Channel state information determination method and communication apparatus

Abstract

Provided in the present application are a channel state information determination method and a communication apparatus, which can reduce the complexity of channel filtering and noise reduction, and can be applied to a communication system. The method comprises: a first communication apparatus receiving a first reference signal from a second communication apparatus; and the first communication apparatus sending first information to the second communication apparatus, wherein the first information is used for indicating K first vectors, the K first vectors are used for determining channel state information, the K first vectors are determined on the basis of the first reference signal, each first vector is used for indicating an angle vector corresponding to one beam, and K is an integer greater than or equal to 1.

Description

Channel state information determination method and communication device

[0001] This application claims priority to Chinese Patent Application No. 202510098675.2, filed on January 21, 2025, entitled “Method and Communication Apparatus for Determining Channel State Information”, 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 method for determining channel state information and a communication device. Background Technology

[0003] As frequency bands increase and antenna apertures expand, the probability of current network users falling within the near-field range grows, making the characteristics of the propagation channel more consistent with the near-field spherical wavefront assumption. In the near-field environment, the nonlinear phase characteristics (spherical wave characteristics) of electromagnetic wave propagation cannot be ignored. Therefore, when utilizing the spatial sparsity of the channel for filtering and noise reduction, compared to angle-domain filtering in far-field channels, near-field channels require further introduction of a range-domain dimension to match the nonlinear phase characteristics of near-field spherical waves and improve channel estimation accuracy. However, due to the introduction of the range-domain dimension, the total number of beams in the beamset used for filtering and noise reduction in near-field channels is greater than that in the beamset used for filtering and noise reduction in far-field channels, and the beams in the beamset are not perfectly orthogonal. This makes the beam selection scheme for channel filtering and noise reduction in near-field channels more complex. In other words, the above-mentioned filtering and noise reduction scheme for near-field channels suffers from high complexity. Summary of the Invention

[0004] This application provides a method for determining channel state information and a communication device, which can reduce the complexity of near-field channel filtering and noise reduction schemes.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, a method for determining channel state information is provided. The method includes: a first communication device receiving a first reference signal from a second communication device; the first communication device sending first information to the second communication device, the first information indicating K first vectors, the K first vectors being used to determine channel state information, the K first vectors being determined based on the first reference signal, the first vectors indicating angle vectors corresponding to a beam, and K being an integer greater than or equal to 1.

[0007] Based on the method provided in the first aspect, the first communication device can determine K first vectors according to the received first reference signal, and indicate the K first vectors to the second communication device through the first information. In this way, when the second communication device determines the channel state information, it can perform filtering and noise reduction based on the K first vectors indicated by the first communication device, that is, use fewer beams in the angular domain for filtering and noise reduction, thereby reducing the complexity of filtering and noise reduction.

[0008] As an example, the first communication device may be a terminal device, a communication module, a circuit or chip responsible for communication functions, a chip system, or other components or parts. This communication module, circuit or chip responsible for communication functions, chip system, or other components or parts may be used in the terminal device.

[0009] In one possible implementation, the method provided by the first aspect further includes: a first communication device determining a first covariance matrix based on a first reference signal, wherein K first vectors are determined based on the first covariance matrix.

[0010] In one possible implementation, before the first communication device sends the first information to the second communication device, the method provided by the first aspect further includes: the first communication device receiving second information from the second communication device, the second information indicating the number K of first vectors reported by the first communication device or the maximum number Kmax of first vectors reported by the first communication device, where Kmax is an integer greater than or equal to 1, and K is less than or equal to Kmax. Thus, the second communication device can control the number of first vectors that need to be reported, thereby controlling the overhead of reporting the first vectors.

[0011] In one possible implementation, the method provided by the first aspect further includes: the first communication device sending a third reference signal to the second communication device, the third reference signal being used for channel measurement.

[0012] Secondly, a method for determining channel state information is provided. This method includes: a second communication device sending a first reference signal to a first communication device; the second communication device receiving first information from the first communication device; the second communication device receiving a third reference signal from the first communication device; and the second communication device determining channel state information based on K first vectors and the third reference signal. The first information is used to indicate the K first vectors, the K first vectors are used to obtain channel state information between the first and second communication devices, the K first vectors are determined based on the first reference signal, and the first vectors are used to indicate the angle vector corresponding to a beam, where K is an integer greater than or equal to 1.

[0013] Based on the method provided in the second aspect, the second communication device can send a first reference signal and acquire K first vectors determined by the first reference signal. Thus, when determining channel state information, the second communication device can perform filtering and noise reduction based on the K first vectors indicated by the first communication device, that is, use fewer beams in the angular domain for filtering and noise reduction, thereby reducing the complexity of filtering and noise reduction.

[0014] As an example, the second communication device may be a network device, a communication module, a circuit or chip responsible for communication functions, a chip system, or other components or parts. This communication module, circuit or chip responsible for communication functions, chip system, or other components or parts may be used in a network device.

[0015] In one possible implementation, the method provided by the second aspect further includes: the second communication device determining channel state information based on K first vectors and a third reference signal, including: the second communication device determining the channel state information based on multiple polar beams and the third reference signal, wherein the multiple polar beams are determined based on the K first vectors and at least one distance. Thus, the second communication device can perform filtering and noise reduction on the multiple polar beams determined based on the K first vectors and at least one distance, thereby narrowing the selection range of polar beams for filtering and noise reduction, and thus reducing the complexity of filtering and noise reduction.

[0016] In one possible implementation, the K first vectors are determined based on the first covariance matrix, which is determined based on the first reference signal.

[0017] In one possible implementation, the method provided by the second aspect further includes: the second communication device sending second information, the second information indicating the number K of the first vectors reported by the first communication device or the maximum number Kmax of the first vectors reported by the first communication device, where Kmax is an integer greater than or equal to 1, and K is less than or equal to Kmax. Thus, the number of first vectors that need to be reported can be controlled by the second communication device, thereby controlling the overhead of reporting the first vectors.

[0018] In one possible implementation, the method provided by the second aspect further includes: the second communication device determining channel state information between the first communication device and the second communication device based on the first information. Thus, the second communication device can perform channel filtering and noise reduction based on the first information. For example, the second communication device can combine the first information with polar-domain beams corresponding to different distances to perform channel filtering and noise reduction, thereby obtaining more accurate channel state information.

[0019] In a possible implementation combining the methods provided in the first or second aspect, each element of the first covariance matrix corresponds to two antenna ports of the second communication device, and the antenna elements corresponding to each of the two antenna ports are centrally symmetric. That is, by utilizing the centrally symmetric characteristic of the antenna elements corresponding to each group of antenna ports to construct the first covariance matrix, the influence of angle and distance in the channel's nonlinear phase characteristics can be eliminated; that is, the angle domain and the distance domain can be decoupled, allowing the first communication device to better determine the K first vectors based on the first covariance matrix.

[0020] In some examples, each element in the first covariance matrix corresponds to a port group of the second communication device. Each port group of the second communication device includes two antenna ports, and the sum of the port numbers of the antenna ports in different port groups of the second communication device is the same. One antenna port corresponds to one antenna element of the second communication device. When the antenna ports are numbered according to the positional order of the antenna elements, the fact that the sum of the port numbers of the antenna ports in different port groups is the same means that the two antenna elements corresponding to the two antenna ports in different port groups are centrally symmetric. In this case, constructing the first covariance matrix using the centrally symmetric characteristic of the antenna elements corresponding to each group of ports can eliminate the influence of angle and distance in the nonlinear phase characteristics of the channel; that is, the angle domain and the distance domain can be decoupled, allowing the first communication device to better determine the K first vectors based on the first covariance matrix.

[0021] In one possible implementation, the information used to determine the first covariance matrix further includes at least one of the following: channel measurement results corresponding to all antenna ports of the second communication device in one or more frequency domain units, one or more receiving antennas, or one or more polarization directions.

[0022] In one possible implementation, the information used to determine the first covariance matrix further includes at least one of the following: a second covariance matrix or a third covariance matrix, wherein the second covariance matrix is ​​determined based on channel measurement results of the first reference signal, and the third covariance matrix is ​​determined based on channel measurement results of the second reference signal, the second reference signal being located before the first reference signal in the time domain. Thus, by combining the covariance matrices corresponding to the reference signals at different times to determine the first covariance matrix, the statistical characteristics of the channel can be obtained, making the first covariance matrix more closely match the actual channel, thereby improving the channel filtering and noise reduction effect.

[0023] In one possible implementation, the first covariance matrix satisfies the following relationship: m = 0, ..., N1N2-1; where... Let α represent the first covariance matrix, and α be the time-domain filtering factor. Let R be the third covariance matrix. v Let N be the second covariance matrix. f Where f is the number of frequency domain cells, and f is the index of the frequency domain cell, 0 <f≤N f N rx The total number of receive antenna ports, where x is the index of the receive antenna port, 0. <x≤N rx N P represents the total number of polarization directions, and q represents the index of the polarization direction, 0. <q≤N P V(f,x,q) represents the covariance matrix determined by the channel measurement results corresponding to the frequency domain cell with index f, the receiving antenna with index x, and all antenna ports of the second communication device in the polarization direction with index q. For V(f,x,q), the p-th m -p0 line, number The elements of the column, N1, represent the number of antenna ports of the second communication device in the first direction, and N2 represent the number of antenna ports of the second communication device in the second direction. It is the second communication device with index p among all antenna ports. m The channel matrix of the antenna ports, It is the index of all antenna ports of the second communication device. The channel matrix corresponding to the antenna port is conjugate. In this way, by combining the channel state information obtained from the reference signal at different times in different frequency domain units, different receiving antenna ports, and different polarization directions, the first covariance matrix can be determined. This allows for the acquisition of more accurate statistical spatial characteristics of the channel, making the first covariance matrix more closely match the actual channel and thus improving the effect of channel filtering and noise reduction.

[0024] In one possible implementation, the first covariance matrix is ​​determined based on channel measurements of the first reference signal. This allows the first covariance matrix to better match the statistical spatial characteristics of the actual channel, thereby obtaining a first vector that better matches the channel characteristics and assisting the second communication device in improving the noise reduction and filtering effect.

[0025] In one possible implementation, the first covariance matrix satisfies the following relationship: m = 0, ..., N1N2-1; where... Let N represent the first covariance matrix, which is constructed based on the channel measurement results of the first reference signal. f Where f is the number of frequency domain cells, and f is the index of the frequency domain cell, 0 <f≤N f N rxThe total number of receive antenna ports, where x is the index of the receive antenna port, 0. <x≤N rx N P q represents the polarization quantity, and q represents the index of the polarization direction. <q≤N P V(f,x,q) represents the covariance matrix determined by the channel measurement results corresponding to the frequency domain cell with index f, the receiving antenna with index x, and all antenna ports of the second communication device in the polarization direction with index q. For V(f,x,q), the p-th m -p0 line, number The column elements are: N1 represents the number of antenna ports of the second communication device in the first direction, and N2 represents the number of antenna ports of the second communication device in the second direction. It is the second communication device with index p among all antenna ports. m The channel matrix of the antenna ports, It is the index of all antenna ports of the second communication device. The channel matrix corresponding to the antenna port is taken as its conjugate. In this way, by combining the channel state information of different frequency domain units, different receiving antenna ports, and different polarization directions to determine the first covariance matrix, more accurate real-time spatial characteristics of the channel can be obtained, so that the first covariance matrix is ​​more in line with the actual channel, thereby improving the effect of channel filtering and noise reduction.

[0026] In one possible implementation, the K first vectors are the K first vectors in the set of first vectors whose projection energy of the first covariance matrix onto the first vector is the strongest, and the number of first vectors in the set of first vectors is greater than K.

[0027] In one possible implementation, the first information is used to indicate the number of combinations of the K first vector indices. Indicating the K first vectors by the number of combinations can reduce overhead.

[0028] In one possible implementation, the number of bits occupied by the first information satisfies the following relationship: Where B is the number of bits occupied by the first information, N1 is the number of antenna ports of the second communication device in the first direction, and N2 is the number of antenna ports of the second communication device in the second direction.

[0029] In one possible implementation, the first information includes the index of each of the K first vectors. Thus, directly indicating the index of the first vector can reduce implementation complexity.

[0030] In one possible implementation, the first information occupies M bits, where each of the M bits corresponds to one of the M first vectors, and different bits correspond to different first vectors. Each bit is used to indicate whether the K first vectors include the first vector corresponding to each bit. One bit corresponds one-to-one with one first vector, and each bit can be 0 or 1 to indicate whether the corresponding first vector is included in the K first vectors, resulting in low complexity.

[0031] In one possible implementation, the first information is determined based on multiple reference signals, including a first reference signal and a second reference signal preceding the first reference signal. Thus, reporting the first information based on multiple reference signals reduces the reporting frequency of the first information, thereby lowering reporting overhead.

[0032] Thirdly, a communication device is provided. This communication device is used to perform the channel state information determination method described in any implementation of the first or second aspect.

[0033] In this application, the communication device described in the third aspect can be a terminal device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in the terminal device. Alternatively, the communication device can be a network device (such as a radio access network (RAN) node), a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in the network device.

[0034] It should be understood that the communication apparatus described in the third aspect includes modules, units, or means that implement the channel state information determination method described in either the first or second aspect. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units for performing the functions involved in the aforementioned channel state information determination method.

[0035] Fourthly, a communication apparatus is provided. The communication apparatus includes a processor configured to execute the channel state information determination method described in any possible implementation of the first or second aspect.

[0036] In one possible implementation, the communication device described in the fourth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the fourth aspect and other communication devices.

[0037] In one possible implementation, the communication device described in the fourth aspect may further include a memory. Optionally, the memory may be integrated with the processor or disposed separately. Optionally, the memory may be located outside the communication device.

[0038] The memory can be used to store the computer program (or code instructions or program instructions) and / or data involved in the channel state information determination method described in either the first or second aspect. In this application, the communication device described in the fourth aspect can be a terminal device, a communication module, a circuit with communication functions, a chip, a chip system, or other components or assemblies; the communication module, the circuit with communication functions, the chip, the chip system, or other components or assemblies can be applied in a terminal device. Alternatively, the communication device can be a network device, a communication module, a circuit with communication functions, a chip, a chip system, or other components or assemblies; the communication module, the circuit with communication functions, the chip, the chip system, or other components or assemblies can be applied in a network device.

[0039] Fifthly, a communication device is provided. The communication device includes a processor coupled to a memory, the processor executing a computer program stored in the memory, such that the communication device performs the channel state information determination method described in any possible implementation of the first or second aspect.

[0040] In one possible implementation, the communication device described in the fifth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the fifth aspect and other communication devices.

[0041] In this application, the communication device described in the fifth aspect can be a terminal device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in a terminal device. Alternatively, the communication device can be a network device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in a network device.

[0042] A sixth aspect provides a communication device, comprising: a processor and a memory; the memory being used to store a computer program, which, when executed by the processor, causes the communication device to perform the channel state information determination method described in either the first or second aspect.

[0043] In one possible implementation, the communication device described in the sixth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the sixth aspect and other communication devices.

[0044] In this application, the communication device described in the sixth aspect can be a terminal device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in a terminal device. Alternatively, the communication device can be a network device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, the circuit with communication function, the chip, the chip system, or other components or assemblies can be applied in a network device.

[0045] A seventh aspect provides a communication device, comprising: a processor; the processor being coupled to a memory, and after reading a computer program from the memory, executing a channel state information determination method as described in any implementation of the first or second aspect according to the computer program.

[0046] In one possible implementation, the communication device described in the seventh aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the seventh aspect and other communication devices.

[0047] In this application, the communication device described in the seventh aspect can be a terminal device, a communication module, a circuit with communication function, a chip, a chip system, or other components or assemblies. The communication module, or the circuit, chip, chip system, or other components or assemblies with communication function can be applied in the terminal device. Alternatively, the communication device can be a network device (such as a radio access network (RAN) node), a communication module, a circuit, chip, chip system, or other components or assemblies with communication function. The communication module, the circuit, chip, chip system, or other components or assemblies with communication function can be applied in the network device.

[0048] Eighthly, a communication system is provided. The communication system includes one or more terminal devices and one or more network devices.

[0049] A ninth aspect provides a computer-readable storage medium comprising: a computer program or instructions; wherein, when the computer program or instructions are executed on a computer, the computer performs the channel state information determination method described in any possible implementation of the first or second aspect.

[0050] In a tenth aspect, a computer program product is provided, comprising a computer program or instructions that, when executed on a computer, cause the computer to perform the channel state information determination method described in any possible implementation of the first or second aspect.

[0051] Furthermore, the technical effects of the third to tenth aspects mentioned above can be referred to the technical effects of the channel state information determination method described in the first or second aspects, and will not be repeated here. Attached Figure Description

[0052] Figure 1 is a schematic diagram of the architecture of the communication system provided in an embodiment of this application;

[0053] Figure 2 is an application scenario diagram of a communication system provided in an embodiment of this application;

[0054] Figure 3 is a schematic diagram of an interactive process for channel estimation based on a probe reference signal;

[0055] Figure 4 is a schematic diagram of a channel state information reporting process;

[0056] Figure 5 shows a schematic diagram of plane waves and spherical waves;

[0057] Figure 6 is a schematic diagram showing the relationship between angle and power in far-field and near-field channels;

[0058] Figure 7 is a flowchart illustrating the method for determining track status information provided in an embodiment of this application;

[0059] Figure 8 is a schematic diagram of the antenna array provided in an embodiment of this application;

[0060] Figure 9 is a schematic diagram of the port number distribution provided in the embodiments of this application;

[0061] Figure 10 is a schematic diagram of the positional relationship of the symmetrical antenna elements provided in the embodiments of this application;

[0062] Figure 11 is a schematic diagram of the communication device provided in an embodiment of this application;

[0063] Figure 12 is a schematic diagram of the structure of the communication device provided in the embodiment of this application. Detailed Implementation

[0064] The technical solutions of this application embodiment can be applied to various communication systems, such as wireless fidelity (WiFi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, 4th generation (4G) mobile communication systems, such as long term evolution (LTE) systems, 5th generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems, etc.

[0065] This application will present various aspects, embodiments, or features relating to systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

[0066] Furthermore, in the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as an "example" in this application should not be construed as being better or more advantageous than other embodiments or designs. Rather, the use of the word "example" is intended to present the concept in a specific manner.

[0067] First, in this application, "for indicating" can include both direct and indirect indication. When describing "information" for indicating A, it can include whether the information directly indicates A or indirectly indicates A, but does not necessarily mean that the information carries A.

[0068] The information indicated by a given 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, such as, but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or its index. It can also be indirectly indicated by indicating other information, where there is a relationship between the other information and the information to be indicated. It can also indicate only a part of the information to be indicated, while the other parts are known or pre-agreed upon. For example, the indication of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing the indication overhead to some extent. At the same time, common parts of various pieces of information can be identified and indicated uniformly to reduce the indication overhead caused by individually indicating the same information.

[0069] Furthermore, the specific indication method can also be any existing indication method, such as, but not limited to, the above-mentioned indication methods and their various combinations. Specific details of various indication methods can be found in existing technologies, and will not be repeated here. As described above, for example, when multiple pieces of information of the same type need to be indicated, the indication methods for different pieces of information may differ. In the specific implementation process, the required indication method can be selected according to specific needs. This application embodiment does not limit the selected indication method; therefore, the indication methods involved in this application embodiment should be understood to cover various methods that enable the party to be indicated to obtain the information to be indicated.

[0070] The information to be instructed can be sent as a whole or divided into multiple sub-information messages, and the sending period and / or timing of these sub-information messages can be the same or different. This application does not limit the specific sending method. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the transmitting device by sending configuration information to the receiving device. This configuration information can include, for example, but not limited to, one or a combination of at least two of radio resource control (RRC) signaling, medium access control (MAC) layer signaling, and physical layer signaling. MAC layer signaling includes, for example, a MAC control element (CE); physical (PHY) layer signaling includes, for example, downlink control information (DCI).

[0071] Second, in the embodiments shown below, the first, second, and various numerical designations are merely distinctions for descriptive convenience and are not intended to limit the scope of the embodiments of this application. For example, to distinguish different indication information.

[0072] Third, "pre-defined," "pre-configured," or "pre-specified" can be achieved by pre-saving corresponding codes, tables, or other means of indicating relevant information in the device (e.g., including terminal devices and network devices), or by pre-defining them in a protocol. This application does not limit the specific implementation method. "Saving" can refer to saving in one or more memories. These memories can be separate installations or integrated into the encoder, decoder, processor, or communication device. Alternatively, some memories can be separately installed, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0073] Fourth, the “protocol” involved in the embodiments of this application may refer to standard protocols in the field of communications, such as LTE protocols of the 3rd generation partnership project (3GPP) (such as technical specification (TS) 36, i.e., the TS36 series of technical specifications), NR protocols (such as the TS38 series of technical specifications), and related protocols applied to future communication systems. This application does not limit this.

[0074] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0075] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0076] To facilitate understanding of the embodiments of this application, the communication system applicable to the embodiments of this application will be described in detail first using the communication system shown in FIG1 as an example. Exemplarily, FIG1 is a schematic diagram of the architecture of a communication system to which the method provided in the embodiments of this application applies. As shown in FIG1, the communication system includes network devices and terminal devices.

[0077] As shown in Figure 1, the communication system includes at least one network device (such as network device 110a and network device 110b) and at least one terminal device (such as terminal device 120a to terminal device 120j).

[0078] Terminal devices can connect to network devices wirelessly, and network devices can connect to the core network 130 via wired or wireless means. Network devices can connect to the Internet 140, and the core network 130 can connect to the Internet 140.

[0079] Among them, network devices and terminal devices can exchange information.

[0080] Terminal equipment can be a terminal with transceiver capabilities. This terminal equipment can also be referred to as user equipment (UE), access terminal, subscriber unit, user station, mobile station (MS), mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user apparatus. The terminal devices in the embodiments of this application may be mobile phones, cellular phones, smartphones, tablets, wireless data cards, personal digital assistants (PDAs), wireless modems, handsets, laptop computers, machine-type communication (MTC) terminals, computers with wireless transceiver capabilities, virtual reality (VR) terminals, augmented reality (AR) terminals, smart home devices (e.g., refrigerators, televisions, air conditioners, electricity meters, etc.), intelligent robots, robotic arms, workshop equipment, wireless terminals in autonomous driving, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, vehicle-mounted terminals, and roadside units with terminal functions. The terminal device in this application can also be an onboard module, onboard unit, onboard component, onboard chip, or onboard unit, which is built into a vehicle as one or more components or units. The terminal device can also be other devices with terminal functions; for example, it can be a device that performs terminal functions in D2D communication. The embodiments of this application do not limit the device form of the terminal device. The device used to implement the function of the terminal device can be the terminal device itself; it can also be a device that supports the terminal device in implementing the function, such as a communication module, chip, chip system, other components or parts, or circuits or functional components. This device can be installed in the terminal device or used in conjunction with the terminal device. The chip system can be composed of chips or include chips and other discrete devices.Among them, the various forms of terminal devices mentioned above can also be referred to as terminal-side devices.

[0081] In this application embodiment, the network device can be a device with wireless transceiver capabilities. For example, the network device can be a device located in the access network (AN) of a communication system, which can be used to provide access services for terminals. In one possible scenario, the network device can be a radio access network (RAN) device, such as a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), or a base station in a future communication system. In future mobile communication systems, the network device may also have other naming conventions, all of which are covered within the protection scope of this application embodiment, and this application does not impose any limitations on them. Alternatively, the network device may also include 5G, such as a next-generation mobile communication base station (gNB) in an NR system, or one or a group of antenna panels (including multiple antenna panels) of a 5G base station, or it may be a network node constituting a gNB, a transmission and reception point (TRP or transmission point (TP)) or a transmission measurement function (TMF). Alternatively, the network device can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a wireless controller in a cloud radio access network (CRAN) scenario. Optionally, the network device can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network device in V2X technology can be a roadside unit (RSU). All or part of the functions of the network device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The network device in this application can also be a logical node, logical module, or software capable of implementing all or part of the network device functions.

[0082] In another possible scenario, multiple network devices collaborate to assist terminal devices in achieving wireless access, with each network device performing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be configured separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0083] In different systems, CU (or centralized unit control plane (CU-CP)) and centralized unit user plane (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 (O-RAN or ORAN) system, CU can also be called an open centralized unit (O-CU) (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). For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the CU (or CU-CP, CU-UP), DU and RU units in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0084] In this embodiment, the form of the network device is not limited. The device used to implement the function of the network device can be the network device itself; it can also be any device that supports the network device in implementing that function, such as a communication module, chip, chip system, other components or parts, or circuits or functional components. This device can be installed in the network device or used in conjunction with the network device. The chip system can be composed of chips or can include chips and other discrete devices. The network devices of the various forms described above can also be referred to as network-side devices.

[0085] It should be understood that Figure 1 is a simplified schematic diagram for ease of understanding only, and the communication system may also include other network devices and / or other terminal devices, which are not shown in Figure 1.

[0086] As shown in Figure 2, the network device includes an RRC signaling interaction module (RRC in Figure 2), a MAC signaling interaction module (MAC in Figure 2), and a PHY signaling and data interaction module (PHY in Figure 2). The terminal device includes an RRC signaling interaction module, a MAC signaling interaction module, and a PHY signaling and data interaction module.

[0087] Network devices and terminal devices can exchange RRC signaling via the RRC signaling interaction module. They can also exchange Media Access Control-Control Element (MAC-CE) signaling via the MAC signaling interaction module. Finally, they can exchange one or more of the following via the PHY interaction module: uplink control signaling, downlink control signaling (such as DCI), uplink data, or downlink data.

[0088] The technical terms and related technical solutions in this application will be described below with reference to the accompanying drawings.

[0089] 1. First Vector: The first vector is an angle vector corresponding to a beam. One first vector corresponds to a transmit or receive beam of a first communication device, or one first vector corresponds to a transmit or receive beam of a second communication device. Each transmit or receive beam of the first or second communication device corresponds to a set of vertical and horizontal angles, representing a spatial angular direction. The length of the first vector can be T, where T represents the number of transmit antenna ports in a polarization direction, T≥1, and T is an integer.

[0090] Optionally, the first vector can be, for example but not limited to, a column vector of a two-dimensional discrete Fourier transform (DFT) matrix or a column vector of an oversampled two-dimensional DFT matrix; that is, the first vector can be a two-dimensional DFT vector. A two-dimensional DFT vector can be used to describe a beam formed by the superposition of beams in the horizontal and vertical directions. The first vector can also be an eigenvector determined based on the channel's spatial statistical characteristics. For example, it can be an eigenvector obtained by performing singular value decomposition (SVD) on the channel's spatial statistical covariance matrix, i.e., a column vector of the unitary matrix of the channel's spatial statistical covariance matrix after SVD. Of course, this application is not limited to this.

[0091] In the specific implementation, the first vector set can be predefined by both the receiving and transmitting devices, such as according to a protocol, but this application is not limited to this. In the embodiments of this application, the first vector can also be called a spatial vector, a spatial basis vector, an angle domain vector, an angle domain basis vector, etc., which will not be elaborated further.

[0092] Massive multiple input multiple output (MIMO) technology can improve the spectral efficiency of a system. When using MIMO technology, the base station needs to pre-encode the data before sending it to the terminal device. How to perform pre-coding relies on the channel state information (CSI) between the terminal device and the network device. The following describes how the network device obtains CSI.

[0093] In a time division duplex (TDD) system, the uplink and downlink channels use the same frequency band, meaning that the uplink signal and downlink channel are reciprocal. Based on this reciprocity, network devices, such as base stations, can use uplink reference signals, such as channel sounding reference signals (SRS), to perform channel estimation and obtain channel state information for precoding. The following explanation focuses on SRS. The interaction process between network devices and terminal devices for SRS estimation can be seen in Figure 3.

[0094] As shown in Figure 3, the process includes:

[0095] S301, the network device sends channel sounding configuration information to the terminal device. Correspondingly, the network device receives channel sounding configuration information from the terminal device.

[0096] Channel sounding signal configuration information can be carried in signaling sent from network devices to terminal devices, such as RRC signaling, MAC CE, DCI, etc. The type of signaling is not limited here.

[0097] Channel sounding signal configuration information can be used to instruct terminal equipment to transmit SRS and the resources carrying SRS, such as time domain resources, frequency domain resources, or code domain resources, at least one of them.

[0098] S302, the terminal device can send an SRS to the network device based on the channel sounding signal configuration information. Correspondingly, the network device receives the SRS from the terminal device.

[0099] S303, the network device performs channel measurement based on the received SRS, and performs SRS channel estimation based on the channel measurement results, thereby obtaining the CSI of the channel between the terminal device and the network device.

[0100] Alternatively, the method provided in Figure 3 further includes:

[0101] S304, the network device uses the CSI of this channel to select an appropriate precoding matrix to precode the downlink data to be transmitted, and sends the precoded downlink data to the terminal device.

[0102] The precoding matrix can be identified by the precoding matrix indicator (PMI).

[0103] Alternatively, CSI can be reported by the terminal device based on downlink reference signals, such as the channel state information reference signal (CSI-RS). The following section describes the process by which network devices obtain CSI, using CSI-RS as an example. (See Figure 4.)

[0104] S401, the network device sends channel measurement configuration information to the terminal device.

[0105] The channel measurement configuration information is used to indicate the channel measurement to be performed and the configuration parameters for performing the channel measurement, such as the parameters for configuring time-domain and frequency-domain resources. For example, the channel measurement configuration information can indicate the resources used to carry CSI-RS, i.e., CSI-RS resources.

[0106] S402, the network device sends a CSI-RS to the terminal device on the CSI-RS resource. Correspondingly, the terminal device receives a CSI-RS from the network device on the CSI-RS resource.

[0107] In mobile communication systems, such as New Radio (NR) systems, network devices transmit CSI-RS on CSI-RS resources for terminal devices to probe the downlink channel, and terminal devices receive CSI-RS on pre-configured CSI-RS resources to perform channel estimation.

[0108] S403, the terminal device obtains CSI based on CSI-RS.

[0109] CSI includes PMI.

[0110] It is understandable that S403 can also be understood as the terminal device measuring the received CSI-RS to obtain CSI.

[0111] S404, the terminal device reports CSI to the network device.

[0112] S405, network devices send data to terminal devices according to CSI.

[0113] Understandably, network devices can pre-encode the data to be sent based on the PMI in the CSI, and then send the pre-encoded data.

[0114] In communication systems with small antenna arrays or where the distance between the terminal device and the network device is long, the angular differences between the antenna ports at different locations of the network device and the terminal device or environmental scatterers are small. The phase difference of the signals transmitted between the antenna ports at different locations of the network device and the terminal device is approximately linear. In this case, under the same carrier conditions, the wavefront of the signal at different antenna ports can satisfy the plane wave assumption. As shown in Figure 5(a), for a plane wave, the transmission paths of the signals at different antenna ports are parallel to each other. The transmission distance difference of the signals at different antenna ports is only related to the distance between the antenna ports and the angle between the transmission path and the antenna array. Therefore, the phase change of the signal at different antenna ports of the network device can be represented by the angle between the signal transmission path and the antenna array. Due to the increase in frequency or the expansion of the antenna physical aperture (e.g., increasing the number of antennas, or changing the antenna arrangement, such as moving the antennas further away or sparsely arranging them), the phase difference of the signals transmitted between the antenna ports at different locations of the network device and the terminal device becomes nonlinear. In this case, under the same carrier conditions, the wavefront of the signal satisfies the spherical wavefront assumption. As shown in Figure 5(b), for spherical waves, the angle between the signal transmission path and the antenna array is different at different antenna ports. The phase change of the signal at different antenna ports of the network device needs to be represented by the angle between the signal transmission path and the antenna array, as well as the transmission distance.

[0115] As shown in Fig. 6, plane waves are sparse in the angular domain. That is to say, the channels in the plane wave scenario (far-field channels) can be filtered and denoised by the combination of a finite number of first vectors. Spherical waves will cause power dispersion in the angular domain, which destroys the sparsity in the angular domain and thus affects the performance of channel estimation. In the channel estimation scheme provided in Fig. 3, in order to utilize the sparsity of near-field spherical waves in space, based on the angular domain, a distance domain is introduced to obtain a polar domain (angle-distance domain) beam that better matches the non-linear phase characteristics for filtering and denoising the channels in the spherical wave scenario (near-field channels). Among them, the set of polar domain beams for filtering and denoising can be constructed by sampling in the angular domain (N1 sampling points in the vertical dimension and N2 sampling points in the horizontal dimension) and sampling in the distance domain (N d sampling points), and the set of polar domain beams can include at least one polar domain beam. The polar domain beam matches the steering vector of the antenna array (dimension: N1N2*1). In other words, the polar domain beam can be expressed by the following formula (1):

[0116] where, represents the polar domain beam corresponding to the l-th path, represents the azimuth angle of the l-th path of the channel, θ l represents the elevation angle of the l-th path of the channel; r l represents the distance from the reference antenna element to the scatterer or the terminal device (or the user using the terminal device) corresponding to the l-th path. N1 represents the number of antenna elements in the first direction (such as the vertical direction), N2 represents the number of antenna elements in the second direction (such as the horizontal direction), λ represents the wavelength of the signal, n1 represents the index of the antenna element in the first direction, <n1≤N1, n2 represents the index of the antenna element in the second direction, <n2≤N2, represents the distance from the n1-th antenna element in the first direction and the n2-th antenna element in the second direction to the scatterer (in the non-line-of-sight (NLOS) scenario) or the terminal device (or the user using the terminal device) (in the line-of-sight (LOS) scenario) corresponding to the l-th path.

[0117] represents the wave path difference between the antenna element with index n1 in the first direction and the antenna element with index n2 in the second direction and the reference antenna element, and this wave path difference satisfies the relationship shown in the following formula (2):

[0118] where, is the position coordinate of the antenna element with index n1 in the first direction in the first direction, Let n2 be the position coordinate of the antenna element with index n2 in the second direction, d1 be the distance between two adjacent antenna elements in the first direction, and d2 be the distance between two adjacent antenna elements in the second direction.

[0119] The following provides a detailed explanation of the process for constructing polar beam sets.

[0120] Uniform sampling is performed in the angle domain. That is, the above angle domain sampling can be uniform sampling, and the azimuth and elevation angles of the angle domain sampling satisfy the relationships shown in the following formulas (3) and (4):

[0121] k1 represents the k1th angle domain sampling point in the first direction, and k2 represents the k2th angle domain sampling point in the second direction.

[0122] After angle domain sampling, non-uniform sampling can be performed in the range domain according to the beam domain low correlation criterion. That is, the above range domain sampling can be non-uniform sampling, and for each set of angle domain sampling points, N is generated. d There are N distance sampling points, such that the corresponding N d Each beam satisfies a beam correlation below the correlation threshold △ th That is, satisfying In this way, we can construct N1*N2*N d A set of polar-domain beams. The correlation threshold can be determined based on the antenna topology and processing capabilities of the network device.

[0123] Compared to the angle-domain filtering scheme for far-field channels, the filtering scheme for near-field channels introduces a range-domain dimension to match the nonlinear phase characteristics of near-field spherical waves, thereby improving the accuracy of channel estimation. Specifically, the total number of beams in the beamset used for filtering and noise reduction in the near-field channel is N1*N2*N. d Compared to the total number of beams N1*N2 in the beamset used for far-field channel filtering and noise reduction, the beamset contains more beams, and the beams are not perfectly orthogonal, which leads to a more complex filtering and noise reduction scheme in the near-field channel. In other words, the above-mentioned filtering and noise reduction scheme for the near-field channel suffers from high complexity.

[0124] To address the aforementioned technical problems, some embodiments of this application provide a channel state information determination method. In this method, a first communication device receives a first reference signal from a second communication device and sends first information to the second communication device. The first information indicates K first vectors, which are used to determine the channel state information. The K first vectors are determined based on the first reference signal, and K is an integer greater than or equal to 1. This allows the second communication device to perform channel filtering and noise reduction based on polar-domain beams at different distances of the K first vectors when determining the channel state information, narrowing the selection range of polar-domain beams used for filtering and noise reduction, thereby reducing the complexity of filtering and noise reduction.

[0125] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0126] It should be noted that the method provided in this application embodiment can be applied between any two devices shown in Figure 1, such as between a terminal device and a network device, between two terminal devices, or between two network devices. For specific implementation, please refer to the following method embodiment, which will not be repeated here.

[0127] It should be noted that the solutions in the embodiments of this application can also be applied to other communication systems, and the corresponding names can be replaced by the names of the corresponding functions in other communication systems.

[0128] The method provided in the embodiments of this application will be described in detail below with reference to Figures 7-10.

[0129] In the following embodiments, the first communication device and the second communication device are used for description and will not be repeated. The first communication device may be a terminal device in the communication system shown in Figure 1, and the second communication device may be a network device in the communication system shown in Figure 1, which will not be described further.

[0130] The following explanation is based on the method shown in Figure 7. As shown in Figure 7, the channel state information determination method includes:

[0131] S701, the second communication device sends a first reference signal to the first communication device. Correspondingly, the first communication device receives the first reference signal from the second communication device.

[0132] The first reference signal is used for channel measurement. Optionally, the first reference signal is CSI-RS. The second communication device can transmit periodically or be semi-statically scheduled (SPS). It should be understood that the first reference signal here is for illustrative purposes; in actual implementation, the first reference signal can also be other signals used for channel measurement, which will not be elaborated further.

[0133] It is understood that in the embodiments of this application, the first reference signal is transmitted on multiple beams. For example, the first reference signal may be transmitted on the beams corresponding to different angle sampling points.

[0134] In some examples, after receiving the first reference signal, the first communication device can measure the channel based on the first reference signal to obtain the channel measurement result.

[0135] S702, the first communication device sends first information to the second communication device. Correspondingly, the second communication device receives the first information from the first communication device.

[0136] The first information is used to indicate K first vectors, which are used to determine channel state information. The K first vectors are determined based on the first reference signal, where K is an integer greater than or equal to 1.

[0137] It is understandable that the number of the first vectors indicated by the first information, i.e. K, can be agreed upon by the protocol, such as pre-configuration, or it can be configured by the second communication device.

[0138] The first vector set may include multiple first vectors. Optionally, the first vector in the first vector set may be a DFT vector, in which case the first vector may also be called a DFT basis.

[0139] For an introduction to the first vector, please refer to the relevant description in the technical terminology section; it will not be repeated here.

[0140] In this embodiment of the application, the first information can indicate K first vectors in different ways, which will be described below in conjunction with methods one to four.

[0141] In Method 1, the first information is used to indicate the number of combinations of K first vector indices.

[0142] Optionally, the number of bits occupied by the first information satisfies the relationship shown in the following formula (5):

[0143] Where B is the number of bits occupied by the first information, N1 is the number of antenna ports of the second communication device in the first direction, and N2 is the number of antenna ports of the second communication device in the second direction. This indicates rounding up to the nearest integer.

[0144] For example, if N1 = 8 and N2 = 8, then It is understandable that the values ​​of K, N1, and N2 are used here as examples. In actual implementation, K, N1, and N2 may have other values, which will not be elaborated here.

[0145] Method 2: The first information includes the index of each of the K first vectors.

[0146] Among them, the index of each of the K first vectors is relative to the first vector in the set of first vectors.

[0147] Method 3: The first information occupies M bits, where each of the M bits corresponds to one of the M first vectors, and different bits correspond to different first vectors. Each bit is used to indicate whether the K first vectors include the first vector corresponding to each bit. In this way, each bit can use 0 and 1 to indicate whether a reference signal is transmitted or received on the corresponding time slot. One bit corresponds one time slot, resulting in low implementation complexity.

[0148] Optionally, the number of bits occupied by the first information is determined based on the number of first vectors that the first information needs to indicate. For example, M = K.

[0149] In some examples, the m-th bit of the M bits corresponds to the m-th first vector among the M first vectors, and the m-th bit is used to indicate whether the m-th first vector among the M first vectors is included in the K first vectors. That is, the M bits, from the most significant bit to the least significant bit, indicate whether the first vector with the index in ascending order belongs to the K first vectors. Combining the M first vectors, including 4 first vectors (M=4), namely first vector #0 to first vector #3, this bit diagram includes 4 bits "1010". Then, the highest bit "1" indicates that the first first vector (first vector #0) among the 4 first vectors belongs to the K first vectors. The second highest bit "0" indicates that the second first vector (first vector #1) among the 4 consecutive time slots does not belong to the K first vectors. The second lowest bit "1" indicates that the third first vector (first vector #2) among the 4 first vectors belongs to the K first vectors. The lowest bit "0" indicates that the fourth first vector (first vector #3) among the 4 first vectors does not belong to the K first vectors.

[0150] It is understandable that the M bits, from high to low, can also indicate whether the first vector with the largest index belongs to the K first vectors. A bit of "0" can also indicate that the K first vectors include the first vector corresponding to that bit, and a bit of "1" can indicate that the K first vectors do not include the first vector corresponding to that bit. The relationship between the bit diagram and the first vectors described above is for illustrative purposes. In actual implementation, there may be other possible correspondences between the bits in the bit diagram and the M first vectors, as long as each bit corresponds to one first vector and the first vectors corresponding to different bits are different. This will not be elaborated further.

[0151] Method 4: The first information includes binary values, where each binary value indicates which of the K first vectors are included in the set of first vectors.

[0152] Assuming the first vector set includes first vector #0 to first vector #3, then the relationship between the first vector and the binary value among the K first vectors is shown in Table 1 below.

[0153] Table 1

[0154] Referring to Table 1, assuming K = 1, and the first vector among the K first vectors includes first vector #1, then the first communication device can determine that the binary value carried in the first information is "0001". After receiving the first information, the second communication device can determine, based on "0001" and Table 1, that the K first vectors include first vector #1. Assuming K = 3, and the first vector among the K first vectors includes first vector #1, first vector #2, and first vector #3, then the first communication device, referring to Table 1, can determine that the binary value carried in the first information is "1101". After receiving the first information, the second communication device can determine, based on "1101" and Table 1, that the K first vectors include first vector #1, first vector #2, and first vector #3.

[0155] Table 1 above is for illustrative purposes only. In actual implementation, there may be other possible correspondences between binary values ​​and the first vector among the K first vectors, which will not be elaborated here.

[0156] It is understandable that the above methods one to four are used as examples. In actual implementation, the first information can also indicate K first vectors in other possible ways, which will not be elaborated here.

[0157] In one possible implementation, the first information is determined based on multiple reference signals, including a first reference signal and a second reference signal preceding the first reference signal. Thus, reporting the first information based on multiple reference signals reduces the reporting frequency of the first information, thereby lowering reporting overhead. Specific implementation details are provided below and will not be elaborated further.

[0158] In one possible implementation, the first information is determined solely based on the first reference signal. For example, the first information could be determined based on channel measurement results of the first reference signal. Specific implementation details are provided below and will not be elaborated further. The channel measurement results of the first reference signal can also be referred to as channel state information, including the channel matrix measured based on the first reference signal.

[0159] One possible implementation scheme is to determine K first vectors based on the symmetrical characteristics of the antenna array structure, which will be explained in detail below.

[0160] As shown in Fig. 8, assume that the antenna array plane is located on the XOZ plane, and the geometric center of the antenna array plane is the origin O of the XOZ plane. The n1-th antenna element in the first direction and the n2-th antenna element in the second direction are centrosymmetric with the (N1 - n1 + 1)-th antenna element in the first direction and the (N2 - n2 + 1)-th antenna element in the second direction. The channel between the first communication device and the second communication device (hereinafter simply referred to as the channel) is a near-field channel, and the number of paths is L. Then, the near-field channel h approximately satisfies the relationship shown in the following formula (6):

[0161] Among them, the steering vector of the l-th path of the channel satisfies the relationship shown in the following formula (7):

[0162] Among them, represents the azimuth angle of the l-th path of the channel, θ l represents the elevation angle of the l-th path of the channel, r l represents the distance from the reference antenna element to the scatterer or the terminal device (or the user using the terminal device) corresponding to the l-th path. N1 represents the number of antenna elements in the first aspect (such as the vertical direction), N2 represents the number of antenna elements in the second direction (such as the horizontal direction), λ represents the wavelength of the signal, n1 represents the index of the antenna element in the first direction, 0 < n1 ≤ N1, n2 represents the index of the antenna element in the second direction, 0 < n2 ≤ N2, represents the distance from the (N1 - n1 + 1)-th antenna element in the first direction and the (N2 - n2 + 1)-th antenna element in the second direction to the scatterer (in the NLOS scenario) or the terminal device (or the user using the terminal device) (in the LOS scenario) corresponding to the l-th path, then represents the distance from the n1-th antenna element in the first direction and the n2-th antenna element in the second direction to the scatterer (in the NLOS scenario) or the terminal device (or the user using the terminal device) (in the LOS scenario) corresponding to the l-th path. represents the wave path difference between the n1-th antenna element in the first direction and the n2-th antenna element in the second direction and the reference antenna element. satisfies the relationship shown in the following formula (8). The position coordinates of the n1-th antenna element in the first direction and the n2-th antenna element in the second direction are (c1, c2). c1 and c2 are real numbers.

[0163] Combined with formula (8), it can be seen that contains the first-order term in the angle domain and the second-order term in the angle-distance domain

[0164] This represents the path difference between the N1-n1+1th antenna element in the first direction and the N2-n2+1th antenna element in the second direction and the reference antenna element. The position coordinates of the N1-n1+1th antenna element in the first direction and the N2-n2+1th antenna element in the second direction are (-c1,-c2). It satisfies the relationship shown in the following formula (9).

[0165] Combining formula (9), we can see that Includes linear terms in the angle domain and the quadratic term in the angle-distance domain

[0166] Assuming that the n1th antenna element in the first direction and the n2th antenna element in the second direction are centrally symmetric to the N1-n1+1th antenna element in the first direction and the N2-n2+1th antenna element in the second direction about the origin of the antenna array (i.e., the geometric center of the antenna array), then combining formulas (8) and (9), it can be seen that the first-order term in the angle domain is centrally symmetric about the origin of the array, and the second-order term in the angle-range domain is axially symmetric about the Z-axis and X-axis, respectively. For the l-th path, the corresponding second-order terms in the angle-range domain of the centrally symmetric elements are the same, and the first-order terms in the angle domain are opposites of each other.

[0167] Based on the symmetrical structure of the antenna array, a channel covariance matrix can be constructed, which is a symmetric covariance matrix. The elements in the n1-th row and n2-th column of the constructed channel covariance matrix are shown in the following equation. The channels corresponding to the n1th antenna element in the first direction and the n2th antenna element in the second direction. The channels corresponding to the N1-n1+1th antenna elements in the first direction and the N2-n2+1th antenna elements in the second direction Find the expected value of the inner product, i.e. The following relationship is satisfied: (10)

[0168] β l and β l′ Let l and l′ represent the channel gains of the l-th path and the l′ path, respectively. '*' indicates taking the expected value, and '*' indicates taking the conjugate. In formula (10), The following relationship is satisfied: (11)

[0169] Combining formulas (8) and (9), we can further obtain The following relationship is satisfied: (12)

[0170] cosθ l Let it be denoted as the vertical angle parameter Φ l , Let it be denoted as the horizontal angle parameter Ψ l , can be obtained The following relationship is satisfied: (13)

[0171] By approximating the above formula (12) or formula (13), the quadratic terms in the angle-range domain can be eliminated using symmetry, leaving only the linear terms in the angle domain. In other words, when the antenna array structure is symmetrical, the angle domain and range domain can be decoupled, thereby allowing the angle information to be estimated separately, such as obtaining the first vector.

[0172] Based on the aforementioned characteristics of the structurally symmetrical antenna array, the method shown in Figure 7 also includes S703:

[0173] S703, the first communication device determines the first covariance matrix based on the first reference signal.

[0174] It is understandable that the first reference signal in S703 refers to the first reference signal transmitted to the first communication device through the channel.

[0175] In this case, the K first vectors are determined based on the first covariance matrix.

[0176] Optionally, the aforementioned K first vectors are the K first vectors in the set of first vectors whose projection energy of the first covariance matrix onto the first vector is the strongest, and the number of first vectors in the set of first vectors is greater than K.

[0177] In one possible implementation, each element of the first covariance matrix corresponds to two antenna ports of the second communication device, and the antenna elements corresponding to each of these two antenna ports are centrally symmetric. Alternatively, each element of the first covariance matrix corresponds to a port group of the second communication device, which includes two antenna ports, and the antenna elements corresponding to each of these two antenna ports are centrally symmetric. That is, by utilizing the centrally symmetric characteristic of the antenna elements corresponding to each group of ports to construct the first covariance matrix, the influence of angle and distance in the channel's nonlinear phase characteristics can be eliminated; that is, the angle domain and the distance domain can be decoupled, allowing the first communication device to better determine the K first vectors based on the first covariance matrix.

[0178] For the antenna ports of the second communication device, each antenna port corresponds to one antenna element in the antenna array of the second communication device. It can be seen that each element in the first covariance matrix corresponds to two antenna elements, and these two antenna elements are centrally symmetrical. In other words, after rotating 180 degrees around the center of the antenna array, the position of any one of the two antenna elements corresponding to each element in the first covariance matrix coincides with the position of the other antenna element. Referring to Figure 9, if the antenna array is located on the XOZ plane, and the position of one antenna element corresponding to an element in the first covariance matrix is ​​(a1, a2), then the position coordinates of the other antenna element corresponding to that element are (-a1, -a2). Both a1 and a2 are real numbers. The antenna element located at position coordinates (a1, a2) will be located at position coordinates (-a1, -a2) after rotating 180 degrees around the origin O. In other words, the antenna element at position coordinates (a1, a2) will be located at position coordinates (-a1, -a2) after rotating 180 degrees around the origin O. Similarly, the antenna element located at position coordinates (-a1, -a2) will be located at position coordinates (a1, a2) after rotating 180 degrees around the origin O.

[0179] Optionally, each element in the first covariance matrix corresponds to two antenna ports of the second communication device. The antenna elements corresponding to each of the two antenna ports are centrally symmetrical. Alternatively, each element in the first covariance matrix corresponds to a port group of the second communication device. Each port group of the second communication device includes two antenna ports, and the sum of the port numbers of the antenna ports in different port groups of the second communication device is the same.

[0180] One antenna port corresponds to one antenna element of the second communication device. When the antenna ports are numbered sequentially according to the position of the antenna elements, the fact that the sum of the port numbers of antenna ports in different port groups is the same means that the two antenna elements corresponding to the two antenna ports in different port groups are centrally symmetric. In this case, constructing a first covariance matrix using the centrally symmetric characteristic of the antenna elements corresponding to each group of ports can eliminate the influence of angle and distance in the nonlinear phase characteristics of the channel; that is, the angle domain and the distance domain can be decoupled, allowing the first communication device to better determine K first vectors based on the first covariance matrix.

[0181] In this configuration, each antenna port of the second communication device corresponds to an antenna element in the antenna array, and is centrally symmetrical with the antenna elements corresponding to the two antenna ports in the port group corresponding to each element of the first covariance matrix.

[0182] For example, suppose the port numbers of the transmitting antenna are arranged in ascending order, row first, then column (i.e., in the same column, the port number in the i-th row is less than the port number in the (i+1)-th row; in the same row, the port number in the j-th column is less than the port number in the (j+1)-th column). Each row has 2 antenna ports, and each column has 4 antenna ports, as shown in Figure 10. Then, the two antenna ports with port numbers "3000" and "3007" belong to one port group; the two antenna ports with port numbers "3001" and "3006" belong to another; the two antenna ports with port numbers "3002" and "3005" belong to another; and the two antenna ports with port numbers "3003" and "3004" belong to another. Therefore, the sum of the port numbers in each pair of port groups is 6007. i and j are positive integers, 1 ≤ i ≤ N1, 1 ≤ j ≤ N2. It is understood that the arrangement of port numbers here is only for example. In actual implementation, the port numbers of antenna ports can also be arranged from largest to smallest in the order of row first and column second. That is, in the same column of antenna ports, the port number in the i-th row is greater than the port number in the (i+1)-th row, and in the same row of antenna ports, the port number in the j-th column is greater than the port number in the (j+1)-th column. This will not be elaborated further.

[0183] In one possible implementation, the information used to determine the first covariance matrix further includes at least one of the following: channel measurement results corresponding to all antenna ports of the second communication device in one or more frequency domain units, one or more receiving antennas, or one or more polarization directions.

[0184] In one possible implementation, the first covariance matrix is ​​determined based on channel measurements of the first reference signal.

[0185] Thus, the first covariance matrix can better match the statistical spatial characteristics of the actual channel, thereby obtaining a first vector that better matches the channel characteristics, which helps the second communication device improve the noise reduction filtering effect.

[0186] Optionally, the first covariance matrix satisfies the relationships shown in Equations (14) to (16) below:

[0187] Formulas (14) and (15) above can also be expressed as formula (17) below. In this case, it can also be said that the first covariance matrix satisfies the relationship shown in formulas (17) and (16):

[0188] Thus, by combining channel state information from different frequency domain units, different receiving antenna ports, and different polarization directions to determine the first covariance matrix, more accurate real-time spatial characteristics of the channel can be obtained, making the first covariance matrix more closely match the actual channel, thereby improving the effect of channel filtering and noise reduction.

[0189] in, Let R represent the first covariance matrix, which is constructed based on the channel measurement results of the first reference signal. v Let N be the covariance matrix corresponding to the channel state information measured based on the first reference signal. f Where f is the number of frequency domain cells, and f is the index of the frequency domain cell, 0 <f≤N f N rx The total number of receive antenna ports, where x is the index of the receive antenna port, 0. <x≤N rx N P q represents the polarization quantity, and q represents the index of the polarization direction. <q≤N P V(f,x,q) represents the covariance matrix determined by the channel measurement results corresponding to the frequency domain cell with index f, the receiving antenna with index x, and all antenna ports of the second communication device in the polarization direction with index q. For V(f,x,q), the p-th m -p0 line, number The elements of the column, N1, represent the number of antenna ports of the second communication device in the first direction, and N2 represent the number of antenna ports of the second communication device in the second direction. It is the second communication device with index p among all antenna ports. m The channel matrix of the antenna ports, It is the index of all antenna ports of the second communication device. The channel matrix corresponding to the antenna port is taken as its conjugate. m p0 represents the port number of the (m+1)th antenna port, and p0 is the port number of the first antenna port. This represents the port number of the N1N2-m-th antenna port. In this embodiment, the port number can also be called a port index or port identifier, etc., which will not be elaborated further. f, x, q are integers. The frequency domain unit with index f can also be called the f-th frequency domain unit, and the frequency domain unit with index p... m The antenna port can also be referred to as the pth. m There are several antenna ports, and the polarization direction with index q can also be referred to as the q-th polarization direction. In this embodiment, the example is illustrated by setting the starting value of the frequency domain element index (the starting value of f) to 1, the starting value of the port index (i.e., the starting value of x) to 1, and the starting value of the polarization direction index (i.e., the starting value of q) to 1.

[0190] It is understandable that, in practical implementation, the initial value of the frequency domain cell index can be 0, in which case 0 ≤ f <N f The frequency domain cell with index f can also be referred to as the (f+1)th frequency domain cell. The starting value of the port index can be 0, in which case 0 ≤ x <N rx The index is p m The antenna port can also be referred to as the pth. m +1 antenna port. The starting value of the polarization direction index can be 0, in which case 0 ≤ q <N P The polarization direction with index q can also be referred to as the (q+1)th polarization direction.

[0191] In the first covariance matrix, each element corresponds to a port group of the second communication device. Each port group of the second communication device includes two antenna ports. When the sum of the port numbers of the antenna ports in different port groups of the second communication device is the same, the above formula (16) can also be replaced by the following formula (18). That is, at this time, the first covariance matrix satisfies the relationship shown by formulas (14), (15) and (18), or in other words, the first covariance matrix satisfies the relationship shown by formulas (17) and (18).

[0192] in, This represents the element in V(f,x,q) that corresponds to the n1th antenna element in the first direction and the n2th antenna element in the second direction. This represents the channel matrix corresponding to the n1th antenna element in the first direction and the n2th antenna element in the second direction. This represents the conjugate of the channel matrix corresponding to the N1-n1+1th antenna element in the first direction and the N2-n2+1th antenna element in the second direction.

[0193] It is understandable that when the second communication device is the transmitting end, the antenna port of the second communication device can also be called the transmitting antenna port or the transmitting port, which will not be elaborated further.

[0194] For the covariance matrix of the channel acquired at different times, the covariance matrix after being accumulated according to the corresponding time-domain filter factors still satisfies the characteristics of the above formula (12) or formula (13). In one possible implementation scheme, the information used to determine the first covariance matrix also includes at least the following: a second covariance matrix or a third covariance matrix. The second covariance matrix is ​​determined based on the channel measurement results of the first reference signal, and the third covariance matrix is ​​determined based on the channel measurement results of the second reference signal. The time-domain position of the second reference signal is located before the first reference signal.

[0195] Thus, by combining the covariance matrices corresponding to the reference signals at different times to determine the first covariance matrix, the statistical characteristics of the channel can be obtained, making the first covariance matrix more compatible with the actual channel, thereby improving the effect of channel filtering and noise reduction.

[0196] Optionally, the first covariance matrix satisfies the relationships shown in Equations (19) to (21):

[0197] In the first covariance matrix, each element corresponds to a port group of the second communication device. Each port group of the second communication device includes two antenna ports. When the sum of the port numbers of the antenna ports in different port groups of the second communication device is the same, the above formula (21) can also be replaced by the above formula (18). In this case, the first covariance matrix satisfies the relationship shown by formulas (19), (20) and (18).

[0198] Thus, by combining the channel state information obtained from the reference signals at different times in different frequency domain units, different receiving antenna ports, and different polarization directions to determine the first covariance matrix, more accurate statistical spatial characteristics of the channel can be obtained, making the first covariance matrix more compatible with the actual channel, thereby improving the effect of channel filtering and noise reduction.

[0199] in, The first covariance matrix is ​​obtained from the (t-1)th measurement of the first reference signal.

[0200] In this embodiment of the application, the method shown in FIG7 further includes S704 and S705:

[0201] S704, the first communication device sends a third reference signal to the second communication device. Correspondingly, the second communication device receives the third reference signal from the first communication device.

[0202] The third reference signal is used for channel measurement.

[0203] When the first communication device is a terminal device and the second communication device is a network device, the third reference signal can be an uplink reference signal, such as SRS.

[0204] S705, the second communication device determines the channel state information based on K first vectors and a third reference signal.

[0205] For example, S705 includes: a second communication device determining channel state information based on a plurality of polar beams and a third reference signal, wherein the plurality of polar beams are determined based on K first vectors and at least one distance. Here, the plurality of polar beams are obtained based on a subset of polar beams in a first set of polar beams; the plurality of polar beams may also be referred to as a subset of the first set of polar beams, which will not be elaborated further below. The first set of polar beams includes polar beams determined based on multiple angles and multiple distances. The number of these multiple angles is greater than K.

[0206] Thus, the second communication device can perform filtering and noise reduction on multiple polar beams determined according to K first vectors and at least one distance, thereby narrowing the selection range of polar beams for filtering and noise reduction and reducing the complexity of filtering and noise reduction.

[0207] The following example further illustrates the principle of S705.

[0208] In some examples, the second communication device can determine the angle information corresponding to each of the K first vectors based on the information in the first information used to indicate the K first vectors. Each of the K first vectors corresponds to the angle information of a radius. This represents the path corresponding to the p-th first vector among the K first vectors estimated by the second communication device, that is, the angle information of the p-th path in the first direction among the K paths. This indicates that the second communication device estimates the path corresponding to the p-th first vector out of K first vectors, that is, the angle information of the p-th path out of K paths in the second direction. Wherein, The relationship shown in formula (22) and the relationship shown in formula (23) are satisfied.

[0209] in, Let represent the azimuth angle of the path corresponding to the p-th first vector among the K first vectors. This represents the pitch angle of the path corresponding to the p-th first vector among the K first vectors.

[0210] Based on the K angle information determined by the second communication device, the second communication device can construct a first polar-domain beam subset according to the K angle information for polar-domain filtering. The first polar-domain beam subset includes the polar-domain beam corresponding to each of the P angle information. (Angle information) The corresponding polar beam satisfies the relationship shown in the following formula (24):

[0211] r p,sThis represents the distance between the reference antenna element and the s-th distance sampling point on the p-th path of the K paths. When the second communication device constructs the polar beam in the first polar beam subset, it can uniformly sample the quadratic coefficients, where the s-th distance sampling point on the p-th path of the K paths satisfies the relationship shown in formulas (25) and (26) below:

[0212] Where s = 1, ..., N d r min The minimum distance from the reference antenna element to the scatterer on the p-th path of the K paths (in a non-line-of-sight (NLOS) scenario) or the terminal device (or the user using the terminal device) (in a line-of-sight (LOS) scenario) can also be understood as non-uniform sampling of the range domain, where rps satisfies the relationship shown in the following formula (27):

[0213] The second communication device performs channel measurements based on the received third reference signal and can estimate a channel state information, which includes a second channel matrix.

[0214] Based on the first polar region beam subset, the second communication device can project the second channel matrix onto different polar region beams in the first polar region beam subset. From the polar region beams corresponding to sampling points at different distances on each of the K paths, it selects the polar region beam with the largest projection vector of the second channel matrix, obtaining K polar region beams. These K polar region beams are then used to filter the channel. The second channel matrix is ​​obtained by the second communication device measuring the third reference signal transmitted by the first communication device. The filtered channel includes a frequency domain unit, a receiving antenna port, and a channel corresponding to the polarization direction. The following relationship is satisfied: (28)

[0215] in, γ represents the channel on frequency domain unit f. p is the linear superposition coefficient corresponding to the p-th polar beam.

[0216] Thus, the second communication device can filter and reduce noise in the channel based on the first information. For example, the second communication device can combine the first information with polar beams corresponding to different distances to filter and reduce noise in the channel, thereby obtaining more accurate channel state information.

[0217] Optionally, when K is configured by a second communication device, the method provided in FIG7 further includes S706:

[0218] S706, the second communication device sends second information to the first communication device. Correspondingly, the first communication device receives the second information from the second communication device.

[0219] The second information is used to indicate the number of first vectors K reported by the first communication device or the maximum number of first vectors Kmax reported by the first communication device, where Kmax is an integer greater than or equal to 1, and K is less than or equal to Kmax.

[0220] In this way, the number of first vectors that need to be reported can be controlled by the second communication device, so that the overhead of reporting the first vectors can be controlled.

[0221] When the second information is used to indicate the maximum number of first vectors reported by the first communication device, the number of first vectors reported by the first communication device, i.e., K, is determined by the first communication device. In this case, the first information may also indicate the number of first vectors reported by the first communication device, i.e., K.

[0222] It is understood that in the embodiments of this application, the order in which the steps appear does not represent the order in which the steps are executed, as long as they are logically consistent. For example, S706 can be executed before S701 or after S701; S704 can be executed before S703, after S702, or between S703 and S702, as long as the execution step is before S705.

[0223] Based on the method provided in Figure 7, the first communication device can determine K first vectors according to the received first reference signal, and indicate the K first vectors to the second communication device through the first information. In this way, when the second communication device determines the channel state information, it can perform filtering and noise reduction based on the K first vectors indicated by the first communication device, that is, use fewer beams in the angular domain for filtering and noise reduction, thereby reducing the complexity of filtering and noise reduction.

[0224] Based on the method shown in Figure 7, for the first communication device, the first covariance matrix is ​​projected onto the first vector set, and then K first vectors are selected from N1*N2 first vectors. After determining the K first vectors, the second communication device selects K*N vectors from the K*N set. d K polar beams are selected from N1*N2*N polar beams. However, in the filtering scheme described in technical terminology and related technical introductions, the second communication device needs to select K polar beams from N1*N2*N. d Polar beams are selected one by one from each beam for filtering and noise reduction. Based on the above analysis, the method shown in Figure 7 can reduce the complexity of the filtering and noise reduction scheme, thereby improving the filtering and noise reduction efficiency.

[0225] It should be understood that in the embodiments of this application, "greater than or equal to" can also be replaced with "greater than" or "equal to", and "less than or equal to" can also be replaced with "less than" or "equal to".

[0226] The channel state information determination method provided by the embodiments of this application has been described in detail above with reference to Figures 7-10. The communication apparatus used to perform the channel state information determination method provided by the embodiments of this application is described in detail below with reference to Figures 11 and 12.

[0227] For example, FIG11 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. As shown in FIG11, the communication device 1100 includes a processing module 1101 and a transceiver module 1102. For ease of explanation, FIG11 only shows the main components of the communication device.

[0228] In some embodiments, the communication device 1100 may be adapted to the communication system shown in FIG1 to perform the functions of the first communication device in the channel state information determination method shown in FIG7.

[0229] The transceiver module 1102 is used to receive a first reference signal from the second communication device.

[0230] Processing module 1101 is used to generate first information, which is used to indicate K first vectors. The K first vectors are used to determine channel state information. The K first vectors are determined based on the first reference signal. The first vectors are used to indicate the angle vector corresponding to a beam. K is an integer greater than or equal to 1.

[0231] The transceiver module 1102 is also used to send the first information to the second communication device.

[0232] Optionally, the processing module 1101 is further configured to determine a first covariance matrix based on a first reference signal, wherein the K first vectors are determined based on the first covariance matrix.

[0233] Optionally, the transceiver module 1102 is also configured to receive second information from the second communication device, the second information being used to indicate the number of K first vectors.

[0234] Optionally, the transceiver module 1102 may include a receiving module and a transmitting module (not shown in FIG11). The transceiver module is used to implement the transmitting and receiving functions of the communication device 1100.

[0235] Optionally, the communication device 1100 may further include a storage module (not shown in FIG11) that stores programs or instructions. When the processing module 1101 executes the program or instructions, the communication device 1100 can perform the functions of the first communication device in the channel state information determination method shown in any of FIG7.

[0236] It should be understood that the communication device 1100 may be a terminal device, a communication module, a circuit or chip responsible for communication functions, a chip system, or other components or assemblies. This application does not limit the application of such communication module, circuit or chip responsible for communication functions, chip system, or other components or assemblies to any terminal device.

[0237] Furthermore, the technical effects of the communication device 1100 can be referenced by the technical effects of the channel state information determination method shown in any of Figure 7, which will not be elaborated here.

[0238] In other embodiments, the communication device 1100 may be adapted to the communication system shown in FIG1 to perform the function of the second communication device in the channel state information determination method shown in FIG7.

[0239] The processing module 1101 is used to generate the first reference signal.

[0240] The transceiver module 1102 is used to send a first reference signal to the first communication device.

[0241] The transceiver module 1102 is also used to receive first information from the first communication device. The first information is used to indicate K first vectors. The K first vectors are used to obtain channel state information between the first communication device and the second communication device. The K first vectors are determined according to the first reference signal. The first vectors are used to indicate the angle vector corresponding to a beam. K is an integer greater than or equal to 1.

[0242] Optionally, the transceiver module 1102 is also used to send second information, which indicates the number of the K first vectors.

[0243] Optionally, the processing module 1101 is further configured to determine channel status information between the first communication device and the second communication device based on the first information.

[0244] Optionally, the communication device 1100 may further include a storage module (not shown in FIG11) that stores programs or instructions. When the processing module 1101 executes the program or instructions, the communication device 1100 can perform the functions of the second communication device in the channel state information determination method shown in FIG7.

[0245] It should be understood that the processing module 1101 involved in the communication device 1100 can be implemented by a processor or processor-related circuit components, and can be a processor or processing unit; the transceiver module 1102 can be implemented by a transceiver or transceiver-related circuit components, and can be a transceiver or transceiver unit.

[0246] It should be noted that the communication device 1100 can be a network device, a communication module, a circuit or chip responsible for communication functions, a chip system, or other components or assemblies. This communication module, circuit or chip responsible for communication functions, chip system, or other components or assemblies can be used in network devices.

[0247] Furthermore, the technical effects of the communication device 1100 can be referred to in the technical effects of the channel state information determination method shown in any of the items in Figure 7, which will not be elaborated here.

[0248] For example, Figure 12 is a second schematic diagram of the structure of a communication device provided in an embodiment of this application. This communication device can be a terminal device or a network device, or it can be a chip (system) or other component or assembly that can be disposed in a terminal device or network device. As shown in Figure 12, the communication device 1200 may include a processor 1201. Optionally, the communication device 1200 may also include a memory 1202 and / or a transceiver 1203. The processor 1201 is coupled to the memory 1202 and the transceiver 1203, for example, they can be connected via a communication bus.

[0249] The following is a detailed description of each component of the communication device 1200 with reference to Figure 12:

[0250] The processor 1201 is the control center of the communication device 1200. It can be a single processor or a collective term for multiple processing elements. For example, the processor 1201 can be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0251] Optionally, the processor 1201 can perform various functions of the communication device 1200 by running or executing software programs stored in the memory 1202 and calling data stored in the memory 1202.

[0252] In a specific implementation, as one embodiment, processor 1201 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG12.

[0253] In a specific implementation, as one embodiment, the communication device 1200 may also include multiple processors, such as processors 1201 and 1204 shown in FIG. 12. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0254] The memory 1202 is used to store the software program that executes the solution of this application, and is controlled by the processor 1201 to execute it. The specific implementation method can be referred to the above method embodiment, and will not be repeated here.

[0255] Optionally, the memory 1202 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 1202 may be integrated with the processor 1201 or may exist independently and be coupled to the processor 1201 through the interface circuit of the communication device 1200 (not shown in FIG. 12). This application embodiment does not specifically limit this.

[0256] Alternatively, the memory may be located outside the communication device.

[0257] Transceiver 1203 is used for communication with other communication devices. For example, if communication device 1200 is a terminal device, transceiver 1203 can be used to communicate with a network device or with another terminal device. As another example, if communication device 1200 is a network device, transceiver 1203 can be used to communicate with a terminal device or with another network device.

[0258] Optionally, transceiver 1203 may include a receiver and a transmitter (not shown separately in Figure 12). The receiver is used to implement the receiving function, and the transmitter is used to implement the transmitting function.

[0259] Optionally, the transceiver 1203 can be integrated with the processor 1201 or exist independently and be coupled to the processor 1201 through the interface circuit of the communication device 1200 (not shown in FIG12). This application embodiment does not specifically limit this.

[0260] It should be noted that the structure of the communication device 1200 shown in Figure 12 does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0261] Furthermore, the technical effects of the communication device 1200 can be referred to the technical effects of the channel state information determination method described in the above method embodiments, and will not be repeated here.

[0262] It should be understood that the processor in the embodiments of this application can be a CPU, but it can also be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0263] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), EEPROM, or flash memory. Volatile memory can be RAM, which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0264] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0265] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0266] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0267] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0268] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0269] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0270] 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 through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0271] 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.

[0272] In addition, 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.

[0273] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion 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, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0274] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining channel state information, characterized in that, Applied to a first communication device, the method includes: Receive a first reference signal from the second communication device; Send first information to the second communication device. The first information is used to indicate K first vectors. The K first vectors are used to determine channel state information. The K first vectors are determined based on the first reference signal. K is an integer greater than or equal to 1. The first vectors are used to indicate the angle vector corresponding to a beam.

2. The method according to claim 1, characterized in that, The method further includes: The first covariance matrix is ​​determined based on the first reference signal, and the K first vectors are determined based on the first covariance matrix.

3. The method according to claim 1 or 2, characterized in that, Before sending the first information to the second communication device, the method further includes: Receive second information from the second communication device, the second information being used to indicate the number of the K first vectors.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: A third reference signal is sent to the second communication device, the third reference signal being used for channel measurement.

5. A method for determining channel state information, characterized in that, Applied to a second communication device, the method includes: Send a first reference signal to the first communication device; Receive first information from the first communication device, the first information being used to indicate K first vectors, the K first vectors being used to determine channel state information, the K first vectors being determined based on the first reference signal, the first vectors being used to indicate an angle vector corresponding to a beam, and K being an integer greater than or equal to 1; Receive a third reference signal from the first communication device; Channel state information is determined based on the K first vectors and the third reference signal.

6. The method according to claim 5, characterized in that, The step of determining the channel state information based on the K first vectors and the third reference signal includes: Channel state information is determined based on multiple polar beams and the third reference signal, wherein the multiple polar beams are determined based on the K first vectors and at least one distance.

7. The method according to claim 5 or 6, characterized in that, The K first vectors are determined based on the first covariance matrix, which is determined based on the first reference signal.

8. The method according to any one of claims 5-7, characterized in that, The method further includes: Send a second message, which indicates the number K of the first vectors reported by the first communication device or the maximum number Kmax of the first vectors reported by the first communication device, where Kmax is an integer greater than or equal to 1, and K is less than or equal to Kmax.

9. The method according to claim 2 or 7, characterized in that, Each element in the first covariance matrix corresponds to a port group of the second communication device. Each port group of the second communication device includes two antenna ports, and the sum of the port numbers of the antenna ports in different port groups of the second communication device is the same.

10. The method according to claim 2, 7 or 9, characterized in that, The information used to determine the first covariance matrix also includes at least one of the following: channel measurement results corresponding to all antenna ports of the second communication device in one or more frequency domain units, one or more receiving antennas, or one or more polarization directions.

11. The method according to claim 10, characterized in that, The information used to determine the first covariance matrix further includes at least one of the following: a second covariance matrix or a third covariance matrix, wherein the second covariance matrix is ​​determined based on the channel measurement results of the first reference signal, and the third covariance matrix is ​​determined based on the channel measurement results of the second reference signal, wherein the time domain position of the second reference signal is located before the first reference signal.

12. The method according to claim 11, characterized in that, The first covariance matrix satisfies the following relationship: in, Let α represent the first covariance matrix, and α be the time-domain filtering factor. Let R be the third covariance matrix. v Let N be the third covariance matrix. f Where f is the number of frequency domain cells, and f is the index of the frequency domain cell, 0 <f≤N f N rx The total number of receive antenna ports, where x is the index of the receive antenna port, 0. <x≤N rx N P represents the total number of polarization directions, and q represents the index of the polarization direction, 0. <q≤N P V(f,x,q) represents the covariance matrix determined by the channel measurement results corresponding to the frequency domain cell with index f, the receiving antenna with index x, and all antenna ports of the second communication device in the polarization direction with index q. For V(f,x,q), the p-th m -p0 line, number The column elements are: N1, which represents the number of antenna ports of the second communication device in the first direction; and N2, which represents the number of antenna ports of the second communication device in the second direction. It is the antenna port with index p in the second communication device. m The channel matrix of the antenna ports, It is the index of all antenna ports of the second communication device. The channel matrix corresponding to the antenna port is taken as conjugate.

13. The method according to claim 10, characterized in that, The first covariance matrix is ​​determined based on the channel measurement results of the first reference signal.

14. The method according to claim 13, characterized in that, The first covariance matrix satisfies the following relationship: in, Let N represent the first covariance matrix, which is constructed based on the channel measurement results of the first reference signal. f Where f is the number of frequency domain cells, and f is the index of the frequency domain cell, 0 <f≤N f N rx The total number of receive antenna ports, where x is the index of the receive antenna port, 0. <x≤N rx N P q represents the polarization quantity, and q represents the index of the polarization direction. <q≤N P V(f,x,q) represents the covariance matrix determined by the channel measurement results corresponding to the frequency domain cell with index f, the receiving antenna with index x, and all antenna ports of the second communication device in the polarization direction with index q. For V(f,x,q), the p-th m -p0 line, number The column elements are: N1, which represents the number of antenna ports of the second communication device in the first direction, and N2, which represents the number of antenna ports of the second communication device in the second direction. It is the antenna port with index p in the second communication device. m The channel matrix of the antenna ports, It is the index of all antenna ports of the second communication device. The channel matrix corresponding to the antenna port is taken as conjugate.

15. The method according to any one of claims 1-14, characterized in that, The K first vectors are the K first vectors in the first vector set whose projection energy of the first covariance matrix on the first vector is the strongest, and the number of first vectors in the first vector set is greater than K.

16. The method according to any one of claims 1-15, characterized in that, The first information is used to indicate the number of combinations of the K first vector indices.

17. The method according to claim 16, characterized in that, The number of bits occupied by the first information satisfies the following relationship: Wherein, B is the number of bits occupied by the first information, N1 is the number of antenna ports of the second communication device in the first direction, and N2 is the number of antenna ports of the second communication device in the second direction.

18. The method according to any one of claims 1-17, characterized in that, The first information is determined based on a plurality of reference signals, including the first reference signal and a second reference signal located before the first reference signal.

19. A communication device, characterized in that, The communication device includes a module for performing the method as described in any one of claims 1-18.

20. A communication device, characterized in that, include: Processor and interface circuits; among which, The interface circuit is used to receive code instructions and transmit them to the processor; The processor is used to run the code instructions to perform the method as described in any one of claims 1-18.

21. A communication device, characterized in that, The communication device includes a processor and a transceiver, the transceiver being used for information exchange between the communication device and other communication devices, and the processor executing code instructions to perform the method as described in any one of claims 1-18.

22. A communication device, characterized in that, include: A processor for executing code instructions to implement the method as described in any one of claims 1-18.

23. The communication device according to any one of claims 19-22, characterized in that, The communication device further includes a memory for storing the code instructions.

24. The communication device according to any one of claims 19-22, characterized in that, The communication device is a chip.

25. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program or instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-18.

26. A computer program product, characterized in that, The computer program product includes: a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-18.

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