Channel state information determination method and device

Abstract

A channel state information determination method and device, in the method, a network device determines N rows of base vectors corresponding to N time units based on mobile state information and a channel map of a terminal device, each row of the N rows of base vectors comprises X base vectors, and the channel map is used for indicating channel characteristics based on a location area; the network equipment sends first indication information, wherein the first indication information is used for indicating N rows of base vectors; the network equipment respectively sends pilot signals in N time units; the network equipment receives second indication information, the second indication information is used for indicating weighting coefficients of Y base vectors in the X base vectors, and the weighting coefficients of the Y base vectors are determined based on the pilot signal; and the network equipment determines channel state information corresponding to M time units based on the weighting coefficients of the Y base vectors and the N rows of base vectors, and the M time units comprise N time units. The method can improve the accuracy of the channel state information.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method and apparatus for determining channel state information. Background Art

[0002] In the massive multiple input multiple output (Massive MIMO) technology, a network device determines the precoding used for transmitting data to a terminal device based on the channel state information (CSI) fed back by the terminal device.

[0003] The network device uses the CSI reported by the terminal device most recently as the CSI used for determining precoding during the entire CSI reporting period. However, the current actual channel may be different from the channel when the terminal device feeds back the CSI, which may cause the precoding determined by the network device using the CSI fed back by the terminal device to not match the current actual channel, thereby affecting the transmission performance. Summary of the Invention

[0004] Embodiments of this application provide a method and apparatus for determining channel state information, which can improve the accuracy of channel state information.

[0005] In a first aspect, an embodiment of this application provides a communication method, which can be executed by a network device. Here, the network device may refer to the network device itself, or may refer to a processor, module, chip, or chip system in the network device that implements this method. In this method, the network device determines N rows of basis vectors corresponding to N time units based on the movement state information of the terminal device and a channel map. Each row of the N rows of basis vectors includes X basis vectors, and the channel map is used to indicate channel characteristics based on a location area. The network device sends first indication information, where the first indication information is used to indicate the N rows of basis vectors. The network device sends pilot signals in N time units respectively. The network device receives second indication information, where the second indication information is used to indicate the weighting coefficients of Y basis vectors among the X basis vectors, and the weighting coefficients of the Y basis vectors are determined based on the pilot signals. The network device determines the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units. Here, N is a positive integer, M is an integer greater than N, X is an integer greater than 1, and Y is an integer greater than 1 and less than or equal to X.

[0006] It can be seen that in the embodiments of the present application, the N row basis vectors corresponding to N time units are determined by the network device based on the movement state information of the terminal device and the channel map. Therefore, the N row basis vectors can characterize the time-varying channels of the terminal device during movement. Then, the network device determines the channel state information corresponding to M time units based on the N row basis vectors and the weighting coefficients of the Y basis vectors fed back by the terminal device in N time units, which can improve the accuracy of the channel state information and further improve the transmission performance.

[0007] In addition, the manner in which the network device determines the channel state information corresponding to M time units based on the measurement feedback of the terminal device in N time units out of M time units can reduce signaling overhead.

[0008] In an alternative embodiment, the network device determines the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N row basis vectors, including: the network device determines the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the M row basis vectors. Among them, the M row basis vectors are determined by the network device based on the movement state information of the terminal device and the channel map, and are the basis vectors corresponding to M time units.

[0009] In an alternative embodiment, the basis vector is a time-frequency-space basis vector. Among them, the time-frequency-space basis vector includes a time-domain basis vector, a frequency-domain basis vector, and a space-domain basis vector, or the time-frequency-space basis vector is a basis vector jointly in the time domain, frequency domain, and space domain.

[0010] In another alternative embodiment, the basis vector is a Doppler basis vector. Among them, the Doppler basis vector is a basis vector obtained by projecting the space-frequency coefficient onto the Doppler domain, and the space-frequency coefficient is determined based on the channel characteristics and the space-frequency basis vector.

[0011] In an alternative embodiment, when the basis vector is a Doppler basis vector, the weighting coefficients of the Y basis vectors are the weighting coefficients obtained by projecting the weighting coefficients of the space-frequency basis vector onto the Doppler basis vector.

[0012] In an alternative embodiment, the second indication information includes the indexes of the Y basis vectors and the weighting coefficients of the Y basis vectors. This method enables the network device to determine the Y basis vectors among the X basis vectors based on the indexes of the Y basis vectors, and further determines that the weighting coefficients included in the second indication information are the weighting coefficients of the Y basis vectors.

[0013] In another alternative embodiment, the second indication information includes the weighting coefficients of the Y basis vectors and the indexes of the weighting coefficients of the Y basis vectors. This method enables the network device to determine the Y basis vectors among the X basis vectors based on the indexes of the weighting coefficients of the Y basis vectors, and further determines that the Y weighting coefficients included in the second indication information are the weighting coefficients of the Y basis vectors.

[0014] In an alternative embodiment, the weighting coefficients of the Y basis vectors are the Y weighting coefficients with the largest numerical values among the weighting coefficients of the X basis vectors, which is conducive to improving the accuracy of the channel state information.

[0015] In an alternative embodiment, Y is configured by the network device or pre-negotiated between the network device and the terminal device.

[0016] In an alternative embodiment, before the network device determines the N rows of basis vectors corresponding to N time units based on the mobile state information of the terminal device and the channel map, the network device also receives the mobile state information of the terminal device, and the mobile state information includes one or more of the following: moving speed, moving direction, and location area information. This method enables the network device to obtain the mobile state information of the terminal device.

[0017] In a second aspect, an embodiment of the present application further provides a communication device. The communication device has some or all of the functions of the network device described in the first aspect above. For example, the functions of the communication device may have some or all of the functions of the network device in the first aspect of the embodiments of the present application, or may have the functions of implementing any one of the embodiments of the present application alone. The functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0018] In a possible design, the structure of the communication device may include a processing unit and a communication unit. The processing unit is configured to support the communication device to execute the corresponding functions in the above method. The communication unit is used to support the communication between the communication device and other communication devices. The communication device may further include a storage unit, and the storage unit is used to be coupled with the processing unit and the communication unit, and stores the necessary program instructions and data of the communication device.

[0019] In an embodiment, the communication device includes: a processing unit and a communication unit;

[0020] The processing unit is configured to determine N rows of basis vectors corresponding to N time units based on the mobile state information of the terminal device and the channel map. Each row of the N rows of basis vectors includes X basis vectors, and the channel map is used to indicate the channel characteristics based on the location area;

[0021] The communication unit is used to send first indication information, and the first indication information is used to indicate the N rows of basis vectors;

[0022] The communication unit is further used to send pilot signals in the N time units respectively;

[0023] The communication unit is further configured to receive second indication information for indicating the weighting coefficients of Y basis vectors among the X basis vectors, where the weighting coefficients of the Y basis vectors are determined based on the pilot signal;

[0024] The processing unit is further configured to determine the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units;

[0025] Wherein, N is a positive integer, M is an integer greater than N, X is an integer greater than 1, and Y is an integer greater than 1 and less than or equal to X.

[0026] In addition, in this aspect, for other optional implementation manners of the communication device, reference may be made to the relevant content of the first aspect above, which will not be elaborated here.

[0027] As an example, the communication unit may be a transceiver or a communication interface, the storage unit may be a memory, and the processing unit may be a processor.

[0028] In one implementation manner, the communication device includes: a processor and a transceiver;

[0029] The processor is configured to determine N rows of basis vectors corresponding to N time units based on the mobile state information of the terminal device and the channel map, where each row of the N rows of basis vectors includes X basis vectors, and the channel map is used to indicate the channel characteristics based on the location area;

[0030] The transceiver is configured to send first indication information for indicating the N rows of basis vectors;

[0031] The transceiver is further configured to send pilot signals in the N time units respectively;

[0032] The transceiver is further configured to receive second indication information for indicating the weighting coefficients of Y basis vectors among the X basis vectors, where the weighting coefficients of the Y basis vectors are determined based on the pilot signal;

[0033] The processor is further configured to determine the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units;

[0034] Wherein, N is a positive integer, M is an integer greater than N, X is an integer greater than 1, and Y is an integer greater than 1 and less than or equal to X.

[0035] In addition, in this aspect, for other optional implementation manners of the communication device, reference may be made to the relevant content of the first aspect above, which will not be elaborated here.

[0036] In another implementation manner, the communication device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; the communication unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or a related circuit, etc. on the chip or the chip system.

[0037] In the implementation process, the processor can be used for, for example but not limited to, baseband-related processing, and the transceiver can be used for, for example but not limited to, radio frequency transceiver. The above-mentioned devices can be respectively arranged on independent chips, or at least partially or wholly arranged on the same chip. For example, the processor can be further divided into an analog baseband processor and a digital baseband processor. Among them, the analog baseband processor can be integrated with the transceiver on the same chip, and the digital baseband processor can be arranged on an independent chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, the digital baseband processor can be integrated with multiple application processors (such as but not limited to a graphics processor, a multimedia processor, etc.) on the same chip. Such a chip can be called a system on a chip (SoC). Whether to arrange the various devices on different chips independently or to integrate them on one or more chips often depends on the needs of product design. The embodiments of the present application do not limit the implementation forms of the above-mentioned devices.

[0038] In a third aspect, an embodiment of the present application further provides a processor for executing the above various methods. In the process of executing these methods, the processes of sending the above information and receiving the above information in the above methods can be understood as the process of the processor outputting the above information, and the process of the processor receiving the input above information. When outputting the above information, the processor outputs the above information to the transceiver so that the transceiver can transmit it. After the above information is output by the processor, other processing may be required before it reaches the transceiver. Similarly, when the processor receives the input above information, the transceiver receives the above information and inputs it to the processor. Further, after the transceiver receives the above information, the above information may need to be processed otherwise before it is input to the processor.

[0039] For operations such as sending and receiving involved in the processor, if there is no special description, or if it does not conflict with its actual role or internal logic in the relevant description, it can generally be understood as operations such as the processor outputting, receiving, and inputting, rather than the sending and receiving operations directly performed by the radio frequency circuit and the antenna.

[0040] In the implementation process, the above-mentioned processor can be a processor specifically used to execute these methods, or a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. The above-mentioned memory can be a non-transitory memory, such as a read only memory (ROM), which can be integrated with the processor on the same chip, or can be separately provided on different chips. The embodiments of the present application do not limit the type of the memory and the setting manner of the memory and the processor.

[0041] Fourthly, an embodiment of the present application further provides a communication system, which includes a terminal device and a network device. In another possible design, the system may further include other devices / functional network elements that interact with the terminal device and / or the network device.

[0042] Fifthly, an embodiment of the present application provides a computer-readable storage medium for storing instructions. When the instructions are run by a computer, the method described in the first aspect above is implemented.

[0043] Sixthly, an embodiment of the present application further provides a computer program product including instructions. When it runs on a computer, the method described in the first aspect above is implemented.

[0044] Seventhly, an embodiment of the present application provides a chip system, which includes a processor and an interface. The interface is used to obtain a program or instructions, and the processor is used to call the program or instructions to implement or support the network device to implement the functions involved in the first aspect. For example, determining or processing at least one of the data and information involved in the above method. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the terminal. The chip system can be composed of chips or can include chips and other discrete devices.

[0045] Eighthly, an embodiment of the present application provides a communication device, which includes a processor for executing a computer program or executable instructions stored in a memory. When the computer program or executable instructions are executed, the device executes the methods in various possible implementations of the first aspect.

[0046] In a possible implementation, the processor and the memory are integrated together;

[0047] In another possible implementation, the above-mentioned memory is located outside the communication device.

[0048] The beneficial effects of the second aspect to the eighth aspect can refer to the beneficial effects of the first aspect, which will not be elaborated here. Description of the Drawings

[0049] Figure 1 It is a schematic diagram of the system architecture;

[0050] Figure 2 It is a structural diagram of network equipment and terminal equipment;

[0051] Figure 3 It is a schematic diagram of a channel map;

[0052] Figure 4 It is a three-dimensional schematic diagram of space, time and frequency;

[0053] Figure 5 It is a schematic diagram of the interaction between network equipment and terminal equipment to obtain CSI;

[0054] Figure 6 It is a schematic diagram of a multi-user mobile scenario;

[0055] Figure 7 It is a CSI measurement and feedback schematic diagram;

[0056] Figure 8 This is a comparison diagram of CSI in a time-varying scenario;

[0057] Figure 9 It is a schematic diagram of multipath mutation in time domain;

[0058] Figure 10 This is an interactive diagram of a channel state information determination method provided by an embodiment of the present application;

[0059] Figure 11 This is a schematic diagram of a terminal device moving according to an embodiment of the present application;

[0060] Figure 12 is a schematic diagram of a basis vector provided in an embodiment of the present application;

[0061] Figure 13 This is a schematic diagram of CSI determination provided by an embodiment of the present application;

[0062] Figure 14 This is another CSI determination schematic diagram provided in an embodiment of the present application;

[0063] Figure 15 This is a schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0064] Figure 16 It is a structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] To better understand the embodiments of the present application, the following first introduces the system architecture involved in the embodiments of the present application:

[0066] Figure 1 This is a schematic diagram of the architecture of a communication system 1000 provided by an embodiment of the present application. As Figure 1 shown, the communication system 1000 includes a radio access network (RAN) 100. Among them, the RAN 100 includes at least one RAN node (such as Figure 1 110a and 110b in, collectively referred to as 110), and may also include at least one terminal device (such as Figure 1 120a - 120j in, collectively referred to as 120). The RAN 100 may also include other RAN nodes. For example, wireless relay devices and / or wireless backhaul devices ( Figure 1 not shown in). The terminal device 120 is connected to the RAN node 110 wirelessly. The terminal devices can be connected to each other and the RAN nodes can be connected to each other in a wired or wireless manner. The communication system 1000 may also include a core network 200. The RAN node 110 is connected to the core network 200 wirelessly or by wire. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be independent different physical devices, or the same physical device integrating the logical functions of the core network devices and the logical functions of the RAN nodes. The communication system 1000 may also include the Internet 300.

[0067] The RAN 100 may be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, and a future wireless access system defined in the 3rd generation partnership project (3GPP). The RAN 100 may also include two or more different wireless access systems described above. The RAN 100 may also be an open RAN (O-RAN).

[0068] A RAN node, also known as a radio access network device, RAN entity, or access node, is used to help a terminal device access a communication system wirelessly. In one application scenario, the RAN node can be a base station, evolved NodeB (eNodeB), transmission reception point (TRP), next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, next generation NodeB in a 6th generation (6G) mobile communication system, or a base station in a future mobile communication system. The RAN node can be a macro base station (such as Figure 1 110a in Figure 1 ), a micro base station or an indoor station (such as

[0069] 110b in

[0070] ), or a relay node or a donor node. In another application scenario, multiple RAN nodes can cooperate to help a terminal achieve wireless access, and different RAN nodes respectively implement some functions of the base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU completes the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station, and can also complete the function of the service data adaptation protocol (SDAP); the DU completes the functions of the radio link control layer and medium access control (MAC) layer of the base station, and can also complete some or all of the functions of the physical layer. For specific descriptions of the above protocol layers, reference can be made to the relevant technical specifications of 3GPP. The RU can be used to implement the functions of transmitting and receiving radio frequency signals. The CU and DU can be two independent RAN nodes, or integrated in the same RAN node, for example, integrated in the baseband unit (BBU). The RU can be included in the radio frequency device, for example, included in the remote radio unit (RRU) or active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.In different systems, RAN nodes may have different names. For example, in the O-RAN system, the CU can be called an open CU (O-CU), the DU can be called an open DU (O-DU), and the RU can be called an open RU (O-RU). The RAN nodes in the embodiments of the present application can be implemented by software modules, hardware modules, or a combination of software modules and hardware modules. For example, the RAN node can be a server loaded with the corresponding software module. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the RAN nodes. For ease of description, in the following text, a base station is used as an example of an RAN node for description.

[0071] A terminal device is a device with wireless transceiver capabilities that can send signals to a base station or receive signals from a base station. A terminal device can also be referred to as a terminal, a user equipment (UE), a mobile station, a mobile terminal, etc. Terminals can be widely applied in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, remote medical treatment, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, etc. The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a wearable device, a vehicle, an airplane, a ship, a robot, a robotic arm, a smart home device, etc. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the terminal.

[0072] The base station and the terminal can be fixed in position or movable. The base station and the terminal can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed on airplanes, balloons, and artificial satellites. The embodiments of the present application do not limit the application scenarios of the base station and the terminal.

[0073] The roles of the base station and the terminal can be relative. For example, Figure 1The helicopter or drone 120i therein can be configured as a mobile base station. For the terminals 120j accessing the radio access network 100 through 120i, 120i is a base station; but for the base station 110a, 120i is a terminal, that is, the communication between 110a and 120i is through the radio air interface protocol. Of course, the communication between 110a and 120i can also be through the interface protocol between base stations. At this time, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be uniformly referred to as communication devices. Figure 1 110a and 110b therein can be referred to as communication devices with base station functions. Figure 1 120a - 120j therein can be referred to as communication devices with terminal functions.

[0074] The communication between base stations and terminals, between base stations and base stations, and between terminals and terminals can be carried out through authorized spectrum, or through unlicensed spectrum, or through both authorized spectrum and unlicensed spectrum at the same time; it can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6 GHz, or use both the spectrum below 6 GHz and the spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0075] In the embodiments of the present application, the functions of the base station can be executed by modules (such as chips) in the base station, or by a control subsystem including base station functions. The control subsystem including base station functions here can be the control center in the above application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal can also be executed by modules (such as chips or modems) in the terminal, or by a device including terminal functions.

[0076] In the embodiments of the present application, the network device (for example) can be the RAN node described above.

[0077] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of a network device and a terminal device. As Figure 2As shown in the figure, both the network device and the terminal device include a radio resource control (RRC) signaling interaction module, a medium access control (MAC) signaling interaction module, and a physical (PHY) signaling interaction module. Among them, the RRC signaling interaction module is used to send and receive RRC signaling between the network device and the terminal device. The MAC signaling interaction module is used to send and receive media access control-control element (MAC-CE) signaling between the network device and the terminal device. The PHY signaling interaction module is used to send and receive uplink / downlink control signaling and uplink / downlink data between the network device and the terminal device. The uplink control signaling is, for example, a physical uplink control channel, and the uplink data is, for example, a physical uplink shared channel. The downlink control signaling is, for example, a physical downlink control channel, and the downlink data is, for example, a physical downlink shared channel.

[0078] The following elaborates on the relevant concepts involved in the embodiments of this application:

[0079] 1. Channel information and channel map.

[0080] Channel information can be used to characterize channel features or characteristics. For example, the channel information can be channel matrix information, and / or, it can be CSI, and / or, it can be a channel feature vector. Or, the channel information can also be a CSI report. Or, the channel information can also be the time-domain information, frequency-domain information, spatial-domain information, time-frequency-domain information, space-frequency-domain information, delay-doppler domain information, or time-frequency-spatial-domain information of the channel, etc., and no specific limitation is made thereto.

[0081] Among them, CSI can be used to describe information related to channel quality. For example, CSI describes the propagation process of wireless signals between a transmitter and a receiver, including the effects of distance, scattering, fading, etc. on the signals. For downlink transmission, CSI can be used for a terminal device to feedback the downlink channel quality to a network device so that the network device can perform downlink transmission according to the CSI. The CSI sent by the terminal device to the network device can be carried in a CSI report. For example, CSI can also include at least one of the following: channel state information-reference signal resource indicator (CRI), rank indicator (RI), channel quality indicator (CQI), precoding matrix indicator (PMI), layer indicator (LI), layer 1-reference signal receiving power (L1-RSRP), layer 1-signal to interference plus noise ratio (L1-SINR), capability index, time-domain channel properties (TDCP), etc.

[0082] The terminal device can perform channel measurement through downlink reference signals to obtain channel information. Measurement can also be described as evaluation, detection, estimation, etc. Among them, the downlink reference signals can include, but are not limited to, channel state information-reference signal (CSI-RS), synchronization signal block (SSB), or physical broadcast channel demodulation reference signal (PBCH DMRS), etc. For example, the terminal device can perform downlink channel measurement according to CSI-RS to obtain CSI.

[0083] The channel map can be understood as a database for storing / indicating channel characteristics based on location areas, which include channel statistical covariance matrices, angular spectra, delay spectra, path losses, and eigenbasis vectors, etc. The channel map can be determined and managed in advance by core network devices, access network devices, or other entities based on channel characteristics at a large number of locations. For example, Figure 3 is a schematic diagram of a channel map. As Figure 3 shown, the channel map can divide physical cells into two-dimensional grid points, and each two-dimensional grid point stores several channel characteristics of the location area in the form of matrices, vectors, or scalars.

[0084] 2. Variation characteristics of the channel.

[0085] The variation characteristics of the channel include variation characteristics in the spatial domain, frequency domain, and time domain. Among them, the physical parameter corresponding to the variation characteristics of the channel in space is the angle, the physical parameter corresponding to the variation characteristics of the channel in the frequency domain is the multipath delay, and the physical parameter corresponding to the variation characteristics of the channel in the time domain is the Doppler shift. The terminal device can use the angles, multipath delays, and Doppler of the limited transmission paths to perform compressed feedback on the channel, and then enable the network device to obtain the variation characteristics of the channel.

[0086] In addition, if the time-domain channel is projected into the Doppler domain, the variation trend of the channel can be equivalently described by the characteristics of the channel in the Doppler domain. Therefore, the Doppler characteristics can characterize the time-varying characteristics of the channel. The Doppler information of the time-varying channel changes slowly relative to the time domain, and the network device can reconstruct the time-varying characteristics of the channel based on the Doppler information.

[0087] In summary, the channel can be characterized by three dimensions: the Doppler domain, angle, and delay. For example, Figure 4 is a three-dimensional spatio-temporal-frequency schematic diagram. Figure 4 The angles, Doppler domain, and delay shown respectively characterize the three dimensions of the channel: space, time, and frequency. Furthermore, multiple spatio-frequency matrices in time can be aggregated into a three-dimensional matrix of spatio-temporal-frequency.

[0088] The Massive MIMO technology in the 5G communication system plays a crucial role in the spectral efficiency of the system. In the Massive MIMO technology, the network device relies on the CSI fed back by the terminal device for downlink data transmission. Therefore, the accuracy of the CSI is very important for the performance of the system.

[0089] Please refer to Figure 5 , Figure 5 which is a schematic diagram of the interaction between a network device and a terminal device for obtaining CSI. As Figure 5As shown in the figure, the network device sends channel measurement configuration information to the terminal device to notify the terminal device of the time and behavior for channel measurement; the network device sends a pilot signal to the terminal device, and the pilot signal is used to measure the channel; the terminal device feeds back CSI to the network device according to the pilot measurement result; the network device sends data according to the CSI fed back by the terminal device. Among them, the terminal device can feed back CSI through a type II codebook, and the fed-back CSI includes parameters such as RI, CQI, and PMI. The type II codebook represents the channel direction by weighted superposition of multiple discrete Fourier transform (DFT) beams. The network device sends data according to the CSI fed back by the terminal device, including: the network device determines the number of data streams transmitted to the terminal device through the RI fed back by the terminal device; the network device determines the modulation order and code rate of channel coding for transmitting data to the terminal device according to the CQI fed back by the terminal device; the network device determines the precoding matrix for transmitting data to the terminal device according to the PMI fed back by the terminal device.

[0090] Among them, the feedback mechanism of PMI can be a mechanism based on specific codebook selection and reporting, that is, the information bits reported by the terminal device are used to indicate the position of the codeword selected by the terminal device in the overall codebook set. Thus, the network device determines the PMI for downlink data transmission through the known overall codebook and the codebook position fed back by the terminal device.

[0091] However, there is usually a delay in the CSI fed back by the terminal device, which will lead to the problem of CSI expiration obtained by the network device, and further affect the performance of data transmission. This problem is particularly obvious in the scenario of time-varying channels, and the multi-user mobile scenario is one of the key scenarios of 5G. Figure 6 It is a schematic diagram of a multi-user mobile scenario. As Figure 6 shown, the terminal device 1, the terminal device 2, and the terminal device 3 move in the corresponding arrow directions at speeds V1, V2, and V3 respectively. Figure 6 In the multi-user mobile scenario shown, the expiration of CSI of multiple terminal devices will cause the precoding of multiple users to be unable to match the real channel conditions, thus introducing more multi-user interference, and further causing a significant decline in system performance.

[0092] Exemplarily, Figure 7 It is a schematic diagram of CSI measurement and feedback. As Figure 7As shown in the figure, within the time period t1, the network device sends CSI-RS to the terminal device; the terminal device performs channel estimation based on the received CSI-RS to obtain CSI, and feeds back the CSI to the network device via the uplink. Additionally, before the terminal device reports CSI next time, the network device uses the CSI reported by the terminal device most recently for downlink data transmission. That is to say, within the time period t2, the network device uses the CSI reported by the terminal device within the time period t1 for downlink data transmission.

[0093] Regarding Figure 7 the CSI feedback process shown in the figure, the latency causing CSI expiration includes the CSI effective latency t1 and the channel time-varying latency t2. As Figure 7 shown in the figure, t1 is the time between "the network device sends CSI-RS -> the terminal device receives CSI-RS, estimates the channel -> the terminal device quantifies and feeds back the estimated channel -> the network device receives the uplink CSI feedback from the terminal device -> the network device calculates the precoding matrix based on the CSI fed back by the terminal device and uses it for downlink data transmission". The existence of t1 results in a delay between the channel H1 when the network device issues CSI-RS and H2 determined by the network device according to the CSI reported by the terminal device, that is, the reported CSI already has a delay with the current actual channel CSI. In a stationary scenario, the impact of t1 on system performance is relatively small, but when the channel changes rapidly over time, t1 will cause a significant decline in system performance. Additionally, t1 is determined by the hardware capabilities of the network device and the terminal device, and cannot be solved through the configuration of the network device.

[0094] Moreover, CSI is fixed within the time period t2, that is, the network device assumes that the channel is unchanged within the CSI feedback period. When the channel is time-varying, such as in a mobile scenario, the channel will also change drastically within the time period t2, resulting in the channel time-varying latency t2, which will cause the precoding matrix calculated by the network device based on the CSI reported within the time period t1 to not match the actual channel, thereby leading to a performance decline. The duration of t2 can usually be configured by the network device, but a shorter CSI feedback period will increase the feedback overhead of CSI.

[0095] Exemplarily, Figure 8 is a comparison schematic diagram of CSI in a time-varying scenario. Specifically, Figure 8 is obtained in a time-varying channel scenario of 30 km / h. As Figure 8 shown in the figure, as time changes, the correlation between the CSI fed back by the terminal device and the CSI of the actual channel shows an obvious downward trend. Then, if the network device uses the CSI fed back by the terminal device most recently for data transmission for a long time in the future, it will cause a decline in system performance.

[0096] In another implementation, the network device can also determine future CSI based on an autoregressive model (AR) and historical channel information, that is, the network device determines CSI for a future period based on the CSI reported by the terminal device historically and the AR. Among them, the AR model can be, for example:

[0097] h(n + 1) = h(n)w1 + h(n - 1)w2 + h(n - 2)w3 (1)

[0098] where h(n) is the channel information at the current moment, h(n - 1) and h(n - 2) are the channel information at the two moments before the current moment, h(n + 1) is the channel information at the next moment of the current moment, and w1, w2, and w3 are different weighting coefficients.

[0099] However, during the movement of the terminal device, the channel may undergo a time-domain multipath mutation phenomenon. For example, Figure 9 is a schematic diagram of time-domain multipath mutation. As Figure 9 shown, when the terminal device is at position A, the sub-path disappears, that is, there is no time-domain sub-path at position A; when the terminal device is at position B, the sub-path is generated, that is, there is a time-domain sub-path at position B. Both the Doppler phenomenon and the mutation of the multipath over time will affect the CSI prediction performance. The method by which the network device determines future CSI based on historical channel information and AR cannot obtain future mutation information, which will also lead to the determined channel not conforming to the actual channel, resulting in performance degradation.

[0100] An embodiment of the present application proposes a channel state information determination method 100, Figure 10 which is an interaction schematic diagram of the channel state information determination method 100. The channel state information determination method 100 is described from the interaction perspective of the network device and the terminal device. The channel state information determination method 100 includes but is not limited to the following steps:

[0101] S101. The network device determines N rows of basis vectors corresponding to N time units based on the movement state information of the terminal device and the channel map, and each row of the N rows of basis vectors includes X basis vectors. The channel map is used to indicate the channel characteristics based on the location area.

[0102] Among them, the channel map includes the channel information of the area where the terminal device is located, such as the full-dimensional channel feature basis vectors of the area where the terminal device is located, etc. N is a positive integer, and X is an integer greater than 1.

[0103] In an alternative embodiment, the movement status information of the terminal device includes one or more of the following: movement speed, movement direction, and location area information. Among them, the movement speed of the terminal device includes at least one of the following: the absolute speed based on the geographical location, and the relative speed with respect to the network device or other reference objects. The movement direction of the terminal device includes whether the terminal device moves in a straight line in a certain direction, the angle of movement with respect to a specific coordinate axis, etc. The location area information of the terminal device refers to the location information of the terminal device at a certain time point. For example, the location area information of the terminal device may be the x coordinate, y coordinate, and z coordinate of the terminal device at a certain time point. For another example, the location area information of the terminal device may be the global positioning system (GPS) location information of the terminal device at a certain time point.

[0104] In an alternative embodiment, before determining the N row basis vectors corresponding to N time units based on the movement status information of the terminal device and the channel map, the network device also receives the movement status information of the terminal device. That is to say, the terminal device can report the movement status information of the terminal device to the network device. The terminal device can actively report the movement status information of the terminal device to the network device. Or, the network device requests the movement status information of the terminal device through a request message. After receiving the request message from the network device, the terminal device reports the movement status information of the terminal device to the network device.

[0105] Optionally, the way for the terminal device to report the movement speed to the network device can be to directly report the speed value of the movement. For example, report to the network device that the movement speed of the terminal device is 10 km / h, or 200 m / s, etc. Optionally, the way for the terminal device to report the movement speed can also be to report the index of the speed from a predefined candidate speed set, where the candidate speed set includes multiple candidate speed values. For example, the candidate speed set includes 30 km / h, 60 km / h, 120 km / h, and 150 km / h. The terminal device selects the speed value closest to its own movement speed from the candidate set for reporting. For example, if the movement speed of the terminal device is 56 km / h, the terminal device reports the index corresponding to 60 km / h to the network device. The way for the terminal device to report the movement speed by reporting the speed index can reduce the signaling overhead.

[0106] The terminal device reports the movement direction by reporting the angle with the standard coordinate system or longitude and latitude, etc. Optionally, the terminal device reports the movement direction by reporting the relative direction with respect to the geographical location of the network device, such as the relative angle or longitude and latitude with respect to the geographical location of the network device. The terminal device reports the location area information by reporting the location coordinates of the terminal device at a certain time point during the future movement process, etc.

[0107] Optionally, the terminal device may also report the moving speed, moving direction, and location area information in other implementation manners, which are not limited in the embodiments of the present application.

[0108] Optionally, the network device may determine the moving state information of the terminal device by itself. For example, the network device determines the moving state information of the terminal device in a future period of time based on the historical movement trajectory of the terminal device.

[0109] In addition, the N time units are partial time units during the movement of the terminal device. All the time units during the movement of the terminal device may be determined by the network device based on the moving state information of the terminal device, or may be pre-negotiated between the network device and the terminal device. For example, if the network device determines that all the time units during the movement of the terminal device include 10 time units based on the moving state information of the terminal device, then the N time units may be partial time units among the 10 time units. The interval between every two adjacent time units among the N time units may be multiple time slots (slot), or may be x seconds (s), or may be x milliseconds (ms), etc., where x is a real number greater than 0. For example, the interval between every two adjacent time units among the N time units is 5 time slots, or 5 s, or 10 ms.

[0110] In an optional implementation manner, the network device determines the N row basis vectors corresponding to the N time units based on the moving state information of the terminal device and the channel map, which may be: determining a row of basis vectors corresponding to each of the N time units based on the moving state information of the terminal device and the channel map. For example, if the N time units are 5 time slots, then the network device determines a row of basis vectors corresponding to each of the 5 time slots based on the moving state information of the terminal device and the channel map, that is, the 5 row basis vectors determined by the network device correspond one-to-one to the 5 time slots.$

[0111] While the characteristics of the channel map indicate that the channel map can provide multiple basis vectors for each location area among multiple location areas. Then, the N row basis vectors corresponding to the N time units determined by the network device based on the moving state information of the terminal device and the channel map can characterize the channel time variation during the movement of the terminal device. That is to say, a row of basis vectors corresponding to the nth time unit among the N time units can characterize the channel time variation information within the nth time unit, where n is a positive integer less than or equal to N. Each row of the N row basis vectors includes X basis vectors, indicating that each of the N time units corresponds to X basis vectors. Then, there are X basis vectors for each of the N time units to characterize the channel time variation of that time unit.

[0112] It can be seen that by determining the N - row basis vectors corresponding to N time units of the terminal device based on the mobile state information and channel map of the terminal device, the network device can determine the channel time - variation for each of the N time units.

[0113] In an alternative implementation, the basis vector is a time - frequency - space basis vector. Among them, the time - frequency - space basis vector includes a time - domain basis vector, a frequency - domain basis vector, and a space - domain basis vector, or the time - frequency - space basis vector is a basis vector jointly composed of time, frequency, and space.

[0114] Exemplarily, the channel information H and the basis vector satisfy formula (2):

[0115]

[0116] where U N×1 is the time - frequency - space basis vector, α m is the weighting coefficient of the time - frequency - space basis vector and is a complex number. N and M are both integers greater than 0, and m is an integer greater than 0 and less than M. are the space - domain basis vector, the frequency - domain basis vector, and the time - domain basis vector respectively. N s 、N f 、N t are their lengths respectively. In addition, N s can be equal to the number of spatial domain antennas; N f can be equal to the number of frequency - domain resources. For example, N f is equal to the number of sub - bands / resource blocks (RB) / resource block groups (RBG); N t can be equal to the number of time - domain resources. For example, N t is equal to the number of time slots / mini - slots / symbols.

[0117] Optionally, the basis vector includes a time - domain basis vector a space - domain basis vector and a frequency - domain basis vector Optionally, the basis vector can be a basis vector jointly composed of time, frequency, and space. For example, the basis vector can be a vector obtained by performing singular value decomposition (SVD) on the channel information H to characterize the time - domain channel characteristics, frequency - domain channel characteristics, and space - domain channel characteristics. Another example is that the basis vector can be a basis vector obtained by performing a Kronecker operation on the time - domain basis vector, the frequency - domain basis vector, and the space - domain basis vector.

[0118] In another alternative embodiment, the basis vector is a Doppler basis vector. The Doppler basis vector is a basis vector obtained by projecting the spatio-frequency coefficients into the Doppler domain, and the spatio-frequency coefficients are determined based on the channel characteristics and the spatio-frequency basis vectors.

[0119] Exemplarily, the channel information H and the basis vector satisfy formula (3):

[0120]

[0121] where c m is the coefficient of the spatio-frequency coefficients of a certain time unit on the Doppler basis vector, and V N×1 are the spatio-frequency coefficients.

[0122] In addition:

[0123]

[0124] where C is the set of c m for different time units, d s，f，t represents the weighted coefficient of the weighted coefficient of the spatio-frequency basis vector under the projection of the Doppler basis vector, and D * is the basis vector obtained by projecting the spatio-frequency coefficients into the Doppler domain, that is, D * is the Doppler basis vector.

[0125] As can be seen from formula (3), the network device can determine the spatio-frequency coefficients c m of a certain time unit based on the channel characteristics and the spatio-frequency vector of that time unit, and further can determine the corresponding Doppler domain basis vector D * of that time unit based on the spatio-frequency coefficients.

[0126] Optionally, the basis vector can also be in other forms, and can be a basis vector capable of representing time-domain channel characteristics, frequency-domain channel characteristics, and spatial-domain channel characteristics. The embodiments of the present application do not limit this.

[0127] Optionally, the Doppler codebook or the time-frequency domain codebook can be an N×N matrix negotiated between a network device and a terminal. This matrix can be, for example, a DFT matrix or a wavelet matrix, etc. For example, for the DFT form, the p-th basis vector in the Doppler codebook satisfies formula (5):

[0128]

[0129] where p = 0,..., N - 1, N is a positive integer, and T represents a time unit. Optionally, the representation form of the p-th basis vector in the time-frequency domain basis vector can also refer to formula (5). The embodiments of the present application do not limit the representation form of the basis vector.

[0130] Optionally, when the entity that manages the channel map is a core network device, the network device in S101 may refer to the core network device or may refer to an access network device. When the entity that manages the channel map is a core network device and the network device in S101 is an access network device, the method further includes: the access network device requests the core network device to obtain the channel map; correspondingly, the core network device sends the channel map it manages to the access network device so that the access network device can execute S101.

[0131] Optionally, when the entity that manages the channel map is an access network device, the access network device can directly execute S101.

[0132] Optionally, when the entity that manages the channel map is an entity other than the core network device and the access network device, the core network device or the access network device requests the entity that manages the channel map to obtain the channel map, so that the core network device or the access network device can execute S101.

[0133] S102. The network device sends first indication information, and the first indication information is used to indicate N rows of basis vectors. Correspondingly, the terminal device receives the first indication information.

[0134] The network device indicates the N rows of basis vectors corresponding to N time units to the terminal device through the first indication information, so that the terminal device obtains X basis vectors corresponding to each of the N time units.

[0135] In an optional implementation manner, the network device can indicate the N rows of basis vectors to the terminal device in the form of a vector group. Specifically, the first indication information may include a vector group, the vector group includes N rows of basis vectors, and each row of the N rows of basis vectors includes X basis vectors. For example, when N is 9 and X is 10, the vector group included in the first indication information is:

[0136]

[0137] where, w 1,1 ,..., w 1,10 is a row of basis vectors corresponding to the first time unit, and w 9,1 ,..., w 9,10 is a row of basis vectors corresponding to the first time unit.

[0138] It can be seen that the network device can indicate the N rows of basis vectors corresponding to N time units to the terminal device through the vector group shown in formula (6).

[0139] Optionally, the network device can also indicate the N rows of basis vectors to the terminal device in other forms, that is, the first indication information can also be in other forms, and the embodiments of the present application do not limit this.

[0140] S103. The network device sends pilot signals in N time units respectively. Correspondingly, the terminal device receives pilot signals in N time units respectively.

[0141] Among them, the pilot signal can be CSI-RS, SSB, DMRS, etc., and the embodiments of the present application do not limit this.

[0142] Through S102, the network device indicates N rows of basis vectors corresponding to N time units to the terminal device. Then, in order to enable the terminal device to feedback multiple basis vectors among the X basis vectors corresponding to each of the N time units, the network device sends pilot signals in N time units respectively.

[0143] The network device sending pilot signals in N time units respectively means that the network device sends pilot signals in each of the N time units. Correspondingly, the terminal device receives pilot signals in each of the N time units and measures the received pilot signals.

[0144] Optionally, before the network device executes S103, it also sends measurement configuration information to the terminal device, and the measurement configuration information is used to configure the terminal device to receive and measure pilot signals in N time units respectively.

[0145] S104. The terminal device sends second indication information, and the second indication information is used to indicate the weighting coefficients of Y basis vectors among the X basis vectors, and the weighting coefficients of the Y basis vectors are determined by the terminal device based on the pilot signals. Correspondingly, the network device receives the second indication information.

[0146] Among them, Y is an integer greater than 1 and less than or equal to X.

[0147] After the terminal device receives pilot signals in each of the N time units, it measures the received pilot signals to obtain the channel information at this time unit. The terminal device determines Y basis vectors among the X basis vectors and the weighting coefficients of the Y basis vectors based on the channel information measured in each of the N time units and the X basis vectors corresponding to this time unit.

[0148] For example, when the basis vector is a time-frequency domain basis vector, for each of the N time units, the terminal device can be based on the measured channel information H N×1 and the above formula (2) to determine Y basis vectors among the X basis vectors corresponding to this time unit and the weighting coefficients α m .

[0149] For another example, the basis vector is a Doppler basis vector D *At this time, for each of the N time units, as can be seen from the above formula (3), the terminal device can, based on the measured H N×1 and V N×1 , determine the corresponding c m for this time unit, where V N×1 is pre-negotiated between the network device and the terminal device. The terminal device then, based on the c m corresponding to multiple time units (i.e., C) and formula (4), can determine Y Doppler basis vectors among the X Doppler basis vectors corresponding to each of the multiple time units, and the weighting coefficients d s,f,t of the Y Doppler basis vectors. Among them, the weighting coefficients d s,f,t of the Y Doppler basis vectors are the weighting coefficients under the projection of the weighting coefficients of the spatio-frequency basis vectors on the Doppler basis vectors.

[0150] It should be noted that for each of the N time units, the indexes of the Y basis vectors determined by the terminal device and the weighting coefficients of the Y basis vectors are the same. Thus, the weighting coefficients of the Y basis vectors indicated by the terminal device to the network device via the second indication information are applicable to the determination of the channel information corresponding to the N time units.

[0151] In an optional implementation manner, the second indication information includes the indexes of the Y basis vectors and the weighting coefficients of the Y basis vectors. For example, the N rows of basis vectors sent by the network device to the terminal device are as shown in the above formula (5). If the basis vectors determined by the terminal device based on the received pilot signal are the basis vectors with indexes from 1 to 8 among 10 basis vectors, then the second indication information includes indexes 1 to 8 and the weighting coefficients, and the weighting coefficients are the weighting coefficients of the basis vectors with indexes from 1 to 8. For example, the second indication information includes w 1,1 , w 1,2 ,..., w 1,10 among which the indexes of w 1,1 , w 1,2 ,..., w 1,8 and the weighting coefficients of w 1,1 , w 1,2 ,..., w 1,8 .

[0152] Among them, the indexes of the X basis vectors corresponding to each of the N time units are sent by the network device to the terminal device or are pre-negotiated between the network device and the terminal device. Thus, the way that the second indication information includes the indexes of the Y basis vectors is beneficial for the network device to determine Y basis vectors among the X basis vectors based on the indexes of the Y basis vectors.

[0153] In another alternative embodiment, the second indication information includes the weighting coefficients of Y basis vectors and the indices of the weighting coefficients of the Y basis vectors. Among them, the indices of the weighting coefficients of the X basis vectors correspond to the X basis vectors. The indices of the weighting coefficients of the X basis vectors corresponding to each of the N time units are sent by the network device to the terminal device or are pre-negotiated between the network device and the terminal device. Thus, the manner in which the second indication information includes the indices of the weighting coefficients of the Y basis vectors can also enable the network device to determine Y basis vectors among the X basis vectors based on the indices of the weighting coefficients of the Y basis vectors.

[0154] For example, if the indices of the weighting coefficients included in the second indication information are from 1 to 6, then the second indication information indicates the weighting coefficients of the basis vectors with indices from 1 to 6.

[0155] Optionally, the weighting coefficients of the Y basis vectors are the Y weighting coefficients with the largest numerical values among the weighting coefficients of the X basis vectors. Among them, Y is configured by the network device or is pre-negotiated between the network device and the terminal device.

[0156] Exemplarily, the N time units are N time slots, and each time slot among the N time slots corresponds to 10 basis vectors. The terminal device receives a pilot signal on the nth time slot and measures the received pilot signal to obtain the channel information of the nth time slot. The terminal device determines the weighting coefficient of each of the 10 basis vectors based on the channel information of the nth time slot obtained by measurement and the 10 basis vectors corresponding to the nth time slot, and feeds back the Y weighting coefficients with the largest numerical values among the 10 weighting coefficients to the network device. Among them, n is a positive integer less than N.

[0157] S105. The network device determines the channel state information corresponding to the M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors.

[0158] Among them, M is an integer greater than N, and the M time units include the N time units.

[0159] Optionally, the network device determines the CSI corresponding to the M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors, including: determining the CSI corresponding to the M time units based on the weighting coefficients of the Y basis vectors and the M rows of basis vectors. Among them, the M rows of basis vectors are the basis vectors respectively corresponding to the M time units, and each row of the M rows of basis vectors includes X basis vectors. The M rows of basis vectors are determined by the network device based on the mobile state information of the terminal device and the channel map, and the M rows of basis vectors include the N rows of basis vectors. The determination method of the M rows of basis vectors can refer to S101 and will not be elaborated here.

[0160] Specifically, for the m-th row of basis vectors among the M rows of basis vectors, the network device determines Y basis vectors among the X basis vectors of the m-th row of basis vectors based on the indices of the Y basis vectors or the indices of the weighting coefficients of the Y basis vectors indicated by the second indication information, and then determines the CSI corresponding to the m-th time unit based on the Y basis vectors and the Y weighting coefficients indicated by the second indication information. Here, m is a positive integer less than or equal to M.

[0161] It can be seen that the network device determines the CSI corresponding to each of the M time units based on the CSI information fed back by the terminal device in N of the M time units and the M rows of basis vectors. The M rows of basis vectors are determined by the network device based on the prior information provided by the channel map and the movement state information of the terminal device, thereby more accurately reconstructing the time-varying channel, and further making the determined CSI more accurate, which is beneficial to improving the transmission performance.

[0162] In the embodiments of the present application, the N rows of basis vectors indicated by the network device to the terminal device corresponding to N time units are determined based on the movement state information of the terminal device and the channel map, so that the N rows of basis vectors can represent the time-varying channel of the terminal device during movement. Then, the network device determines the CSI corresponding to each of the M time units based on the weighting coefficients of the Y basis vectors fed back by the terminal device in N time units and the N rows of basis vectors, which can improve the accuracy of the CSI, and further improve the transmission performance.

[0163] In addition, N time units are a part of the M time units. The network device determines the CSI corresponding to each of the M time units based on the weighting coefficients of the Y basis vectors fed back by the terminal device in N time units and the N rows of basis vectors, which can reduce the signaling overhead.

[0164] The following takes M = 64, N = 9, X = 10, and Y = 8 as an example to illustrate the above channel state information determination method 100:

[0165] Please refer to Figure 11 , Figure 11 which is a schematic diagram of the movement of a terminal device. As Figure 11 shown, the terminal device moves from position A to position B based on the movement direction indicated by the arrow. In addition, the terminal device moves from position A to position B, corresponding to 64 time units, represented by t1 to t64. Alternatively, it can be that the network device divides the movement process of the terminal device into 64 time units based on the movement position information of the terminal device, represented by t1 to t64.

[0166] The network device determines a row of basis vectors corresponding to each of the time units t1 to t9 during the process of the terminal device moving from position A to position B based on the movement position information of the terminal device and the channel map. Each row of basis vectors includes 10 basis vectors. As Figure 11As shown, the row of basis vectors corresponding to t1 is [w 1,1 , …, w 1,10 . Similarly, the row of basis vectors corresponding to t2 is [w 2,1 , …, w 2,10 . Additionally, the representation of the row of basis vectors corresponding to each time unit from t3 to t9 is similar, which will not be elaborated here.

[0167] Optionally, the terminal device also determines the row of basis vectors corresponding to each time unit from t10 to t64 based on the mobile location information of the terminal device and the channel map. The representation of the row of basis vectors corresponding to each time unit from t10 to t64 is similar to that of the row of basis vectors corresponding to t1. For example, the row of basis vectors corresponding to t64 is [w 64,1 , …, w 64,10 . Thus, the 64 rows of basis vectors corresponding to t1 to t64 determined by the network device for the terminal device during movement are as Figure 11 shown. Each basis vector in the 64 rows of basis vectors corresponding to t1 to t64 can be a time-frequency-space basis vector or a Doppler basis vector. The implementation manners of the time-frequency-space basis vector and the Doppler basis vector can be referred to in the above-mentioned channel state information determination method 100 and will not be elaborated here.

[0168] Additionally, the row of basis vectors corresponding to each time unit from t1 to t64 is used to characterize the channel change within that time unit. For example, [w 1,1 , …, w 1,10 corresponding to t1 is used to characterize the channel change at t1. For another example, [w 64,1 , …, w 64,10 corresponding to t64 is used to characterize the channel change at t64.

[0169] The network device indicates the 9 rows of basis vectors corresponding to t1 to t9 to the terminal device through the first indication information, and each row of basis vectors includes 10 basis vectors. As Figure 11 shown, the 9 rows of basis vectors corresponding to t1 to t9 indicated by the first indication information are the basis vectors within the dashed box in Figure 11 .

[0170] The network device sends pilot signals respectively at t1 to t9. Correspondingly, the terminal device receives the pilot signals respectively at t1 to t9, measures the received pilot signals, and obtains channel information. The terminal device determines the weighting coefficients of the 10 basis vectors corresponding to each time unit based on the channel information measured in each time unit from t1 to t9 and the 10 basis vectors corresponding to that time unit, and feeds back the weighting coefficients of some or all of the 10 basis vectors.

[0171] For example, the terminal device determines the weighting coefficients of the 10 basis vectors corresponding to t1 based on the channel information h1 measured at t1 and [w1,1 ,…,w 1,10 ], confirm [w 1,1 ,…,w 1,10 The weighted coefficients [c1,…,c 10 For another example, the terminal device obtains the channel information h2 and [w 2,1 ,…,w 2,10 ], confirm [w 2,1 ,…,w 2,10 The weighted coefficients [c1,…,c 10 ]. For t3 to t9, the terminal device determines the weighting coefficients of the 10 basis vectors corresponding to each time unit in the same manner, which will not be repeated here.

[0172] Exemplarily, the network device configures the terminal device to feed back the weighting coefficients of 8 of the 10 basis vectors. The terminal device then determines the 10 weighting coefficients corresponding to the 10 basis vectors based on the channel information measured in each time unit and the 10 basis vectors corresponding to the time unit, and determines the 8 weighting coefficients with the largest values among the 10 weighting coefficients, and then feeds back the 8 weighting coefficients with the largest values to the network device. For example, if the terminal device determines that the weighting coefficients of the 8 basis vectors indexed from 1 to 8 are the 8 weighting coefficients with the largest values, the terminal device feeds back the weighting coefficients of the basis vectors indexed from 1 to 8 to the network device. In other words, the terminal device sends a second indication message to the network device, and the second indication message is used to indicate the weighting coefficients of the basis vectors indexed from 1 to 8. Figure 12 is a schematic diagram of a basis vector. Figure 12 As shown, the terminal device feeds back the second indication information as follows: Figure 12 The weight coefficients of the eight basis vectors with indices 1 to 8 in each row of basis vectors from t1 to t9. For example, for t1, the terminal device feeds back [w 1,1 ,…,w 1,8 ] weighted coefficients [c1, ..., c8]; for another example, for t9, the terminal device feeds back [w 9,1 ,…,w 9,10 ]’s weighting coefficients [c1,…,c8].

[0173] Therefore, the network device determines the CSI corresponding to each of t1 to t64 based on the second indication information. Specifically, for each time unit, the network device determines the CSI corresponding to the time unit based on the basis vectors indexed 1 to 8 and the weighting coefficient C corresponding to the time unit. Figure 13 Schematic diagram of determining CSI, where C = [c1, ..., c8]. Figure 13 As shown, for the channel information h1 corresponding to t1 = [w 1,1 ,…,w1,8 C; For the channel information h9 corresponding to t9 = [w 9,1 , …, w 9,8 C; For the channel information h 10 corresponding to t10 = [w 10,1 , …, w 10,8 C; For the channel information h 64 corresponding to t64 = [w 64,1 , …, w 64,8 C. In addition, the determination methods of the CSI corresponding to t2 to t8 respectively, and the CSI corresponding to t11 to t63 respectively, are similar and will not be elaborated.

[0174] Among them, the network device determines the CSI corresponding to t1 to t9 respectively based on the pilot signals received by the terminal device for t1 to t9 and feedback. Thus, the CSI corresponding to t1 to t9 determined by the network device can be understood as being measured by the network device. The network device determines the CSI corresponding to t10 to t64 respectively based on the index feedback of the basis vectors of the terminal device for t1 to t9. Thus, the CSI corresponding to t1 to t9 determined by the network device can be understood as the predicted CSI by the network device. For example, Figure 14 is a schematic diagram of another CSI determination. As Figure 14 shown, the CSI corresponding to t1 to t9 respectively is the CSI feedback by the terminal device based on CSI-RS, and the CSI corresponding to t10 to t64 respectively is the predicted CSI by the network device.

[0175] It can be seen that the network device determines 64 rows of basis vectors corresponding to t1 to t64 respectively during the movement of the terminal device based on the movement state information of the terminal device and the channel map. Each row of basis vectors includes 10 basis vectors. The network device sends 9 rows of basis vectors corresponding to t1 to t9 respectively to the terminal device, and sends pilot signals respectively at t1 to t9. Thus, the terminal device measures based on the pilot signals received at t1 to t9, obtains the channel information corresponding to t1 to t9 respectively, and feeds back the channel information through the weighting coefficients of the basis vectors with indexes 0 to 8 among the 10 basis vectors. Furthermore, for each time unit among t1 to t64, the network device determines the CSI corresponding to this time unit based on the basis vectors with indexes 0 to 8 among the basis vectors corresponding to this time unit and the weighting coefficients fed back by the terminal device.

[0176] The nine rows of basis vectors corresponding to t1 to t9 sent by the network device to the terminal device are determined based on the movement state information of the terminal device and the channel map, so that the basis vector corresponding to each time unit in t1 to t9 can represent the channel time variation during the movement of the terminal device. Then, the network device determines the CSI corresponding to t1 to t64 based on the weighting coefficients of the basis vectors with indices 0 to 8 fed back by the terminal device in t1 to t9 and the nine rows of basis vectors corresponding to t1 to t9, which can improve the accuracy of the CSI and thus improve the transmission performance.

[0177] For the technical solution described above, the corresponding apparatus implementation solution is further described below.

[0178] It can be understood that, in order to implement the functions in the above embodiments, the network device and the terminal device include the corresponding hardware structures and / or software modules for performing 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 the present application, the present 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 the hardware depends on the specific application scenario and design constraint conditions of the technical solution.

[0179] Figure 15 and Figure 16 FIG. is a schematic structural diagram of a possible communication device provided by an embodiment of the present application. These communication devices can be used to implement the functions of the network device or the terminal device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of the present application, the communication device can be, for example, Figure 1 the terminal device 120 shown in Figure 1 FIG., or the base station 110a shown in

[0180] such as Figure 15 shown, the communication device 1500 includes a processing unit 1510 and a transceiver unit 1520. The communication device 1500 is used to implement the functions of the network device or the terminal device in the method embodiment shown in the above Figure 10 FIG.

[0181] When the communication device 1500 is used to implement the function of the network device in the method embodiment shown in Figure 10 FIG.:

[0182] The processing unit 1510 is configured to determine N rows of basis vectors corresponding to N time units based on the movement state information of the terminal device and the channel map, each row of the N rows of basis vectors including X basis vectors, and the channel map is used to indicate the channel characteristics based on the location area;

[0183] A transceiver unit 1520, configured to send first indication information for indicating the N row basis vectors.

[0184] The transceiver unit 1520 is further configured to send pilot signals respectively in the N time units.

[0185] The transceiver unit 1520 is further configured to receive second indication information for indicating the weighting coefficients of Y basis vectors among the X basis vectors, where the weighting coefficients of the Y basis vectors are determined based on the pilot signals.

[0186] A processing unit 1510 is further configured to determine channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N row basis vectors, where the M time units include the N time units.

[0187] Wherein, N is a positive integer, M is an integer greater than N, X is an integer greater than 1, and Y is an integer greater than 1 and less than or equal to X.

[0188] When the communication device 1500 is used to implement Figure 10 the functions of the terminal device in the method embodiment shown:

[0189] A transceiver unit 1520, configured to receive first indication information for indicating N row basis vectors.

[0190] The transceiver unit 1520 is further configured to receive pilot signals respectively in the N time units.

[0191] The transceiver unit 1520 is further configured to send second indication information for indicating the weighting coefficients of Y basis vectors among the X basis vectors, where the weighting coefficients of the Y basis vectors are determined based on the pilot signals.

[0192] For a more detailed description of the above processing unit 1510 and transceiver unit 1520, reference may be made to Figure 10 the relevant description in the method embodiment shown.

[0193] Such as Figure 16As shown, the communication device 1600 includes a processor 1610 and an interface circuit 1620. The processor 1610 and the interface circuit 1620 are coupled to each other. It can be understood that the interface circuit 1620 can be a transceiver or an input / output interface. Optionally, the communication device 1600 may further include a memory 1630 for storing instructions executed by the processor 1610 or input data required for the processor 1610 to run instructions or data generated after the processor 1610 runs instructions. Sometimes, the interface circuit 1620 can also be understood as part of the processor 1610. In this case, the communication device 1600 includes the processor 1610.

[0194] When the communication device 1600 is used to implement Figure 10 the method shown, the processor 1610 is used to implement the functions of the above-mentioned processing unit 1510, and the interface circuit 1620 is used to implement the functions of the above-mentioned transceiver unit 1520.

[0195] 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 a terminal device. It can be understood that the information is first received by other modules (such as a radio frequency module or an antenna) in the network device and then sent to the network device chip by these modules. The network device chip sends information to the terminal device. It can be understood that the information is sent to other modules (such as a radio frequency module or an antenna) in the network device first and then sent to the terminal device by these modules.

[0196] 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 a network device. It can be understood that the information is first received by other modules (such as a radio frequency module or an antenna) in the terminal device and then sent to the terminal device chip by these modules. The terminal device chip sends information to the network device. It can be understood that the information is sent to other modules (such as a radio frequency module or an antenna) in the terminal device first and then sent to the network device by these modules.

[0197] The embodiment of the present application also provides a communication system, which may include a terminal device and a network device. In another possible design, the system may further include other devices / functional network elements that interact with the terminal device and the network device.

[0198] The embodiment of the present application also provides a computer-readable storage medium for storing computer software instructions, which, when executed by a communication device, implement the functions of any of the above method embodiments.

[0199] The embodiment of the present application further provides a computer program product for storing computer software instructions, which, when executed by a communication device, implement the functions of any of the above method embodiments.

[0200] The embodiment of the present application further provides a computer program, which, when running on a computer, implements the functions of any of the above method embodiments.

[0201] In the present application, when entity A sends information to entity B, it can be that A directly sends to B, or A indirectly sends to B through other entities. Similarly, when entity B receives information from entity A, it can be that entity B directly receives the information sent by entity A, or entity B indirectly receives the information sent by entity A through other entities. Here, entity A and B can be network devices or terminal devices, or modules inside network devices or terminal devices. The sending and receiving of information can be the information interaction between a network device and a terminal device, for example, the information interaction between a base station and a terminal device; the sending and receiving of information can also be the information interaction between two network devices, for example, the information interaction between a CU and a DU; the sending and receiving of information can also be the information interaction between different modules inside a device, for example, the information interaction between a terminal device chip and other modules of the terminal device, or the information interaction between a network device chip and other modules in the network device.

[0202] It can be understood that the processor in the embodiment of the present application can be a central processing unit (CPU), or 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 can be a microprocessor or any conventional processor.

[0203] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read only memory (ROM), a programmable read only memory, an erasable programmable read only memory, an electrically erasable programmable read only memory, a register, a hard disk, a removable hard disk, a compact disc read only memory (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from the storage medium and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. Additionally, the ASIC can be located in a network device or a terminal device. The processor and the storage medium can also exist as discrete components in a network device or a terminal device.

[0204] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable devices. The computer program or instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or a data center integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital video disc; or it can be a semiconductor medium, such as a solid state drive. The computer-readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile types of storage media.

[0205] In the various embodiments of the present application, if there is no special description and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0206] In this application, "at least one" means one or more, and "a plurality of" means two or more. "And / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates that the related objects before and after are in an "or" relationship; in the formulas of this application, the character " / " indicates that the related objects before and after are in a "division" relationship. "Including at least one of A, B, and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0207] It can be understood that the various numerical numbers involved in the embodiments of this application are only for the convenience of description and are not used to limit the scope of the embodiments of this 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.

Claims

1. A method for determining channel state information, characterized in that The method includes: Determining N rows of basis vectors corresponding to N time units based on the mobile state information of the terminal device and the channel map, where each row of the N rows of basis vectors includes X basis vectors, and the channel map is used to indicate the channel characteristics based on the location area; Sending first indication information, where the first indication information is used to indicate the N rows of basis vectors; Sending pilot signals respectively in the N time units; Receiving second indication information, where the second indication information is used to indicate the weighting coefficients of Y basis vectors among the X basis vectors, and the weighting coefficients of the Y basis vectors are determined based on the pilot signals; Determining the channel state information corresponding to M time units based on the weighting coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units; Wherein, N is a positive integer, M is an integer greater than N, X is an integer greater than 1, and Y is an integer greater than 1 and less than or equal to X.

2. The method according to claim 1, wherein: The basis vectors are time-frequency-space basis vectors; Wherein, the time-frequency-space basis vectors include time-domain basis vectors, frequency-domain basis vectors, and space-domain basis vectors, or the time-frequency-space basis vectors are basis vectors jointly of time domain, frequency domain, and space domain.

3. The method according to claim 1, wherein: The basis vectors are Doppler basis vectors; Wherein, the Doppler basis vectors are basis vectors obtained by projecting the space-frequency coefficients onto the Doppler domain, and the space-frequency coefficients are determined based on the channel characteristics and the space-frequency basis vectors.

4. The method according to claim 3, wherein: The weighting coefficients of the Y basis vectors are the weighting coefficients under the projection of the weighting coefficients of the space-frequency basis vectors onto the Doppler basis vectors.

5. The method according to any one of claims 1 to 4, wherein: The second indication information includes the indexes of the Y basis vectors and the weighting coefficients of the Y basis vectors; or The second indication information includes the weighting coefficients of the Y basis vectors and the indexes of the weighting coefficients of the Y basis vectors.

6. The method according to any one of claims 1 to 5, wherein: The weighting coefficients of the Y basis vectors are the Y weighting coefficients with the largest numerical values among the weighting coefficients of the X basis vectors.

7. The method according to claim 6, wherein Y is configured by the network device, or is pre-negotiated between the network device and the terminal device.

8. The method according to any one of claims 1 to 7, characterized in that, Before determining the N rows of basis vectors corresponding to N time units based on the mobile state information of the terminal device and the channel map, the method further includes: Receiving the mobile state information of the terminal device, where the mobile state information includes one or more of the following: moving speed, moving direction, and location area information.

9. A communication device, characterized in that, The communication device includes a module for performing the method according to any one of claims 1 to 8.

10. A communication device, characterized in that, The communication device includes a processor, and the processor is configured to perform the method according to any one of claims 1 to 8.

11. A chip, characterized in that, Including a processor, and the processor calls a computer program stored in a memory to enable the communication device including the chip to implement the method according to any one of claims 1 to 8.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store instructions which, when run on a computer, cause the method according to any one of claims 1 to 8 to be executed.

13. A computer program product comprising instructions, characterized in that, When run on a computer, it causes the method according to any one of claims 1 to 8 to be executed.

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