Channel state information reporting method and related product

Abstract

The invention discloses a channel state information reporting method and a related product. The method comprises the following steps: receiving a first reference signal; first information is sent based on a received first reference signal, the first information comprises indication information of at least one first spatial base vector corresponding to a first precoding matrix, and the first precoding matrix is obtained based on the at least one first spatial base vector and at least one second spatial base vector, the at least one second airspace basis vector is obtained based on n second precoding matrixes. In the embodiment of the invention, the terminal equipment determines a part of airspace base vectors according to the historical measurement result, and only needs to report the indication information of the other part of airspace base vectors corresponding to the precoding matrix, so that the network equipment can determine the part of airspace base vectors according to the indication information of the airspace base vectors reported by the terminal equipment and the historical measurement result; and the pre-coding matrix is recovered, so that the reporting overhead of the channel state information can be saved.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method for reporting channel state information (CSI) and related products. Background Art

[0002] In the frequency division duplex (FDD) mode, a terminal device needs to report the CSI of the downlink channel to a network device. Among them, the CSI includes a precoding matrix indicator (PMI), and the network device determines the precoding for transmitting data to the terminal device according to the PMI reported by the terminal device.

[0003] The PMI reporting is determined and reported according to a set of codebooks. The design of the FDD CSI codebook is a basic and important issue in the fifth generation (5G) and future communication systems. th generation, 5G) and future communication systems.

[0004] The PMI reporting method supported by existing protocols is to report in real time for each measurement. When considering high-precision codebooks, the reporting overhead is relatively large.

[0005] In view of this, how to reduce the reporting overhead of CSI is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a method for reporting channel state information and related products to reduce the reporting overhead of CSI.

[0007] In a first aspect, a method for obtaining channel state information is provided. This method can be implemented by a terminal device, or a chip or circuit for the terminal device.

[0008] Among them, the method includes: receiving a first reference signal; and based on the first reference signal, sending first information, where the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, and the at least one second spatial domain basis vector is obtained based on n second precoding matrices, where n is a positive integer greater than or equal to 1.

[0009] In this aspect, the terminal device determines some spatial domain basis vectors according to historical measurement results, and only needs to report the indication information of the remaining spatial domain basis vectors corresponding to the precoding matrix, so that the network device can restore the precoding matrix according to the indication information of the spatial domain basis vectors reported by the terminal device and the some spatial domain basis vectors determined according to historical measurement results. Considering the slow-varying characteristic of the channel in the spatial domain, the some spatial domain basis vectors determined according to historical measurement results can better reflect the spatial domain characteristics of the precoding matrix to be reported, and only a small number of additional spatial domain basis vectors need to be indicated to correct the spatial domain beam direction, thereby saving the reporting overhead of channel state information.

[0010] Both the at least one first spatial domain basis vector and the at least one second spatial domain basis vector are used to characterize the spatial domain characteristics of the first precoding matrix. The at least one first spatial domain basis vector can be understood as being used to correct the spatial domain beam direction of the at least one second spatial domain basis vector, so that the spatial domain basis vector set composed of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector can better characterize the spatial domain characteristics of the first precoding matrix with as few spatial domain basis vectors as possible.

[0011] In a possible implementation, before receiving the first reference signal, the method further includes: receiving the second reference signal n times; based on the second reference signals received n times, respectively sending the indication information of the n second precoding matrices.

[0012] In this implementation, the indication information of the n second precoding matrices is used to obtain at least one second spatial domain basis vector. The n second precoding matrices are precoding matrices obtained by historical measurement reporting relative to the first precoding matrix.

[0013] In another possible implementation, the at least one second spatial domain basis vector is obtained based on the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0014] In this implementation, since the change of spatial domain characteristics is slow, the precoding vectors corresponding to X transmission layers of the first frequency domain unit of the n second precoding matrices can be extracted to obtain at least one second spatial domain basis vector, which is used to characterize the spatial domain characteristics of the first precoding matrix.

[0015] In still another possible implementation, n = 1, and X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

[0016] In this implementation, the precoding vectors corresponding to X transmission layers of the first frequency domain unit of the second precoding matrix reported in the previous measurement can be extracted to obtain at least one second spatial domain basis vector.

[0017] In another possible implementation, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on the average value of the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0018] In this implementation, by extracting the average value of the precoding vectors corresponding to X transmission layers of the first frequency domain unit of the n second precoding matrices to obtain the at least one second spatial domain basis vector, the accuracy of the first precoding matrix can be improved with limited overhead or the reporting overhead can be reduced under the same reporting accuracy.

[0019] In another possible implementation, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0020] In this implementation, by extracting the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of the first frequency domain unit of the n second precoding matrices to obtain the at least one second spatial domain basis vector, the accuracy of the first precoding matrix can be improved.

[0021] In another possible implementation, X is less than or equal to the minimum value among the numbers of transmission layers corresponding to the n second precoding matrices respectively.

[0022] In another possible implementation, the first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, and each of the n second precoding matrices corresponds to K frequency domain units, where 1 ≤ k ≤ K.

[0023] In another possible implementation, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, including: the first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0024] In this implementation, by making the at least one first spatial domain basis vector and the at least one second spatial domain basis vector orthonormal, the set of spatial domain basis vectors obtained after orthonormalization can more accurately represent the spatial domain characteristics of the first spatial domain basis vector with as few spatial domain basis vectors as possible, and the accuracy of the first precoding matrix can be improved with limited overhead or the reporting overhead can be reduced under the same reporting accuracy.

[0025] In a second aspect, a method for obtaining channel state information is provided, and this method can be implemented by a network device, or a chip or circuit for a network device.

[0026] Wherein, the method includes: sending a first reference signal; receiving first information, where the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1; and obtaining the first precoding matrix based on the first information.

[0027] In this aspect, the network device receives indication information of partial spatial domain basis vectors corresponding to the precoding matrix reported by the terminal device. The network device can recover the precoding matrix according to the indication information of the spatial domain basis vectors reported by the terminal device and historical measurement results. Considering the slow-varying characteristic of the channel in the spatial domain, partial spatial domain basis vectors determined according to historical measurement results can better reflect the spatial domain characteristics of the precoding matrix to be reported, and only a small number of additional spatial domain basis vectors need to be indicated to correct the spatial domain beam direction, thereby saving the reporting overhead of channel state information.

[0028] The at least one first spatial domain basis vector and the at least one second spatial domain basis vector are both used to characterize the spatial domain characteristics of the first precoding matrix. The at least one first spatial domain basis vector can be understood as being used to correct the spatial domain beam direction of the at least one second spatial domain basis vector, so that the set of spatial domain basis vectors composed of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector can better characterize the spatial domain characteristics of the first precoding matrix with as few spatial domain basis vectors as possible.

[0029] In a possible implementation, before sending the first reference signal, the method further includes: sending the second reference signal n times; and respectively receiving indication information of the n second precoding matrices based on the second reference signal sent n times.

[0030] In this implementation, the indication information of the n second precoding matrices is used to obtain at least one second spatial domain basis vector. The n second precoding matrices are precoding matrices obtained through historical measurement reports relative to the first precoding matrix.

[0031] In another possible implementation, the at least one second spatial domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

[0032] In this implementation, since the change of spatial domain characteristics is slow, the at least one second spatial domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit in n second precoding matrices and is used to characterize the spatial domain characteristics of the first precoding matrix.

[0033] In yet another possible implementation, n = 1, and X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

[0034] In this implementation, at least one second spatial domain basis vector is obtained based on the precoding vectors corresponding to X transmission layers of the first frequency domain unit of the second precoding matrix reported in the previous measurement.

[0035] In yet another possible implementation, n > 1, and at least one second spatial domain basis vector is obtained based on the average value of the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0036] In this implementation, at least one second spatial domain basis vector is obtained based on the average value of the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices, which can improve the accuracy of the first precoding matrix under limited overhead or reduce the reporting overhead under the same reporting accuracy.

[0037] In yet another possible implementation, n > 1, and at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0038] In this implementation, at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices, which can improve the accuracy of the first precoding matrix.

[0039] In yet another possible implementation, X is less than or equal to the minimum value of the numbers of transmission layers corresponding to the n second precoding matrices respectively.

[0040] In yet another possible implementation, the first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, each of the n second precoding matrices corresponds to K frequency domain units, and 1 ≤ k ≤ K.

[0041] In yet another possible implementation, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, including: the first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0042] In this implementation, by making at least one first spatial domain basis vector and at least one second spatial domain basis vector orthogonal, the set of spatial domain basis vectors obtained after orthogonalization can more accurately represent the spatial domain characteristics of the first spatial domain basis vector with as few spatial domain basis vectors as possible, which can improve the accuracy of the first precoding matrix with limited overhead or reduce the reporting overhead under the same reporting accuracy.

[0043] In another possible implementation, obtaining the first precoding matrix based on the first information includes: obtaining the at least one second spatial domain basis vector based on the indication information of the n second precoding matrices; and obtaining the first precoding matrix based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0044] In this implementation, before the current measurement report, the network device has received the indication information of n second precoding matrices. Therefore, the at least one second spatial domain basis vector can be obtained based on the indication information of the n second precoding matrices, and after receiving the indication information of the at least one first spatial domain basis vector, the first precoding matrix can be recovered based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0045] In a third aspect, a communication device is provided. The communication device can implement the method in the above first aspect or any implementation of the first aspect. For example, the communication device can be a chip or a terminal device. The above method can be implemented by software, hardware, or by hardware executing corresponding software.

[0046] In a possible implementation manner, the device includes: a transceiver unit and a processing unit; where: the transceiver unit is configured to receive a first reference signal; the processing unit is configured to generate first information based on the first reference signal, the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1; and the transceiver unit is further configured to send the first information.

[0047] Optionally, the transceiver unit is further configured to receive the second reference signal n times before receiving the first reference signal; and the transceiver unit is further configured to respectively send the indication information of the n second precoding matrices based on the n times of received second reference signals.

[0048] Optionally, the at least one second spatial domain basis vector is obtained based on the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0049] Optionally, n = 1, and X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

[0050] Optionally, n > 1, and the at least one second spatial domain basis vector is obtained based on the average value of the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0051] Optionally, n > 1, and the at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of the first frequency domain unit in the n second precoding matrices.

[0052] Optionally, X is less than or equal to the minimum value of the numbers of transmission layers corresponding to the n second precoding matrices respectively.

[0053] Optionally, the first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, and each of the n second precoding matrices corresponds to K frequency domain units, where 1 ≤ k ≤ K.

[0054] Optionally, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, including: the first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0055] For further features and beneficial effects, reference may be made to the relevant descriptions in the first aspect.

[0056] In a fourth aspect, a communication device is provided. The communication device can implement the method in the second aspect or any one of the implementations of the second aspect. For example, the communication device can be a chip or a network device. The above method can be implemented through software, hardware, or by hardware executing corresponding software.

[0057] In a possible implementation, the device includes: a transceiver unit and a processing unit; where: the transceiver unit is configured to send a first reference signal; the transceiver unit is further configured to receive first information, the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1; and the processing unit is configured to obtain the first precoding matrix based on the first information.

[0058] Optionally, the transceiver unit is further configured to transmit the second reference signal n times before transmitting the first reference signal; the transceiver unit is further configured to respectively receive the indication information of the n second precoding matrices based on the n transmitted second reference signals.

[0059] Optionally, the at least one second spatial domain basis vector is obtained based on the precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

[0060] Optionally, n = 1, and X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

[0061] Optionally, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on the average value of the precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

[0062] Optionally, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from the precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

[0063] Optionally, X is less than or equal to the minimum value of the numbers of transmission layers corresponding to the n second precoding matrices respectively.

[0064] Optionally, the first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, each second precoding matrix in the n second precoding matrices corresponds to K frequency domain units, and 1 ≤ k ≤ K.

[0065] Optionally, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, including: the first precoding matrix is obtained based on the orthogonalization result of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0066] Optionally, the processing unit is further configured to obtain the at least one second spatial domain basis vector based on the indication information of the n second precoding matrices; and the processing unit is further configured to obtain the first precoding matrix based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

[0067] For further features and beneficial effects, reference may be made to the relevant descriptions in the second aspect.

[0068] In yet another possible implementation, the communication device in the above third aspect to fourth aspect includes a processor coupled to a memory; the processor is configured to support the device to execute the corresponding functions in the above channel state information reporting method. The memory is used to be coupled to the processor and stores the necessary computer programs (or computer-executable instructions) and / or data of the device. Optionally, the communication device may further include a communication interface for supporting the communication between the device and other network elements, such as the sending or receiving of data and / or signals. Exemplarily, the communication interface may be a transceiver, a circuit, a bus, a module, or other types of communication interfaces. Optionally, the memory may be located inside the communication device and integrated with the processor; or it may be located outside the communication device.

[0069] In yet another possible implementation, the communication device in the above third aspect to fourth aspect includes a processor and a transceiver device, the processor is coupled to the transceiver device, and the processor is configured to execute a computer program or instruction to control the transceiver device to receive and send information; when the processor executes the computer program or instruction, the processor is further configured to implement the above method through a logic circuit or execute code instructions. Wherein, the transceiver device may be a transceiver, a transceiver circuit, or an input / output interface, and is used to receive signals from other communication devices outside the communication device and transmit them to the processor, or send signals from the processor to other communication devices outside the communication device. When the communication device is a chip, the transceiver device is a transceiver circuit or an input / output interface.

[0070] When the communication device in the above third aspect to fourth aspect is a chip, the sending unit may be an output unit, such as an output circuit or a communication interface; the receiving unit may be an input unit, such as an input circuit or a communication interface. When the communication device is a terminal device, the sending unit may be a transmitter; the receiving unit may be a receiver.

[0071] In a fifth aspect, a communication system is provided, the communication system includes the communication device implemented as described in the third aspect or any implementation of the third aspect, and the communication device implemented as described in the fourth aspect or any implementation of the fourth aspect.

[0072] In a sixth aspect, a computer-readable storage medium is provided, on which a computer program or instruction is stored, and when the program or instruction is executed by a processor, it implements the method as described in the first aspect or any implementation of the first aspect, or implements the method as described in the second aspect or any implementation of the second aspect.

[0073] In a seventh aspect, a computer program product is provided which, when executed on a computing device, implements the method described in the first aspect or any implementation of the first aspect, or implements the method described in the second aspect or any implementation of the second aspect. Description of the Drawings

[0074] Figure 1 FIG. 6 is a schematic diagram of the architecture of a communication system 1000 to which embodiments of the present application are applied;

[0075] Figures 2A to 2D FIG. 10 is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0076] Figure 3 FIG. 14 is a schematic diagram of the basic process of CSI estimation by a network device and a terminal device;

[0077] Figure 4 FIG. 18 is a schematic diagram of the structure of an existing PMI codebook;

[0078] Figure 5 FIG. 22 is a schematic diagram of the process of a method for reporting channel state information provided by an embodiment of the present application;

[0079] Figure 6 FIG. 26 is a schematic diagram of the structure of a PMI codebook provided by an embodiment of the present application;

[0080] Figure 7 FIG. 30 is a schematic diagram of the structure of a communication device provided by an embodiment of the present application;

[0081] Figure 8 FIG. 34 is a schematic diagram of the structure of another communication device provided by an embodiment of the present application. Detailed Embodiments

[0082] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

[0083] The technical solution provided by this application can be applied to various communication systems. For example, it can be applied to 5G communication systems, future evolved systems, or various communication convergence systems, etc., and can also be applied to existing communication systems, etc. The application scenarios of the technical solution provided by this application can include various types, such as machine to machine (M2M), macro-micro communication, enhanced mobile broadband (eMBB), ultra-reliable & low-latency communication (uRLLC), and massive machine type communication (mMTC), etc. These scenarios can include but are not limited to: communication scenarios between terminal devices, communication scenarios between network devices, communication scenarios between network devices and terminal devices, etc. Among them, network devices include network devices and core network devices. In the following, the scenario of communication between network devices and terminal devices is taken as an example for illustration.

[0084] Figure 1 It is a schematic diagram of the architecture of the communication system 1000 to which the embodiments of this application are applied. As Figure 1 shown, the communication system includes a radio access network 100 and a core network 200. Optionally, the communication system 1000 may further include the Internet 300. Among them, the radio access network 100 may include at least one network device (such as Figure 1 110a and 110b in Figure 1 ), and may also include at least one terminal device (such as Figure 1 120a - 120j in Figure 1 ). The terminal device is connected to the network device wirelessly, and the network device is connected to the core network wirelessly or wired. The core network device and the network device can be independent different physical devices, or the functions of the core network device and the logical functions of the network device can be integrated on the same physical device, or the functions of part of the core network device and part of the network device can be integrated on one physical device. Terminal devices can be connected to each other and network devices can be connected to each other by wired or wireless means.

[0085] Optionally, in practical applications, the wireless communication system may simultaneously include multiple network devices (also referred to as access network devices), and may also simultaneously include multiple terminal devices. A network device may serve one or more terminal devices simultaneously. A terminal device may also access one or more network devices simultaneously. The embodiments of the present application do not limit the number of terminal devices and network devices included in the wireless communication system.

[0086] Among them, the network device can be an entity on the network side for transmitting or receiving signals. The network device can be an access device for the terminal device to access the wireless communication system wirelessly. For example, the network device can be a base station. The base station can generally cover various names in the following, or be replaced with the following names. For example: radio access network (RAN) node, Node B, evolved Node B (eNB), next generation Node B (gNB), access network device in open radio access network (O-RAN), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNB (MeNB), secondary eNB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, building baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), distributed unit (DU), radio unit (RU), centralized unit control plane (CU controlplane, CU-CP) node, centralized unit user plane (CU user plane, CU-UP) node, positioning node, etc. The base station can be a macro base station, micro base station, relay node, donor node or the like, or a combination thereof. The network device can also refer to a communication module, a modem or a chip disposed in the foregoing device or apparatus. The network device can also be a mobile switching center and a device that undertakes the function of a base station in device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communication, a network-side device in a 6G network, a device that undertakes the function of a base station in a future communication system, etc. The network device can support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0087] The network device can be fixed or mobile. For example, base stations 110a and 110b are stationary and are responsible for wireless transmission and reception in one or more cells from the terminal device 120. Figure 1 The helicopter or drone 120i shown in FIG. can be configured to act as a mobile base station, and one or more cells can move according to the position of the mobile base station 120i. In other examples, the helicopter or drone (120i) can be configured to be used as a terminal device communicating with the base station 110b.

[0088] In this application, the communication device for implementing the above access network function can be an access network device, or a network device with partial functions of the access network, or a device capable of supporting the implementation of the access network function, such as a chip system, a hardware circuit, a software module, or a combination of a hardware circuit and a software module. This device can be installed in the access network device or used in conjunction with the access network device. In the method of this application, the communication device for implementing the access network device function is described by taking the access network device as an example.

[0089] A terminal device can be an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal device can be used to connect people, things, and machines. The terminal device can communicate with one or more core networks through network devices. The terminal device includes a handheld device with wireless connection capabilities, other processing devices connected to a wireless modem, or in-vehicle devices, etc. The terminal device can be a portable, pocket-sized, handheld, computer-integrated, or in-vehicle mobile device. The terminal device 120 can be widely applied in various scenarios, such as cellular communication, D2D, V2X, end-to-end (point-to-point, P2P), machine-to-machine (M2M), machine type communication (MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.Some examples of the terminal device 120 are: user equipment (UE) compliant with the 3GPP standard, fixed devices, mobile devices, handheld devices, wearable devices, cellular phones, smart phones, session initiation protocol (SIP) phones, laptop computers, personal computers, smart books, vehicles, satellites, global positioning system (GPS) devices, target tracking devices, drones, helicopters, aircraft, vessels, remote control devices, smart home devices, industrial devices, personal communication service (PCS) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), wireless network cameras, tablet computers, palmtop computers, mobile internet devices (MIDs), wearable devices such as smart watches, VR devices, AR devices, wireless terminals in industrial control, terminals in vehicle-to-everything (V2X) systems, wireless terminals in self-driving, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities such as smart fuel dispensers, terminal devices on high-speed trains, and wireless terminals in smart homes such as smart speakers, smart coffee machines, smart printers, etc. The terminal device 120 may be a wireless device in the above various scenarios or a device for being disposed in a wireless device. For example, communication modules, modems, or chips in the above devices, etc. The terminal device may also be referred to as a terminal, a terminal device, a user equipment (UE), a mobile station (MS), a mobile terminal (MT), etc. The terminal device may also be a terminal device in a future wireless communication system. The terminal device may be used in a dedicated network device or a general device. Embodiments of the present application do not limit the specific technologies and specific device forms adopted by the terminal device.

[0090] Optionally, the terminal device may be used to act as a base station. For example, a UE may act as a scheduling entity that provides sidelink signals between UEs in V2X, D2D, or P2P, etc. As Figure 1As shown, the cellular phone 120a and the vehicle 120b communicate with each other using sidelink signals. Communication occurs between the cellular phone 120a and the smart home device 120e without relaying the communication signals through the base station 110b.

[0091] In this application, the communication device for implementing the functions of the terminal device can be the terminal device itself, or a terminal device with some of the functions of the above terminal device, or a device capable of supporting the implementation of the functions of the above terminal device, such as a chip system. This device can be installed in the terminal device or used in conjunction with the terminal device. In this application, the chip system can be composed of chips or can include chips and other discrete devices. In the technical solutions provided in this application, the communication device is described by taking the terminal device or UE as an example.

[0092] Optionally, a wireless communication system usually consists of cells, and the base station provides the management of the cells. The base station provides communication services to multiple mobile stations (MS) in the cell. The base station includes a baseband unit (BBU) and a remote radio unit (RRU). The BBU and the RRU can be placed in different locations. For example, the RRU is remotely located in a high-traffic area, and the BBU is placed in the central computer room. The BBU and the RRU can also be placed in the same computer room. The BBU and the RRU can also be different components under the same rack. Optionally, a cell can correspond to one carrier or a member carrier.

[0093] In some deployments, the network device mentioned in the embodiments of this application can be a device including a CU, or a DU, or a device including a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)) and a user plane CU node (central unit-user plane (CU-UP)) and a DU node. For example, the network device can include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0094] In some deployments, multiple RAN nodes cooperate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement some functions of the base station. For example, the RAN node can be a CU, a DU, a CU-CP, a CU-UP, or an RU, etc. The CU and the DU can be set separately or can also be included in the same network element, such as in the BBU. The RU can be included in the radio frequency device or radio frequency unit, such as included in the RRU, AAU, or RRH.

[0095] RAN nodes can support one or more types of fronthaul interfaces. Different fronthaul interfaces respectively correspond to DUs and RUs with different functions. If the fronthaul interface between the DU and the RU is the Common Public Radio Interface (CPRI), the DU is configured to implement one or more of the baseband functions, and the RU is configured to implement one or more of the radio frequency functions. If the fronthaul interface between the DU and the RU is another interface, compared with CPRI, some of the downlink and / or uplink baseband functions, for example, for the downlink, one or more of precoding, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / cyclic prefix (CP) addition, are moved from the DU to the RU for implementation; for the uplink, one or more of digital beamforming (BF), or fast Fourier transform (FFT) / cyclic prefix (CP) removal, are moved from the DU to the RU for implementation. In a possible implementation, this interface can be the Enhanced Common Public Radio Interface (eCPRI). In the eCPRI architecture, different splitting methods between the DU and the RU correspond to different categories (Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, F.

[0096] Taking eCPRI Cat A as an example, for downlink transmission, with layer mapping as the segmentation, the DU is configured to implement one or more functions before layer mapping (i.e., one or more of encoding, rate matching, scrambling, modulation, and layer mapping), while other functions after layer mapping (e.g., one or more of RE mapping, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / adding cyclic prefix (CP)) are moved to the RU for implementation. For uplink transmission, with de-RE mapping as the segmentation, the DU is configured to implement one or more functions before de-mapping (i.e., one or more of decoding, de-rate matching, descrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping), while other functions after de-mapping (e.g., one or more of digital BF or fast Fourier transform (FFT) / removing CP) are moved to the RU for implementation. It can be understood that for the function descriptions of DU and RU corresponding to various types of eCPRI, reference can be made to the eCPRI protocol, which will not be elaborated here.

[0097] In a possible design, the processing unit in the BBU for implementing baseband functions is called the baseband high (BBH) unit, and the processing unit in the RRU / AAU / RRH for implementing baseband functions is called the baseband low (BBL) unit.

[0098] In different systems, the CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be called O-CU (open CU), the DU can also be called O-DU, the CU-CP can also be called O-CU-CP, the CU-UP can also be called O-CU-UP, and the RU can also be called O-RU. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0099] In the embodiments of the present application, the device for implementing the functions of a network device may be a network device; it may also be a device capable of supporting the network device to implement such functions, such as a chip system, a hardware circuit, a software module, or a combination of a hardware circuit and a software module. This device may be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the case where the device for implementing the functions of the network device is a network device is taken as an example for illustration, which does not limit the solutions of the embodiments of the present application.

[0100] It can be understood that the present application can be applied between a network device and a terminal device.

[0101] The communication between the network device and the terminal device follows a certain protocol layer structure. This protocol layer structure may include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure may include functions of protocol layers such as the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical layer. For example, the user plane protocol layer structure may include functions of protocol layers such as the PDCP layer, the RLC layer, the MAC layer, and the physical layer. In a possible implementation, a service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0102] Optionally, the protocol layer structure between the network device and the terminal device may further include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0103] Taking the data transmission between a network device and a terminal device as an example, the data transmission needs to go through the user plane protocol layer, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. Among them, the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer can also be collectively referred to as the access layer. According to the data transmission direction, it is divided into transmission or reception, and each of the above layers is further divided into a transmission part and a reception part. Taking the downlink data transmission as an example, after the PDCP layer obtains data from the upper layer, it transmits the data to the RLC layer and the MAC layer. Then, the MAC layer generates a transport block, and then performs wireless transmission through the physical layer. The data is encapsulated correspondingly in each layer. For example, the data received by a certain layer from the upper layer of this layer is regarded as the service data unit (SDU) of this layer. After being encapsulated by this layer, it becomes a protocol data unit (PDU), and then is passed to the next layer.

[0104] Exemplarily, the terminal device may also have an application layer and a non-access layer. Among them, the application layer can be used to provide services for the application programs installed in the terminal device. For example, the downlink data received by the terminal device can be sequentially transmitted from the physical layer to the application layer, and then provided to the application program by the application layer; for another example, the application layer can obtain the data generated by the application program and sequentially transmit the data to the physical layer to be sent to other communication devices. The non-access layer can be used to forward user data, such as forwarding the uplink data received from the application layer to the SDAP layer, or forwarding the downlink data received from the SDAP layer to the application layer.

[0105] In order to support AI technology in a wireless network, an AI node may also be introduced into the network.

[0106] Optionally, the AI node can be deployed at one or more of the following positions in the communication system: access network device, terminal device, or core network device, etc. Or, the AI node can also be deployed separately. For example, it can be deployed at a position outside any of the above devices, such as the host of an over the top (OTT) system or a cloud server. The AI node can communicate with other devices in the communication system, and other devices can be, for example, one or more of the following: network device, terminal device, or network element of the core network, etc.

[0107] It can be understood that the number of AI nodes in this application is not limited. For example, when there are multiple AI nodes, the multiple AI nodes can be divided based on functions, such as different AI nodes being responsible for different functions.

[0108] It can also be understood that the AI nodes can be separate devices, or can be integrated into the same device to implement different functions, or can be network elements in a hardware device, or can be software functions running on dedicated hardware, or can be virtualized functions instantiated on a platform (such as a cloud platform). The present application does not limit the specific form of the above AI nodes.

[0109] The AI node can be an AI network element or an AI module.

[0110] One or more AI modules are provided in one or more of these network element nodes, such as core network devices, access network nodes (RAN nodes), terminals, or OAM devices. The access network node can be a separate RAN node or can include multiple RAN nodes. For example, it includes a CU and a DU. One or more AI modules can also be provided in the CU and / or the DU. Optionally, the CU can also be split into a CU-CP and a CU-UP. One or more AI models are provided in the CU-CP and / or the CU-UP.

[0111] The AI module is used to implement the corresponding AI function. The AI modules deployed in different network elements can be the same or different. According to different parameter configurations of the model of the AI module, the AI module can implement different functions. The model of the AI module can be configured based on one or more of the following parameters: structural parameters (such as at least one of the number of neural network layers, the width of the neural network, the connection relationship between layers, the weights of neurons, the activation function of neurons, or the bias in the activation function), input parameters (such as the type and / or dimension of the input parameters), or output parameters (such as the type and / or dimension of the output parameters). Among them, the bias in the activation function can also be referred to as the bias of the neural network.

[0112] An AI module can have one or more models. One model can infer an output, and the output includes one parameter or multiple parameters. The learning process, training process, or inference process of different models can be deployed in different nodes or devices, or can be deployed in the same node or device.

[0113] The communication system includes a RAN intelligent controller (RIC). For example, the RIC can be the above AI module for implementing AI-related functions. The RIC includes a near-real time RIC (near-RT RIC) and a non-real time RIC (Non-RT RIC). Among them, the non-real time RIC mainly processes non-real time information, such as data that is not sensitive to latency, and the latency of this data can be in seconds. The real-time RIC mainly processes near-real time information, such as data that is relatively sensitive to latency, and the latency of this data is in tens of milliseconds.

[0114] The near-RT RIC is used for model training and inference. For example, it is used to train an AI model and perform inference using this AI model. The near-RT RIC can obtain network-side and / or terminal-side information from RAN nodes (such as CU, CU-CP, CU-UP, DU, and / or RU) and / or terminals. This information can be used as training data or inference data. Optionally, the near-RT RIC can submit the inference result to the RAN node and / or the terminal. Optionally, the inference result can be exchanged between the CU and the DU, and / or between the DU and the RU. For example, the near-RT RIC submits the inference result to the DU, and the DU sends it to the RU.

[0115] The non-RT RIC is also used for model training and inference. For example, it is used to train an AI model and perform inference using this model. The non-RT RIC can obtain network-side and / or terminal-side information from RAN nodes (such as CU, CU-CP, CU-UP, DU, and / or RU) and / or terminals. This information can be used as training data or inference data, and the inference result can be submitted to the RAN node and / or the terminal. Optionally, the inference result can be exchanged between the CU and the DU, and / or between the DU and the RU. For example, the non-RT RIC submits the inference result to the DU, and the DU sends it to the RU.

[0116] The near-RT RIC and the non-RT RIC can also be separately set as a network element. Optionally, the near-RT RIC and the non-RT RIC can also be part of other devices. For example, the near-RT RIC is set in a RAN node (such as in the CU or DU), while the non-RT RIC is set in the OAM, cloud server, core network device, or other network devices.

[0117] Exemplarily, the settings of the near-RT RIC and the non-RT RIC in the network architecture can be as Figures 2A to 2D shown:

[0118] As Figure 2AAs shown in (a) thereof, in the first possible implementation, the access network device includes a near-real-time RIC module for model learning and / or inference.

[0119] As Figure 2A shown in (b) thereof, in the second possible implementation, in the communication system, a non-real-time RIC may be included outside the access network device. Optionally, the non-real-time RIC may be located in the OAM or the core network device.

[0120] As Figure 2A shown in (c) thereof, in the third possible implementation, the access network device includes a near-real-time RIC, and a non-real-time RIC is also included outside the access network device. Optionally, the non-real-time RIC may be located in the OAM or the core network device.

[0121] Relative Figure 2A to (c) thereof, Figure 2B in which the CU is separated into CU-CP and CU-UP. The settings of the near-real-time RIC and the non-real-time RIC are the same as those in Figure 2A (c) thereof.

[0122] As Figure 2C shown, optionally, the access network device includes one or more AI entities, and the functions of the AI entities are similar to those of the above-mentioned near-real-time RIC. Optionally, the OAM includes one or more AI entities, and the functions of the AI entities are similar to those of the above-mentioned non-real-time RIC. Optionally, the core network device includes one or more AI entities, and the functions of the AI entities are similar to those of the above-mentioned non-real-time RIC. When both the OAM and the core network device include AI entities, the models trained by their respective AI entities are different, and / or the models used for inference are different. In this application, different models may include at least one of the following differences: the structural parameters of the model (such as the number of layers of the model, and / or weights, etc.), the input parameters of the model, or the output parameters of the model.

[0123] Relative Figure 2C , Figure 2D the access network device in which is separated into CU and DU. Optionally, the CU may include an AI entity, and the function of the AI entity is similar to that of the above-mentioned near-real-time RIC. Optionally, the DU may include an AI entity, and the function of the AI entity is similar to that of the above-mentioned near-real-time RIC. When both the CU and the DU include AI entities, the models trained by their respective AI entities are different, and / or the models used for inference are different. Optionally, Figure 2D the CU in which may be further split into CU-CP and CU-UP. Optionally, one or more AI models may be deployed in the CU-CP. And / or, one or more AI models may be deployed in the CU-UP. Optionally, Figure 2C or Figure 2DIn this case, the OAM of the access network device and the OAM of the core network device can be deployed separately and independently.

[0124] It should be understood that Figure 1 The quantity and type of each device in the shown communication system are only for illustration, and this application is not limited thereto. In actual applications, the communication system may further include more terminal devices, more access network devices, and may also include other network elements, such as core network devices, and / or network elements for implementing artificial intelligence functions.

[0125] It can be understood that all or part of the functions implemented by one or more of the terminal device, the access network device, the core network device, or the network element for implementing artificial intelligence functions can be virtualized, that is, implemented by one or more of a dedicated processor or a general-purpose processor and corresponding software modules. Among them, since the terminal device and the access network device involve the interface for air interface transmission, the transceiver function of this interface can be implemented by hardware. Core network devices, such as operation administration and maintenance (OAM) network elements, can all be virtualized. Optionally, one or more functions of the virtualized terminal device, access network device, core network device, or network element for implementing artificial intelligence functions can be implemented by a cloud device, such as a cloud device in an over the top (OTT) system.

[0126] Taking a 5G communication system as an example, the 5G communication system has higher requirements for aspects such as system capacity and spectral efficiency. In a 5G communication system, the application of massive multiple input multiple output (massive MIMO) technology plays a crucial role in improving the spectral efficiency of the system. When using multi-input multi-output (MIMO) technology, before the network device sends data to the terminal device, it needs to perform precoding on the data. And how to perform precoding depends on the downlink channel CSI reported by the terminal device to the network device. Therefore, accurate CSI information is an important factor affecting system performance.

[0127] In a time division duplexing (TDD) system, the uplink and downlink channels transmit signals on different time resources of the same frequency domain resource. Within a relatively short time (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, and thus has reciprocity. The base station can utilize channel reciprocity to obtain the CSI of the downlink channel through the uplink channel, and then perform precoding.

[0128] In an FDD system, since the interval between the uplink and downlink frequency bands is greater than the bandwidth, the uplink and downlink channels do not have complete reciprocity. In a traditional FDD system, the reciprocity of the uplink and downlink channels cannot be utilized, and the terminal device needs to report the CSI of the downlink channel to the network device. As Figure 3 shown, it is a schematic diagram of the basic process of CSI estimation between the network device and the terminal device. This process includes the following steps: S301. The network device needs to first send the configuration information for channel measurement to the terminal device. This configuration information is used for the configuration of channel measurement, notifying the terminal device of the time and behavior of channel measurement, that is, informing the terminal device on which resources to measure the channel state information-reference signal (CSI-RS); S302. The network device sends CSI-RS to the terminal device for channel measurement; S303. The terminal device measures according to the CSI-RS sent by the network device, calculates the final CSI reporting quantity, and reports the CSI to the network device; and S304. The network device then sends data according to the CSI reported by the terminal device. Among them, the network device uses the channel rank indicator (RI) reported by the terminal device to determine the number of data streams transmitted to the terminal device; the network device uses the channel quality indicator (CQI) reported by the terminal device to determine the modulation order of data transmitted to the terminal device and the coding rate of channel coding; the network device uses the PMI reported by the terminal device to determine the precoding of data transmitted to the terminal device.

[0129] The PMI reporting is determined and reported according to a set of codebooks. The design of the FDD CSI codebook is a basic and important issue in the 5G communication system.

[0130] In the current standard protocol of new radio (NR), the FDD CSI reporting is based on the information on the base station side for channel quantization. The PMI reported by the UE is determined according to at least one channel principal eigenvector with the base station side as the transmitting end. The first type of codebook adopts the idea of spatial (angle) compression, and represents multiple principal eigenvectors (i.e., the precoding matrix of a single user) by a linear combination of several discrete Fourier transform (DFT) basis vectors in the spatial domain. The second type of codebook, on the basis of the first type of codebook, further performs frequency domain (delay) compression by using the frequency domain correlation of the amplitude and phase coefficients of different subbands, and represents the principal eigenvector by a bilinear combination of several spatial DFT basis vectors and several frequency domain DFT basis vectors. As Figure 4As shown in the figure, it is a schematic structural diagram of the codebook of the existing PMI of type II in the NR standard protocol version 16 (R16). The codebook structure of the second codebook is PMI is the precoding of one or more transmission layers in multiple frequency domain units. The number of transmission layers R is determined according to the value reported by RI; the frequency domain unit can be the number of subbands or the number of resource blocks (RB). In the codebook structure, W is the precoding matrix of the spatial-frequency dimension formed by the precoding vectors (dimension P×1) to be reported for each of the N3 frequency domain units corresponding to each of the R transmission layers, with a dimension of P×N3. P is the number of ports on the base station side. Considering polarization, P = 2N1*N2, where N1 and N2 are the numbers of horizontal and vertical ports respectively, and N3 is the number of frequency domain units; W1 is the selected set of spatial DFT basis vectors, and there are L orthogonal DFT basis vectors of dimension N1*N2×1 corresponding to two polarizations; is the conjugate transpose matrix of W f ; is the selected set of frequency domain DFT basis vectors, is M orthogonal DFT basis vectors of dimension N3×1; is the 2LM linear combination coefficients corresponding to 2L spatial basis vectors and M frequency domain basis vectors. The UE only needs to select several non-zero coefficients to report, and the non-zero coefficients to be reported are indicated by a bitmap. The PMI reporting amount of the UE includes spatial basis vector indication information, frequency domain basis vector indication information, the amplitude and phase indication information of non-zero linear combination coefficients, and the bitmap indicating the positions of non-zero coefficients. The base station restores the precoding matrix according to the UE reporting amount.

[0131] Based on the above codebook, the UE reports the corresponding PMI in real time using the channel characteristics obtained from current measurements, resulting in a relatively large reporting overhead. The inventor found that within a certain period of time, the spatial characteristics of the channel change slowly. How to utilize the slow change characteristics of the channel in the spatial domain to reduce the reporting overhead of CSI is a problem worthy of study.

[0132] To address the problem of relatively large CSI reporting overhead, this application provides a CSI reporting scheme. The terminal device determines some of the spatial basis vectors according to historical measurement results and only needs to report the indication information of the remaining spatial basis vectors corresponding to the precoding matrix, enabling the network device to determine some of the spatial basis vectors according to the indication information of the spatial basis vectors reported by the terminal device and the historical measurement results and restore the precoding matrix; considering the slow change characteristics of the channel in the spatial domain, the part of the spatial basis vectors determined according to historical measurement results can better reflect the spatial characteristics of the precoding matrix to be reported, and only a small number of additional spatial basis vectors need to be indicated to correct the spatial beam direction, thereby saving the reporting overhead of channel state information.

[0133] The method for reporting channel state information provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings:

[0134] As Figure 5 shown, it is a schematic flowchart of a method for reporting channel state information provided by the embodiments of the present application. Exemplarily, the method may include the following steps:

[0135] S501. The terminal device respectively sends indication information of n second precoding matrices based on the second reference signals received n times. Correspondingly, the network device receives the indication information of the n second precoding matrices.

[0136] The network device may send reference signals to the terminal device periodically or based on event triggering, etc. The terminal device measures the reference signals sent by the network device each time, generates indication information of the second precoding matrix, and reports the indication information of the second precoding matrix to the network device.

[0137] In this embodiment, the network device sends the second reference signals n times, and the terminal device sends the indication information of n second precoding matrices to the network device. Wherein, n is a positive integer greater than or equal to 1.

[0138] Exemplarily, the terminal device may send the indication information of n second precoding matrices in an existing manner (such as based on the first codebook or the second codebook mentioned above), that is, the indication information of each second precoding matrix includes the indication information for characterizing all the spatial domain basis vectors corresponding to the second precoding matrix; or it may send the indication information of n second precoding matrices based on the solution of the present application, that is, for each second precoding matrix, the set of spatial domain basis vectors for characterizing the second precoding matrix includes two parts of spatial domain basis vectors. One part of the spatial domain basis vectors is determined according to the precoding matrix obtained from several measurements before the measurement corresponding to the second precoding matrix, and the other part of the spatial domain basis vectors is selected from a predefined set of spatial domain basis vectors. At this time, only the indication information of the other part of the spatial domain basis vectors is sent.

[0139] The embodiments of the present application mainly describe the reporting of spatial domain channel state information. Actually, the indication information of the second precoding matrix may further include the indication information of the frequency domain basis vectors, the amplitude and phase of the non-zero linear combination coefficients, and the bitmap indicating the positions of the non-zero coefficients.

[0140] It can be understood that the network device may also obtain the indication information of the n second precoding matrices in other ways. Therefore, this step is optional and is represented by a dashed line in the figure.

[0141] Exemplarily, the above second reference signal may be a channel state information-reference signal (CSI-RS), or a demodulation reference signal (DMRS), etc. The embodiments of the present application do not limit the type of the second reference signal.

[0142] S502. The network device sends a first reference signal to the terminal device. Correspondingly, the terminal device receives the first reference signal.

[0143] In step S501, the network device sends the second reference signal to the terminal device n times. Relative to this step, it is a historical behavior and is the behavior before the current CSI measurement and reporting in terms of time.

[0144] In this step, the network device may send the first reference signal to the terminal device again. The first reference signal may be the same as or different from the second reference signal sent by the network device n times in step S501.

[0145] S503. The terminal device sends a first piece of information to the network device based on the first reference signal. Correspondingly, the network device receives the first piece of information.

[0146] After receiving the first reference signal, the terminal device measures the first reference signal and determines a first precoding matrix based on the measurement result and based on the codebook structure as shown in Figure 6 :

[0147] where is the precoding matrix in the spatial-frequency dimension of this measurement (the t-th measurement). Its dimension is P*N3, that is, N3 precoding vectors with a dimension of P*1 are combined into a spatial-frequency matrix form. Exemplarily, t≥n + 1.

[0148] where W S is the set of spatial domain basis vectors used to determine the first precoding matrix, and W S includes two parts. Among them, W0 includes at least one second spatial domain basis vector, with a dimension of P*X, including X second spatial domain basis vectors, which are obtained based on the precoding vectors corresponding to the X transmission layers of the first frequency domain unit of the second precoding matrix reported in n historical measurements. is 2L' (L' for each of the two polarization directions) first spatial domain basis vectors selected from a pre-configured or pre-defined set of spatial domain basis vectors and are determined according to this measurement. It should be understood that if there is only one polarization direction, 2L' in the following text is replaced by L'.

[0149] They are (X + 2L′)M linear combination coefficients corresponding to (X + 2L′) spatial domain basis vectors and M frequency domain basis vectors. The terminal device only needs to select several non-zero coefficients among them for reporting, and the non-zero coefficients to be reported are indicated by a bitmap.

[0150] is W f the conjugate transpose matrix of is the selected set of frequency domain DFT basis vectors, is M orthogonal DFT basis vectors of dimension N3×1.

[0151] In this embodiment, the terminal device sends first information to the network device, and the first information includes indication information of at least one first spatial domain basis vector corresponding to the first precoding matrix, that is, indication information of the above-mentioned selected 2L′ spatial domain DFT basis vectors. Exemplarily, the first information may include indices of the selected same L′ spatial domain DFT basis vectors corresponding to two polarization directions.

[0152] In this embodiment, the protocol needs to stipulate, or both the network device and the terminal device need to negotiate the design of the spatial domain basis vectors, so as to be able to determine at least one second spatial domain basis vector for characterizing the first precoding matrix according to n second precoding matrices obtained from historical measurements. Exemplarily, W0 is obtained based on the precoding vectors corresponding to the X transmission layers of the first frequency domain unit in n second precoding matrices.

[0153] Further, the acquisition of W0 can be implemented in the following ways:

[0154] One implementation is that n = 1, and W0 is obtained based on the precoding vectors corresponding to the X transmission layers of the first frequency domain unit in the second precoding matrix obtained from the previous measurement.

[0155] Among them, the first frequency domain unit is the same k frequency domain units corresponding to the second precoding matrix obtained from the previous measurement (the (t - 1)-th measurement). Among them, each second precoding matrix in the second precoding matrix obtained from the previous measurement corresponds to K frequency domain units, and 1 ≤ k ≤ K.

[0156] For example, according to the second precoding matrix obtained from the previous measurement, the precoding vectors corresponding to the first X transmission layers of a frequency domain unit (which can be any one of the K frequency domain units, such as the j-th frequency domain unit, 1 ≤ j ≤ K) can be extracted as W0, and W0 satisfies the following formula 1:

[0157]

[0158] Among them, represents R on the j-th frequency domain unit t-1A precoding matrix composed of precoding vectors corresponding to each transmission layer, with dimensions of P*R t-1 ; It means taking the first X column vectors of this matrix.

[0159] For another example, based on the second precoding matrix obtained from the previous measurement, the average value of the precoding vectors corresponding to the first X transmission layers of k frequency domain units can be extracted as W0, and W0 satisfies the following formula 2:

[0160]

[0161] Among them, k can be predefined by the protocol, or configured by the network device, or reported by the terminal device.

[0162] Among them, represents the index set of k frequency domain units extracted from K frequency domain units. Which k frequency domain units are extracted from K frequency domain units can be predefined by the protocol, or configured by the network device, or reported by the terminal device.

[0163] Among them, this X can be predefined by the protocol, or configured by the network device, or reported by the terminal device.

[0164] Exemplarily, if this X is predefined by the protocol, then X is equal to the number R of transmission layers corresponding to the second precoding matrix obtained from the previous measurement t-1 .

[0165] Exemplarily, if this X is configured by the network device or reported by the terminal device, then X is less than or equal to the number R of transmission layers corresponding to the second precoding matrix obtained from the previous measurement t-1 .

[0166] In this implementation manner, the precoding vectors corresponding to the first X transmission layers of the first frequency domain unit of the second precoding matrix reported in the previous measurement can be extracted to obtain at least one second spatial domain basis vector.

[0167] Another implementation manner is that n>1, and W0 is obtained based on the average value of the precoding vectors corresponding to the first X transmission layers of the first frequency domain unit in n second precoding matrices, and W0 satisfies the following formula 3:

[0168]

[0169] Among them, represents the precoding matrix composed of the precoding vectors corresponding to the R t-i th transmission layer on the jth frequency domain unit, with dimensions of P*R t-i .

[0170] Among them, the first frequency-domain unit is the same k frequency-domain units corresponding to the second precoding matrix obtained from the previous measurement (the (t-1)-th measurement). Among them, each second precoding matrix in the second precoding matrix obtained from the previous measurement corresponds to K frequency-domain units, and 1≤k≤K.

[0171] In Equation 3, first obtain the precoding vectors corresponding to the X transmission layers of the first frequency-domain unit in each of the n second precoding matrices, and then obtain the average value of these n precoding vectors.

[0172] Among them, the value of n can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0173] Among them, k can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0174] Among them, represents the index set of k frequency-domain units extracted from K frequency-domain units. Which k frequency-domain units are extracted from K frequency-domain units can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0175] Among them, this X can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0176] Exemplarily, if this X is pre-defined by the protocol, then X is equal to the minimum value among the numbers of transmission layers corresponding to the n second precoding matrices respectively, that is, X = min{R t-i |i = 1,..., n}.

[0177] Exemplarily, if this X is configured by the network device or reported by the terminal device, then X is less than or equal to the minimum value among the numbers of transmission layers corresponding to the n second precoding matrices respectively, that is, X ≤ min{R t-i |i = 1,..., n}.

[0178] In this implementation manner, by extracting the average value of the precoding vectors corresponding to the X transmission layers of the first frequency-domain unit of the n second precoding matrices to obtain at least one second spatial domain basis vector, the accuracy of the first precoding matrix can be improved with limited overhead or the reporting overhead can be reduced under the same reporting accuracy.

[0179] Another implementation manner is that n is greater than 1, and W0 is obtained from the singular value decomposition (SVD) result of the covariance matrix obtained based on the precoding vectors corresponding to the X transmission layers of the first frequency-domain unit in the n second precoding matrices The W0 is the covariance matrix The first X column vectors corresponding to the decomposed right unitary matrix Satisfy the following formula 4:

[0180]

[0181] Wherein, Represents the precoding matrix composed of the precoding vectors corresponding to the R t-i th transmission layer on the kth frequency domain unit, with a dimension of P*R t-i . Is The conjugate transpose matrix of.

[0182] Wherein, the first frequency domain unit is the same k frequency domain units corresponding to the second precoding matrix obtained from the previous measurement (the (t-1)th measurement). Wherein, each second precoding matrix in the second precoding matrix obtained from the previous measurement corresponds to K frequency domain units, and 1≤k≤K.

[0183] Wherein, the value of n can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0184] Wherein, k can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0185] Wherein, Represents the index set of k frequency domain units extracted from K frequency domain units. Which k frequency domain units are extracted from K frequency domain units can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0186] Wherein, this X can be pre-defined by the protocol, or configured by the network device, or reported by the terminal device.

[0187] Exemplarily, if this X is pre-defined by the protocol, then X is equal to the minimum value among the numbers of the transmission layers corresponding to the n second precoding matrices respectively, that is, X = min{R t-i |i = 1,..., n}.

[0188] Exemplarily, if this X is configured by the network device or reported by the terminal device, then X is less than or equal to the minimum value among the numbers of the transmission layers corresponding to the n second precoding matrices respectively, that is, X≤min{R t-i |i = 1,..., n}.

[0189] In this implementation manner, the singular value decomposition values of the covariance matrix obtained by extracting the precoding vectors of the X transmission layers of the first frequency domain units of the n second precoding matrices are obtained, and at least one second spatial domain basis vector can be obtained, which can improve the accuracy of the first precoding matrix.

[0190] It can be seen that the CSI reporting scheme proposed in this embodiment is an airspace difference CSI reporting scheme. At least one airspace basis vector (i.e., W0) determined according to n second precoding matrices is used as a part of the airspace basis, and is combined with a selected number of DFT basis vectors (here, 2L' airspace DFT basis vectors) to form an airspace basis for airspace compression. Therefore, it can be understood that the first precoding matrix is obtained based on at least one first airspace basis vector and at least one second airspace basis vector.

[0191] It can be understood that both the above-mentioned at least one first airspace basis vector and the above-mentioned at least one second airspace basis vector are used to characterize the airspace characteristics of the first precoding matrix. The at least one first airspace basis vector can be understood as being used to correct the airspace beam direction of the at least one second airspace basis vector, so that the airspace basis vector set composed of the at least one first airspace basis vector and the at least one second airspace basis vector can better characterize the airspace characteristics of the first precoding matrix with as few airspace basis vectors as possible.

[0192] In order to further save the reporting overhead, the first precoding matrix can also be obtained based on the orthogonalization result of at least one first airspace basis vector and at least one second airspace basis vector, that is: This application does not limit the orthogonalization method. Exemplarily, the Gram - Schmidt orthogonalization method or the Householder transformation can be used for the orthogonalization operation of the basis vectors. In this implementation, by making at least one first airspace basis vector and at least one second airspace basis vector orthogonal, the obtained airspace basis vector set after orthogonalization can more accurately characterize the airspace characteristics of the first airspace basis vector with as few airspace basis vectors as possible, which can improve the accuracy of the first precoding matrix under limited overhead or reduce the reporting overhead under the same reporting accuracy.

[0193] The embodiments of this application mainly describe the reporting of airspace channel state information. In fact, the first information can also include the indication information of the frequency - domain basis vectors (i.e., the above - mentioned ), the amplitude and phase indication information of the non - zero linear combination coefficients (i.e., the above - mentioned ), and the bitmap indicating the positions of the non - zero coefficients.

[0194] S504. The network device obtains the first precoding matrix based on the first information.

[0195] After receiving the first information, the network device can parse and obtain the indication information of at least one first airspace basis vector of the first precoding matrix. And the network device can obtain at least one second airspace basis vector based on the indication information of the n second precoding matrices received in step S501. Then, the network device restores the first precoding matrix based on at least one first airspace basis vector and at least one second airspace basis vector.

[0196] Among them, the network device can obtain at least one second spatial domain basis vector in the same manner as the terminal device, and obtain at least one second spatial domain basis vector based on the indication information of n second precoding matrices.

[0197] It should be noted that if the above first precoding matrix can also be obtained based on the orthogonality result of at least one first spatial domain basis vector and at least one second spatial domain basis vector, after the network device obtains at least one first spatial domain basis vector and at least one second spatial domain basis vector, it first performs orthogonality processing on at least one first spatial domain basis vector and at least one second spatial domain basis vector, and then obtains W S , and finally restores the first precoding matrix based on W S .

[0198] Therefore, the network device can perform data transmission with the terminal device based on this first precoding matrix.

[0199] In this embodiment, the terminal device and the network device obtain at least one second spatial domain basis vector in the same manner, and construct the spatial domain basis in the same manner. Therefore, after the network device receives the indication information of at least one first spatial domain basis vector of the first precoding matrix reported by the terminal device, it can restore the first precoding matrix.

[0200] According to a channel state information reporting method provided by an embodiment of the present application, the terminal device determines some spatial domain basis vectors according to historical measurement results, and only needs to report the indication information of the remaining spatial domain basis vectors corresponding to the precoding matrix, so that the network device can determine some spatial domain basis vectors according to the indication information of the spatial domain basis vectors reported by the terminal device and the historical measurement results, and restore the precoding matrix; considering the slow change characteristic of the channel in the spatial domain, the partial spatial domain basis vectors determined according to the historical measurement results can better reflect the spatial domain characteristics of the precoding matrix to be reported, and only a small number of additional spatial domain basis vectors need to be indicated to correct the spatial domain beam direction, thereby saving the reporting overhead of the channel state information.

[0201] In the present application, "sending information to... (such as the terminal device)" or the relevant schematic in the drawings can be understood as the destination of the information is the terminal device. It can include directly or indirectly sending information to the terminal device. "Receiving information from... (such as the terminal device)" or "receiving information from... (such as the terminal device)", or the relevant schematic in the drawings can be understood as the source of the information is the terminal device, and it can include directly or indirectly receiving information from the terminal device. Necessary processing may be performed on the information between the source and the destination of the information transmission, such as format change, etc., but the destination can understand the valid information from the source. Similar expressions in the present application can be understood similarly, and will not be elaborated here.

[0202] It can be understood that in this application, the terminal device and the network device are taken as examples of the execution entities of this interaction schematic for illustration, but this application does not limit the execution entities of the interaction schematic. For example, the terminal device in the method provided by this application can also be a chip, a chip system, or a processor applied to the terminal device, and can also be a logical node, a logical module, or software that can implement all or part of the functions of the terminal device; the network device in the method provided by this application can also be a chip, a chip system, or a processor applied to the network device, and can also be a logical node, a logical module, or software that can implement all or part of the functions of the network device.

[0203] It can be understood that in order to implement the functions in the above embodiments, the network device and the terminal device include corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0204] Figure 7 and Figure 8 FIG. is a schematic structural diagram of a possible communication device provided by an embodiment of this application. These communication devices can be used to implement the functions of the terminal device or the network device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In the embodiments of this application, the communication device can be one of the terminal devices 120a - 120j shown in Figure 1 as shown, or can be the network device 110a or 110b shown in Figure 1 as shown, or can also be a module (such as a chip) applied to the terminal device or the network device.

[0205] As Figure 7 shown, the communication device 700 includes a processing unit 710 and a transceiver unit 720. The communication device 700 is used to implement the functions of the terminal device or the network device in the method embodiment shown in the above Figure 5 .

[0206] When the communication device 700 is used to implement the function of the terminal device in the method embodiment shown in Figure 5 : The transceiver unit 720 is used to implement the functions of the terminal device in steps S501 - S503 in the embodiment shown in Figure 5 .

[0207] When the communication device 700 is used to implement the function of the network device in the method embodiment shown in Figure 5 : The transceiver unit 720 is used to implement the functions of the network device in the embodiment shown in Figure 5The functions of the network device in steps S501 to S503 in the illustrated embodiment, and the processing unit 710 is used to implement as Figure 5 step S504 in the illustrated embodiment. For example, the transceiver unit 720 may be deployed on Figure 2A , Figure 2B the DU or RU in, and the processing unit 710 may be deployed on Figure 2A , Figure 2B the DU in; or a functional part of the processing unit 710 is deployed on Figure 2A , Figure 2B the DU in, and part is deployed on the CU. For another example, both the transceiver unit 720 and the processing unit 710 may be deployed on Figure 2D the DU in.

[0208] For a more detailed description of the above processing unit 710 and transceiver unit 720, reference can be directly made to Figure 5 the relevant description in the method embodiment shown, which will not be elaborated here.

[0209] When the above communication device is a chip applied to a terminal device, the terminal device chip implements the functions of the terminal device in the above method embodiment. The terminal device chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal device, and this information is sent by the network device to the terminal device; or, the terminal device chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal device, and this information is sent by the terminal device to the network device.

[0210] When the above communication device is a chip applied to a network device, the network device chip implements the functions of the network device in the above method embodiment. The network device chip receives information from other modules (such as a radio frequency module or an antenna) in the network device, and this information is sent by the terminal device to the network device; or, the network device chip sends information to other modules (such as a radio frequency module or an antenna) in the network device, and this information is sent by the network device to the terminal device.

[0211] In addition, it should be noted that the foregoing transceiver unit and / or processing unit may be implemented by a virtual module. For example, the processing unit may be implemented by a software functional unit or a virtual device, and the transceiver unit may be implemented by a software function or a virtual device. Or, the processing unit or the transceiver unit may also be implemented by a physical device. For example, if the device is implemented by a chip / chip circuit, the transceiver unit may be an input / output circuit and / or a communication interface, performing an input operation (corresponding to the foregoing receiving operation) and an output operation (corresponding to the foregoing sending operation); the processing unit is an integrated processor or a microprocessor or an integrated circuit.

[0212] As Figure 8As shown, the communication device 800 includes a processor 810, and may further include an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It can be understood that the interface circuit 820 may be a transceiver or an input / output interface. Optionally, the communication device 800 may further include a memory 830 (shown in dashed lines in the figure), which is used to store instructions executed by the processor 810, or input data required for the processor 810 to run the instructions, or data generated after the processor 810 runs the instructions.

[0213] When the communication device 800 is used to implement Figure 5 the functions of the terminal device in the method embodiment shown: the interface circuit 820 is used to implement the functions of the terminal device in steps S501 to S503 in the embodiment shown in Figure 5 the figure.

[0214] When the communication device 800 is used to implement Figure 5 the functions of the network device in the method embodiment shown: the interface circuit 820 is used to implement the functions of the network device in steps S501 to S503 in the embodiment shown in Figure 5 the figure, and the processor 810 is used to implement step S504 in the embodiment shown in Figure 5 the figure.

[0215] For a more detailed description of the above-mentioned processor 810 and interface circuit 820, reference can be directly made to Figure 5 the relevant description in the method embodiment shown in the figure, and details are not repeated here.

[0216] The division of modules in this application is illustrative, and is only a logical function division. In actual implementation, there may be other division methods. In addition, in each example of this application, each functional module may be integrated in a processor, or may exist separately physically, or two or more modules may be integrated in one module. The above integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0217] It can be understood that the processor in the embodiments of this application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0218] The embodiments of the present application also provide a computer-readable storage medium, in which computer programs or instructions are stored. When the computer programs or instructions are executed, the methods in the above embodiments are implemented.

[0219] The embodiments of the present application also provide a computer program product containing instructions. When the instructions run on a computer, the computer is caused to execute the methods in the above embodiments.

[0220] The embodiments of the present application also provide a communication system, including the above communication device.

[0221] The embodiments of the present application also provide a circuit, which is coupled to a memory and is used to execute the method shown in the above embodiments. The circuit may include a chip circuit.

[0222] When the above communication device is a module applied to a network device, the network device module implements the functions of the network device in the above method embodiments. The network device module receives information from other modules (such as a radio frequency module or an antenna) in the network device, and the information is sent by a UE to the network device; or, the network device module sends information to other modules (such as a radio frequency module or an antenna) in the network device, and the information is sent by the network device to the UE. Here, the network device module may be a baseband chip of the network device, or a CU, a DU or other modules, or a device under an open radio access network (O-RAN) architecture, such as an open CU, an open DU, etc.

[0223] It should be noted that the above unit or one or more of the units can be implemented by software, hardware, or a combination of both. When any of the above units is implemented by software, the software exists in the form of computer program instructions and is stored in a memory. The processor can be used to execute the program instructions and implement the above method flow.

[0224] In the present application, the processor can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Or, all or part of the circuits for implementing the processing function in the foregoing devices can implement or execute the various methods, steps, and logic block diagrams disclosed in the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the present application can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0225] When the above units or unit are implemented in hardware, the hardware may be any one or any combination of a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, an SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator, or a non-integrated discrete device, which may run the necessary software or execute the above method flow without relying on software.

[0226] Optionally, an embodiment of the present application further provides a chip system, including: at least one processor and an interface, the at least one processor is coupled to a memory through the interface, and when the at least one processor runs a computer program or instruction in the memory, the chip system executes the method in any of the above method embodiments. Optionally, the chip system may be composed of chips or may include chips and other discrete devices, and the embodiments of the present application do not make specific limitations thereto.

[0227] The memory in the present application may also be a circuit or any other device capable of implementing a storage function, for storing program instructions and / or data. The memory is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. For example, the memory may be a non-volatile memory, such as a digital versatile disc (DVD), a hard disk drive (HDD), or a solid-state drive (SSD), etc., or may also be a volatile memory, such as a random-access memory (RAM).

[0228] It should be understood that in the description of this application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship. For example, A / B can represent A or B; where A and B can be singular or plural. Also, in the description of this application, unless otherwise specified, "a plurality of" means two or more than two. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of a single item or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple. Additionally, for the convenience of clearly describing the technical solutions of the embodiments of this application, in the embodiments of this application, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and terms such as "first" and "second" do not necessarily mean different. At the same time, in the embodiments of this application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner for easy understanding.

[0229] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, 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. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. 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 one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.).

[0230] Although the present application has been described in connection with various embodiments, those skilled in the art will understand and realize other variations of the disclosed embodiments by referring to the accompanying drawings, the disclosure, and the appended claims during the implementation of the claimed present application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit may implement several functions recited in the claims. Certain measures are recited in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0231] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The magnitudes of the serial numbers of the above processes do not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic.

[0232] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0233] The components in the device embodiments of the present application can be combined, divided, and deleted according to actual needs. Those skilled in the art can combine or combine the different embodiments and the features of different embodiments described in this specification.

[0234] In the present application, on the premise of no logical contradiction, the examples can refer to each other. For example, the methods and / or terms between method embodiments can refer to each other, for example, the functions and / or terms between device embodiments can refer to each other, for example, the functions and / or terms between device examples and method examples can refer to each other.

Claims

1. A method for reporting channel state information, characterized in that, The method includes: Receiving a first reference signal; Based on the first reference signal, sending first information, where the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1.

2. The method according to claim 1, characterized in that, Before receiving the first reference signal, the method further includes: Receiving a second reference signal n times; Based on the second reference signals received n times, respectively sending indication information of the n second precoding matrices.

3. The method according to claim 1 or 2, characterized in that, The at least one second spatial domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit among the n second precoding matrices.

4. The method according to claim 3, wherein When n = 1, X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

5. The method according to claim 3, characterized in that, When n > 1, the at least one second spatial domain basis vector is obtained based on the average value of precoding vectors corresponding to X transmission layers of a first frequency domain unit among the n second precoding matrices.

6. The method according to claim 3, wherein When n > 1, the at least one second spatial domain basis vector is obtained based on the singular value decomposition values of the covariance matrix obtained from precoding vectors corresponding to X transmission layers of a first frequency domain unit among the n second precoding matrices.

7. The method according to claim 5 or 6, characterized in that, X is less than or equal to the minimum value of the numbers of transmission layers corresponding to the n second precoding matrices respectively.

8. The method according to any one of claims 3 to 7, characterized in that, The first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, each of the n second precoding matrices corresponds to K frequency domain units, and 1 ≤ k ≤ K.

9. The method according to any one of claims 1-8, characterized in that, The first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, including: The first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial domain basis vector and at least one second spatial domain basis vector.

10. A method for reporting channel state information, characterized in that, The method includes: Sending a first reference signal; Receiving first information, where the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1; Obtaining the first precoding matrix based on the first information.

11. The method according to claim 10, wherein Before sending the first reference signal, the method further includes: Sending a second reference signal n times; Based on the second reference signals sent n times, respectively receiving indication information of the n second precoding matrices.

12. The method according to claim 10 or 11, characterized in that The at least one second spatial domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit among the n second precoding matrices.

13. The method according to claim 12, wherein When n = 1, X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

14. The method according to claim 12, wherein n is greater than 1, and the at least one second spatial domain basis vector is obtained based on an average value of precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

15. The method according to claim 12, characterized in that, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on singular value decomposition values of a covariance matrix obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

16. The method according to claim 14 or 15, characterized in that X is less than or equal to a minimum value among the numbers of transmission layers respectively corresponding to the n second precoding matrices.

17. The method according to any one of claims 12-16, characterized in that, The first frequency domain unit is the same k frequency domain units corresponding to the n second precoding matrices, and each of the n second precoding matrices corresponds to K frequency domain units, where 1 ≤ k ≤ K.

18. The method according to any one of claims 10-17, characterized in that, The first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, including: The first precoding matrix is obtained based on an orthonormalization result of the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

19. The method according to any one of claims 11-18, characterized in that, Obtaining the first precoding matrix based on the first information includes: Obtaining the at least one second spatial domain basis vector based on indication information of the n second precoding matrices; Obtaining the first precoding matrix based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector.

20. A communication device, characterized in that, The apparatus includes: a transceiver unit and a processing unit; wherein: The transceiver unit is configured to receive a first reference signal; The processing unit is configured to generate first information based on the first reference signal, where the first information includes indication information of at least one first spatial domain basis vector corresponding to a first precoding matrix, the first precoding matrix is obtained based on the at least one first spatial domain basis vector and the at least one second spatial domain basis vector, the at least one second spatial domain basis vector is obtained based on n second precoding matrices, and n is a positive integer greater than or equal to 1; The transceiver unit is further configured to send the first information.

21. The device according to claim 20, characterized in that, Before receiving the first reference signal, the transceiver unit further receives the second reference signal n times; and the transceiver unit is further configured to respectively send indication information of the n second precoding matrices based on the n times of received second reference signals.

22. The device according to claim 20 or 21, characterized in that, The at least one second spatial domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

23. The device according to claim 22, wherein n = 1, and X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

24. The device according to claim 22, wherein n is greater than 1, and the at least one second spatial domain basis vector is obtained based on an average value of precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

25. The device according to claim 22, characterized in that, n is greater than 1, and the at least one second spatial domain basis vector is obtained based on singular value decomposition values of a covariance matrix obtained based on precoding vectors corresponding to X transmission layers of a first frequency domain unit in the n second precoding matrices.

26. The device according to claim 24 or 25, characterized in that, X is less than or equal to a minimum value among the numbers of transmission layers respectively corresponding to the n second precoding matrices.

27. The device according to any one of claims 22-26, characterized in that, The first frequency-domain unit is the same k frequency-domain units corresponding to the n second precoding matrices, each of the n second precoding matrices corresponding to K frequency-domain units, where 1 ≤ k ≤ K.

28. The device according to any one of claims 20-27, characterized in that, The first precoding matrix is obtained based on the at least one first spatial-domain basis vector and at least one second spatial-domain basis vector, including: The first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial-domain basis vector and at least one second spatial-domain basis vector.

29. A communication device, characterized in that, The apparatus includes: a transceiver unit and a processing unit; wherein: The transceiver unit is configured to send a first reference signal. The transceiver unit is further configured to receive first information, the first information including indication information of at least one first spatial-domain basis vector corresponding to a first precoding matrix, the first precoding matrix being obtained based on the at least one first spatial-domain basis vector and at least one second spatial-domain basis vector, the at least one second spatial-domain basis vector being obtained based on n second precoding matrices, where n is a positive integer greater than or equal to 1. The processing unit is configured to obtain the first precoding matrix based on the first information.

30. The device according to claim 29, characterized in that, The transceiver unit is further configured to send a second reference signal n times before sending the first reference signal; and the transceiver unit is further configured to receive indication information of the n second precoding matrices respectively based on the n times of sending of the second reference signal.

31. The device according to claim 29 or 30, characterized in that, The at least one second spatial-domain basis vector is obtained based on precoding vectors corresponding to X transmission layers of a first frequency-domain unit in the n second precoding matrices.

32. The device according to claim 31, characterized in that, When n = 1, X is less than or equal to the number of transmission layers corresponding to the second precoding matrix.

33. The device according to claim 31, characterized in that, When n > 1, the at least one second spatial-domain basis vector is obtained based on the average value of precoding vectors corresponding to X transmission layers of a first frequency-domain unit in the n second precoding matrices.

34. The device according to claim 31, characterized in that, When n > 1, the at least one second spatial-domain basis vector is obtained based on the singular value decomposition value of the covariance matrix obtained from precoding vectors corresponding to X transmission layers of a first frequency-domain unit in the n second precoding matrices.

35. The device according to claim 33 or 34, characterized in that, X is less than or equal to the minimum value of the numbers of transmission layers corresponding to the n second precoding matrices respectively.

36. The device according to any one of claims 31-35, characterized in that, The first frequency-domain unit is the same k frequency-domain units corresponding to the n second precoding matrices, each of the n second precoding matrices corresponding to K frequency-domain units, where 1 ≤ k ≤ K.

37. The device according to any one of claims 29-36, characterized in that The first precoding matrix is obtained based on the at least one first spatial-domain basis vector and at least one second spatial-domain basis vector, including: The first precoding matrix is obtained based on the orthonormalization result of the at least one first spatial-domain basis vector and at least one second spatial-domain basis vector.

38. The apparatus according to any one of claims 29 - 37, wherein: The processing unit is further configured to obtain the at least one second spatial-domain basis vector based on the indication information of the n second precoding matrices. The processing unit is further configured to obtain the first precoding matrix based on the at least one first spatial-domain basis vector and the at least one second spatial-domain basis vector.

39. A communication system, characterized in that, The system includes a first communication device and a second communication device. The first communication device is configured to implement the method according to any one of claims 1-9, and the second communication device is configured to implement the method according to any one of claims 10-19.

40. A communication device, characterized in that, It includes a processor and an interface circuit. The interface circuit is configured to receive signals from other communication devices outside the communication device and transmit them to the processor, or send signals from the processor to other communication devices outside the communication device. The processor is configured to implement the method according to any one of claims 1-9 or the method according to any one of claims 10-19 through logic circuits or by executing code instructions.

41. The communication device according to claim 40, wherein The communication device is a chip.

42. A chip module, characterized in that, It includes a transceiver component and a chip. The chip is configured to execute the method according to any one of claims 1-9 or the method according to any one of claims 10-19.

43. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method according to any one of claims 1-9 or the method according to any one of claims 10-19.

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