layers).

[0136] When a CU includes CU-CP and CU-UP, CU-CP is used to implement the control plane functions of the CU, and CU-UP is used to implement the user plane functions of the CU. For example, when a CU is configured to implement the functions of the PDCP layer, RRC layer, and SDAP layer, CU-CP is used to implement the RRC layer functions and the control plane functions of the PDCP layer, and CU-UP is used to implement the SDAP layer functions and the user plane functions of the PDCP layer.

[0137] The CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. The AMF is responsible for mobility management in the mobile network, such as terminal device location updates, terminal device registration with the network, and terminal device handover.

[0138] CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements, such as the user plane function (UPF) in a 5G system, are responsible for forwarding and receiving data in terminal devices.

[0139] Optionally, the ORAN architecture also includes a RAN intelligent controller (RIC) module.

[0140] Furthermore, in wireless communication systems (such as the communication system shown in Figure 1), MIMO technology, as a key technology in wireless communication, can be used to meet the demand for high-speed transmission. Taking the communication process between network devices and terminal devices as an example, the network device performs channel measurement using a reference signal to obtain channel state information (CSI). Subsequently, the network device can use this channel information to calculate the precoding information between the network device and the terminal device. MIMO communication can then be achieved between the network device and the terminal device using this precoding information.

[0141] In one implementation example, to send data to the terminal device, the network device can perform precoding on the digital port, while selecting appropriate coding and modulation orders. For example, the role of precoding is to better match the antenna (or beam) with the channel, ensuring better signal quality and less interference when the transmitted data arrives at the terminal. A better modulation order and code rate can maximize channel transmission capacity while ensuring reliable data transmission. The settings for precoding and modulation coding scheme (MCS) need to be determined based on channel quality and channel response. A common method is for the network device to send a downlink reference signal, the terminal device to determine the channel based on the downlink reference signal, and then feed back the corresponding channel state information, including precoding information, the number of transport streams supported by the channel (i.e., RI), and CQI (used to provide feedback on the MCS recommended by the terminal under the current channel quality). This process is called channel state information feedback (CSI feedback). Another approach is to measure and obtain uplink channel information using an uplink reference signal, and then further obtain downlink channel information based on channel reciprocity.

[0142] Figure 2 is a schematic diagram of a downlink channel measurement. As shown in Figure 2, the channel measurement process based on the downlink reference signal includes the following steps.

[0143] S201. The network device sends configuration information to the terminal device, wherein the configuration information includes channel information reporting (or measurement) configuration information.

[0144] Specifically, the channel information reporting configuration information can be sent from the network device to the terminal device via RRC signaling, and can include two parts: resource configuration information and reporting configuration information.

[0145] Resource configuration information refers to information related to measurement resources and can be configured through a three-level structure (resource configuration (resourceConfig) - resource set (resource) - resource (resource)). In other words, a network device can configure one or more resource configurations for a terminal device. Each resource configuration includes one or more resource sets, and each resource set can include one or more resources. Each resource configuration / resource set / resource includes its own index. Optionally, the channel information reporting configuration information may also include other parameters, such as the resource period and the signal type corresponding to the resource.

[0146] In addition, the reporting configuration information refers to the information related to the reporting of measurement results, which is configured in the protocol through the reporting configuration (ReportConfig). Network devices can configure one or more reporting configurations (ReportConfig) for terminal devices. Each reporting configuration includes reporting metrics, reporting time and period, reporting format, and other reporting-related information. Furthermore, the reporting configuration also includes an index of resource configurations, indicating which measurement configuration was used to obtain the reported results.

[0147] Optionally, the channel information reporting configuration information includes codebook configuration information (CodebookConfig), which is used to configure the first type or the second type of codebook.

[0148] S202. The network device sends a downlink reference signal. For example, the network device sends a downlink signal (usually a downlink reference signal) on the resources configured in the resource configuration information so that the terminal device can measure the downlink signal and determine the quality of each resource (i.e., the quality of the beam corresponding to the resource).

[0149] S203. The terminal equipment measures the downlink reference signal based on the configuration information reported by the channel information. The downlink reference signal mainly includes the synchronization signal / physical broadcast channel block (SSB or SS / PBCH block), CSI-RS, and tracking reference signal (TRS). The PBCH can carry the master information block (MIB), which is used to configure the main system information of the cell.

[0150] S204. The terminal device sends channel information to the network device. For example, the channel information may include a beam measurement report, which includes channel state information (CSI). The channel state information may include one or more of the following: indexes of one or more resources, CQI, reference signal received power (RSRP), PMI, rank indicator (RI), layer indicator (LI), CRI, SSB resource indicator (SS / PBCH Block Resource Indicator, SSBRI), etc.

[0151] Optionally, channel state information can be carried in uplink control information (UCI) and transmitted via the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH).

[0152] In addition, after obtaining channel information in step S204, the network device can determine scheduling information, including one or more of the following: MCS, resource block (RB) resource allocation, transmit beam, and receive beam, thereby improving the degree of beam matching with the channel and thus helping to improve communication rate and efficiency.

[0153] In summary, to improve the reception quality of wireless signals received by terminal devices and the spectral efficiency of the communication system, network devices need to perform precise beamforming on the data stream. To this end, the network device sends a pilot signal CSI-RS to the terminal device for channel estimation. The terminal device receives the CSI-RS and calculates the channel state information. Then, the terminal device calculates the beamforming matrix, also known as the precoding matrix, based on this channel state information. The terminal device can use various algorithms to determine this precoding matrix, such as singular value decomposition (SVD). To feed back the precoding matrix to the network device, the terminal device needs to convert the precoding matrix into a precoding matrix indication (PMI). The network device can then select the corresponding precoding matrix from the codebook based on the PMI.

[0154] A codebook is a predefined, optimized set of beamforming matrices that allows network devices and terminal devices to efficiently exchange information over a communication link. The Type II codebook is a high-precision codebook designed for massive MIMO systems, incorporating finer-grained beamforming options to accommodate more complex channel conditions and higher system performance requirements. In the Type II codebook, spatial weights (or spatial parameters) determine the shape and orientation of the beam. These parameters are selected from multiple candidate spatial bases, each corresponding to a specific spatial orientation. The terminal device sends a Pre-Minute Indicator (PMI) to the network device based on the selected spatial base, enabling the terminal device to instruct the network device to precisely focus the wireless signal onto its location, reducing interference to other terminal devices.

[0155] For clarity, please refer to Figure 3, which is a schematic diagram of a spatial basis combination. The terminal device receives and measures the downlink reference signal from the network device to determine channel state information. Then, based on the channel state information, the terminal device selects basis 3, basis 6, basis 9, and basis 11 from a pool of candidate spatial basis units (basis 1 to basis 11). The terminal device then feeds back a PMI (Presentation Management Interface) to the network device, indicating the aforementioned basis units 3, 6, 9, and 11. The network device performs beamforming based on this PMI to determine beam 1 and beam 2.

[0156] As described above, the concept of a beam is similar to that of a spatial basis; a beam can be replaced by a spatial basis. The terminal device uses the PMI to indicate the selected beam and its combination coefficients. Currently, any column of the precoding matrix determined based on the Type II codebook can be represented as:

[0157] In this application, the first row within the brackets "[]" corresponds to the precoding vector for the first polarization direction, and the second row within the brackets "[]" corresponds to the precoding vector for the second polarization direction. It should be understood that the polarization direction in this application refers to the direction of the electric field vector of the electromagnetic wave radiated by the antenna in space. β is the power adjustment coefficient. This is the amplitude coefficient. This represents the phase coefficient at the antenna port. Let i be the spatial basis, i∈{0,1,...,L-1}.

[0158] Combining equation (1) above, the terminal device needs to feed back a total of L beams. The terminal device needs to select these L beams from the beam set N1N2, where the beam set N1N2 is an oversampled DFT beam set. N1 can also be understood as the number of beams in the horizontal dimension of an oversampled DFT beam set, and N2 can also be understood as the number of beams in the vertical dimension of an oversampled DFT beam set. The terminal device obtains channel information based on the CSI-RS port group measurement, and then determines the L beams to be fed back and the oversampled DFT beam set in which these L beams belong based on the channel information. The CSI-RS port group can be replaced by the CSI-RS antenna port group to distinguish the groups in which different CSI-RS ports (or CSI-RS antenna ports) belong. CSI-RS ports within the same CSI-RS port group can reuse resources in various ways, such as code division multiplexing, frequency division multiplexing, or time division multiplexing. Since the number of horizontal ports in a CSI-RS port group is N1 and the number of vertical ports in a CSI-RS port group is N2, the horizontal dimension of the CSI-RS port group is the same as that of the oversampled DFT beam set, and the vertical dimension of the CSI-RS port group is the same as that of the oversampled DFT beam set. The number of beams included in the beam set N1N2 can also be understood as the number of ports included in a CSI-RS port group (P). CSI-RS That is, N1N2=P CSI-RS N1 is an integer greater than or equal to 1, and N2 is an integer greater than or equal to 1. It should be noted that the beams included in the oversampled DFT beam set are mutually orthogonal; therefore, the oversampled DFT beam set can also be called an orthogonal beam set. In the embodiments of this application, the beam set can also be called a beam group.

[0159] The precoding matrix based on the Type II codebook can be represented as: Where W is the precoding matrix, W1 is the spatial sparse basis of the codebook, and W... f It is the frequency domain sparse basis of the codebook. These are the parameters of the feedback. The spatial sparse basis of the type II codebook can be specifically described as follows: Among them, v m These are the basis vectors in the sparse spatial basis, i.e., the spatial basis, m = 0, 1, ..., L-1. Type II codebooks currently include phase scanning (PS) codebooks and regular codebooks, where the basis vectors of the regular codebook are v. l,m v l,m It is a DFT vector. l,m Specifically as follows:

[0160] Where m = 0, 1, ..., N2-1, l = 0, 1, ..., N1-1. O1 represents the oversampling factor in the horizontal dimension of the antenna port, and O2 represents the oversampling factor in the vertical dimension of the antenna port. The number of oversampled DFT beam sets used by the terminal device is O1O2. All beams within an oversampled DFT beam set are combined into a DFT matrix, which serves as a complete spatial basis.

[0161] The PMI fed back by the terminal device includes codebook parameter information (or codebook indices, or codebook indicators). When the value υ related to the rank indicator (RI) is ≤ 2, the PMI value corresponds to parameters i1 and i2. Parameters i1 and i2 can be understood as codebook indices i1 and i2, where...

[0162] Among them, subbandAmplitude is the subband amplitude.

[0163] The L vectors formed by combining codebooks are determined by parameters i1 and i2. These L vectors correspond to L beams; therefore, the L beams fed back by the terminal device are determined by parameters i1 and i2. The indices of the L beams are determined by parameters i1 and i2. 1,1 and parameter i 1,2 The instructions are as follows:

[0164] parameter i 1,1 i 1,1 =[q1 q2] q1∈{0,1,...,O1-1}, q2∈{0,1,...,O2-1}

[0165] parameter i 1,2 :

[0166] , parameter i 1,2 Indicator parameters and parameters

[0167] parameter and parameters

[0168] The i-th beam among the L beams fed back by the terminal device can use parameters and parameters This means, that is:

[0169] In summary, the PMI reported by the terminal device includes parameter i 1,1 and parameter i1,2 Network devices, based on the parameters i included in the PMI, 1,1 Determine parameters q1 and q2, and then determine the oversampled DFT beam set containing the L beams fed back by the terminal device. The network device then uses parameters i included in the PMI... 1,2 Determine L beams in the oversampled DFT beam set. In other words, parameter i 1,1 Indicates the set of orthogonal beams containing L beams, parameter i 1,2 Indicates the position of L beams within an orthogonal beam set, or parameter i 1,2 Indicates the horizontal and vertical angles of L beams in an orthogonal beam set. For clarity, please refer to Figure 4, a schematic diagram of the spatial basis combination. Parameter i 1,1 The orthogonal beam set illustrated in Figure 4 comprises 8*4=32 beams. The horizontal dimension N1=8 and the vertical dimension N2=4 of this orthogonal beam set. Parameter i 1,2 This indicates the four beams in the orthogonal beam set, i.e., L = 4. The i-th beam among these four beams is determined by parameters. and parameters Instructions: The network device, based on parameter i 1,2 Determine this parameter and this parameter

[0170] In the above method, the network device uses the parameters i included in the PMI. 1,1 Determine parameters q1 and q2, and then determine the set of oversampled DFT beams containing the L beams fed back by the terminal device, that is, the network device determines the set of oversampled DFT beams based on parameter i. 1,1 The orthogonal beam set (or simply beam set) containing the L beams that the terminal device needs to feed back is determined. Currently, the terminal device supports O1O2 beam sets, meaning the total number of beam sets supported by the terminal device depends on the oversampling factor of the antenna ports in the horizontal dimension and the oversampling factor of the antenna ports in the vertical dimension. When O1=2 and O2=2, the terminal device supports a total of 4 beam sets. For easier understanding, please refer to Figure 5, which is a schematic diagram of multiple beam sets supported by the terminal device. As shown in Figure 5, the terminal device supports a total of 4 beam sets: the first beam set, the second beam set, the third beam set, and the fourth beam set. Each beam set includes 4 beams in the horizontal dimension and 4 beams in the vertical dimension, i.e., N1=4 and N2=4 for each beam set. The beams in the above 4 beam sets are mutually orthogonal. After determining the L beams that need to be fed back, the terminal device further determines the beam set containing these L beams, and then uses parameter i 1,1 Indicates the beam set, via i 1,2Indicates the L beams in this beam set.

[0171] The terminal device receives a reference signal and performs channel measurements based on the reference signal to determine channel information, and then determines the PMI based on the channel information. This channel information indicates that there are multiple wireless propagation paths between the terminal device and the network device, and each wireless propagation path has a path angle or azimuth angle relative to the network device. The terminal device feeds back L beams, with different beams pointing in different directions in space, characterized by horizontal and vertical dimensions. Ideally, the number L of beams fed back by the terminal device is the same as the number of wireless propagation paths, i.e., there are L wireless propagation paths between the network device and the terminal device, and the beam directions of these L beams correspond one-to-one with these L wireless propagation paths. Referring to Figure 5, when the number of beams L=6 that the terminal device needs to feed back, please refer to Figure 6 for a schematic diagram of these 6 beams. Figure 6 is a schematic diagram of beam feedback from the terminal device in an embodiment of this application. In Figure 6, the 6 wireless propagation paths determined by the terminal device correspond to 6 of the 64 beams supported by the terminal device, which belong to 4 beam sets. The four beam sets specifically include a first beam set, a second beam set, a third beam set, and a fourth beam set. Each beam set includes 16 beams. A schematic diagram of these 64 beams is shown in Figure 7a, which is a stem-and-leaf plot of different beam sets in an embodiment of this application. As shown in Figure 7a, the six beams corresponding to the path angles of the six wireless propagation paths determined by the terminal device are not within the same beam set. Of these six beams, four belong to the third beam set, and two belong to the fourth beam set. Because the beams in different beam sets are not orthogonal, energy leakage exists between multiple beams in different orthogonal beam sets. For example, if the path angle corresponding to the second wireless propagation path in Figure 6 is represented by a beam from the fourth beam set, then the energy of path angle #2 of this second wireless propagation path will be entirely concentrated in beam (3,2) of the fourth beam set. Beam (3,2) of the fourth beam set carries all the energy of path angle #2, and path angle #2 can be represented using beam (3,2) of the fourth beam set. If the path angle #2 is represented by a beam from the third beam set, the energy of path angle #2 will leak across all beams included in the third beam set. In this case, if only one beam from the third beam set can be used to represent path angle #2, it will result in energy loss.

[0172] Currently, the terminal device can only feed back multiple beams from one beam set. If the multiple beams that the terminal device needs to feed back belong to different beam sets, the terminal device needs to determine the beam set with the minimum energy loss from feeding back multiple beams, and then determine the multiple beams to be fed back from that beam set. Referring to the examples in Figures 5-7a, taking the first, second, and third beam sets as examples, the energy distribution of each beam in the above three beam sets is shown in Figures 7b-7d, which are schematic diagrams of the energy distribution of each beam in the beam set. Within each beam set of the first, second, and third beam sets, the terminal device selects the 6 beams with the highest energy carrying the path angle. The energy carried by the remaining beams in this beam set, excluding the 6 beams with the highest energy carrying the path angle, is considered as energy loss. Therefore, the sum of the energy of the other beams besides the 6 beams with the highest energy carrying the path angle can be considered as loss. The terminal device selects the beam set with the least loss as the beam set to be fed back. For example, among the three beam sets illustrated in Figures 7b and 7d, the third beam set is selected as the beam set with the least loss. The terminal device then selects the six beams with the highest energy from the multiple beams included in the third beam set as the six beams to be fed back.

[0173] Because the multiple beams that the terminal device needs to feed back are not entirely consistent with the multiple beams actually fed back by the terminal device, the precoding matrix determined by the network device based on the multiple beams fed back by the terminal device cannot perfectly correspond to the wireless propagation path between the network device and the terminal device. When the network device sends wireless signals to the terminal device based on this precoding matrix, it will affect the communication quality of the wireless signal, reducing the spectral efficiency and data throughput of the communication system. Therefore, current terminal devices suffer from low beam feedback accuracy.

[0174] Based on this, this application proposes a precoding matrix indication method and related apparatus. A first communication device receives a reference signal; the first communication device performs measurements based on the reference signal to determine a precoding matrix indication (PMI). The PMI includes first information and second information, wherein the first information indicates G beam sets, where G is an integer greater than 1, and any one of the G beam sets includes multiple mutually orthogonal beams; the second information indicates L beams in the G beam sets, where L beams are used to determine the precoding matrix, and L is an integer greater than 1; the first communication device transmits the PMI. After receiving the reference signal, the first communication device first performs channel measurements based on the reference signal to determine channel state information. Then, based on the channel state information, the first communication device determines the L beams that need to be fed back from the multiple beam sets supported by the first communication device, and determines the G beam sets to which the L beams belong, and the G beam sets belong to the multiple beam sets. Finally, the first communication device uses first information and second information to indicate the G beam sets and L beams respectively, ensuring that the L beams indicated by the first communication device accurately correspond to the L wireless propagation paths between the first and second communication devices, effectively improving the accuracy of the precoding matrix indication. While keeping the communication overhead occupied by the precoding matrix indication unchanged, the matching accuracy between the beams indicated by the precoding matrix and the wireless propagation paths in the actual communication environment can be improved, effectively enhancing the communication quality between the first and second communication devices.

[0175] Next, an embodiment of this application will be described using an example communication scenario. Please refer to Figure 8, which is a schematic diagram of a communication scenario according to an embodiment of this application. This communication scenario includes a first communication device and a second communication device. The first communication device may be a terminal device, or it may be a device or apparatus with a chip, or a device or apparatus with integrated circuits, or a chip, chip system, functional module, control unit, circuit, processor, or integrated circuit that can be applied to a terminal device or apparatus; the specifics are not limited in this application. The second communication device may be a network device, or it may be a device or apparatus with a chip, or a device or apparatus with integrated circuits, or a chip, chip system, functional module, control unit, circuit, processor, or integrated circuit that can be applied to a network device or apparatus; the specifics are not limited in this application. The cell managed by the second communication device includes the first cell. The first communication device is located in the first cell and can receive signals from the second communication device.

[0176] Based on the communication scenarios illustrated above, the precoding matrix indication method proposed in the embodiments of this application will be introduced next.

[0177] Please refer to FIG. 9. FIG. 9 is a schematic flowchart of an embodiment of a precoding matrix indication method in an embodiment of the present application. A precoding matrix indication method proposed by an embodiment of the present application includes:

[0178] 901. The second communication device sends a reference signal to the first communication device. Correspondingly, the first communication device receives the reference signal.

[0179] In step 901, the reference signal may be a CSI-RS. The reference signal may also be other types of downlink reference signals, and the embodiments of the present application do not limit this. In the embodiments of the present application, the direction from the second communication device to the first communication device is defined as the downlink direction. For example, the direction from a network device to a terminal device is defined as the downlink direction; the direction from the first communication device to the second communication device is defined as the uplink direction. For example, the direction from a terminal device to a network device is defined as the uplink direction.

[0180] 902. The first communication device measures according to the reference signal to determine a precoding matrix indication (PMI). The PMI includes first information and second information. The first information indicates G beam sets, where G is an integer greater than 1. Any one of the G beam sets includes multiple orthogonal beams. The second information indicates L beams among the G beam sets. The L beams are used to determine the precoding matrix, and L is an integer greater than 1.

[0181] First, introduce how the first communication device determines the G beam sets and the L beams to be fed back.

[0182] In a possible implementation, the first communication device performs channel measurement according to the reference signal to determine channel state information. Then, the first communication device determines L beams according to the channel state information. For example, the first communication device determines a precoding matrix according to the channel state information; then the first communication device determines L beams from the multiple beams included in X beam sets according to the precoding matrix. The energy loss of the L beams for constructing the precoding matrix is the smallest. The X beam sets are the beam sets supported by the first communication device.

[0183] The number X of the beam sets supported by the first communication device is determined by O1 and O2, where O1 is the oversampling multiple of the antenna ports supported by the first communication device in the horizontal dimension, and O2 is the oversampling multiple of the antenna ports supported by the first communication device in the vertical dimension. For example, when O1 = 2 and O2 = 2, the number of the beam sets supported by the first communication device is O1O2 = 4, where O1O2 refers to O1 multiplied by O2, or O1×O2. Correspondingly, in the process of determining the L beams, the first communication device determines the G beam sets to which the L beams belong, and G is an integer greater than or equal to 1 and less than or equal to X.

[0184] In another possible implementation, the first communication device performs channel measurement based on a reference signal to determine channel state information. Then, the first communication device determines G beam sets from X beam sets supported by the first communication device according to the channel state information. Finally, the first communication device determines L beams from the multiple beams included in the G beam sets according to the precoding matrix determined by the channel state information, and the energy loss of the L beams constructing the precoding matrix is the smallest.

[0185] In an example, the X beam sets supported by the first communication device are 10 beam sets, the number G of beam sets that the first communication device needs to feedback is 3, and the number L of beams to be feedback by the first communication device is 8. The first communication device performs channel measurement based on the reference signal to determine channel state information. Specifically, the first communication device selects the optimal 8 beams from all the beams included in the 10 beam sets according to the channel state information, and the 8 beams are the beams to be feedback by the first communication device (i.e., L = 8). The optimal 8 beams meet the following condition: the error between the precoding matrix formed by the 8 vectors corresponding to the 8 beams and the precoding matrix directly determined by the first communication device according to the channel state information is the smallest.

[0186] If the number of beam sets to which the 8 beams belong is less than or equal to 3, the first communication device determines the beam sets to which the 8 beams belong as the beam sets to be feedback. For example, if the 8 beams belong to beam set 1, beam set 2, and beam set 3 respectively, the first communication device determines that the beam sets to be feedback include: beam set 1, beam set 2, and beam set 3. Another example is that if the 8 beams belong to beam set 1 and beam set 2 respectively, the first communication device determines that the beam sets to be feedback include: beam set 1, beam set 2, and any one of the 10 beam sets other than beam set 1 and beam set 2.

[0187] If the number of beam sets to which the 8 beams belong is greater than 3, the first communication device selects the top 3 beam sets with the largest number of beams to be feedback from the 10 beam sets according to the number of beams to be feedback included in each beam set of the 10 beam sets as the beam sets to be feedback. For example, the 8 beams include: beam 1 to beam 8, where beam set 1 includes beam 1 and beam 2; beam set 2 includes beam 3 and beam 4; beam set 3 includes beam 5 and beam 6; beam set 4 includes beam 7; beam set 5 includes beam 8. Then, the first communication device re - selects 8 beams from all the beams included in the above beam set 1, beam set 2, and beam set 3 as the beams to be feedback, and the beam set 1, beam set 2, and beam set 3 are used as the beam sets to be feedback.

[0188] In the above implementation, the first communication device can determine G beam sets from X beam sets by using various methods. For example, the first communication device determines G beam sets from X beam sets by using a first algorithm, where the first algorithm includes any one of the following: least absolute shrinkage and selection operator (Lasso) algorithm, orthogonal matching pursuit (OMP) algorithm, iterative soft thresholding algorithm (ISTA), or approximate message passing (AMP) algorithm.

[0189] Optionally, the first communication device can determine the number G of beam sets to be fed back by the first communication device according to the third information. The third information can be configured by the second communication device, and the third information can also be information pre-configured in the first communication device, and the third information can also be information predefined by the protocol. The embodiments of the present application do not limit this.

[0190] In one example, the third information is carried in configuration information, and the configuration information is used to configure the resources of the reference signal. For example, the first communication device receives configuration information from the second communication device, and the configuration information includes radio resource control report configuration (RRC reportconfig) information. The RRC reportconfig information includes the third information. <4000584>

[0191] Optionally, the first communication device can determine the number L of beams to be fed back by the first communication device according to the fourth information. The fourth information can be configured by the second communication device, and the fourth information can also be information pre-configured in the first communication device, and the fourth information can also be information predefined by the protocol. The embodiments of the present application do not limit this.

[0192] Optionally, the fourth information can also indicate the number L of beams to be fed back by the first communication device in other ways. For example, the fourth information is used to configure the number L of beams to be fed back for the g-th beam set among the G beam sets to be fed back by the first communication device g where the number of beams to be fed back for the g-th beam set among the G beam sets is L g where g ∈ {1, ···, G}, and L g is an integer greater than or equal to 0, and the relationship between L g and L satisfies: The first communication device determines the number of beams to be fed back for each of the G beam sets to be fed back according to the fourth information. A total of L beams need to be fed back for the G beam sets.

[0193] Correspondingly, if the fourth information is used to configure the number of beams L to be fed back by the first communication device, the first communication device determines the number of beams to be fed back for each of the G beam sets according to the fourth information and the channel state information obtained by channel measurement. If the fourth information is used to configure the number of beams L to be fed back for the g-th beam set among the G beam sets to be fed back by the first communication device g , the first communication device directly determines the number of beams to be fed back for each of the G beam sets according to the fourth information.

[0194] In an example, the fourth information is carried in the configuration information, and the configuration information is used to configure the resources of the reference signal. For example, the fourth information is the parameter beam number (numberOfBeams) information, and the numberOfBeams information is carried in the configuration information.

[0195] Secondly, the specific contents of the first information and the second information are introduced.

[0196] In a possible implementation, the first information includes: [q 1,1 , q 1,2 , ···, q g,1 , q g,2 , ···, q G,1 , q G,2 , where the parameter q g,1 and the parameter q g,2 indicate the g-th beam set among the G beam sets, the parameter q g,1 ∈{0, 1, …, O1 - 1}, the parameter q g,2 ∈{0, 1, …, O2 - 1}, O1 is the oversampling multiple of the antenna ports of the first communication device in the horizontal dimension, and O2 is the oversampling multiple of the antenna ports of the first communication device in the vertical dimension.

[0197] Optionally, the first information belongs to the parameter i 1,1 included in the PMI, where the parameter i 1,1 is used to indicate the beam set where the L beams fed back by the first communication device are located.

[0198] In a possible implementation, the second information includes: [i 1,2,1 , …, i 1,2,g , …, i 1,2,G , where the parameter i 1,2,g indicates the beam to be fed back for the g-th beam set among the G beam sets, Lg is the number of beams to be fed back in the g-th beam set among G beam sets, N1 is the number of horizontal ports in the reference signal port group, N2 is the number of vertical ports in the reference signal port group, and the reference signal port group corresponds to the beam set.

[0199] Optionally, the second information belongs to parameter i 1,2 , parameter i 1,2 is used to indicate the positions of L beams in the beam set where the L beams are located.

[0200] In an exemplary scenario, the first communication device sends a PMI to the second communication device, and the PMI includes parameter i1, and the parameter i1 includes parameter i 1,1 and parameter i 1,2 . Among them, parameter i 1,1 indicates the G beam sets to be fed back by the first communication device, and parameter i 1,1 = [q 1,1 , q 1,2 , q 2,1 , q 2,2 , …, q g,1 , q g,2 , …, q G,1 , q G,2 , ], [q 1,1 , q 1,2 indicates the first beam set to be fed back by the first communication device, [q 2,1 , q 2,2 indicates the second beam set to be fed back by the first communication device, [q g,1 , q g,2 indicates the g-th beam set to be fed back by the first communication device, [q G,1 , q G,2 indicates the G-th beam set to be fed back by the first communication device. q g,1 and q g,2 satisfy: q g,1 ∈ {0, 1, …, O1 - 1}, q g,2 ∈ {0, 1, …, O2 - 1}. Parameter i 1,2 indicates the L beams to be fed back by the first communication device, and the L beams belong to the G beam sets indicated by parameter i 1,1 . Among them, i 1,2 = [i 1,2,1 , i 1,2,2 , …, i 1,2,g , …, i 1,2,G , parameter i 1,2,1 indicates the beam to be fed back in the first beam set fed back by the first communication device, and parameter i 1,2,2 indicates the beam to be fed back in the second beam set fed back by the first communication device, and parameter i1,2,g The beam to be fed back in the g-th beam set fed back by the first communication device, parameter i 1,2,G The beam to be fed back in the G-th beam set fed back by the first communication device. Parameter N1 is the number of horizontal ports of the reference signal port group, and N2 is the number of vertical ports of the reference signal port group. Specifically, the reference signal port group can be a CSI-RS port group, and the reference signal in step 901 corresponding thereto is CSI-RS. The reference signal port group can also be replaced by: an orthogonal beam group, an oversampled orthogonal beam group, a DFT beam group, a DFT orthogonal beam group, or an oversampled DFT orthogonal beam group. Correspondingly, the dimension N1N2 of the reference signal port group can specifically be: N1 is the number of horizontal ports of the CSI-RS port group, and N2 is the number of vertical ports of the CSI-RS port group; or, N1 is the number of beams in the horizontal dimension of the orthogonal beam group (or oversampled orthogonal beam group, or DFT beam group, or DFT orthogonal beam group, or oversampled DFT orthogonal beam group), and N2 is the number of beams in the vertical dimension of the orthogonal beam group (or oversampled orthogonal beam group, or DFT beam group, or DFT orthogonal beam group, or oversampled DFT orthogonal beam group). Operator can be represented by the formula or can be indicated by the expansion in Table 2.

[0201] Table 2

[0202] It should be noted that the number of beams to be fed back in the g-th beam set fed back by the first communication device to the second communication device can be 0. At this time, the second information corresponding to the g-th beam set is 0. That is, when L g = 0, i 1,2,g = 0. For example, the second communication device configures the first communication device to feed back 3 beam sets and determines 5 beams to be fed back in the 3 beam sets. The first communication device sends PMI indicating beam set 1, beam set 2, and beam set 3 to the second communication device. Among them, PMI indicates 0 beams in beam set 1, PMI indicates 2 beams in beam set 2, and PMI indicates 3 beams in beam set 3.

[0203] 903. The first communication device sends PMI to the second communication device. Correspondingly, the second communication device receives the PMI. The second communication device determines G beam sets according to the first information included in the PMI, and determines L beams in the G beam sets according to the second information included in the PMI.

[0204] The following introduces the specific method for the second communication device to determine L beams according to the PMI:

[0205] In one example, the second communication device determines parameter i according to the PMI 1,1 and parameter i 1,2 . Among them, parameter i 1,1 = [q 1,1 , q 1,2 , ···, q g,1 , q g,2 , ···, q G,1 , q G,2 . Parameter i 1,1 indicates G beam sets as the first information. The second communication device determines the first beam set fed back by the first communication device according to [q 1,1 , q 1,1 included in parameter i. The second communication device determines the g-th beam set fed back by the first communication device according to [q 1,2 , q 1,1 included in parameter i, and so on. The second communication device determines the G-th beam set fed back by the first communication device according to [q g,1 , q g,2 included in parameter i. Parameter i 1,1 = [i G,1 , …, i G,2 , …, i 1,2 . Parameter i 1,2,1 indicates L beams in the G beam sets as the second information. The second communication device determines the beams to be fed back in the first beam set fed back by the first communication device according to the parameter i 1,2,g included in parameter i. The second communication device determines the beams to be fed back in the g-th beam set fed back by the first communication device according to the parameter i 1,2,G included in parameter i, and so on. The second communication device determines the beams to be fed back in the G-th beam set fed back by the first communication device according to the parameter i 1,2 included in parameter i. The total number of beams to be fed back indicated by parameter i 1,2 is L. 1,2,1 1,2 1,2,g 1,2 1,2,G [[ID=;57]] 1,2

[0206] Taking parameter i 1,2,g as an example, the second communication device calculates the L 1,2,g beams indicated by parameter i g using an algorithm. Since the current L beams are determined using the parameter , the second communication device uses the corresponding algorithm of parameter i 1,2,g to to determine these L g beams.​​​​​​

[0207] The embodiments of this application do not limit the above algorithm. In one example, the parameter i 1,2,g to has the following corresponding algorithm:

[0208] Using the following algorithm, the above parameters n1 and n2 can be determined according to the parameter i 1,2,g :

[0209] s -1 = 0; for i = 0,..., L g -1; find the maximum value x in Table 2 * ∈{L g -1-i,..., N1N2-1-i}, such that the parameter i 1,2,g -s i-1 ≥C(x * ,L g -i); e i = C(x * ,L g -i); s i = s i-1 +e i ; n (i) = N1N2-1-x * ;

[0210] After the second communication device determines the L beams fed back by the first communication device, the second communication device determines the corresponding L vectors according to the L beams, and then determines the corresponding precoding matrix according to the L vectors. The second communication device uses the precoding matrix to send data to the first communication device, that is, the second device uses the precoding matrix to implement the precoding mapping from the data stream to the CSI-RS port.

[0211] It can be understood that the above beam set can be replaced by a beam set, a beam set or a CSI-RS port group, and the above beam subset can be replaced by a beam subset, a support set, a boundary set or a CSI-RS port subset.

[0212] Combined with the above technical solution, the first communication device realizes the feedback of multiple beam sets and multiple beams in the multiple beam sets to the second communication device through the first information and the second information, ensuring that the L beams indicated by the first communication device accurately correspond to the L wireless propagation paths between the first communication device and the second communication device, effectively improving the accuracy of the precoding matrix indication. Without changing the communication overhead occupied by the precoding matrix indication, the matching accuracy between the beams indicated by the precoding matrix indication and the wireless propagation paths in the actual communication environment can be improved, effectively improving the communication quality between the first communication device and the second communication device.

[0213] Exemplarily, an application scenario related to an embodiment of the present application will be introduced in conjunction with FIGS. 10 to 11. FIGS. 10 to 11 are schematic diagrams of an application scenario in an embodiment of the present application. The second communication device sends a reference signal to the first communication device. Correspondingly, the first communication device receives and measures the reference signal to determine five wireless propagation paths between the first communication device and the second communication device. The first communication device determines the path angles corresponding to the five wireless propagation paths. Five beams corresponding to the five path angles are determined from the O1O2 beam sets supported by the first communication device. Specifically, beam set 1 in the O1O2 beam sets includes three beams corresponding to the five wireless propagation paths, and beam set 2 in the O1O2 beam sets includes the remaining two beams corresponding to the five wireless propagation paths. Then, the first communication device sends a PMI to the second communication device. The first information in the PMI indicates the beam set 1 and the beam set 2. The second information in the PMI indicates three beams to be fed back in the beam set 1. The second information in the PMI indicates two beams to be fed back in the beam set 2. Correspondingly, the second communication device determines three beams in the beam set 1 and two beams in the beam set 2 according to the PMI. The second communication device determines a precoding matrix according to the five determined beams. Furthermore, the second communication device uses the precoding matrix to perform precoding processing on the data sent from the second communication device to the first communication device.

[0214] Next, the communication device related to the embodiment of the present application will be introduced. The communication device can be used for at least one of the first communication device or the second communication device in the foregoing embodiments.

[0215] FIG. 12 is a schematic structural diagram of the communication device in an embodiment of the present application. Referring to FIG. 12, the communication device 1200 includes a transceiver module 1201 and a processing module 1202.

[0216] The communication device 1200 includes the first communication device or components (such as chips or chip systems), modules or units within the first communication device. Or, the communication device 1200 includes the second communication device or components (such as chips or chip systems), modules or units within the second communication device.

[0217] The communication device 1200 can be used to execute all or part of the steps executed by the first communication device in the embodiments shown in FIGS. 9 to 11. Specifically, reference can be made to the relevant descriptions in the foregoing embodiments shown in FIGS. 9 to 11.

[0218] The communication device 1200 can be used to execute all or part of the steps executed by the second communication device in the embodiments shown in FIGS. 9 to 11. Specifically, reference can be made to the relevant descriptions in the foregoing embodiments shown in FIGS. 9 to 11.

[0219] The processing module 1202 is used for data processing. The transceiver module 1201 is used to implement corresponding communication functions.

[0220] Optionally, the transceiver module 1201 may include a sending module and a receiving module. The sending module is used to perform the sending operation in the foregoing method embodiments. The receiving module is used to perform the receiving operation in the foregoing method embodiments.

[0221] Optionally, the communication device 1200 may include a sending module but not a receiving module. Or, the communication device 1200 may include a receiving module but not a sending module. Specifically, it depends on whether the foregoing solution executed by the communication device 1200 includes a sending action and a receiving action.

[0222] Optionally, the communication device 1200 may further include a storage module, which can be used to store at least one of instructions or data. The processing module 1202 can read at least one of the instructions or data in the storage module, so that the communication device 1200 can implement the foregoing method embodiments.

[0223] The communication device 1200 can be used to perform the actions executed on the first communication device side in the embodiments shown in FIGS. 9 to 11. The processing module 1202 is used to perform the operations related to processing on the first communication device side in the embodiments shown in FIGS. 9 to 11. The transceiver module 1201 is used to perform the operations related to receiving or sending on the first communication device side in the embodiments shown in FIGS. 9 to 11.

[0224] The communication device 1200 can be used to perform the actions executed on the second communication device side in the embodiments shown in FIGS. 9 to 11. The processing module 1202 is used to perform the operations related to processing on the second communication device side in the embodiments shown in FIGS. 9 to 11. The transceiver module 1201 is used to perform the operations related to receiving or sending on the second communication device side in the embodiments shown in FIGS. 9 to 11.

[0225] For example, the communication device 1200 is used to execute the following solution.

[0226] In one example, when the communication device 1200 is applied to the first communication device, the communication device 1200 includes:

[0227] The transceiver module 1201, which is used to receive a reference signal;

[0228] Processing module 1202 is used to perform measurements based on the reference signal to determine a precoding matrix indicator (PMI). The PMI includes first information and second information, wherein the first information indicates G beam sets, where G is an integer greater than 1, and any one of the G beam sets includes multiple mutually orthogonal beams; the second information indicates L beams in the G beam sets, where the L beams are used to determine the precoding matrix, and L is an integer greater than 1.

[0229] The transceiver module 1201 is also used to send the PMI.

[0230] The possible implementation methods and descriptions of the first and second information can be found in the corresponding contents of the embodiments in Figures 9 to 11, and will not be repeated here.

[0231] In another example, communication device 1200 is applied to a second communication device, the communication device 1200 comprising:

[0232] Transceiver module 1201 is used to transmit reference signals;

[0233] The transceiver module 1201 is further configured to receive a precoding matrix indication (PMI) corresponding to the reference signal. The PMI includes first information and second information. The first information indicates G beam sets, where G is an integer greater than 1. Each of the G beam sets includes multiple mutually orthogonal beams. The second information indicates L beams in the G beam sets, where L beams are used to determine the precoding matrix, and L is an integer greater than 1.

[0234] The transceiver module 1201 is also used to send data, which is precoded by the precoding matrix determined by the PMI.

[0235] For other implementation methods, please refer to the relevant descriptions in the embodiments shown in Figures 9 to 11 above, which will not be repeated here.

[0236] It should be understood that the specific procedures for each module to perform the above-mentioned corresponding processes have been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0237] The processing module 1202 in the above embodiments can be implemented by at least one processor or processor-related circuitry. The transceiver module 1201 can be implemented by a transceiver or transceiver-related circuitry. The transceiver module 1201 can also be referred to as a communication module or communication interface. The storage module can be implemented by at least one memory.

[0238] In one example, the transceiver module 1201 is used to perform the aforementioned steps 901 to 903.

[0239] This application also provides another communication device, and FIG13 is another structural schematic diagram of the communication device according to an embodiment of this application. Referring to FIG13, the communication device 1300 includes a processor 1301.

[0240] Optionally, the communication device 1300 may also include a memory 1302.

[0241] Optionally, the communication device 1300 may also include a transceiver 1303.

[0242] In one possible implementation, the processor 1301, memory 1302, and transceiver 1303 are connected via a bus, and the memory 1302 stores computer instructions.

[0243] In one possible implementation, when the communication device 1300 includes a second communication device, or a CU or DU included in the second communication device, or a component (e.g., a chip or chip system), module, or unit within the second communication device, the communication device 1300 can be used to perform the steps performed by the second communication device in the above method embodiments, as can be referred to the relevant descriptions in the above method embodiments.

[0244] Optionally, the processing module 1202 in the embodiment shown in FIG12 may be the processor 1301, and the transceiver module 1201 in the embodiment shown in FIG12 may be the transceiver 1303. Alternatively, the processing module 1202 in the embodiment shown in FIG12 may be the processor 1301, and the transceiver module 1201 in the embodiment shown in FIG12 may be the transceiver 1303.

[0245] The aforementioned memory 1302 can be built into the communication device 1300 or externally placed in the communication device 1300. This application embodiment does not limit this.

[0246] This application also provides a communication device. Figure 14 is another structural schematic diagram of the communication device according to an embodiment of this application. Referring to Figure 14, the communication device 1400 can be the first communication device in the above method embodiments, or it can be a component (e.g., a chip or chip system), module, or unit of the first communication device in the above method embodiments. The communication device 1400 can be used to perform the steps performed by the first communication device in the above method embodiments, and can be referred to the relevant descriptions in the above method embodiments.

[0247] Processors are mainly used to process data or signals, control communication devices, execute corresponding software programs, and process the data of software programs.

[0248] The memory is mainly used to store software programs and data. The radio frequency (RF) circuit is mainly used for the conversion between baseband signals and RF signals, as well as the processing of RF signals.

[0249] Antennas are primarily used for transmitting and receiving radio frequency signals in the form of electromagnetic waves.

[0250] Optionally, the communication device 1400 may also include input / output devices, such as a touch screen, a display screen, a keyboard, etc., primarily used to receive user input data and output data to the user.

[0251] When data needs to be transmitted, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit then processes the baseband signal and transmits it outward as electromagnetic waves through the antenna. When data is sent to the communication device, the RF circuit receives the RF signal through the antenna, converts it into a baseband signal, and outputs the baseband signal to the processor. The processor then converts the baseband signal back into data and processes it.

[0252] For ease of explanation, only one memory and processor are shown in Figure 14. In actual communication device products, there may be one or more processors and one or more memories. Memory may also be called storage medium or storage device, etc. Memory may be set up independently of the processor or integrated with the processor; this application embodiment does not limit this.

[0253] In this embodiment, the antenna and radio frequency circuit with transceiver functions can be regarded as the transceiver unit of the communication device, and the processor with processing functions can be regarded as the processing unit of the communication device. As shown in FIG14, the communication device 1400 includes a transceiver unit 1410 and a processing unit 1420. The transceiver unit can also be called a transceiver, transceiver machine, transceiver device, etc. The processing unit can also be called a processor, processing board, processing module, processing device, etc.

[0254] Optionally, the devices in transceiver unit 1410 used for receiving functions can be considered as receiving units, and the devices in transceiver unit 1410 used for transmitting functions can be considered as transmitting units. That is, transceiver unit 1410 includes both receiving and transmitting units. A transceiver unit can also be called a transceiver, transceiver circuit, etc. A receiving unit can also be called a receiver, receiver, or receiving circuit, etc. A transmitting unit can also be called a transmitter, transmitter, or transmitting circuit, etc.

[0255] It should be understood that the transceiver unit 1410 is used to perform the transmission and reception operations of at least one of the devices in the first communication device in the above method embodiment, and the processing unit 1420 is used to perform other operations on at least one of the devices in the first communication device in the above method embodiment besides the transmission and reception operations.

[0256] When the communication device is a chip or chip system, the chip or chip system includes a transceiver unit and a processing unit. The transceiver unit can be an input / output circuit or a communication interface; the processing unit is a processor, microprocessor, integrated circuit, or logic circuit integrated on the chip or chip system. In the above method embodiments, the sending operation corresponds to the output of the input / output circuit, and the receiving operation corresponds to the input of the input / output circuit.

[0257] This application also provides another communication system, which includes a second communication device and a first communication device. The second communication device is used to perform all or part of the steps performed by the second communication device in the embodiments shown in Figures 9 to 11, and the first communication device is used to perform all or part of the steps performed by the first communication device in the embodiments shown in Figures 9 to 11.

[0258] This application also provides a computer program product including a computer program or instructions, which, when run on a computer, causes the computer to perform the method of the embodiments shown in Figures 9 to 11 above.

[0259] This application also provides a computer-readable storage medium including computer instructions that, when executed on a computer, cause the computer to perform the methods shown in the embodiments of Figures 9 to 11 above.

[0260] This application also provides a chip device, including a processor, for calling a computer program or computer instructions stored in a memory, so that the processor executes the method of the embodiments shown in Figures 9 to 11 above.

[0261] Optionally, the processor is coupled to the memory via an interface.

[0262] Optionally, the chip device may also include a memory in which computer programs or computer instructions are stored.

[0263] The processor mentioned above can be a general-purpose central processing unit, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of a program for controlling the methods of the embodiments shown in Figures 9 to 11. The memory mentioned above can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, such as random access memory (RAM).

[0264] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0265] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0266] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0267] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the part of the technical solution that makes an essential contribution, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a second communication device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0268] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A precoding matrix indication method, characterized in that, The method is applied to a first communication device, and the method includes: Receive reference signal; Based on the reference signal, a precoding matrix indicator (PMI) is determined. The PMI includes first information and second information, wherein the first information indicates G beam sets, where G is an integer greater than 1, and any one of the G beam sets includes multiple mutually orthogonal beams; the second information indicates L beams in the G beam sets, where L is an integer greater than 1. Send the PMI.

2. The method according to claim 1, characterized in that, The method further includes: Receive third information, which is used to configure the number G of beam sets to be fed back by the first communication device.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Receive fourth information, the fourth information being used to configure the number L of beams to be fed back by the first communication device, or the fourth information being used to configure the number L of beams to be fed back from the g-th beam set among the G beam sets to be fed back by the first communication device. g ,in, The number of beams requiring feedback in the g-th beam set among the G beam sets is L. g , g∈{1,…,G},L g L is an integer greater than or equal to 0. g The relationship between L and L satisfies:

4. A precoding matrix indication method, characterized in that, The method is applied to a second communication device, and the method includes: Send a reference signal; The precoding matrix indication (PMI) corresponding to the reference signal is received. The PMI includes first information and second information. The first information indicates G beam sets, where G is an integer greater than 1. Each of the G beam sets includes multiple mutually orthogonal beams. The second information indicates L beams in the G beam sets. The L beams are used to determine the precoding matrix, where L is an integer greater than 1. Data is transmitted, which is precoded using the precoding matrix determined by the PMI.

5. The method according to claim 4, characterized in that, The method further includes: Send a third message, which is used to configure the number G of beam sets to be fed back by the first communication device.

6. The method according to claim 4 or 5, characterized in that, The method further includes: Sending a fourth message, the fourth message being used to configure the number L of beams to be fed back by the first communication device, or the fourth message being used to configure the number L of beams to be fed back from the g-th beam set among the G beam sets to be fed back by the first communication device. g ,in, L is an integer greater than 1, and the number of beams requiring feedback in the g-th beam set among the G beam sets is L. g , g∈{1,…,G},L g L is an integer greater than or equal to 0. g The relationship between L and L satisfies:

7. The method according to any one of claims 2-3 or 5-6, characterized in that, The third information is carried within configuration information, which is used to configure the resources of the reference signal.

8. The method according to claim 3, 6 or 7, characterized in that, The fourth piece of information is the number of parameter beams (numberOfBeams), which is carried in the configuration information.

9. The method according to any one of claims 1-8, characterized in that, The first information includes: [q 1,1 ,q 1,2 ,…,q g,1 ,q g,2 ,…,q G,1 ,q G,2 ], where parameter q g,1 and parameter q g,2 The parameter q indicates the g-th beam set among the G beam sets. g,1 ∈{0,1,…,O1-1}, the parameter q g,2 ∈{0,1,…,O2-1}, where O1 is the oversampling factor of the antenna port of the first communication device in the horizontal dimension, and O2 is the oversampling factor of the antenna port of the first communication device in the vertical dimension.

10. The method according to claim 9, characterized in that, The first information belongs to the parameter i included in the PMI. 1,1 , where the parameter i 1,1 This is used to indicate the beam set where the L beams fed back by the first communication device are located.

11. The method according to any one of claims 1-10, characterized in that, The second information includes: [i 1,2,1 ,…,i 1,2,g ,…,i 1,2,G ], where parameter i 1,2,g Indicates the beam to be fed back in the g-th beam set among the G beam sets. L g N1 represents the number of beams to be fed back in the g-th beam set among the G beam sets, N2 represents the number of horizontal ports in the reference signal port group, and N2 represents the number of vertical ports in the reference signal port group, which corresponds to the reference signal.

12. The method according to claim 11, characterized in that, The second information belongs to parameter i 1,2 The parameter i 1,2 Used to indicate the position of the L beams within the beam set containing the L beams.

13. The method according to any one of claims 1-12, characterized in that, The second information indicates L vectors, which correspond to the L beams.

14. The method according to any one of claims 1-13, characterized in that, The PMI is used to indicate the G beam sets and the L beams in the G beam sets, wherein the G beam sets are determined based on the L beams, and the L beams are determined based on channel state information, which is information determined by measurement based on the reference signal.

15. A communication device, characterized in that, Used to perform the method as described in any one of claims 1 to 14.

16. A communication device, characterized in that, Includes a processor, which implements the method as described in any one of claims 1 to 14 via logic circuits or executing code instructions.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed, cause the method as described in any one of claims 1 to 14 to be implemented.

18. A computer program product, characterized in that, Includes a computer program or instructions that, when executed, cause the method as described in any one of claims 1 to 14 to be implemented.

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