Update method and communication device

Abstract

The present application provides an updating method and communication device. The method includes: generating spatial vector update information, the spatial vector update information is used to update a first group of spatial vectors to obtain a second group of spatial vectors; wherein the spatial vector update information includes multiple groups of spatial vector coefficients, each group of spatial vector coefficients is used to weighted combine the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors; and sending the spatial vector update information. The spatial vector update information is obtained by measuring the statistics of the spatial characteristics of the downlink channel, and the downlink channel measurement based on the updated second group of spatial vectors can obtain more accurate downlink channel information.

Description

Technical Field

[0001] The present application relates to the field of wireless communications, and more particularly, to an updated method and communication device. Background Art

[0002] In massive multiple-input multiple-output (Massive MIMO) technology, network equipment can reduce interference between multiple users and interference between multiple signal streams of the same user through precoding, which is beneficial to improving signal quality, realizing space division multiplexing, and improving spectrum utilization.

[0003] In some communication technologies, such as frequency division duplexing (FDD), there is partial reciprocity between uplink and downlink channels, and network equipment can construct a precoding matrix using the spatial domain vector and frequency domain vector obtained based on the partial reciprocity of the uplink and downlink channels and one or more weighting coefficients fed back by the terminal equipment. However, the precoding matrix constructed using the spatial domain vector and frequency domain vector obtained based on the reciprocity of the uplink and downlink channels has a large error. Summary of the invention

[0004] The present application provides an updating method and a communication device, in order to utilize the statistical information of a downlink channel to update a spatial domain vector and a frequency domain vector obtained according to the reciprocity of an uplink channel and a downlink channel.

[0005] In a first aspect, an updating method is provided, which can be executed by a terminal device, or can also be executed by a component (such as a chip or a chip system) configured in the terminal device.

[0006] Specifically, the method includes: generating spatial domain vector update information, which is used to update a first group of spatial domain vectors to obtain a second group of spatial domain vectors; wherein the spatial domain vector update information includes multiple groups of spatial domain vector coefficients, each group of spatial domain vector coefficients is used to perform weighted merging on the first group of spatial domain vectors to obtain a spatial domain vector in the second group of spatial domain vectors; and sending the spatial domain vector update information.

[0007] Based on the above technical solution, the terminal device can generate spatial vector update information corresponding to the first set of spatial vectors based on the statistics of the spatial characteristics of the downlink channel, and send it to the network device. Further, the network device corrects the first set of spatial vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial vector update information to obtain the second set of spatial vectors, thereby solving the problem that the sparsity of the spatial information of the uplink and downlink channels is not large enough. Further, the network device performs downlink channel measurement based on the corrected second set of spatial vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the method also includes: generating frequency domain vector update information, which is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, each group of frequency domain vector coefficients is used to weightedly combine the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; and sending the frequency domain vector update information.

[0009] Based on the above technical solution, the terminal device can generate spatial domain vector update information corresponding to the first group of spatial domain vectors based on the statistics of the spatial domain characteristics of the downlink channel, and generate frequency domain vector update information corresponding to the first group of frequency domain vectors based on the statistics of the frequency domain characteristics of the downlink channel, and send it to the network device. Further, the network device corrects the first group of spatial domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial domain vector update information to obtain a second group of spatial domain vectors; and can correct the first group of frequency domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the frequency domain vector update information to obtain a second group of frequency domain vectors, thereby solving the problem that the sparsity of the spatial and frequency domain information of the uplink and downlink channels is not large enough. Further, the network device performs downlink channel measurement based on the corrected second group of spatial domain vectors and the second group of frequency domain vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the spatial domain vector update information is generated based on space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to a first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a spatial domain vector in the first group of spatial domain vectors and a frequency domain vector in the first group of frequency domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the frequency domain vector update information is generated based on space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to a first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a space-domain vector in the first group of space-domain vectors and a frequency-domain vector in the first group of frequency-domain vectors, and each group of space-frequency coefficients is used to perform weighted combination of the first group of space-frequency vectors to obtain a precoding vector.

[0012] In combination with the first aspect, in certain implementations of the first aspect, each group of space-frequency coefficients in the at least one group of space-frequency coefficients is generated based on a received group of reference signals, and the group of reference signals is obtained by precoding based on the first group of space-frequency vectors.

[0013] In combination with the first aspect, in some implementations of the first aspect, the method further includes: receiving first indication information, where the first indication information is used to indicate a position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the feedback frequency of the space-frequency coefficient is greater than the feedback frequency of the space-domain vector update information and the frequency-domain vector update information.

[0015] In combination with the first aspect, in some implementations of the first aspect, the method further includes: receiving second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

[0016] Based on the above technical solution, when the network device indicates the number of groups of multiple spatial vector coefficients, it can avoid that the number of groups of spatial vector coefficients determined by the terminal device according to the statistics of the spatial characteristics of the downlink channel varies within a large range, thereby saving the feedback overhead of the terminal device. Further, when the terminal device determines the number of groups of spatial vector coefficients according to the second indication information, it can be beneficial for the terminal device to generate multiple groups of spatial vector coefficients according to the information of the downlink channel.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: receiving second indication information, wherein the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

[0018] Based on the above technical solution, when the network device indicates the number of groups of multiple spatial domain vector coefficients and the number of groups of multiple frequency domain vector coefficients, it can be avoided that the terminal device determines the number of groups of spatial domain vector coefficients based on the statistics of the spatial domain characteristics of the downlink channel, and the number of groups of frequency domain vector coefficients determined based on the statistics of the frequency domain characteristics of the downlink channel varies within a large range, thereby saving the feedback overhead of the terminal device. Further, when the terminal device determines the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients based on the second indication information, it can be beneficial for the terminal device to generate multiple groups of spatial domain vector coefficients and multiple groups of frequency domain vector coefficients based on the information of the downlink channel.

[0019] In a second aspect, an updating method is provided, which can be executed by a network device, or can also be executed by a component (such as a chip or a chip system) configured in the network device.

[0020] Specifically, the method includes: receiving spatial domain vector update information, the spatial domain vector update information is used to update a first group of spatial domain vectors to obtain a second group of spatial domain vectors; wherein the spatial domain vector update information includes multiple groups of spatial domain vector coefficients, each group of spatial domain vector coefficients is used to perform weighted merging on the first group of spatial domain vectors to obtain a spatial domain vector in the second group of spatial domain vectors; and obtaining the second group of spatial domain vectors based on the spatial domain vector update information.

[0021] Based on the above technical solution, the terminal device can generate spatial vector update information corresponding to the first set of spatial vectors based on the statistics of the spatial characteristics of the downlink channel, and send it to the network device. Further, the network device corrects the first set of spatial vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial vector update information to obtain the second set of spatial vectors, thereby solving the problem that the sparsity of the spatial information of the uplink and downlink channels is not large enough. Further, the network device performs downlink channel measurement based on the corrected second set of spatial vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0022] In combination with the second aspect, in certain implementations of the second aspect, the method also includes: receiving frequency domain vector update information, the frequency domain vector update information is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, each group of frequency domain vector coefficients is used to weightedly combine the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; and obtaining the second group of frequency domain vectors based on the frequency domain vector update information.

[0023] Based on the above technical solution, the terminal device can generate spatial domain vector update information corresponding to the first group of spatial domain vectors based on the statistics of the spatial domain characteristics of the downlink channel, and generate frequency domain vector update information corresponding to the first group of frequency domain vectors based on the statistics of the frequency domain characteristics of the downlink channel, and send it to the network device. Further, the network device corrects the first group of spatial domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial domain vector update information to obtain a second group of spatial domain vectors, and can correct the first group of frequency domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the frequency domain vector update information to obtain a second group of frequency domain vectors, thereby solving the problem that the sparsity of the spatial and frequency domain information of the uplink and downlink channels is not large enough. Further, the network device performs downlink channel measurement based on the corrected second group of spatial domain vectors and the second group of frequency domain vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0024] In combination with the second aspect, in certain implementations of the second aspect, the method also includes: sending first indication information, wherein the first indication information is used to indicate the position of each space-frequency vector in a first group of space-frequency vectors in the space-frequency space, and the first group of space-frequency vectors is used to precode a reference signal.

[0025] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: sending second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

[0026] Based on the above technical solution, when the network device indicates the number of groups of multiple spatial vector coefficients, it can avoid that the number of groups of spatial vector coefficients determined by the terminal device according to the statistics of the spatial characteristics of the downlink channel varies within a large range, thereby saving the feedback overhead of the terminal device. Further, when the terminal device determines the number of groups of spatial vector coefficients according to the second indication information, it can be beneficial for the terminal device to generate multiple groups of spatial vector coefficients according to the information of the downlink channel.

[0027] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: sending second indication information, wherein the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

[0028] Based on the above technical solution, when the network device indicates the number of groups of multiple spatial domain vector coefficients and the number of groups of multiple frequency domain vector coefficients, it can be avoided that the number of groups of spatial domain vector coefficients determined by the terminal device based on the statistics of the spatial domain characteristics of the downlink channel and the number of groups of frequency domain vector coefficients determined based on the statistics of the frequency domain characteristics of the downlink channel vary within a large range, thereby saving the feedback overhead of the terminal device. Further, when the terminal device determines the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients based on the second indication information, it can be beneficial for the terminal device to generate multiple groups of spatial domain vector coefficients and multiple groups of frequency domain vector coefficients based on the information of the downlink channel.

[0029] According to a third aspect, a communication device is provided, comprising modules or units for executing the method in the first aspect and any possible implementation manner of the first aspect.

[0030] In a fourth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the method in the first aspect and any possible implementation of the first aspect. Optionally, the communication device also includes a memory. Optionally, the communication device also includes a communication interface, and the processor is coupled to the communication interface.

[0031] In one implementation, the communication device is a terminal device. When the communication device is a terminal device, the communication interface may be a transceiver, or an input / output interface.

[0032] In another implementation, the communication device is a chip configured in a terminal device. When the communication device is a chip configured in a terminal device, the communication interface may be an input / output interface.

[0033] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0034] In a fifth aspect, a communication device is provided, comprising modules or units for executing the method in the second aspect and any possible implementation manner of the second aspect.

[0035] In a sixth aspect, a communication device is provided, comprising a processor. The processor is coupled to a memory and can be used to execute instructions in the memory to implement the method in the second aspect and any possible implementation of the second aspect. Optionally, the communication device also includes a memory. Optionally, the communication device also includes a communication interface, and the processor is coupled to the communication interface.

[0036] In one implementation, the communication device is a network device. When the communication device is a network device, the communication interface may be a transceiver, or an input / output interface.

[0037] In another implementation, the communication device is a chip configured in a network device. When the communication device is a chip configured in a network device, the communication interface may be an input / output interface.

[0038] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0039] In a seventh aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in any possible implementation of the first aspect to the second aspect and the first aspect to the second aspect.

[0040] In the specific implementation process, the processor can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit can be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit can be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation methods of the processor and various circuits.

[0041] In an eighth aspect, a processing device is provided, comprising a processor and a memory. The processor is used to read instructions stored in the memory, and can receive signals through a receiver and transmit signals through a transmitter to execute the method in any possible implementation of the first aspect to the second aspect and the first aspect to the second aspect.

[0042] Optionally, the number of the processors is one or more, and the number of the memories is one or more.

[0043] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0044] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips respectively. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0045] It should be understood that the relevant data interaction process, such as sending indication information, can be a process of outputting indication information from a processor, and receiving capability information can be a process of receiving input capability information from a processor. Specifically, the processed output data can be output to a transmitter, and the input data received by the processor can come from a receiver. Among them, the transmitter and the receiver can be collectively referred to as a transceiver.

[0046] The processing device in the eighth aspect mentioned above may be a chip. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor may be a general-purpose processor implemented by reading software codes stored in a memory. The memory may be integrated in the processor or may be located outside the processor and exist independently.

[0047] In the ninth aspect, a computer program product is provided, comprising: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute the method in any possible implementation of the first aspect to the second aspect and any possible implementation of the first aspect to the second aspect.

[0048] In the tenth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions). When the computer-readable storage medium is run on a computer, the computer executes the method in the above-mentioned first aspect to the second aspect and any possible implementation manner of the first aspect to the second aspect.

[0049] In the eleventh aspect, a communication system is provided, comprising the aforementioned terminal device and network device. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the architecture of a communication system applicable to the updating method provided in an embodiment of the present application;

[0051] Figure 2 is a schematic diagram of precoding a reference signal based on a frequency domain vector provided in an embodiment of the present application;

[0052] Figure 3 is a schematic flow chart of an updating method provided in an embodiment of the present application;

[0053] Figure 4 is a schematic diagram indicating the position of a space-frequency vector provided in an embodiment of the present application;

[0054] Figure 5 is a schematic flow chart of an updating method provided by another embodiment of the present application;

[0055] Figure 6is a schematic flow chart of an updating method provided by yet another embodiment of the present application;

[0056] Figure 7 is a schematic flow chart of an updating method provided in yet another embodiment of the present application;

[0057] Figure 8 is a schematic block diagram of a communication device provided in an embodiment of the present application;

[0058] Fig. 9 is a schematic diagram of the structure of a terminal device provided in an embodiment of the present application;

[0059] Fig.10 It is a structural diagram of the network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0061] The technical solution of the embodiment of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, future fifth generation (5G) mobile communication system or new radio access technology (NR). Among them, the 5G mobile communication system may include non-standalone (NSA) and / or standalone (SA).

[0062] The technical solution provided in the present application can also be applied to machine type communication (MTC), long term evolution technology for machine-to-machine communication (LTE-M), device-to-device (D2D) network, machine-to-machine (M2M) network, Internet of Things (IoT) network or other networks. Among them, IoT network can include vehicle networking, for example. Among them, the communication mode in the vehicle networking system is collectively referred to as vehicle to other devices (vehicle to X, V2X, X can represent anything), for example, the V2X can include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0063] The technical solution provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, etc. This application does not limit this.

[0064] In the embodiment of the present application, the network device may be any device with wireless transceiver function. The device includes but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or homeNode B, HNB), baseband unit (BBU), access point (AP) in wireless fidelity (WiFi) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP), etc., and can also be a gNB in ​​5G, such as NR, system, or a transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a distributed unit (DU), etc.

[0065] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB, for example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, therefore, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or, sent by the DU+AAU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or the CU may be classified as a network device in a core network (core network, CN), which is not limited in the present application.

[0066] The network equipment provides services for the cell, and the terminal equipment communicates with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network equipment. The cell can belong to a macro base station (for example, macro eNB or macro gNB, etc.), or it can belong to a base station corresponding to a small cell. The small cell here may include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0067] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0068] The terminal device can be a device that provides voice / data connectivity to users, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals can be: mobile phones, tablet computers (pad), computers with wireless transceiver functions (such as laptops, PDAs, etc.), mobile Internet devices (mobile internet devices, MIDs), virtual reality (virtual reality, VR) devices, augmented reality (augmented reality, AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (session initiation protocol, SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistants) assistant, PDA), handheld devices with wireless communication function, computing devices or other processing devices connected to a wireless modem, vehicle-mounted devices, wearable devices, terminal devices in 5G networks or terminal devices in future evolved public land mobile communication networks (public land mobile network, PLMN), etc.

[0069] Among them, wearable devices can also be called wearable smart devices, which are a general term for the intelligent design and development of wearable devices for daily wear using wearable technology, such as glasses, gloves, watches, clothing and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also realize powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-sized, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0070] In addition, the terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. IoT technology can achieve massive connections, deep coverage, and terminal power saving through narrowband NB technology, for example.

[0071] In addition, terminal devices can also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (part of the terminal equipment), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0072] To facilitate understanding of the embodiments of the present application, first Figure 1 A communication system applicable to the method provided in the embodiment of the present application is described in detail. Figure 1 FIG. 1 is a schematic diagram of a communication system 100 applicable to the method provided in an embodiment of the present application. As shown in the figure, the communication system 100 may include at least one network device, such as Figure 1 The network device 101 in the 5G system shown in FIG. 1 ; the communication system 100 may also include at least one terminal device, such as Figure 1 The terminal devices 102 to 107 shown in the figure. The terminal devices 102 to 107 can be mobile or fixed. The network device 101 and one or more of the terminal devices 102 to 107 can communicate via wireless links. Each network device can provide communication coverage for a specific geographical area and can communicate with terminal devices located in the coverage area. For example, the network device can send configuration information to the terminal device, and the terminal device can send uplink data to the network device based on the configuration information; for another example, the network device can send downlink data to the terminal device. Therefore, Figure 1 The network device 101 and terminal devices 102 to 107 constitute a communication system.

[0073] Optionally, the terminal devices may communicate directly with each other. For example, direct communication between the terminal devices may be achieved using D2D technology. As shown in the figure, the terminal devices 105 and 106, and the terminal devices 105 and 107 may communicate directly using D2D technology. The terminal devices 106 and 107 may communicate with the terminal device 105 individually or simultaneously.

[0074] Terminal devices 105 to 107 may also communicate with network device 101 respectively. For example, they may communicate directly with network device 101, such as terminal devices 105 and 106 in the figure may communicate directly with network device 101; or they may communicate indirectly with network device 101, such as terminal device 107 in the figure communicates with network device 101 via terminal device 106.

[0075] It should be understood that Figure 1 A network device and multiple terminal devices, as well as communication links between the communication devices are exemplarily shown. Optionally, the communication system 100 may include multiple network devices, and each network device may include other number of terminal devices within its coverage, such as more or fewer terminal devices. This application does not limit this.

[0076] The above-mentioned communication equipment, such as Figure 1 The network device 101 and the terminal devices 102 to 107 in the embodiment may be configured with multiple antennas. The multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also additionally includes a transmitter chain and a receiver chain. It can be understood by those skilled in the art that they may include multiple components related to signal transmission and reception (such as processors, modulators, multiplexers, demodulators, demultiplexers or antennas, etc.). Therefore, the network device and the terminal device may communicate via multi-antenna technology.

[0077] Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0078] In order to better understand the embodiments of the present application, the following points are first explained.

[0079] First, for ease of understanding, here is a brief introduction to the meanings of the several letters involved below.

[0080] N: The number of frequency domain units, N is a positive integer.

[0081] N f : Number of subbands, N f is a positive integer. In one possible design, the frequency domain unit is a subband. In this case, N=N f It should be understood that the frequency domain unit as a subband is only a possible design and should not constitute any limitation to the present application. The following description is based on the frequency domain unit as a subband, that is, N in the following description can represent the number of subbands or the number of frequency domain units.

[0082] n: represents the nth subband, 0≤n≤N-1, n is an integer.

[0083] R: number of receiving antenna ports, R is a positive integer.

[0084] r: represents the rth receiving antenna port, 0≤r≤R-1, and r is an integer.

[0085] N t : The number of transmitting antenna ports in one polarization direction, N t Is a positive integer. If the network device is configured with dual-polarization transmitting antennas, that is, the number of polarization directions of the transmitting antenna is 2, then the number of transmitting antenna ports in the two polarization directions is 2N. t .

[0086] B: represents the number of spatial domain vectors included in the first group of spatial domain vectors, and B is a positive integer.

[0087] K: represents the number of spatial domain vectors included in the second set of spatial domain vectors, and K is a positive integer.

[0088] T: represents the number of frequency domain vectors included in the first group of frequency domain vectors, and T is a positive integer.

[0089] D: represents the number of frequency domain vectors included in the second group of frequency domain vectors, and D is a positive integer.

[0090] J: represents the number of space-frequency vectors included in the first group of space-frequency vectors. In other words, the number of space-frequency vectors determined by B space-domain vectors and T frequency-domain vectors, or the number of combinations of space-domain vectors and frequency-domain vectors determined by B space-domain vectors and T frequency-domain vectors, J is a positive integer. Since the precoded reference signal of each reference signal port is obtained by precoding the reference signal based on a space-domain vector and a frequency-domain vector, each reference signal port can correspond to a combination of a space-domain vector and a frequency-domain vector. Therefore, the number of reference signal ports can be J (corresponding to a single-polarized transmitting antenna) or 2J (corresponding to a dual-polarized transmitting antenna).

[0091] a(θ b ): The b-th spatial domain vector among B spatial domain vectors, 0≤b≤B-1, and b is an integer.

[0092] b(τ t ): the tth frequency domain vector among T frequency domain vectors, 0≤t≤T-1, and t is an integer.

[0093] m(θ k ): The bth spatial vector among the K spatial vectors, 0≤k≤K-1, k is an integer

[0094] l(τ d ): the d-th frequency domain vector among D frequency domain vectors, 0≤d≤D-1, and d is an integer.

[0095] V: The actual downlink channel, which can be represented as a matrix with the dimension of the number of receiving antenna ports × the number of transmitting antenna ports. For example, V can be a matrix with the dimension of R × N t (corresponding to a single-polarized transmitting antenna) or a matrix of R×2N t In the embodiment of the present application, for the convenience of distinction, the real channel corresponding to the nth sub-band is recorded as V n .

[0096] H: The space-frequency matrix determined based on a receive antenna port, or in other words, the space-frequency matrix corresponding to a receive antenna port. H can be represented as a matrix with the dimension of the number of frequency domain elements × the number of transmit antenna ports. For example, H can be a matrix with the dimension of N × N t (corresponding to a single-polarized transmitting antenna) or N×2N t (corresponding to the matrix of dual-polarized transmitting antennas).

[0097] S: represents a matrix composed of K spatial vectors, for example, S = [m(θ0) m(θ1) … m(θ K-1 )].

[0098] S': represents a matrix composed of B spatial vectors, for example, S' = [a(θ0) a(θ1) … a(θ B-1 )].

[0099] F: represents a matrix composed of D frequency domain vectors, for example, F = [l(τ0) l(τ1) … l(τ D-1 )].

[0100] F': represents a matrix composed of T frequency domain vectors, for example, F' = [b(τ0) b(τ1) … b(τ T-1 )].

[0101] C DL : represents a matrix composed of a group of space-frequency coefficients corresponding to the first group of space-frequency vectors, or represents a coefficient matrix composed of weighted coefficients corresponding to each space-domain vector in the B space-domain vectors and each frequency-domain vector in the T frequency-domain vectors. C DL Each element in can represent the weighting coefficient of a corresponding space-frequency vector.

[0102] C1: represents a coefficient matrix composed of multiple groups of spatial vector coefficients, or represents a coefficient matrix composed of weighted coefficients corresponding to each of the K spatial vectors.

[0103] C2: represents a coefficient matrix consisting of weighted coefficients corresponding to a second set of space-frequency vectors consisting of each space-domain vector in the K space-domain vectors and each frequency-domain vector in the T frequency-domain vectors. Alternatively, represents a coefficient matrix consisting of weighted coefficients corresponding to each space-domain vector in the K space-domain vectors and each frequency-domain vector in the D frequency-domain vectors.

[0104] C3: represents a matrix composed of multiple groups of frequency domain vector coefficients, or represents a coefficient matrix composed of weighted coefficients corresponding to each frequency domain vector in the D frequency domain vectors.

[0105] Second, in the embodiments of the present application, for the convenience of description, when numbering is involved, the numbers can be numbered consecutively starting from 0. For example, N s The subbands may include the 0th subband to the Nth subband. s -1 subband, the B spatial domain vectors may include the 0th spatial domain vector to the B-1th spatial domain vector, the T frequency domain vectors may include the 0th frequency domain vector to the T-1th frequency domain vector, etc. Of course, the specific implementation is not limited to this. For example, the serial numbering may also start from 1. For example, N s The subbands may include the 1st to the Nth subbands. s subbands, the B spatial domain vectors may include the 1st spatial domain vector to the Bth spatial domain vector, the T frequency domain vectors may include the 1st frequency domain vector to the Tth frequency domain vector, etc. For the sake of brevity, they are not listed here one by one.

[0106] It should be understood that the above descriptions are all arrangements made to facilitate the description of the technical solutions provided in the embodiments of the present application, and are not intended to limit the scope of the present application.

[0107] Third, in this application, there are many places involving matrix and vector transformations. For ease of understanding, a unified explanation is given here. The superscript H represents the conjugate transpose, such as A H Represents the conjugate transpose of the matrix (or vector) A.

[0108] Fourth, in the embodiments shown below, the embodiments provided by the present application are described by taking the spatial domain vector and the frequency domain vector as column vectors as an example, but this should not constitute any limitation to the present application. Based on the same concept, those skilled in the art can also think of other possible expressions.

[0109] Fifth, in this application, "used for indication" may include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used for indicating A, it may include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A.

[0110] The information indicated by the indication 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, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information can also be achieved with the help of the arrangement order of each information agreed in advance (such as protocol regulations), thereby reducing the indication overhead to a certain extent. At the same time, the common parts of each information can also be identified and uniformly indicated to reduce the indication overhead caused by indicating the same information separately. For example, those skilled in the art should understand that the precoding matrix is ​​composed of precoding vectors, and each precoding vector in the precoding matrix may have the same parts in terms of composition or other attributes.

[0111] In addition, the specific indication method may also be various existing indication methods, such as but not limited to the above-mentioned indication methods and various combinations thereof. The specific details of the various indication methods can refer to the prior art and will not be repeated herein. As can be seen from the above, for example, when it is necessary to indicate multiple information of the same type, different indication methods may be used for different information. In the specific implementation process, the desired indication method can be selected according to specific needs. The embodiment of the present application does not limit the selected indication method. In this way, the indication method involved in the embodiment of the present application should be understood to cover various methods that can enable the party to be indicated to obtain the information to be indicated.

[0112] In addition, the information to be indicated may exist in other equivalent forms, for example, a row vector can be expressed as a column vector, a matrix can be expressed by the transposed matrix of the matrix, a matrix can also be expressed in the form of a vector or an array, and the vector or array can be formed by connecting the row vectors or column vectors of the matrix, etc. The technical solutions provided in the embodiments of the present application should be understood to cover various forms. For example, some or all of the features involved in the embodiments of the present application should be understood to cover various forms of expression of the features.

[0113] The information to be indicated can be sent as a whole, or divided into multiple sub-information and sent separately, and the sending period and / or sending time of these sub-information can be the same or different. The specific sending method is not limited in this application. Among them, the sending period and / or sending time of these sub-information can be pre-defined, for example, pre-defined according to the protocol, or configured by the transmitting device by sending configuration information to the receiving device. Among them, the configuration information can include, for example but not limited to, one or a combination of at least two of radio resource control signaling, medium access control (MAC) layer signaling and physical layer signaling. Among them, radio resource control signaling, for example, radio resource control (RRC) signaling; MAC layer signaling, for example, includes MAC control element (CE); physical layer signaling, for example, includes downlink control information (DCI).

[0114] Sixth, the first, second and various digital numbers in the embodiments shown below are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application. For example, to distinguish different indication information.

[0115] Seventh, "predefinition" or "preconfiguration" can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including a terminal device and a network device), and the present application does not limit its specific implementation method. Among them, "saving" can mean saving in one or more memories. The one or more memories can be set separately or integrated in an encoder or decoder, a processor, or a communication device. The one or more memories can also be partially set separately and partially integrated in a decoder, a processor, or a communication device. The type of memory can be any form of storage medium, which is not limited by the present application.

[0116] Eighth, the “protocol” involved in the embodiments of the present application may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0117] Ninth, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Where a, b and c can be single or multiple, respectively.

[0118] Tenth, in the embodiments of the present application, descriptions such as "when...", "in the case of...", "if" and "if" all mean that under certain objective circumstances, the device (such as a terminal device or a network device) will make corresponding processing, which is not a limited time, and does not require the device (such as a terminal device or a network device) to have a judgment action when implementing it, nor does it mean that there are other limitations.

[0119] Eleventh, in the embodiments of the present application, antenna ports (referred to as ports) are mentioned in many places. Antenna ports may include transmitting antenna ports (or transmitting antenna ports) and receiving antenna ports. To avoid ambiguity, the following explanation is made: a transmitting antenna port may refer to an antenna port for transmitting a reference signal (such as a precoding reference signal, etc.). Therefore, a transmitting antenna port may also be referred to as a reference signal port. A receiving antenna port may refer to an antenna port for receiving a reference signal.

[0120] In an embodiment of the present application, the transmitting antenna port may be a port on the network device side, and the receiving antenna port may be a port on the terminal device side.

[0121] Twelfth, for ease of understanding, the following embodiments take the interaction process between a network device and a terminal device as an example to illustrate the updating method provided by the embodiments of the present application, which is used to update a spatial domain vector or a frequency domain vector.

[0122] To facilitate understanding of the embodiments of the present application, the following is a brief introduction to the terms involved in the embodiments of the present application.

[0123] 1. Precoding technology: The network device can process the signal to be transmitted by means of a precoding matrix matching the channel state when the channel state is known, so that the precoded signal to be transmitted is adapted to the channel, thereby reducing the complexity of the receiving device to eliminate the influence between channels. Therefore, by precoding the signal to be transmitted, the quality of the received signal (such as signal to interference plus noise ratio (SINR), etc.) is improved. Therefore, by adopting the precoding technology, the transmitting device and multiple receiving devices can be transmitted on the same time-frequency resources, that is, multiple user multiple input multiple output (MU-MIMO) is realized. It should be understood that the relevant description of the precoding technology in this article is only for ease of understanding and is not intended to limit the scope of protection of the embodiment of the present application. In the specific implementation process, the transmitting device can also perform precoding in other ways. For example, when the channel information (such as but not limited to the channel matrix) cannot be obtained, a pre-set precoding matrix or a weighted processing method is used for precoding. For the sake of brevity, the specific content is not repeated here.

[0124] 2. Channel reciprocity: In some communication modes, such as TDD, uplink and downlink channels transmit signals on the same frequency domain resources but different time domain resources. Within a relatively short time (e.g., the coherence time of channel propagation), it can be considered that the channel fading experienced by the signals on the uplink and downlink channels is the same. This is the reciprocity of the uplink and downlink channels. Based on the reciprocity of the uplink and downlink channels, network equipment can measure the uplink channel based on the uplink reference signal, such as the sounding reference signal (SRS). And the downlink channel can be estimated based on the uplink channel, so that the precoding matrix for downlink transmission can be determined.

[0125] When a signal is transmitted through a wireless channel, it can reach the receiving antenna through multiple paths from the transmitting antenna. Multipath delay causes frequency selective fading, which is the change of the frequency domain channel. Delay is the transmission time of a wireless signal on different transmission paths, which is determined by distance and speed and has nothing to do with the frequency domain of the wireless signal. When a signal is transmitted on different transmission paths, there are different transmission delays due to different distances. Since the physical position between the network device and the terminal device is fixed, the multipath distribution of the uplink and downlink channels is the same in terms of delay. Therefore, the delay in the uplink and downlink channels in FDD mode can be considered to be the same, or reciprocal.

[0126] In addition, the angle may refer to the angle of arrival (angle of arrival, AOA) of the signal arriving at the receiving antenna via the wireless channel, or the angle of departure (angle of departure, AOD) of the signal transmitted by the transmitting antenna. In an embodiment of the present application, the angle may refer to the angle of arrival of the uplink signal arriving at the network device, or the angle of departure of the downlink signal transmitted by the network device. Due to the reciprocity of the transmission paths of the uplink and downlink channels at different frequencies, the angle of arrival of the uplink reference signal and the angle of departure of the downlink reference signal can be considered to be reciprocal.

[0127] In the embodiment of the present application, each angle can be represented by an angle vector. Each delay can be represented by a delay vector. Therefore, in the embodiment of the present application, an angle vector can represent an angle, and a delay vector can represent a delay.

[0128] 3. Reference signal (RS) and precoding reference signal: The reference signal may also be called a pilot, a reference sequence, etc. In an embodiment of the present application, the reference signal may be a reference signal for channel measurement. For example, the reference signal may be a channel state information reference signal (CSI-RS) for downlink channel measurement, or it may be an SRS for uplink channel measurement. It should be understood that the reference signals listed above are only examples and should not constitute any limitation to the present application. The present application does not exclude the possibility of defining other reference signals in future protocols to achieve the same or similar functions.

[0129] The precoded reference signal may refer to a reference signal obtained after precoding the reference signal. Precoding may specifically include beamforming and / or phase rotation. Beamforming may be achieved, for example, by precoding the downlink reference signal based on the above one or more angle vectors, that is, by spatial domain precoding. Phase rotation may be achieved, for example, by precoding the downlink reference signal with the above one or more delay vectors, that is, by frequency domain precoding.

[0130] In an embodiment of the present application, precoding a downlink reference signal based on one or more angle vectors may also be referred to as loading one or more angle vectors onto a downlink reference signal to achieve beamforming. Precoding a downlink reference signal based on one or more delay vectors may also be referred to as loading one or more delay vectors onto a downlink reference signal to achieve phase rotation.

[0131] The precoded reference signal involved in the embodiments of the present application may specifically include a reference signal that has been precoded in the spatial domain and precoded in the frequency domain, or in other words, a reference signal that has been loaded with an angle vector and a delay vector.

[0132] In the embodiment of the present application, based on an angle vector a(θ b ) and a time delay vector b(τ t ) is used to precode the reference signal, the precoding matrix used to precode the reference signal can be expressed as the product of the conjugate transpose of an angle vector and a delay vector, for example, it can be expressed as a(θ b )×b(τ t ) H , whose dimension can be N t ×N. Alternatively, the precoding matrix used to precode the reference signal can also be expressed as the Kronecker product of an angle vector and a delay vector, for example, Its dimension can be N t ×N.

[0133] It should be understood that the various mathematical expressions listed above for an angle delay pair are only examples and should not constitute any limitation to the present application. For example, the precoding matrix used to precode the reference signal can also be expressed as the product of a delay vector and the conjugate transpose of an angle vector, or the Kronecker product of a delay vector and an angle vector, and its dimension can be N t ×T. Alternatively, the precoding matrix used to precode the reference signal can also be expressed as a mathematical transformation of the above various expressions. For the sake of brevity, they are not listed here one by one.

[0134] 4. Angle vector: It can also be called spatial vector, beam vector, etc. Angle vector can be understood as a precoding vector used to beamform the reference signal. Through beamforming, the reference signal transmitted by the transmitting device (such as a network device) can have a certain spatial directivity. Therefore, the process of precoding the reference signal based on the angle vector can also be regarded as the process of spatial domain (or simply, spatial domain) precoding.

[0135] If the actual downlink channel is denoted as V, then V can be expressed as a matrix of dimension R×T or R×2T. Where R is the number of receiving antenna ports, N t is the number of transmitting antenna ports in one polarization direction, 2N t is the number of transmitting antenna ports in the two polarization directions; R, N tare all positive integers. In downlink transmission, since the reference signal loaded with the angle vector can be transmitted to the terminal device through the downlink channel, the channel measured by the terminal device based on the received precoding reference signal is equivalent to the channel loaded with the angle vector. For example, the angle vector a(θ b ) is loaded into the downlink channel V, which can be expressed as Va(θ b ).

[0136] The number of ports of the precoded reference signal obtained after precoding the reference signal based on one or more angle vectors can be the same as the number of angle vectors. Therefore, if the reference signal corresponding to the transmitting antenna port in each polarization direction is precoded based on B angle vectors, the total number of ports of the precoded reference signal can be 2B, where 2 corresponds to the two polarization directions. The channel measured in this way is a precoded channel and can be represented as a matrix of dimension R×2B, where B is a positive integer. It can be understood that if the number of angle vectors B is less than the number of transmitting antenna ports N in each polarization direction. t , the dimensionality of the antenna port can be reduced through spatial domain precoding, thereby reducing the pilot overhead.

[0137] In the embodiment of the present application, the angle vector may be a vector with a length of N t Vector.

[0138] Optionally, the angle vector is a discrete Fourier transform (DFT) vector. The DFT vector may refer to a vector in a DFT matrix.

[0139] Optionally, the angle vector is a conjugate transposed vector of the DFT vector. The DFT conjugate transposed vector may refer to a column vector in a conjugate transposed matrix of the DFT matrix.

[0140] Optionally, the angle vector is an oversampled DFT vector.The oversampled DFT vector may refer to a vector in an oversampled DFT matrix.

[0141] In one possible design, the angle vector may be, for example, a two-dimensional (2D)-DFT vector v defined in a type II codebook in NR protocol TS 38.214 version 15 (release 15, R15). l,m In other words, the angle vector can be a 2D-DFT vector or an oversampled 2D-DFT vector.

[0142] It should be understood that the angle vector is a form of representing angles proposed in this application. The angle vector is named only for the convenience of distinguishing it from the delay vector and should not constitute any limitation to this application. This application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

[0143] 5. Delay vector: It can also be called frequency domain vector. The delay vector can be used to represent the vector of the channel change law in the frequency domain. As mentioned above, multipath delay leads to frequency selective fading. From the Fourier transform, it can be seen that the time delay of the signal in the time domain can be equivalent to the phase gradient in the frequency domain.

[0144] Since the phase change of the channel in each frequency domain unit is related to the delay, the change law of the phase of the channel in each frequency domain unit can be represented by the delay vector. In other words, the delay vector can be used to represent the delay characteristics of the channel.

[0145] Precoding the reference signal based on the delay vector may essentially refer to performing phase rotation on each frequency domain unit in the frequency domain based on the elements in the delay vector, so as to pre-compensate the frequency selective characteristics caused by the multipath delay by precoding the reference signal. Therefore, the process of precoding the reference signal based on the delay vector may be regarded as the process of frequency domain precoding.

[0146] Precoding the reference signal based on different delay vectors is equivalent to performing phase rotation on each subband of the channel based on different delay vectors. Moreover, the phase rotation angles of the reference signals corresponding to different ports on the same subband can be different. In order to distinguish different delays, the network device can precode the reference signal based on each delay vector in the T delay vectors.

[0147] Optionally, the length of the delay vector is N, where N may refer to the number of frequency domain units used to carry a reference signal (eg, a non-precoded reference signal or a precoded reference signal), N≥1, and N is an integer.

[0148] For example, the tth delay vector among T delay vectors can be expressed as b(τ t ), Wherein, t = 0, 2, ..., T-1; T can represent the number of delay vectors; f0, f1, ..., f N-1 Respectively represent the carrier frequencies of the 1st, 2nd to Nth frequency domain units.

[0149] It should be understood that the above examples of specific forms of the delay vector are only examples and should not constitute any limitation to the present application. For example, the delay vector can also be taken from the DFT matrix. The present application does not limit the specific form of the delay vector.

[0150] For the convenience of explanation, the delay vector is denoted as b(τ t ). Each element in the delay vector may correspond to a delay. A delay vector of length N includes elements corresponding to N delays.

[0151] In an embodiment of the present application, if the delay vector is loaded onto a channel, the N elements in the delay vector may be loaded onto N frequency domain units, that is, each element is loaded onto a frequency domain unit. A frequency domain unit may be, for example, a subband, a resource block (RB), a resource block group (RBG), a precoding resource block group (PRG), etc. This application does not limit this.

[0152] Optionally, each frequency domain unit is an RB. Each element in the delay vector can be loaded on an RB. In this case, the length N of the delay vector can be equal to the number of RBs in the broadband. For a delay vector, each element thereof corresponds to an RB.

[0153] Optionally, each frequency domain unit is a subband. Each element in the delay vector can be loaded on a subband. In this case, the length N of the delay vector can be equal to the number of subbands in the broadband. For a delay vector, each element thereof corresponds to a subband.

[0154] It should be understood that the above is only for ease of understanding, taking a delay vector as an example to illustrate the correspondence between the elements in the delay vector and the frequency domain units. However, this should not constitute any limitation to this application. The network device can load one or more delay vectors onto the channel, and each RB can, for example, contain one or more resource elements (RE) that can be used to carry reference signals.

[0155] In downlink transmission, since the reference signal loaded with the delay vector can be transmitted to the terminal device through the downlink channel, the channel measured by the terminal device based on the received precoded reference signal is equivalent to the channel loaded with the delay vector. Taking the frequency domain unit as RB as an example, if the reference signal is frequency-domain precoded based on a delay vector of length N, the N elements in the delay vector can be loaded onto the reference signal carried by N RBs, that is, the N elements in the delay vector are loaded onto N RBs. Load the nth element in the delay vector onto the channel V on the nth RB n For example, it can be expressed as

[0156] It should be understood that precoding the reference signal based on the delay vector is similar to the processing method of spatial precoding, except that the spatial vector (or angle vector) is replaced by a delay vector.

[0157] It should be noted that the frequency domain precoding of the reference signal based on the delay vector can be performed before resource mapping or after resource mapping, and this application does not limit this.

[0158] For ease of understanding, the following Figure 2 Detailed description based on the delay vector b(τ l ) is the process of precoding a reference signal.

[0159] Figure 2 An example of frequency domain precoding of a reference signal carried on N RBs based on a delay vector b(τ1) is shown. The N RBs may include RB#0, RB#1 to RB#N-1. Each of the N RBs may include one or more REs for carrying the reference signal. For example, the RE used to carry the reference signal may be the RE on the first time domain symbol and the first subcarrier in each RB. As shown in the shaded squares in the figure. In this case, the time domain vector b(τ1) may be loaded on the RE on the first time domain symbol and the first subcarrier in each RB. The reference signal carried on the RE on the first time domain symbol and the first subcarrier in each RB of the N RBs may correspond to the same reference signal port.

[0160] Assuming the delay vector If the delay vector b(τ1) is loaded onto N RBs, the corresponding phase rotation can be performed on the N RBs. The N elements in the delay vector can correspond to the N RBs one by one. For example, the elements in the frequency domain vector b(τ1) are can be loaded on RB#0, the element in the frequency domain vector b(τ1) Can be loaded on RB#1, the elements in the delay vector b(τ1) can be loaded on RB#N-1. Similarly, the nth element in the delay vector b(τ1) Can be loaded on RB#n. For the sake of brevity, they are not listed here one by one.

[0161] It should be understood that Figure 2 This is just an example, showing an example of loading the delay vector b(τ1) into N RBs, but this shall not constitute any limitation to the present application. Figure 2 The N RBs used to carry reference signals may be continuous N RBs or discontinuous N RBs, which is not limited in this application. Although not shown in the figure, it can be understood that Figure 2RB#0 to RB#N-1 in the RB may respectively include one or more REs that can be used to carry reference signals.

[0162] It should also be understood that the delay vector is a form of representing the delay proposed by the present application. The delay vector is named only for the convenience of distinguishing it from the angle vector and should not constitute any limitation to the present application. The present application does not exclude the possibility of defining other names in future protocols to represent the same or similar meanings.

[0163] 6. Angle delay pair: It can also be called space-frequency vector. An angle delay pair can be a combination of an angle vector and a delay vector. Each angle delay pair can include an angle vector and a delay vector. At least one of the angle vectors and delay vectors contained in any two angle delay pairs is different. In other words, each angle delay pair can be uniquely determined by an angle vector and a delay vector.

[0164] In an embodiment of the present application, a weighted sum of one or more angle delay pairs may be used to determine a space-frequency matrix. t The matrix of ×N can be called a component of the space-frequency matrix, referred to as the space-frequency component matrix. In the following embodiments, for the convenience of explanation, it is assumed that the dimension N determined by an angle delay pair t The matrix of ×N is composed of a(θ b )×b(τ t ) H get.

[0165] 7. Precoding matrix: In the embodiments of the present application, the precoding matrix is ​​involved in many places and can be divided into two categories according to its function.

[0166] A type of precoding matrix is ​​a precoding matrix used by a network device to precode a reference signal, and may be constructed, for example, by the B angle vectors and T delay vectors described above.

[0167] Another type of precoding matrix is ​​a precoding matrix determined by the terminal device based on the received precoding reference signal for channel measurement. The precoding matrix may be a precoding matrix fed back by the terminal device to the network device. The precoding matrix is ​​adapted to the downlink channel. The network device can further determine the precoding matrix for downlink data transmission based on the precoding matrix fed back by the terminal device. For example, the precoding matrix fed back by the terminal device is directly used as the precoding matrix for downlink data transmission, or, after some beamforming methods, such as zero forcing (ZF), minimum mean-squared error (MMSE), maximization of signal-to-leakage-and-noise (SLNR), etc., a precoding matrix for downlink data transmission is obtained. This application does not limit this.

[0168] The description of the precoding matrix involved in many places in the embodiments of the present application can be understood by those skilled in the art in combination with the context.

[0169] 8. Space-frequency matrix: In the embodiment of the present application, the space-frequency matrix is ​​an intermediate quantity used to determine the precoding matrix.

[0170] In the embodiment of the present application, the space-frequency matrix can be determined based on the receiving port or the transmission layer. As mentioned above, the space-frequency matrix can be determined by the weighted sum of one or more angle delay pairs, so the dimension of the space-frequency matrix can also be N t ×T.

[0171] If the space-frequency matrix is ​​determined based on the receiving port, the space-frequency matrix can be called the space-frequency matrix corresponding to the receiving port. The space-frequency matrix corresponding to the receiving port can be used to construct the downlink channel matrix of each frequency domain unit, and then the precoding matrix corresponding to each frequency domain unit can be determined. The channel matrix corresponding to a certain frequency domain unit can be, for example, the conjugate transpose of a matrix constructed by the column vectors corresponding to the same frequency domain unit in the space-frequency matrix corresponding to each receiving port. For example, the nth column vector in the space-frequency matrix corresponding to each receiving port is extracted and arranged from left to right in the order of the receiving ports to obtain a dimension of N. t ×R matrix, R represents the number of receiving ports, R ≥ 1 and is an integer. After conjugate transposition of this matrix, the channel matrix V of the nth frequency domain unit can be obtained (n) The relationship between the channel matrix and the space-frequency matrix will be described in detail below, and the detailed description of the relationship between the two is omitted here.

[0172] The relationship between the space-frequency matrix, the downlink channel matrix and the precoding matrix is ​​briefly explained.

[0173] The space-frequency matrix is ​​an intermediate quantity that can be used to construct the precoding matrix based on the frequency domain continuity of the channel. The space-frequency matrix H can satisfy: H = S'CF' H .

[0174] In FDD mode, due to the reciprocity of uplink and downlink channels in terms of delay and angle, the space-frequency matrix H obtained by measuring the uplink channel is UL It can be expressed as H UL =S'C UL F' H , the space-frequency matrix H obtained by downlink channel measurement DL It can be expressed as H DL =S'C DL F' H Therefore, in the embodiment of the present application, the coefficient matrix C corresponding to the downlink channel is determined and fed back through downlink channel measurement. DL , the precoding matrix suitable for the downlink channel can be determined.

[0175] As mentioned before, the space-frequency component matrix is ​​defined as a(θ b )×b(τ t ) H Determine, from this we can determine the space-frequency matrix H DL The dimension is: the number of transmit antenna ports × the number of frequency domain units. For example, the dimension of the space-frequency matrix corresponding to the downlink channel is N t In the following embodiments, unless otherwise specified, the space-frequency matrix refers to the space-frequency matrix with dimension N as described above. t The matrix H × N DL .

[0176] However, this is not necessarily the space-frequency matrix determined by the actual channel. In general, the dimension of the channel matrix is ​​defined as: the number of receiving ports × the number of transmitting ports. For example, the dimension of the downlink channel is R × N t The dimension of the space-frequency matrix determined by the channel matrix is ​​N×N t , and the above space-frequency matrix H DL The dimension N t ×N is just the opposite. Therefore, in the embodiment of the present application, the real channel can be the above space-frequency matrix H DL The conjugate transpose of the channel matrix determined by DL The determined downlink channel matrix may be the conjugate transpose of the real channel.

[0177] Furthermore, the space-frequency matrix H DL The precoding matrix may be determined. The precoding matrix of the nth frequency domain unit may be constructed by the nth column vector in the space-frequency matrix corresponding to each transmission layer.

[0178] Taking the singular value decomposition (SVD) of the channel matrix as an example, the conjugate transpose of the precoding matrix can be obtained by performing SVD on the channel matrix V. If the channel matrix is ​​conjugate transposed and then SVD is performed, that is, V H By performing SVD, the precoding matrix can be obtained. Therefore, the space-frequency matrix H determined by the conjugate transpose of the real channel in the embodiment of the present application is DL The precoding matrix corresponding to each frequency domain unit can be directly determined.

[0179] Combined with the above formula H UL =S'C UL F' H To understand the relationship between the space-frequency matrix and the downlink channel matrix.

[0180] For H DL =S'C DL F' H Transformation can get S' H H DL =C DL F' H , further deformation can be obtained (H DL H S') H =C DL F' H , from which we can get the coefficient matrix C DL =(H DL H S') H F'. Among them, H DL H is the space-frequency matrix determined by the real channel; H DL H S' is the real channel after spatial precoding. DL The elements of can be represented by (H DL H S') H In other words, the matrix coefficients C DL Each element in can be represented by the real channel H DL H The conjugate transpose of S' (H DL H S') H A row in is multiplied by a column in F', or in other words, it is obtained by the real channel H DL H It is obtained by multiplying the conjugate transpose of one column of S' by one column of F'.

[0181] Therefore, in the embodiment of the present application, the space-frequency matrix H is determined based on the weighted coefficients of each angle delay pair fed back by the terminal device. DL It can be obtained by the conjugate transpose of the real channel. Conversely, the space-frequency matrix in the embodiment of the present application can also be obtained by the conjugate transpose of the real channel V (ie, V H )get.

[0182] It should be understood that the real channel and the space-frequency matrix H DL The relationship between the space-frequency matrix and the space-frequency component matrix may cause the actual channel to be different from the space-frequency matrix H. DL The relationship between changes. For example, the space-frequency matrix H DL It can be obtained by the conjugate transpose of the real channel, or by the transpose of the real channel.

[0183] When the definitions of the space-frequency matrix and the space-frequency component matrix are different, the operations performed by the network device when loading the delay and angle are also different, and the operations performed by the terminal device when performing channel measurement and feedback also change accordingly. However, this is only the implementation behavior of the terminal device and the network device, and should not constitute any limitation to this application. The embodiment of the present application is only for ease of understanding, and shows the situation where the space-frequency matrix is ​​obtained by the conjugate transpose of the real channel. This application does not limit the definition of the channel matrix, the dimension of the space-frequency matrix and its definition, and the conversion relationship between the two. Similarly, this application does not limit the conversion relationship between the space-frequency matrix and the precoding matrix.

[0184] In FDD systems, since the interval between uplink and downlink frequency bands is much larger than the coherent bandwidth, the uplink and downlink channels do not have complete reciprocity, and it is impossible to directly use the uplink channel information to perform accurate downlink precoding. Therefore, in FDD systems, network devices need to rely on the channel state information (CSI) fed back by the terminal device to reconstruct the downlink channel or determine the precoding matrix.

[0185] At present, the method for network equipment and terminal equipment to perform CSI measurement may include the following steps:

[0186] Step 1: The network device sends the channel measurement configuration to the terminal device through high-level signaling, instructing the terminal device on the time and behavior of channel measurement;

[0187] Step 2: The network device estimates the spatial domain and frequency domain information of the uplink channel based on the uplink channel information;

[0188] Step 3: The network device loads the obtained spatial domain and frequency domain information of the uplink channel onto the downlink pilot, and sends the downlink pilot loaded with the spatial domain and frequency domain information to the terminal device;

[0189] Step 4: The terminal device performs channel measurement based on the pilot signal from the network device, calculates and obtains the final CSI feedback amount, and then sends the obtained CSI feedback amount to the network device;

[0190] Step 5: The network device reconstructs the downlink channel based on the received CSI and sends downlink data to the terminal device.

[0191] However, when there is a timing error in the uplink channel, the frequency domain information estimated by the network device through the uplink channel has a shift deviation relative to the actual frequency domain information of the downlink channel. Furthermore, the sampling point of the downlink channel based on the space-frequency vector estimated by the uplink channel is not the space-frequency vector with a larger power of the downlink channel. Therefore, the error of the network device in constructing the precoding matrix using the space-frequency information obtained based on the reciprocity of the uplink and downlink channels is large.

[0192] Based on this, an embodiment of the present application provides an updating method, which can update the spatial and frequency domain information obtained according to the reciprocity of the uplink and downlink channels, so that a more accurate precoding matrix can be constructed using the updated spatial and frequency domain information.

[0193] The updating method provided by the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0194] It should be understood that the following is only for the convenience of understanding and explanation, and the method provided by the embodiment of the present application is described in detail by taking the interaction between the terminal device and the network device as an example. However, this should not constitute any limitation on the execution subject of the method provided by the present application. For example, the terminal device shown in the embodiment below can be replaced by a component (such as a chip or a chip system) configured in the terminal device. The network device shown in the embodiment below can also be replaced by a component (such as a chip or a chip system) configured in the network device.

[0195] The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, for example, the execution subject of the method provided in the embodiments of the present application may be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0196] In the following embodiments, the network device may precode the reference signal based on the frequency domain vector and the spatial domain vector, or may precode the reference signal based on the frequency domain vector or the spatial domain vector, which is not limited in the present application.

[0197] Figure 3 It is a schematic flow chart of the updating method provided in the embodiment of the present application. Figure 3It is a schematic flow chart of the updating method 300 provided by the embodiment of the present application, shown from the perspective of device interaction. Figure 3 The method 300 shown may include S310 to S330. Each step in the method 300 is described in detail below.

[0198] For ease of understanding, the following describes in detail the process of channel measurement and feedback by the terminal device, taking the precoding reference signal sent by a transmitting antenna in one polarization direction as an example. The transmitting antenna in one polarization direction can be a transmitting antenna in any one of the transmitting antennas in J polarization directions configured by the network device. This application does not limit the number of polarization directions J of the transmitting antenna configured by the network device.

[0199] S310, the terminal device receives a reference signal. Accordingly, in S310, the network device sends a reference signal.

[0200] Exemplarily, the network device may precode the reference signal based on the first set of spatial domain vectors and the first set of frequency domain vectors. In this case, the reference signal sent by the network device to the terminal device is a precoded reference signal.

[0201] The following is an example in which the first group of spatial domain vectors includes B spatial domain vectors and the first group of frequency domain vectors includes T frequency domain vectors. A variety of combinations of spatial domain vectors and frequency domain vectors can be obtained from the B spatial domain vectors and T frequency domain vectors. The spatial domain vectors and / or frequency domain vectors in any two combinations are different. The spatial domain vectors and frequency domain vectors in each combination can be used to precode the reference signal to obtain a precoded reference signal corresponding to a reference signal port. Therefore, the precoded reference signal obtained by the network device based on the precoding of B spatial domain vectors and T frequency domain vectors can correspond to one or more reference signal ports, and the precoded reference signal of each reference signal port can be obtained by precoding the reference signal based on one spatial domain vector in the B spatial domain vectors and one frequency domain vector in the T frequency domain vectors. In other words, the precoded reference signal of each port can be obtained by precoding the reference signal based on a combination of a spatial domain vector and a frequency domain vector. In an embodiment of the present application, each precoded reference signal can correspond to a reference signal port.

[0202] In a possible implementation, the network device may combine each of the B spatial vectors and each of the T frequency vectors in pairs to obtain B×T combinations of spatial vectors and frequency vectors, or in other words, obtain B×T spatial-frequency vectors. That is, the network device may precode the reference signal based on each of the B spatial vectors and each of the T frequency vectors. When the network device precodes the reference signal based on the bth (0≤b≤B-1, b is an integer) spatial vector among the B spatial vectors, it may traverse each of the T frequency vectors to precode the reference signal; or, when the network device precodes the reference signal based on the (0≤t≤T-1, t is an integer)th frequency vector among the T frequency vectors, it may traverse each of the B spatial vectors to precode the reference signal. In other words, the B spatial domain vectors can be considered to be shared by each frequency domain vector, and the T frequency domain vectors can also be considered to be shared by each spatial domain vector. In other words, the B spatial domain vectors and the T frequency domain vectors are shared by each other.

[0203] In another possible implementation, when the network device precodes the reference signal based on the b-th spatial vector among the B spatial vectors, the network device may traverse the T corresponding to the b-th spatial vector. b (0≤T b ≤T-1, T b Each frequency domain vector in the T frequency domain vectors (where T is an integer) precodes the reference signal. The T in the T frequency domain vectors above can satisfy: In this implementation, the frequency domain vectors corresponding to at least two spatial domain vectors are different.

[0204] Here, the frequency domain vectors corresponding to at least two spatial domain vectors are different, which may mean that among the B spatial domain vectors, the frequency domain vectors corresponding to at least two spatial domain vectors are different, and the frequency domain vectors corresponding to the other spatial domain vectors may be the same or different, which is not limited in this application. In other words, the frequency domain vectors corresponding to the spatial domain vectors are partially or completely different.

[0205] Among them, the frequency domain vectors corresponding to the two spatial domain vectors are different, which may mean that the frequency domain vectors corresponding to the two spatial domain vectors are completely different, that is, the frequency domain vectors corresponding to the two spatial domain vectors are not repeated, or in other words, have no intersection. For example, the frequency domain vector corresponding to the spatial domain vector a(θ1) includes b(τ2), and the frequency domain vector corresponding to the spatial domain vector a(θ2) includes b(τ1) and b(τ3). The frequency domain vectors corresponding to the two spatial domain vectors are different, which may also mean that the frequency domain vectors corresponding to the two spatial domain vectors are partially different, that is, the frequency domain vectors corresponding to the two spatial domain vectors are partially repeated but not completely the same, or the frequency domain vectors corresponding to the two spatial domain vectors have an intersection but are not completely the same. For example, the frequency domain vector corresponding to a(θ1) includes b(τ2) and b(τ3), and the frequency domain vector corresponding to the spatial domain vector a(θ2) includes b(τ1) and b(τ3).

[0206] When the frequency domain vectors corresponding to any two of the B spatial domain vectors do not overlap, When there are some duplications in the frequency domain vectors corresponding to two or more of the B spatial domain vectors, Therefore, the network device can obtain the B spatial domain vectors and T frequency domain vectors mentioned above: A combination of a spatial domain vector and a frequency domain vector.

[0207] In another possible implementation, when the network device precodes the reference signal based on the t-th frequency domain vector among the T frequency domain vectors, the network device may traverse the B corresponding to the t-th frequency domain vector. t (0≤B t ≤B-1, B t Each of the B spatial domain vectors (where B is an integer) precodes the reference signal. The B in the B spatial domain vectors may satisfy: In this implementation, the spatial domain vectors corresponding to at least two frequency domain vectors are different.

[0208] Here, the spatial domain vectors corresponding to at least two frequency domain vectors are different, which may mean that among the T frequency domain vectors, the spatial domain vectors corresponding to at least two frequency domain vectors are different, and the spatial domain vectors corresponding to the other frequency domain vectors may be the same or different, which is not limited in this application. In other words, the spatial domain vectors corresponding to the frequency domain vectors are partially or completely different.

[0209] Among them, the different spatial domain vectors corresponding to the two frequency domain vectors may mean that the spatial domain vectors corresponding to the two frequency domain vectors are completely different, that is, the spatial domain vectors corresponding to the two frequency domain vectors do not repeat, or have no intersection. For example, the spatial domain vector corresponding to the frequency domain vector b(τ1) includes a(θ2), and the spatial domain vector corresponding to the frequency domain vector b(τ2) includes a(θ1). The different spatial domain vectors corresponding to the two frequency domain vectors may also mean that the spatial domain vectors corresponding to the two frequency domain vectors are partially different, that is, the spatial domain vectors corresponding to the two frequency domain vectors are partially repeated but not completely the same, or the spatial domain vectors corresponding to the two frequency domain vectors have an intersection but are not completely the same. For example, the spatial domain vector corresponding to the frequency domain vector b(τ1) includes a(θ2), and the spatial domain vector corresponding to the frequency domain vector b(τ2) includes a(θ1) and a(θ2). When the spatial domain vectors corresponding to any two frequency domain vectors among the T frequency domain vectors do not repeat each other, When the spatial vectors corresponding to two or more frequency domain vectors in the T frequency domain vectors are partially repeated, Therefore, the network device can obtain the B spatial domain vectors and T frequency domain vectors mentioned above: A combination of a spatial domain vector and a frequency domain vector.

[0210] It should be understood that the above is only for the sake of understanding, and the correspondence between the spatial domain vector and the frequency domain vector is listed, but this should not constitute any limitation to the present application. The present application does not limit the correspondence between the spatial domain vector and the frequency domain vector.

[0211] It can be understood that if the network device precodes the reference signal based on B spatial vectors and T frequency vectors, the number of ports of the transmitted precoded reference signal can be the number of combinations determined by the B spatial vectors and the T frequency vectors. That is, the number of reference signal ports J can be determined by the number of combinations determined by the B spatial vectors and the T frequency vectors. In the above-mentioned different implementations, the value of J is different, for example, J = B × T, or, or,

[0212] For ease of understanding and explanation, it is assumed that J = B×T below, that is, B spatial domain vectors and T frequency domain vectors are combined in pairs to obtain B×T spatial frequency vectors. Therefore, the precoded reference signal received by the terminal device corresponds to B×T reference signal ports, that is, J reference signal ports.

[0213] Optionally, the B spatial domain vectors and the T frequency domain vectors may be determined based on uplink channel measurement.

[0214] Specifically, since the space domain and the frequency domain have uplink and downlink channel reciprocity, the network device can determine B space domain vectors and T frequency domain vectors according to the pre-estimated uplink channel matrix.

[0215] The network device can, for example, use the methods in the prior art to estimate the B spatial domain vectors and the T frequency domain vectors. For example, the B spatial domain vectors and the T frequency domain vectors are determined by performing DFT on the space-frequency matrix, or by using a joint angle and delay estimation (JADE) algorithm in the spatial domain and the frequency domain. Specifically, the estimation algorithm can be, for example, a multiple signal classification algorithm (MUSIC), a Bartlett algorithm, or an estimation of signal parameters via rotation invariant technique algorithm (ESPRIT), etc. This application does not limit the specific method for the network device to determine the B spatial domain vectors and the T frequency domain vectors.

[0216] From the above description, it can be seen that the channel measured by the terminal device based on the received precoded reference signal is not a real channel, but a channel loaded with spatial domain vectors and frequency domain vectors, or in other words, a channel after precoding.

[0217] It should be understood that the precoded reference signal is not necessarily obtained by precoding the reference signal based on B angle vectors and T delay vectors. In another possible implementation, the network device can perform frequency domain precoding on the reference signal based on the first set of spatial domain vectors, and the number of reference signal ports corresponding to the precoded reference signal received by the terminal device can be equal to the number of the first set of spatial domain vectors, such as J=B, or can also be twice the number of the first set of spatial domain vectors, such as J=2B.

[0218] S320, the terminal device generates spatial vector update information.

[0219] S330, the terminal device sends spatial vector update information. Correspondingly, in S330, the network device receives the spatial vector update information.

[0220] The spatial vector update information is used to update the first set of spatial vectors to obtain the second set of spatial vectors. The spatial vector update information includes multiple sets of spatial vector coefficients, each set of spatial vector coefficients is used to weighted combine the first set of spatial vectors to obtain a spatial vector in the second set of spatial vectors.

[0221] Since the reference signal passes through the downlink channel when being sent to the terminal device via the wireless channel. Therefore, the terminal device can detect the information of the downlink channel that does not have complete reciprocity. The terminal device can determine the weighting coefficients of each space-frequency vector that can be used to construct a precoding matrix adapted to the downlink channel based on the received reference signal. Specifically, the method for the terminal device to determine the weighting coefficients corresponding to each space-frequency vector based on the received precoding reference signal can refer to the prior art, and for the sake of brevity, the embodiments of the present application will not be repeated.

[0222] For ease of understanding, the J space-frequency vectors used by the network device to precode the reference signal are recorded as the first group of space-frequency vectors, and the weighted coefficients corresponding to the first group of space-frequency vectors generated by the terminal device are recorded as space-frequency coefficients. As mentioned above, assuming that J = B × T, therefore, the terminal device determines the coefficient matrix C composed of space-frequency coefficients based on the precoded reference signals received from the J ports. DL The dimension of can be B×T.

[0223] Optionally, before S320, the method 300 may further include: the terminal device receives the first indication information. Accordingly, the network device sends the first indication information to the terminal device.

[0224] The first indication information is used to indicate a position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space.

[0225] The network device may carry the first indication information, for example, through physical layer signaling, such as DCI; the network device may also carry the first indication information through high-layer signaling, such as MAC CE or RRC message. This application does not limit this.

[0226] For example, if the network device precodes the reference signal based on B×T space-frequency vectors composed of B space-domain vectors and T frequency-domain vectors in pairs to obtain a precoded reference signal, the first indication information is used to indicate the position of each of the B×T space-frequency vectors in the space-frequency space.

[0227] like Figure 4 As shown, after receiving the reference signal from the network device, the terminal device cannot determine the specific positions of the B×T space-frequency vectors for precoding the reference signal. In order to enable the terminal device to determine the specific position of the space-frequency coefficient corresponding to each of the B×T space-frequency vectors in the coefficient matrix, the network device can send a first indication information to the terminal device.

[0228] Furthermore, the terminal device may generate space-frequency coefficient information based on at least one set of space-frequency coefficients. In the embodiment of the present application, the matrix composed of the space-frequency coefficient information is denoted as C.

[0229] As an example, if the terminal device generates space-frequency coefficient information based on a set of space-frequency coefficients, the space-frequency coefficient information is equivalent to the space-frequency coefficients.

[0230] Assuming that the period of the terminal device to feedback the space-frequency coefficient is 1 second, in this case, the terminal device generates a set of space-frequency coefficients based on a set of reference signals received every second, and generates space-frequency coefficient information based on this set of space-frequency coefficients. Further, the terminal device generates spatial domain vector update information based on the space-frequency coefficient information, and sends the spatial domain vector update information to the network device. It can be understood that in this case, the terminal device feeds back the space-frequency coefficient and the spatial domain vector update information at the same time, that is, the frequency of the terminal device feeding back the space-frequency coefficient is equal to the frequency of feeding back the spatial domain vector update information.

[0231] As another example, if the terminal device generates space-frequency coefficient information based on multiple groups of space-frequency coefficients, the space-frequency coefficient information may be generated by statistically averaging the multiple groups of space-frequency coefficients.

[0232] Assume that the period for the terminal device to feedback the space-frequency coefficient is 1 second. In this case, the terminal device can generate spatial domain vector update information every 2 seconds based on the two sets of generated space-frequency coefficients, or the terminal device can generate spatial domain vector update information every 3 seconds based on the three sets of generated space-frequency coefficients, or the terminal device can also generate spatial domain vector update information at longer intervals, which is not limited to the embodiments of the present application.

[0233] Assuming that the terminal device generates space-frequency coefficient information every 2 seconds, the terminal device will not generate space-domain vector update information at the first second, and therefore only feeds back the space-frequency coefficient; at the second second, the terminal device generates space-frequency coefficient information based on the two sets of space-frequency coefficients, and generates space-domain vector update information based on the space-frequency coefficient information, so the terminal device feeds back the space-frequency coefficient and space-domain vector update information at the second second. It can be understood that in this case, the frequency of the terminal device feeding back the space-frequency coefficient is greater than the frequency of feeding back the space-domain vector update information.

[0234] In the above, two methods for the terminal device to feed back the spatial vector update information are listed. It can be understood that no matter which method the terminal device feeds back the spatial vector update information, the method for the terminal device to generate the spatial vector update information according to the spatial-frequency coefficient information is the same. The following is an example in which the frequency of the terminal device feeding back the spatial-frequency coefficient is greater than the frequency of feeding back the spatial vector update information.

[0235] Assume that the period for the terminal device to feed back the space-frequency coefficient is 1 second, and the period for feeding back the space-domain vector update information is 3 seconds.

[0236] At the first second, the terminal device generates the first set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Then feedback to the network device

[0237] At the second second, the terminal device generates a second set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Then feedback to the network device

[0238] At the 3rd second, the terminal device generates the third set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Further, the terminal device generates space-frequency coefficient information according to the three sets of space-frequency coefficients, which is recorded as C. For example, Furthermore, the terminal device generates spatial domain vector update information based on the spatial-frequency coefficient information.

[0239] It should be understood that before generating the spatial vector update information, the terminal device may first determine the number of groups of spatial vector coefficients according to the eigenspace of the statistical covariance matrix of the downlink channel.

[0240] Optionally, in order to avoid a large range of variation in the number of groups of spatial vector coefficients determined by the terminal device, before S320, the method further includes: the terminal device receives second indication information, the second indication information being used to indicate the number of groups of spatial vector coefficients. Accordingly, the network device sends the second indication information.

[0241] The network device may carry the second indication information, for example, through physical layer signaling, such as DCI; the network device may also carry the second indication information through high-layer signaling, such as MAC CE or RRC message. This application does not limit this.

[0242] When the terminal device determines the number of groups of spatial vector coefficients according to the second indication information, it can be beneficial for the terminal device to generate spatial vector coefficients based on the space-frequency coefficient information C.

[0243] Assume J = B × T, then The dimension of can be B×T, and further, the dimension of C can also be B×T. Assume that the number of groups of spatial vector coefficients indicated by the second indication information is K. Since each group of spatial vector coefficients is used to weightedly combine the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors, when the first group of spatial vectors includes B spatial vectors, the number of each group of spatial vector coefficients is B. That is, the dimension of the coefficient matrix C1 composed of K groups of spatial vector coefficients can be B×K.

[0244] The relationship between the spatial-frequency coefficient information C and the spatial-domain vector update information C1 satisfies: C=C1C2.

[0245] The relationship between the matrix S' composed of the first group of spatial domain vectors, the matrix S composed of the second group of spatial domain vectors, and the spatial domain vector update information C1 satisfies: S=S'C1.

[0246] As mentioned above, the space-frequency matrix H DL Satisfy H DL =S'C DL F' H Combining C=C1C2 and S=S'C1, we can get H DL =SC2F' H . Further, by transforming the above formula, we can get: C2=S H H DL F'. Therefore, the coefficient matrix C2 can be expressed as H DL The projection coefficients on S and F', in other words, the coefficient matrix C2 can represent the projection coefficients of the downlink instantaneous channel on S and F'. That is, each element in C2 represents a weighting coefficient corresponding to a space-frequency vector composed of a space-domain vector in the second set of space-domain vectors and a frequency-domain vector in the first set of frequency-domain vectors.

[0247] Further, the terminal device feeds back the spatial vector update information C1 and the spatial frequency coefficient C2 to the network device. That is, at the 3rd second, the spatial frequency coefficient fed back by the terminal device to the network device is not generated based on the third reference signal received at the 3rd second. Instead, the space-frequency coefficient C2 is generated based on the space-frequency coefficient information.

[0248] It can be understood that the space-frequency coefficients fed back by the terminal device at the 1st and 2nd seconds can be used to weightedly combine the first group of space-frequency vectors to obtain the precoding vector. The space-frequency coefficients fed back by the terminal device at the 3rd second can be used to weightedly combine multiple space-frequency vectors composed of the second group of space-domain vectors and the first group of frequency-domain vectors to obtain the precoding vector.

[0249] It can be understood that from the 1st second to the 3rd second, the reference signals sent by the network device to the terminal device are all reference signals precoded based on the first group of spatial domain vectors and the first group of frequency domain vectors.

[0250] After the network device receives the spatial domain vector update information fed back by the terminal device at the 3rd second, the network device may update the first group of spatial domain vectors based on the spatial domain vector update information.

[0251] For example, the network device calculates the first set of spatial vectors S'=[a(θ0) a(θ1) … a(θ B-1 )] and the kth group of spatial vector coefficients c in the spatial vector update information C1 1,k =[c 1,k,0 c 1,k,1 … c 1,k,B-1] H , we can get the kth spatial vector in the second set of spatial vectors: m(θ k )=a(θ0)c 1,k,0 +a(θ1)c 1,k,1 +…+a(θ B-1 )c 1,k,B-1 , 0≤k≤K.

[0252] After the network device calculates the second set of spatial vectors, it sends a reference signal precoded based on the second set of spatial vectors and the first set of frequency vectors to the terminal device at the fourth second. Assuming that J = K × T, the spatial-frequency coefficients generated by the terminal device based on the received reference signal at the fourth second are The dimension of can be K×T, then when K is less than B, the dimension of the space-frequency coefficient fed back by the terminal device at the 4th second is less than the dimension of the space-frequency coefficient fed back at the 1st second and the 2nd second. In other words, when the downlink channel is measured based on the updated spatial domain vector, the feedback overhead of the terminal device can be saved.

[0253] As mentioned above, S = S'C1. By transforming the above formula, we can get: C1 = S' H S. Therefore, the spatial domain vector update information C1 may also be expressed as a projection coefficient of S on S'. In other words, the spatial domain vector update information C1 may represent a projection coefficient of the feature space of the statistical covariance matrix of the downlink channel on S'.

[0254] It should be noted that the above text uses one polarization direction and one receiving antenna as an example to illustrate the process of the terminal device generating spatial vector update information. In other words, the above K groups of spatial vector coefficients can be determined based on a precoding reference signal sent by a transmitting antenna in one polarization direction and received on one receiving antenna. However, this should not constitute any limitation to this application.

[0255] When the terminal device is configured with multiple receiving antennas, the one receiving antenna described in the example above may be any one of the multiple receiving antennas configured for the terminal device. That is, the terminal device may determine K groups of spatial vector coefficients for each receiving antenna based on the method described above.

[0256] When the network device is configured with transmitting antennas in multiple polarization directions, the polarization direction described in the example above may be any one of the multiple polarization directions. That is, the terminal device may determine K groups of spatial vector coefficients based on the precoding reference signal sent by the transmitting antenna in each polarization direction based on the method described above.

[0257] Optionally, the spatial vector update information includes R groups of spatial vector update information based on receiving antenna feedback, each group of spatial vector update information based on receiving antenna feedback corresponds to one receiving antenna. Each group of spatial vector update information based on receiving antenna feedback includes K groups of spatial vector coefficients corresponding to one receiving antenna.

[0258] It should be understood that the terminal device feeding back the spatial vector update information based on the receiving port is only one possible implementation method and should not be construed as limiting the present application.

[0259] In another implementation, the terminal device may also feed back spatial vector update information based on the transmission layer. In this implementation, in each group of spatial vector coefficients in the K groups of spatial vector coefficients included in the above spatial vector update information, the spatial vector coefficient corresponding to each spatial vector may include Z spatial vector coefficients corresponding to Z transmission layers.

[0260] For ease of understanding, the spatial vector update information corresponding to two polarization directions is taken as an example to illustrate the process of the terminal device determining the spatial vector update information based on the transmission layer feedback.

[0261] Assume that the number of spatial vector coefficients corresponding to each spatial vector in each set of spatial vector coefficients determined by the terminal device is R, corresponding to the R receiving ports. Then the spatial vector coefficient information C1 determined by the terminal device based on the receiving port can be expressed as:

[0262]

[0263] The coefficient vectors in the first K rows of the matrix correspond to K groups of spatial vector coefficients corresponding to B spatial vectors in the first polarization direction. The coefficient vectors in the last K rows correspond to K groups of spatial vector coefficients corresponding to B spatial vectors in the second polarization direction. Among them, the coefficient vectors in the kth row and rth column in the first K rows represent the kth group of spatial vector coefficients corresponding to the rth receiving port in the first polarization direction; the coefficient vectors in the kth row and rth column in the last K rows represent the kth group of spatial vector coefficients corresponding to the rth receiving port in the second polarization direction.

[0264] The terminal device may, for example, perform SVD on the coefficient matrix C1 to obtain spatial vector coefficients based on transmission layer feedback. The spatial vector coefficients determined by the terminal device based on the transmission layer may be represented by a matrix as follows:

[0265]

[0266] Each group of spatial vector coefficients in the coefficient matrix is ​​represented by p to distinguish them from each group of spatial vector coefficients c based on the feedback of the receiving port. The first K rows in the coefficient matrix can correspond to the first polarization direction, and the last K rows can correspond to the second polarization direction. Z columns correspond to Z transmission layers. Among them, the coefficient vector of the kth row and the zth column in the first K rows represents the kth group of spatial vector coefficients corresponding to the zth transmission layer in the first polarization direction; the coefficient vector of the kth row and the zth column in the last K rows represents the kth group of spatial vector coefficients corresponding to the zth transmission layer in the second polarization direction.

[0267] It can be seen that the terminal device determines the spatial vector coefficients corresponding to B spatial vectors based on the receiving port, and can determine the spatial vector coefficients corresponding to B spatial vectors based on the transmission layer feedback.

[0268] The terminal device can generate spatial vector update information based on the spatial vector coefficients corresponding to the B spatial vectors in each polarization direction and each transmission layer.

[0269] It should be understood that the process of determining the spatial vector update information based on the transmission layer feedback by the terminal device in the above example is only an example and should not constitute any limitation to this application. This application does not limit the specific method for the terminal device to determine the spatial vector update information based on the transmission layer feedback.

[0270] In an embodiment of the present application, the terminal device generates spatial vector update information corresponding to the first set of spatial vectors based on the statistics of the spatial characteristics of the downlink channel, and sends it to the network device. Further, the network device corrects the first set of spatial vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial vector update information to obtain a second set of spatial vectors, thereby solving the problem that the sparsity of the spatial information of the uplink and downlink channels is not large enough. Further, the network device performs downlink channel measurement based on the corrected second set of spatial vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0271] In addition, when the number of spatial domain vectors included in the second group of spatial domain vectors obtained by the network device based on the spatial domain vector update information is less than the number of spatial domain vectors included in the first group of spatial domain vectors, the network device performs precoding based on the second group of spatial domain vectors and the reference signal to reduce the pilot overhead.

[0272] Figure 5 It is a schematic flowchart of an updating method provided in another embodiment of the present application. Figure 5 The method 400 shown may include S410 to S430. The steps in the method 400 are described in detail below. S410 in the method 400 is the same as S310 in the method 300, and for the sake of brevity, the embodiment of the present application will not be repeated.

[0273] S420, the terminal device generates spatial domain vector update information and frequency domain vector update information.

[0274] S430, the terminal device sends spatial domain vector update information and frequency domain vector update information. Correspondingly, in S430, the network device receives the spatial domain vector update information and the frequency domain vector update information.

[0275] The spatial vector update information is used to update the first set of spatial vectors to obtain a second set of spatial vectors. The spatial vector information includes multiple sets of spatial vector coefficients, each set of spatial vector coefficients is used to perform weighted combination on the first set of spatial vectors to obtain a spatial vector in the second set of spatial vectors.

[0276] The frequency domain vector update information is used to update the first set of frequency domain vectors to obtain the second set of frequency domain vectors. The frequency domain vector information includes multiple sets of frequency domain vector coefficients, each set of frequency domain vector coefficients is used to weighted combine the first set of frequency domain vectors to obtain a frequency domain vector in the second set of frequency domain vectors.

[0277] Since the reference signal passes through the downlink channel when being sent to the terminal device via the wireless channel. Therefore, the terminal device can detect the information of the downlink channel that does not have complete reciprocity. The terminal device can determine the weighting coefficients of each space-frequency vector that can be used to construct a precoding matrix adapted to the downlink channel based on the received reference signal. Specifically, the method for the terminal device to determine the weighting coefficients corresponding to each space-frequency vector based on the received precoding reference signal can refer to the prior art, and for the sake of brevity, the embodiments of the present application will not be repeated.

[0278] For ease of understanding, the J space-frequency vectors used by the network device to precode the reference signal are recorded as the first group of space-frequency vectors, and the weighted coefficients corresponding to the first group of space-frequency vectors generated by the terminal device are recorded as space-frequency coefficients. As mentioned above, assuming that J = B × T, therefore, the terminal device determines the coefficient matrix C composed of space-frequency coefficients based on the precoded reference signals received from the J ports. DL The dimension of can be B×T.

[0279] Optionally, before S420, the method 400 may further include: the terminal device receives the first indication information. Accordingly, the network device sends the first indication information to the terminal device.

[0280] The first indication information is used to indicate a position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space.

[0281] The network device may carry the first indication information, for example, through physical layer signaling, such as DCI; the network device may also carry the first indication information through high-layer signaling, such as MAC CE or RRC message. This application does not limit this.

[0282] For example, if the network device precodes the reference signal based on B×T space-frequency vectors composed of B space-domain vectors and T frequency-domain vectors combined in pairs to obtain a precoded reference signal, the first indication information is used to indicate the position of each of the B×T space-frequency vectors in the space-frequency space.

[0283] like Figure 4 As shown, after receiving the reference signal from the network device, the terminal device cannot determine the specific positions of the B×T space-frequency vectors for precoding the reference signal. In order to enable the terminal device to determine the specific position of the space-frequency coefficient corresponding to each of the B×T space-frequency vectors in the coefficient matrix, the network device can send a first indication information to the terminal device.

[0284] Furthermore, the terminal device generates space-frequency coefficient information based on at least one set of space-frequency coefficients in the spatial domain. In the embodiment of the present application, the matrix composed of the space-frequency coefficient information is recorded as C.

[0285] As an example, if the terminal device generates space-frequency coefficient information based on a set of space-frequency coefficients, the space-frequency coefficient information is equivalent to the space-frequency coefficients.

[0286] Assuming that the period of the terminal device to feedback the space-frequency coefficient is 1 second, in this case, the terminal device generates a set of space-frequency coefficients based on a set of received reference signals every second, and generates space-frequency coefficient information based on this set of space-frequency coefficients. Further, the terminal device generates space-domain vector update information and frequency-domain vector update information based on the space-frequency coefficient information, and sends the space-domain vector update information and frequency-domain vector update information to the network device. It can be understood that in this case, the terminal device simultaneously feeds back the space-frequency coefficients, the space-domain vector update information and the frequency-domain vector update information, that is, the frequency of the terminal device feeding back the space-frequency coefficients is equal to the frequency of feeding back the space-domain vector update information and the frequency-domain vector update information.

[0287] As another example, if the terminal device generates space-frequency coefficient information based on multiple groups of space-frequency coefficients, the space-frequency coefficient information may be generated by statistically averaging the multiple groups of space-frequency coefficients.

[0288] Assume that the period for the terminal device to feedback the space-frequency coefficients is 1 second. In this case, the terminal device can generate space-domain vector update information and frequency-domain vector update information every 2 seconds based on the two sets of space-frequency coefficients generated. Alternatively, the terminal device can generate space-domain vector update information and frequency-domain vector update information every 3 seconds based on the three sets of space-frequency coefficients generated. Alternatively, the terminal device can also generate space-domain vector update information and frequency-domain vector update information at longer intervals, and the embodiments of the present application are not limited to this.

[0289] Assuming that the terminal device generates space-frequency coefficient information every 2 seconds, the terminal device will not generate space-domain vector update information and frequency-domain vector update information at the first second, and therefore only feeds back the space-frequency coefficient; at the second second, the terminal device generates space-frequency coefficient information based on the two sets of space-frequency coefficients, and generates space-domain vector update information and frequency-domain vector update information based on the space-frequency coefficient information, therefore, the terminal device feeds back the space-frequency coefficient, space-domain vector update information and frequency-domain vector update information at the second second. It can be understood that in this case, the frequency of the terminal device feeding back the space-frequency coefficient is greater than the frequency of feeding back the space-domain vector update information and the frequency-domain vector update information.

[0290] In the above, two methods for the terminal device to feed back the spatial domain vector update information and the frequency domain vector update information are listed. It can be understood that no matter in which way the terminal device feeds back the spatial domain vector update information and the frequency domain vector update information, the method for the terminal device to generate the spatial domain vector update information and the frequency domain vector update information according to the spatial-frequency coefficient information is the same. The following is an example in which the frequency of the terminal device feeding back the spatial-frequency coefficient is greater than the frequency of feeding back the spatial domain vector update information and the frequency domain vector update information.

[0291] Assume that the period for the terminal device to feed back the space-frequency coefficient is 1 second, and the period for feeding back the space-domain vector update information and the frequency-domain vector update information is 3 seconds.

[0292] At the first second, the terminal device generates the first set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Then feedback to the network device

[0293] At the second second, the terminal device generates a second set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Then feedback to the network device

[0294] At the 3rd second, the terminal device generates the third set of space-frequency coefficients based on the reference signals received from the J ports, denoted as Further, the terminal device generates space-frequency coefficient information according to the three sets of space-frequency coefficients, which is recorded as C. For example, Furthermore, the terminal device generates spatial domain vector update information and frequency domain vector update information based on the spatial-frequency coefficient information.

[0295] It should be understood that before generating spatial domain vector update information and frequency domain vector update information, the terminal device can first determine the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients based on the eigenspace of the statistical covariance matrix of the downlink channel.

[0296] In order to avoid a large range of variation in the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients determined by the terminal device, before S420, the method further includes: the terminal device receives second indication information, the second indication information being used to indicate the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients. Accordingly, the network device sends the second indication information.

[0297] The network device may carry the second indication information, for example, through physical layer signaling, such as DCI; the network device may also carry the second indication information through high-layer signaling, such as MAC CE or RRC message. This application does not limit this.

[0298] When the terminal device determines the number of groups of spatial domain vector coefficients and the number of groups of frequency domain vector coefficients according to the second indication information, it can be beneficial for the terminal device to generate spatial domain vector coefficients and frequency domain vector coefficients according to the spatial-frequency coefficient information.

[0299] Assume J = B × T, then The dimension of C can be B×T, and further, the dimension of C can also be B×T. Assume that the number of groups of spatial domain vector coefficients indicated by the second indication information is K, and the number of groups of frequency domain vector coefficients is D. Since each group of spatial domain vector coefficients is used to weightedly combine the first group of spatial domain vectors to obtain a spatial domain vector in the second group of spatial domain vectors, when the first group of spatial domain vectors includes B spatial domain vectors, the number of each group of spatial domain vector coefficients is B. That is, the dimension of the coefficient matrix C1 composed of K groups of spatial domain vector coefficients can be B×K. Similarly, since each group of frequency domain vector coefficients is used to weightedly combine the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors, when the first group of frequency domain vectors includes T frequency domain vectors, the number of each group of frequency domain vector coefficients is T. That is, the dimension of the coefficient matrix C3 composed of D groups of frequency domain vector coefficients can be D×T

[0300] The relationship between the spatial-frequency coefficient information C and the spatial-domain vector update information C1 and the frequency-domain vector update information C3 satisfies: C=C1C2C3.

[0301] The relationship between the matrix S' composed of the first group of spatial domain vectors, the matrix S composed of the second group of spatial domain vectors, and the spatial domain vector update information C1 satisfies: S=S'C1.

[0302] The relationship between the matrix F' composed of the first set of frequency domain vectors, the matrix F composed of the second set of frequency domain vectors, and the frequency domain vector update information C3 satisfies: H =C3F' H .

[0303] As mentioned above, the space-frequency matrix H DL Satisfy H DL =S'C DLF' H Combining C = C1C2C3, S = S'C1, and F H = C3F' H , we can obtain H DL = SC2F H . Further, by transforming the above equation, we get: C2 = S H H DL F. Therefore, the coefficient matrix C2 can be expressed as the projection coefficients of H DL on S and F. In other words, the coefficient matrix C2 can be expressed as the projection coefficients of the downlink instantaneous channel on S and F. That is to say, each element in C2 represents the weighted coefficient corresponding to a spatial-frequency vector composed of a spatial vector in the second group of spatial vectors and a frequency vector in the second group of frequency vectors.

[0304] Further, the terminal device feeds back the spatial vector update information C1, the frequency vector update information C3, and the spatial-frequency coefficient C2 to the network device. That is to say, at the 3rd second, the spatial-frequency coefficient fed back by the terminal device to the network device is not the one generated based on the received third reference signal at the 3rd second but the spatial-frequency coefficient C2 generated according to the spatial-frequency coefficient information.

[0305] It can be understood that the spatial-frequency coefficients fed back by the terminal device at the 1st second and the 2nd second can be used for weighted combination of the first group of spatial-frequency vectors to obtain the precoding vector. The spatial-frequency coefficients fed back by the terminal device at the 3rd second can be used for weighted combination of multiple spatial-frequency vectors composed of the second group of spatial vectors and the second group of frequency vectors to obtain the precoding vector.

[0306] It can be understood that from the 1st second to the 3rd second, the reference signals sent by the network device to the terminal device are all reference signals precoded based on the first group of spatial vectors and the first group of frequency vectors.

[0307] After the network device receives the spatial vector update information and the frequency vector update information fed back by the terminal device at the 3rd second, the network device can update the first group of spatial vectors based on the spatial vector update information and update the first group of frequency vectors based on the frequency vector update information.

[0308] For example, based on the first group of spatial vectors S' = [a(θ0) a(θ1) … a(θ B-1 )] and the k-th group of spatial vector coefficients c 1,k = [c 1,k,0 c 1,k,1 … c 1,k,B-1 in the spatial vector update information C1 H , the network device can obtain the k-th spatial vector in the second group of spatial vectors: m(θ k ) = a(θ0)c1,k,0 +a(θ1)c 1,k,1 +…+a(θ B-1 )c 1,k,B-1 , 0≤k≤K.

[0309] The network device uses the first set of frequency domain vectors F' H =[b(τ0) b(τ1) … b(τ T-1 )] H and the dth group of frequency domain vector coefficients c in the frequency domain vector update information C3 3,d =[c 3,d,0 c 3,d,1 … c 3,d,T-1 ], we can obtain the dth frequency domain vector in the second set of frequency domain vectors: l(τ d )=c 3,d,0 b(τ0)+c 3,d,1 b(τ1)+…+c 3,d,T-1 b(τ T-1 ), 0≤d≤D.

[0310] After the network device calculates the second set of spatial domain vectors and the second set of frequency domain vectors, it sends a reference signal precoded based on the second set of spatial domain vectors and the second set of frequency domain vectors to the terminal device at the 4th second. Assuming that J = K × D, the spatial frequency coefficient generated by the terminal device at the 4th second based on the received reference signal is The dimension can be K×D. Then, when K is less than B and / or D is less than T, the dimension of the space-frequency coefficient fed back by the terminal device at the 4th second is less than the dimension of the space-frequency coefficient fed back at the 1st and 2nd seconds. In other words, when the downlink channel is measured based on the updated spatial domain vector and frequency domain vector, the feedback overhead of the terminal device can be saved. As mentioned above, S=S'C1. By transforming the above formula, we can get: C1=S' H S. Therefore, the spatial domain vector update information C1 may also be expressed as a projection coefficient of S on S'. In other words, the spatial domain vector update information C1 may represent a projection coefficient of the feature space of the statistical covariance matrix of the downlink channel on S'.

[0311] As mentioned above, F H =C3F' H . By transforming the above formula, we can get: C3=F H Therefore, the frequency domain vector update information C3 can be expressed as the projection coefficient of F on F'. In other words, the frequency domain vector update information C3 can represent the projection coefficient of the feature space of the statistical covariance matrix of the downlink channel on F'.

[0312] Optionally, after receiving the space-frequency coefficient fed back by the terminal device, the network device may determine the precoding vector according to the space-frequency coefficient. Specifically, the method for the network device to determine the precoding vector may refer to the prior art, and for the sake of brevity, the present embodiment will not be described in detail.

[0313] It should be noted that the above text uses one polarization direction and one receiving antenna as an example to illustrate the process of the terminal device generating spatial domain vector update information and frequency domain vector update information. In other words, the above K groups of spatial domain vector coefficients and D groups of frequency domain vector coefficients can be determined based on a precoding reference signal sent by a transmitting antenna in one polarization direction and received on one receiving antenna. However, this should not constitute any limitation to this application.

[0314] When the terminal device is configured with multiple receiving antennas, the receiving antenna described in the example above can be any one of the multiple receiving antennas configured for the terminal device. In other words, the terminal device can determine K groups of spatial domain vector coefficients and D groups of frequency domain vector coefficients for each receiving antenna based on the method described above.

[0315] When the network device is configured with transmitting antennas in multiple polarization directions, the polarization direction described in the example above may be any one of the multiple polarization directions. That is, the terminal device may determine K groups of spatial domain vector coefficients and D groups of frequency domain vector coefficients based on the precoding reference signal sent by the transmitting antenna in each polarization direction based on the method described above.

[0316] Optionally, the spatial domain vector update information and the frequency domain vector update information respectively include R groups of spatial domain vector update information and frequency domain vector update information based on receiving antenna feedback, and each group of spatial domain vector update information and frequency domain vector update information based on receiving antenna feedback corresponds to one receiving antenna. Each group of spatial domain vector update information based on receiving antenna feedback includes K groups of spatial domain vector coefficients corresponding to one receiving antenna, and each group of frequency domain vector update information based on receiving antenna feedback includes D groups of frequency domain vector coefficients corresponding to one receiving antenna.

[0317] It should be understood that the terminal device feeding back the spatial domain vector update information and the frequency domain vector update information based on the receiving port is only one possible implementation manner and should not be construed as limiting the present application.

[0318] In another implementation, the terminal device may also feedback spatial domain vector update information and frequency domain vector update information based on the transmission layer. In this implementation, in each group of K groups of spatial domain vector coefficients included in the above spatial domain vector update information, the spatial domain vector coefficients corresponding to each spatial domain vector may include Z spatial domain vector coefficients corresponding to Z transmission layers; in each group of D groups of frequency domain vector coefficients included in the frequency domain vector update information, the frequency domain vector coefficients corresponding to each frequency domain vector may include Z frequency domain vector coefficients corresponding to Z transmission layers.

[0319] For ease of understanding, the frequency domain vector update information corresponding to two polarization directions is taken as an example to illustrate the process of the terminal device determining the frequency domain vector update information based on the transmission layer feedback.

[0320] Assume that the number of frequency domain vector coefficients corresponding to each frequency domain vector in each group of frequency domain vector coefficients determined by the terminal device is R, corresponding to the R receiving ports. Then the frequency domain vector update information C3 determined by the terminal device based on the receiving port can be expressed as:

[0321]

[0322] The coefficient vectors in the first D rows of the matrix correspond to the D groups of frequency domain vector coefficients corresponding to the T frequency domain vectors in the first polarization direction. The coefficient vectors in the last D rows correspond to the D groups of frequency domain vector coefficients corresponding to the T frequency domain vectors in the second polarization direction. Among them, the coefficient vectors in the d-th row and r-th column in the first D rows represent the d-th group of spatial domain vector coefficients corresponding to the r-th receiving port in the first polarization direction; the coefficient vectors in the d-th row and r-th column in the last D rows represent the d-th group of spatial domain vector coefficients corresponding to the r-th receiving port in the second polarization direction.

[0323] The terminal device may, for example, perform SVD on the coefficient matrix C3 to obtain frequency domain vector coefficients based on transmission layer feedback. The frequency domain vector coefficients determined by the terminal device based on the transmission layer may be represented by a matrix as follows:

[0324]

[0325] Each group of frequency domain vector coefficients in the coefficient matrix is ​​represented by p to distinguish it from the frequency domain vector coefficients c based on the feedback of the receiving port. The first D rows in the coefficient matrix can correspond to the first polarization direction, and the last D rows can correspond to the second polarization direction. The Z columns correspond to the Z transmission layers. Among them, the coefficient vector of the d-th row and the z-th column in the first D rows represents the d-th group of frequency domain vector coefficients corresponding to the z-th transmission layer in the first polarization direction; the coefficient vector of the d-th row and the z-th column in the last D rows represents the d-th group of frequency domain vector coefficients corresponding to the z-th transmission layer in the second polarization direction.

[0326] It can be seen that the terminal device determines the frequency domain vector coefficients corresponding to the T frequency domain vectors based on the receiving port, and can determine the frequency domain vector coefficients corresponding to the T frequency domain vectors based on the transmission layer feedback.

[0327] The terminal device can generate frequency domain vector update information based on the frequency domain vector coefficients corresponding to the T frequency domain vectors in each polarization direction and each transmission layer.

[0328] It should be understood that the process of the terminal device determining the frequency domain vector update information based on the transmission layer feedback in the above example is only an example and should not constitute any limitation to this application. This application does not limit the specific method for the terminal device to determine the frequency domain vector update information based on the transmission layer feedback.

[0329] In an embodiment of the present application, the terminal device generates spatial domain vector update information corresponding to the first group of spatial domain vectors based on the statistics of the spatial domain characteristics of the downlink channel, and generates frequency domain vector update information corresponding to the first group of frequency domain vectors based on the statistics of the frequency domain characteristics of the downlink channel, and sends it to the network device. Furthermore, the network device corrects the first group of spatial domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the spatial domain vector update information to obtain a second group of spatial domain vectors; and can correct the first group of frequency domain vectors obtained according to the reciprocity of the uplink and downlink channels according to the frequency domain vector update information to obtain a second group of frequency domain vectors, thereby solving the problem that the sparsity of the spatial and frequency domain information of the uplink and downlink channels is not large enough. Furthermore, the network device performs downlink channel measurement based on the corrected second group of spatial domain vectors and the second group of frequency domain vectors, so that the determined precoding matrix is ​​more adapted to the downlink channel.

[0330] In addition, when the number of spatial domain vectors included in the second group of spatial domain vectors obtained by the network device based on the spatial domain vector update information is less than the number of spatial domain vectors included in the first group of spatial domain vectors, the network device performs precoding based on the second group of spatial domain vectors and the reference signal, which can reduce the pilot overhead. Alternatively, when the number of frequency domain vectors included in the second group of frequency domain vectors obtained by the network device based on the frequency domain vector update information is less than the number of frequency domain vectors included in the first group of frequency domain vectors, the network device performs precoding based on the second group of frequency domain vectors and the reference signal, which can reduce the pilot overhead.

[0331] Figure 6 It is a schematic flow chart of the updating method provided in the embodiment of the present application. Figure 6 It is a schematic flow chart of the updating method 500 provided by the embodiment of the present application, shown from the perspective of device interaction. Figure 6 The method 500 shown may include S510 to S530. Each step in the method 500 is described in detail below.

[0332] S510, the terminal device receives a reference signal. Accordingly, in S510, the network device sends a reference signal.

[0333] The reference signal sent by the network device is a non-precoded reference signal.

[0334] S520, the terminal device generates spatial vector update information.

[0335] S530, the terminal device sends spatial vector update information. Correspondingly, in S530, the network device receives the spatial vector update information.

[0336] The spatial vector update information is used to update the first set of spatial vectors to obtain a second set of spatial vectors. The spatial vector information includes multiple sets of spatial vector coefficients, each set of spatial vector coefficients is used to perform weighted combination on the first set of spatial vectors to obtain a spatial vector in the second set of spatial vectors.

[0337] The method for the terminal device to generate spatial vector update information can refer to the description of S320. The difference from S320 is that in S520, the terminal device first generates a first group of spatial vectors and a first group of frequency domain vectors based on the received reference signal; further, generates weighted coefficients of each spatial-frequency vector that can be used to construct a precoding matrix adapted to the downlink channel, that is, generates a group of spatial-frequency coefficients corresponding to the first group of spatial-frequency vectors composed of the spatial vectors in the first group of spatial vectors and the frequency vectors in the first group of frequency domain vectors; further, the terminal device generates spatial-frequency coefficient information based on at least one group of spatial-frequency coefficients; further, generates spatial-frequency vector update information based on the spatial-frequency coefficient information, and sends it to the network device.

[0338] It should be understood that in order to avoid the number of spatial domain vectors included in the first group of spatial domain vectors generated by the terminal device and the number of frequency domain vectors included in the first group of frequency domain vectors from varying within a large range, the network device may send indication information to the terminal device for indicating the number of generated spatial domain vectors and the number of frequency domain vectors. In an embodiment of the present application, if the number of the second group of spatial domain vectors obtained by the network device based on the spatial domain vector update information is less than the number of the first group of spatial domain vectors, then in the subsequent channel measurement, the indication information sent by the network device to the terminal device for indicating the number of spatial domain vectors may indicate a reduced number of spatial domain vectors. Furthermore, the terminal device may generate fewer spatial domain vectors based on the received indication information, thereby reducing the feedback overhead of the terminal device.

[0339] Figure 7 It is a schematic flowchart of an updating method provided in another embodiment of the present application. Figure 7 The method 600 shown may include S610 to S630. Each step in the method 600 is described in detail below.

[0340] S610, the terminal device receives a reference signal. Accordingly, in S610, the network device sends a reference signal.

[0341] The reference signal sent by the network device is a non-precoded reference signal.

[0342] S620, the terminal device generates spatial domain vector update information and frequency domain vector update information.

[0343] S630, the terminal device sends spatial domain vector update information and frequency domain vector update information. Correspondingly, in S630, the network device receives the spatial domain vector update information and the frequency domain vector update information.

[0344] The spatial vector update information is used to update the first set of spatial vectors to obtain a second set of spatial vectors. The spatial vector information includes multiple sets of spatial vector coefficients, each set of spatial vector coefficients is used to perform weighted combination on the first set of spatial vectors to obtain a spatial vector in the second set of spatial vectors.

[0345] The frequency domain vector update information is used to update the first set of frequency domain vectors to obtain the second set of frequency domain vectors. The frequency domain vector information includes multiple sets of frequency domain vector coefficients, each set of frequency domain vector coefficients is used to perform weighted combination on the first set of frequency domain vectors to obtain a frequency domain vector in the second set of frequency domain vectors.

[0346] The method for the terminal device to generate spatial domain vector update information and frequency domain vector update information can refer to the description of S420. The difference from S420 is that in S620, the terminal device first generates a first group of spatial domain vectors and a first group of frequency domain vectors based on the received reference signal; further, generates weighted coefficients of each spatial frequency vector that can be used to construct a precoding matrix adapted to the downlink channel, that is, generates a group of spatial frequency coefficients corresponding to the first group of spatial frequency vectors composed of the spatial vectors in the first group of spatial domain vectors and the frequency domain vectors in the first group of frequency domain vectors; further, the terminal device generates spatial frequency coefficient information based on at least one group of spatial frequency coefficients; further, generates spatial domain vector update information and frequency domain vector update information based on the spatial frequency coefficient information, and sends them to the network device.

[0347] It should be understood that in order to avoid the number of spatial domain vectors included in the first group of spatial domain vectors generated by the terminal device and the number of frequency domain vectors included in the first group of frequency domain vectors from varying within a large range, the network device may send indication information to the terminal device for indicating the number of generated spatial domain vectors and the number of frequency domain vectors. In an embodiment of the present application, if the number of the second group of spatial domain vectors obtained by the network device based on the spatial domain vector update information is less than the number of the first group of spatial domain vectors, then in the subsequent channel measurement, the indication information sent by the network device to the terminal device for indicating the number of spatial domain vectors may reduce the number of indicated spatial domain vectors. Further, the terminal device may generate fewer spatial domain vectors according to the received indication information, thereby reducing the feedback overhead of the terminal device. Similarly, if the number of the second group of frequency domain vectors obtained by the network device based on the frequency domain vector update information is less than the number of the first group of frequency domain vectors, the feedback overhead of the terminal device in the subsequent channel measurement may also be reduced.

[0348] Figure 8 is a schematic block diagram of a communication device provided in an embodiment of the present application. Figure 8 As shown, the communication device 1000 may include a processing unit 1100 and a transceiver unit 1200 .

[0349] In one possible design, the communication device 1000 may correspond to the terminal device in the above method embodiment, for example, it may be a terminal device, or a component configured in the terminal device (such as a chip or a chip system, etc.).

[0350] It should be understood that the communication device 1000 may correspond to the terminal device in the method 300 to the method 600 according to the embodiment of the present application, and the communication device 1000 may include a method for executing Figure 3 Method 300, Figure 5 Method 400, Figure 6 Method 500 and Figure 7 The units of the method performed by the terminal device in the method 600 in the communication device 1000 are respectively for implementing Figure 3 Method 300, Figure 5 Method 400, Figure 6 Method 500 and Figure 7 The corresponding process of any method in method 600.

[0351] Wherein, when the communication device 1000 is used to perform Figure 3When the method 300 in the embodiment is executed, the processing unit 1100 can be used to execute S320 in the method 300, and the transceiver unit 1200 can be used to execute S310 and S330 in the method 300. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0352] When the communication device 1000 is used to perform Figure 5 When the method 400 is used, the processing unit 1100 can be used to execute S420 in the method 400, and the transceiver unit 1200 can be used to execute S410 and S430 in the method 400. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0353] When the communication device 1000 is used to perform Figure 6 When the method 500 is used, the processing unit 1100 can be used to execute S520 in the method 500, and the transceiver unit 1200 can be used to execute S510 and S530 in the method 500. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0354] When the communication device 1000 is used to perform Figure 7 When the method 600 in the embodiment is used, the processing unit 1100 can be used to execute S620 in the method 600, and the transceiver unit 1200 can be used to execute S610 and S630 in the method 600. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0355] It should also be understood that when the communication device 1000 is a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented by a transceiver, for example, corresponding to Fig. 9 The transceiver 2020 in the terminal device 2000 shown in FIG. 1 , the processing unit 1100 in the communication device 1000 may be implemented by at least one processor, for example, corresponding to Fig. 9 The processor 2010 in the terminal device 2000 is shown.

[0356] It should also be understood that when the communication device 1000 is a chip configured in a terminal device, the transceiver unit 1200 in the communication device 1000 can be implemented through an input / output interface, and the processing unit 1100 in the communication device 1000 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0357] In another possible design, the communication device 1000 may correspond to the network device in the above method embodiment, for example, it may be a network device, or a component configured in the network device (such as a chip or a chip system, etc.).

[0358] It should be understood that the communication device 1000 may correspond to the network device in the method 300 to the method 600 according to the embodiment of the present application, and the communication device 1000 may include a method for executing Figure 3 Method 300, Figure 5 Method 400, Figure 6 Method 500 and Figure 7 The units of the method performed by the network device in the method 600 in the communication device 1000 are respectively for implementing Figure 3 Method 300, Figure 5 Method 400, Figure 6 Method 500 and Figure 7 The corresponding process of any method in method 600.

[0359] Wherein, when the communication device 1000 is used to perform Figure 3 When the method 300 in the embodiment is executed, the processing unit 1100 can be used to execute S330 in the method 300, and the transceiver unit 1200 can be used to execute S310 and S330 in the method 300. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0360] When the communication device 1000 is used to perform Figure 5 When the method 400 in the embodiment is used, the processing unit 1100 can be used to execute S430 in the method 400, and the transceiver unit 1200 can be used to execute S410 and S430 in the method 300. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0361] When the communication device 1000 is used to perform Figure 6 When the method 500 in the embodiment is used, the processing unit 1100 can be used to execute S530 in the method 500, and the transceiver unit 1200 can be used to execute S510 and S530 in the method 500. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0362] When the communication device 1000 is used to perform Figure 7When the method 600 is used, the processing unit 1100 can be used to execute S630 in the method 600, and the transceiver unit 1200 can be used to execute S610 and S630 in the method 600. It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0363] It should also be understood that when the communication device 1000 is a network device, the transceiver unit in the communication device 1000 may be implemented by a transceiver, for example, corresponding to Fig.10 The transceiver 3200 in the network device 3000 shown in FIG. 1 , the processing unit 1100 in the communication device 1000 may be implemented by at least one processor, for example, corresponding to Fig.10 The processor 3100 in the network device 3000 is shown in FIG.

[0364] It should also be understood that when the communication device 1000 is a chip configured in a network device, the transceiver unit 1200 in the communication device 1000 can be implemented through an input / output interface, and the processing unit 1100 in the communication device 1000 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0365] Fig. 9 2 is a schematic diagram of the structure of a terminal device 2000 provided in an embodiment of the present application. The terminal device 2000 can be applied to Figure 1 In the system shown, the functions of the terminal device in the above method embodiment are performed. As shown in the figure, the terminal device 2000 includes a processor 2010 and a transceiver 2020. Optionally, the terminal device 2000 also includes a memory 2030. Among them, the processor 2010, the transceiver 2002 and the memory 2030 can communicate with each other through an internal connection path to transmit control and / or data signals, and the memory 2030 is used to store a computer program, and the processor 2010 is used to call and run the computer program from the memory 2030 to control the transceiver 2020 to receive and send signals. Optionally, the terminal device 2000 may also include an antenna 2040 for sending the uplink data or uplink control signaling output by the transceiver 2020 through a wireless signal.

[0366] The processor 2010 and the memory 2030 may be combined into a processing device, and the processor 2010 is used to execute the program code stored in the memory 2030 to implement the above functions. In specific implementation, the memory 2030 may also be integrated into the processor 2010, or independent of the processor 2010. The processor 2010 may be combined with the memory 2030 to form a processing device. Figure 8 The processing units in correspondence.

[0367] The above transceiver 2020 can be used with Figure 8 The transceiver 2020 may correspond to the transceiver unit in the embodiment of the present invention, and may also be referred to as a transceiver unit. The transceiver 2020 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0368] It should be understood that Fig. 9 The terminal device 2000 shown can realize Figure 3 and Figures 5 to 7 The method embodiment shown involves various processes of the terminal device. The operations and / or functions of each module in the terminal device 2000 are respectively to implement the corresponding processes in the above method embodiment. For details, please refer to the description in the above method embodiment. To avoid repetition, the detailed description is appropriately omitted here.

[0369] The processor 2010 can be used to execute the actions implemented by the terminal device described in the previous method embodiment, and the transceiver 2020 can be used to execute the actions of the terminal device sending to or receiving from the network device described in the previous method embodiment. Please refer to the description in the previous method embodiment for details, which will not be repeated here.

[0370] Optionally, the terminal device 2000 may further include a power supply 2050 for providing power to various devices or circuits in the terminal device.

[0371] In addition, in order to make the functions of the terminal device more complete, the terminal device 2000 may also include one or more of an input unit 2060, a display unit 2070, an audio circuit 2080, a camera 2090 and a sensor 2100, and the audio circuit may also include a speaker 2082, a microphone 2084, etc.

[0372] Fig.10 3000 is a schematic diagram of the structure of a network device provided in an embodiment of the present application, for example, a schematic diagram of the structure of a base station. The base station 3000 can be applied to Figure 1 In the system shown in the figure, the functions of the network device in the above method embodiment are performed. As shown in the figure, the base station 3000 may include one or more radio frequency units, such as a remote radio unit (RRU) 3100 and one or more baseband units (BBU) (also referred to as distributed units (DU)) 3200. The RRU 3100 may be referred to as a transceiver unit, and Figure 8. Optionally, the transceiver unit 3100 may also be called a transceiver, a transceiver circuit, or a transceiver, etc., and may include at least one antenna 3101 and a radio frequency unit 3102. Optionally, the transceiver unit 3100 may include a receiving unit and a sending unit, the receiving unit may correspond to a receiver (or receiver, receiving circuit), and the sending unit may correspond to a transmitter (or transmitter, transmitting circuit). The RRU 3100 part is mainly used for receiving and sending radio frequency signals and converting radio frequency signals into baseband signals, for example, for sending indication information to terminal devices. The BBU 3200 part is mainly used for baseband processing, controlling the base station, etc. The RRU 3100 and BBU 3200 may be physically arranged together or physically separated, that is, a distributed base station.

[0373] The BBU 3200 is the control center of the base station, which can also be called a processing unit. Figure 8 The processing unit 1200 in the embodiment corresponds to the baseband processing unit 1200, which is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, spread spectrum, etc. For example, the BBU (processing unit) can be used to control the base station to execute the operation process of the network device in the above method embodiment, for example, to generate the above indication information, etc.

[0374] In one example, the BBU 3200 may be composed of one or more single boards, and multiple single boards may jointly support a wireless access network of a single access standard (such as an LTE network), or may respectively support wireless access networks of different access standards (such as an LTE network, a 5G network, or other networks). The BBU 3200 also includes a memory 3201 and a processor 3202. The memory 3201 is used to store necessary instructions and data. The processor 3202 is used to control the base station to perform necessary actions, for example, to control the base station to execute the operation process of the network device in the above method embodiment. The memory 3201 and the processor 3202 can serve one or more single boards. In other words, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may also be set on each single board.

[0375] It should be understood that Fig.10 The base station 3000 shown can achieve Figure 3 and Figures 5 to 7 The illustrated method embodiment involves various processes of the network device. The operations and / or functions of the various modules in the base station 3000 are respectively to implement the corresponding processes in the above method embodiment. For details, please refer to the description in the above method embodiment. To avoid repetition, the detailed description is appropriately omitted here.

[0376] The BBU 3200 can be used to perform the actions implemented by the network device described in the previous method embodiment, and the RRU 3100 can be used to perform the actions of the network device sending to or receiving from the terminal device described in the previous method embodiment. Please refer to the description in the previous method embodiment for details, which will not be repeated here.

[0377] It should be understood that Fig.10 The base station 3000 shown is only one possible form of network equipment and should not constitute any limitation to the present application. The method provided in the present application can be applied to network equipment in other forms. For example, it includes AAU, and may also include CU and / or DU, or include BBU and adaptive radio unit (adaptive radio unit, ARU), or BBU; it may also be customer premises equipment (customer premises equipment, CPE), and may also be in other forms. The present application does not limit the specific form of the network equipment.

[0378] Among them, the CU and / or DU can be used to perform the actions implemented by the network device in the previous method embodiment, and the AAU can be used to perform the actions of the network device sending to or receiving from the terminal device described in the previous method embodiment. Please refer to the description in the previous method embodiment for details, which will not be repeated here.

[0379] An embodiment of the present application also provides a processing device, including a processor and an interface; the processor is used to execute the method in any of the above method embodiments.

[0380] It should be understood that the above-mentioned processing device can be one or more chips. For example, the processing device can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0381] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0382] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined and performed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0383] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0384] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, which includes: a computer program code, when the computer program code is run on a computer, the computer executes Figure 3 and Figures 5 to 7 The methods respectively executed by the terminal device and the network device in the illustrated embodiment.

[0385] According to the method provided in the embodiment of the present application, the present application also provides a computer-readable medium, which stores a program code, and when the program code is run on a computer, the computer executes Figure 3 and Figures 5 to 7 The methods respectively executed by the terminal device and the network device in the illustrated embodiment.

[0386] According to the method provided in the embodiment of the present application, the present application also provides a system, which includes one or more terminal devices and one or more network devices mentioned above.

[0387] The network devices in the above-mentioned various device embodiments completely correspond to the network devices or terminal devices in the terminal devices and method embodiments, and the corresponding modules or units perform the corresponding steps. For example, the communication unit (transceiver) performs the steps of receiving or sending in the method embodiment, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can refer to the corresponding method embodiments. Among them, the processor can be one or more.

[0388] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and / or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components may reside in a process and / or an execution thread, and a component may be located on a computer and / or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0389] Those of ordinary skill in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may 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.

[0390] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0391] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0392] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0393] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0394] In the above embodiments, the functions of each functional unit can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it 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 (programs). When the computer program instructions (programs) are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. 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 computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. 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 available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0395] If the functions are implemented in the form of 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 the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks or optical disks.

[0396] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A updating method, characterized in that: include: Generate spatial vector update information, the spatial vector update information is determined according to the statistics of the spatial characteristics of the downlink channel, and the spatial vector update information is used to update the first group of spatial vectors to obtain a second group of spatial vectors; wherein the spatial vector update information includes multiple groups of spatial vector coefficients, each group of spatial vector coefficients is used to perform weighted combination on the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors; The spatial domain vector update information is sent.

2. The method according to claim 1, characterized in that The method further comprises: Generate frequency domain vector update information, the frequency domain vector update information is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, each group of frequency domain vector coefficients is used to perform weighted combination on the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; The frequency domain vector update information is sent.

3. The method according to claim 2, characterized in that The spatial domain vector update information is generated based on the space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to the first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a spatial domain vector in the first group of spatial domain vectors and a frequency domain vector in the first group of frequency domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

4. The method according to claim 2, characterized in that The frequency domain vector update information is generated based on space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to a first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a space-domain vector in the first group of space-domain vectors and a frequency-domain vector in the first group of frequency-domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

5. The method according to claim 3 or 4, characterized in that Each group of space-frequency coefficients in the at least one group of space-frequency coefficients is generated based on a received group of reference signals, and the group of reference signals is obtained by performing precoding based on the first group of space-frequency vectors.

6. The method according to claim 3 or 4, characterized in that The method further comprises: First indication information is received, where the first indication information is used to indicate a position of each space-frequency vector in the first group of space-frequency vectors in a space-frequency space.

7. The method according to claim 4, characterized in that The feedback frequency of the space-frequency coefficient is greater than the feedback frequency of the space-domain vector update information and the frequency-domain vector update information.

8. The method according to any one of claims 1 to 4, characterized in that The method further comprises: Second indication information is received, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

9. The method according to any one of claims 2 to 4, characterized in that: The method further comprises: Receive second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

10. A method of updating, characterized in that: include: receiving spatial vector update information, the spatial vector update information being determined according to statistics of spatial characteristics of a downlink channel, the spatial vector update information being used to update a first group of spatial vectors to obtain a second group of spatial vectors; wherein the spatial vector update information comprises a plurality of groups of spatial vector coefficients, each group of spatial vector coefficients being used to perform weighted merging on the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors; The second group of spatial domain vectors is obtained based on the spatial domain vector update information.

11. The method according to claim 10, characterized in that The method further comprises: Receive frequency domain vector update information, where the frequency domain vector update information is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, each group of frequency domain vector coefficients is used to perform weighted combination on the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; The second group of frequency domain vectors is obtained based on the frequency domain vector update information.

12. The method according to claim 11, characterized in that The method further comprises: Send first indication information, wherein the first indication information is used to indicate the position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space, and the first group of space-frequency vectors is used to precode a reference signal; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a space-domain vector in the first group of space-domain vectors and a frequency-domain vector in the first group of frequency-domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

13. The method according to any one of claims 10 to 12, characterized in that The method further comprises: Send second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

14. The method according to claim 11 or 12, characterized in that: The method further comprises: Send second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

15. A communication device, characterized in that: Including processing unit and transceiver unit: The processing unit is used to generate spatial vector update information, the spatial vector update information is determined according to the statistics of the spatial characteristics of the downlink channel, and the spatial vector update information is used to update the first group of spatial vectors to obtain the second group of spatial vectors; wherein the spatial vector update information includes multiple groups of spatial vector coefficients, each group of spatial vector coefficients is used to perform weighted combination on the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors; The transceiver unit is used to send the spatial vector update information.

16. The communication device according to claim 15, characterized in that The processing unit is further used to generate frequency domain vector update information, and the frequency domain vector update information is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, and each group of frequency domain vector coefficients is used to perform weighted combination on the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; The transceiver unit is further configured to send the frequency domain vector update information.

17. The communication device according to claim 16, wherein: The spatial domain vector update information is generated based on the space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to the first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a spatial domain vector in the first group of spatial domain vectors and a frequency domain vector in the first group of frequency domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

18. The communication device according to claim 16, characterized in that The frequency domain vector update information is generated based on space-frequency coefficient information, and the space-frequency coefficient information is generated based on at least one group of space-frequency coefficients, and the at least one group of space-frequency coefficients corresponds to a first group of space-frequency vectors; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a space-domain vector in the first group of space-domain vectors and a frequency-domain vector in the first group of frequency-domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

19. The communication device according to claim 17 or 18, characterized in that: Each group of space-frequency coefficients in the at least one group of space-frequency coefficients is generated based on a received group of reference signals, where the group of reference signals is obtained by performing precoding based on the first group of space-frequency vectors.

20. The communication device according to claim 17 or 18, characterized in that: The transceiver unit is further used to receive first indication information, where the first indication information is used to indicate a position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space.

21. The communication device according to claim 18, characterized in that The feedback frequency of the space-frequency coefficient is greater than the feedback frequency of the space-domain vector update information and the frequency-domain vector update information.

22. The communication device according to any one of claims 15 to 18, characterized in that: The transceiver unit is further used to receive second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

23. The communication device according to any one of claims 16 to 18, characterized in that: The transceiver unit is further used to receive second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

24. A communication device, characterized in that: Including processing unit and transceiver unit: The transceiver unit is used to receive spatial vector update information, the spatial vector update information is determined according to the statistics of the spatial characteristics of the downlink channel, and the spatial vector update information is used to update the first group of spatial vectors to obtain the second group of spatial vectors; wherein the spatial vector update information includes multiple groups of spatial vector coefficients, each group of spatial vector coefficients is used to perform weighted combination on the first group of spatial vectors to obtain a spatial vector in the second group of spatial vectors; The processing unit is configured to obtain the second group of spatial vectors based on the spatial vector update information.

25. The communication device according to claim 24, characterized in that The transceiver unit is further used to receive frequency domain vector update information, and the frequency domain vector update information is used to update the first group of frequency domain vectors to obtain a second group of frequency domain vectors; wherein the frequency domain vector update information includes multiple groups of frequency domain vector coefficients, and each group of frequency domain vector coefficients is used to perform weighted combination on the first group of frequency domain vectors to obtain a frequency domain vector in the second group of frequency domain vectors; The processing unit is further configured to obtain the second group of frequency domain vectors based on the frequency domain vector update information.

26. The communication device according to claim 25, characterized in that The transceiver unit is also used to send first indication information, wherein the first indication information is used to indicate the position of each space-frequency vector in the first group of space-frequency vectors in the space-frequency space, and the first group of space-frequency vectors is used to precode a reference signal; wherein each space-frequency vector in the first group of space-frequency vectors is generated based on a space-domain vector in the first group of space-domain vectors and a frequency-domain vector in the first group of frequency-domain vectors, and each group of space-frequency coefficients is used to perform weighted combination on the first group of space-frequency vectors to obtain a precoding vector.

27. The communication device according to any one of claims 24 to 26, characterized in that: The transceiver unit is further used to send second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial vector coefficients.

28. The communication device according to claim 25 or 26, characterized in that: The transceiver unit is further used to send second indication information, where the second indication information is used to indicate the number of groups of the multiple groups of spatial domain vector coefficients and the number of groups of the multiple groups of frequency domain vector coefficients.

29. A communication device, characterized in that: The device comprises at least one processor, wherein the at least one processor is configured to execute a computer program stored in a memory, so that the communication device implements the method according to any one of claims 1 to 14.

30. A computer-readable storage medium, characterized in that: The invention comprises a computer program which, when being run on a computer, causes the computer to execute the method according to any one of claims 1 to 14.

Images