Channel state information determination method and apparatus

Abstract

A channel state information determination method and apparatus. The method comprises: on the basis of moving state information of a terminal device and a channel map, a network device determining N rows of basis vectors corresponding to N time units, wherein each of the N rows of basis vectors comprises X basis vectors, and the channel map is used for indicating a channel feature based on a position region; the network device sending first indication information, wherein the first indication information is used for indicating the N rows of basis vectors; the network device respectively sending pilot signals in the N time units; the network device receiving second indication information, wherein the second indication information is used for indicating weighting coefficients of Y basis vectors among the X basis vectors, and the weighting coefficients of the Y basis vectors are determined on the basis of the pilot signals; and on the basis of the weighting coefficients of the Y basis vectors and the N rows of basis vectors, the network device determining channel state information corresponding to M time units, wherein the M time units comprise the N time units. The method can improve the accuracy of channel state information.

Description

Channel state information determination method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on January 30, 2024, with application number 202410137350.6 and application name “Channel State Information Determination Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a method and device for determining channel state information. Background Art

[0003] In massive multiple input multiple output (Massive MIMO) technology, network equipment relies on channel state information (CSI) fed back by terminal devices to determine the precoding used to send data to the terminal devices.

[0004] The network device uses the most recently reported CSI from the terminal device as the CSI used to determine precoding during the entire CSI reporting period. However, the actual channel and the channel used when the terminal device reported the CSI may be different. This can cause the precoding determined by the network device using the CSI reported by the terminal device to not match the actual channel, thus affecting transmission performance. Summary of the Invention

[0005] The embodiments of the present application provide a method and apparatus for determining channel state information, which can improve the accuracy of channel state information.

[0006] In a first aspect, an embodiment of the present application provides a communication method that can be executed by a network device. The network device here can refer to the network device itself or a processor, module, chip, or chip system that implements the method in the network device. In this method, the network device determines N rows of basis vectors corresponding to N time units based on the mobility status information and channel map of the terminal device, 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; the network device sends a first indication information, the first indication information is used to indicate the N rows of basis vectors; the network device sends a pilot signal in each of the N time units; the network device receives a second indication information, the second indication information is used to indicate the weight coefficients of Y basis vectors in the X basis vectors, and the weight coefficients of the Y basis vectors are determined based on the pilot signal; the network device determines the channel state information corresponding to M time units based on the weight coefficients of the Y basis vectors and the N rows of basis vectors, and the M time units include 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.

[0007] As can be seen, in the embodiment of the present application, the N rows of basis vectors corresponding to N time units are determined by the network device based on the terminal device's mobility state information and channel map. Thus, the N rows of basis vectors can characterize the time-varying channel state of the terminal device during its mobility. Therefore, the network device determines the channel state information corresponding to M time units based on the N rows of basis vectors and the weighted coefficients of the Y basis vectors fed back by the terminal device in N time units. This can improve the accuracy of the channel state information and, in turn, transmission performance.

[0008] In addition, the network device determines the channel state information corresponding to M time units based on the measurement feedback of N time units among the M time units by the terminal device, which can reduce signaling overhead.

[0009] In an optional implementation, the network device determines channel state information corresponding to M time units based on weighted coefficients of Y basis vectors and N rows of basis vectors, including: the network device determines channel state information corresponding to M time units based on weighted coefficients of Y basis vectors and M rows of basis vectors. The M rows of basis vectors are determined by the network device based on mobility state information of the terminal device and a channel map, and are basis vectors corresponding to the M time units.

[0010] In an optional embodiment, 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 of the combination of time domain, frequency domain, and space domain.

[0011] In another optional implementation, the basis vector is a Doppler basis vector, wherein the Doppler basis vector is a basis vector of the space-frequency coefficient projected into the Doppler domain, and the space-frequency coefficient is determined based on the channel characteristics and the space-frequency basis vector.

[0012] In an optional implementation, when the basis vectors are Doppler basis vectors, the weighting coefficients of the Y basis vectors are weighting coefficients of the space-frequency basis vectors under the projection of the Doppler basis vectors.

[0013] In an optional embodiment, the second indication information includes indices of Y basis vectors and weighting coefficients of the Y basis vectors. This approach allows the network device to determine Y basis vectors among the X basis vectors based on the indices of the Y basis vectors, and then determine the weighting coefficients included in the second indication information as the weighting coefficients of the Y basis vectors.

[0014] In another optional implementation, the second indication information includes weighting coefficients of the Y basis vectors and indices of the weighting coefficients of the Y basis vectors. This approach allows 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, and then determine the Y weighting coefficients included in the second indication information as the weighting coefficients of the Y basis vectors.

[0015] In an optional implementation, the weighting coefficients of the Y basis vectors are the Y weighting coefficients with the largest values ​​among the weighting coefficients of the X basis vectors, thereby facilitating improving the accuracy of the channel state information.

[0016] In an optional implementation, Y is configured by the network device, or is pre-negotiated between the network device and the terminal device.

[0017] In one optional embodiment, before determining the N rows of basis vectors corresponding to the N time units based on the terminal device's mobility state information and the channel map, the network device also receives the terminal device's mobility state information, where the mobility state information includes one or more of the following: movement speed, movement direction, and location area information. This approach enables the network device to obtain the terminal device's mobility state information.

[0018] In a second aspect, embodiments of the present application further provide a communication device. The communication device has the capability to implement 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 include some or all of the functions of the network device described in the first aspect of the embodiments of the present application, or may include the capability to independently implement any one of the embodiments of the present application. The functions may be implemented in hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0019] In one possible design, the communication device may include a processing unit and a communication unit. The processing unit is configured to support the communication device in performing the corresponding functions in the above method. The communication unit is configured to support communication between the communication device and other communication devices. The communication device may also include a storage unit, which is coupled to the processing unit and the communication unit and stores program instructions and data necessary for the communication device.

[0020] In one embodiment, the communication device includes: a processing unit and a communication unit;

[0021] The processing unit is configured to determine, based on the mobility state information of the terminal device and the channel spectrum, N rows of basis vectors corresponding to the N time units, each row of the N rows of basis vectors including X basis vectors, the channel spectrum being used to indicate channel characteristics based on the location area;

[0022] The communication unit is configured to send first indication information, where the first indication information is used to indicate the N rows of basis vectors;

[0023] The communication unit is further configured to send pilot signals respectively in the N time units;

[0024] The communication unit is further configured to receive second indication information, where the second indication information is used to indicate 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;

[0025] The processing unit is further configured to determine channel state information corresponding to M time units based on weighted coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units;

[0026] 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.

[0027] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0028] 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.

[0029] In one embodiment, the communication device includes: a processor and a transceiver;

[0030] The processor is configured to determine, based on mobility state information of the terminal device and a channel map, N rows of basis vectors corresponding to N time units, where each row of the N rows of basis vectors includes X basis vectors, and the channel map is configured to indicate channel characteristics based on a location area;

[0031] The transceiver is configured to send first indication information, where the first indication information is used to indicate the N rows of basis vectors;

[0032] The transceiver is further configured to send pilot signals respectively in the N time units;

[0033] The transceiver is further configured to receive second indication information, where the second indication information is used to indicate 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;

[0034] The processor is further configured to determine channel state information corresponding to M time units based on weight coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time units;

[0035] 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.

[0036] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0037] In another embodiment, 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; and the communication unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuits on the chip or chip system.

[0038] During implementation, the processor can be used to perform, for example, but not limited to, baseband-related processing, and the transceiver can be used to perform, for example, but not limited to, radio frequency transceiver processing. The aforementioned devices can be provided on separate chips, or at least partially or entirely on the same chip. For example, the processor can be further divided into an analog baseband processor and a digital baseband processor. The analog baseband processor can be integrated with the transceiver on the same chip, while the digital baseband processor can be provided on a separate chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, a 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 each device is provided independently on different chips or integrated on one or more chips often depends on the needs of the product design. The embodiments of the present application do not limit the implementation form of the aforementioned devices.

[0039] In a third aspect, an embodiment of the present application further provides a processor for executing the various methods described above. In the process of executing these methods, the process of sending the above-mentioned information and receiving the above-mentioned information in the above-mentioned methods can be understood as the process of the processor outputting the above-mentioned information and the process of the processor receiving the above-mentioned information input. When outputting the above-mentioned information, the processor outputs the above-mentioned information to the transceiver so that the transceiver can transmit it. After being output by the processor, the above-mentioned information may also need to undergo other processing before reaching the transceiver. Similarly, when the processor receives the above-mentioned information input, the transceiver receives the above-mentioned information and inputs it into the processor. Furthermore, after the transceiver receives the above-mentioned information, the above-mentioned information may need to undergo other processing before being input into the processor.

[0040] For the sending and receiving operations involved in the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant descriptions, they can be more generally understood as processor output, reception, input and other operations, rather than sending and receiving operations directly performed by the RF circuit and antenna.

[0041] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. The memory may be a non-transitory memory, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or disposed on separate chips. The embodiments of the present application do not limit the type of memory or the configuration of the memory and the processor.

[0042] In a fourth aspect, 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 also include other devices / functional network elements that interact with the terminal device and / or the network device.

[0043] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium for storing instructions, which, when executed by a computer, implements the method described in the first aspect above.

[0044] In a sixth aspect, an embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, implements the method described in the first aspect above.

[0045] In the seventh aspect, an embodiment of the present application provides a chip system, which includes a processor and an interface, wherein the interface is used to obtain a program or instruction, and the processor is used to call the program or instruction 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 one possible design, the chip system also includes a memory, which is used to store program instructions and data necessary for the terminal. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0046] In an eighth aspect, an embodiment of the present application provides a communication device, comprising a processor for executing a computer program or executable instructions stored in a memory, so that when the computer program or executable instructions are executed, the device executes the methods in each possible implementation of the first aspect.

[0047] In one possible implementation, the processor and memory are integrated;

[0048] In another possible implementation, the memory is located outside the communication device.

[0049] The beneficial effects of the second to eighth aspects can refer to the beneficial effects of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a schematic diagram of a system architecture;

[0051] FIG2 is a schematic diagram of the structure of a network device and a terminal device;

[0052] FIG3 is a schematic diagram of a channel map;

[0053] FIG4 is a three-dimensional schematic diagram of space-time-frequency;

[0054] FIG5 is a schematic diagram of the interaction between a network device and a terminal device to obtain CSI;

[0055] FIG6 is a schematic diagram of a multi-user mobile scenario;

[0056] FIG7 is a schematic diagram of CSI measurement and feedback;

[0057] FIG8 is a schematic diagram showing a comparison of CSI in a time-varying scenario;

[0058] FIG9 is a schematic diagram of a time domain multipath mutation;

[0059] FIG10 is an interactive diagram of a method for determining channel state information provided in an embodiment of the present application;

[0060] FIG11 is a schematic diagram of a terminal device moving according to an embodiment of the present application;

[0061] FIG12 is a schematic diagram of a basis vector provided in an embodiment of the present application;

[0062] FIG13 is a schematic diagram of CSI determination provided in an embodiment of the present application;

[0063] FIG14 is another schematic diagram of CSI determination provided in an embodiment of the present application;

[0064] FIG15 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0065] FIG16 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] To better understand the embodiments of the present application, the following first introduces the system architecture involved in the embodiments of the present application:

[0067] Figure 1 is a schematic diagram of the architecture of a communication system 1000 provided in an embodiment of the present application. As shown in Figure 1, the communication system 1000 includes a radio access network (RAN) 100, wherein the RAN 100 includes at least one RAN node (such as 110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal device (such as 120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal device 120 is connected to the RAN node 110 wirelessly. Terminal devices and RAN nodes can be connected to each other via wired or wireless means. The communication system 1000 may also include a core network 200. The RAN node 110 is connected to the core network 200 wirelessly or wired. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be independent and different physical devices, or may be the same physical device that integrates the logical functions of the core network devices and the logical functions of the RAN nodes.

[0068] RAN100 may be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, or a future radio access system defined in the 3rd Generation Partnership Project (3GPP). RAN100 may also include two or more of the aforementioned different radio access systems. RAN100 may also be an open RAN (O-RAN).

[0069] A RAN node, also known as a radio access network device, RAN entity, or access node, facilitates wireless access to a communication system by terminal devices. In one application scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a fifth-generation (5G) mobile communication system, a next-generation base station in a sixth-generation (6G) mobile communication system, or a base station in a future mobile communication system. A RAN node can be a macro base station (such as 110a in Figure 1), a micro base station, an indoor station (such as 110b in Figure 1), a relay node, or a donor node.

[0070] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing portions of the base station's functions. For example, a RAN node can be a centralized unit (CU), a distributed unit (DU), or a radio unit (RU). The CU implements the base station's radio resource control protocol and packet data convergence protocol (PDCP) functions, as well as the service data adaptation protocol (SDAP) functions. The DU implements the base station's radio link control layer and medium access control (MAC) layer functions, as well as some or all of the physical layer functions. For detailed descriptions of each of the above protocol layers, please refer to the relevant 3GPP technical specifications. The RU can be used to implement the transmission and reception of radio frequency signals. The CU and DU can be two independent RAN nodes, or they can be integrated into the same RAN node, such as in a baseband unit (BBU). The RU can be included in radio frequency equipment, such as a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0071] In different systems, RAN nodes may have different names. For example, in an O-RAN system, a CU may be called an open CU (O-CU), a DU may be called an open DU (O-DU), and a RU may be called an open RU (O-RU). The RAN node in the embodiments of the present application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node may be a server loaded with the corresponding software module. The embodiments of the present application do not limit the specific technology and specific device form adopted by the RAN node. For ease of description, the following description takes a base station as an example of a RAN node.

[0072] 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 may also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used 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, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the specific technology and specific device form adopted by the terminal.

[0073] Base stations and terminals can be fixed or mobile. They can be deployed on land, indoors or outdoors, handheld or vehicle-mounted; on water; or on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of base stations and terminals.

[0074] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. To terminals 120j accessing the wireless access network 100 via 120i, terminal 120i is a base station. However, to base station 110a, 120i is a terminal, meaning that communication between 110a and 120i occurs via a wireless air interface protocol. Of course, communication between 110a and 120i can also occur via a base station-to-base station interface protocol. In this case, 120i is also a base station relative to 110a. Therefore, base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be referred to as communication devices with base station functionality, while 120a-120j in Figure 1 can be referred to as communication devices with terminal functionality.

[0075] Communication between base stations and terminals, between base stations, and between terminals can be carried out through authorized spectrum, unauthorized spectrum, or both; communication can be carried out through spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or spectrum below 6 GHz and spectrum above 6 GHz. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0076] In the embodiments of the present application, the functions of the base station may also be performed by a module (such as a chip) in the base station, or by a control subsystem that includes the base station functions. The control subsystem that includes the base station functions here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal may also be performed by a module (such as a chip or modem) in the terminal, or by a device that includes the terminal functions.

[0077] In the embodiment of the present application, the network device (for example) may be the RAN node described above.

[0078] Please refer to Figure 2, which is a schematic diagram of the structure of a network device and a terminal device. As shown in Figure 2, the network device and the terminal device both 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, and 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, 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.

[0079] The following describes the relevant concepts involved in the embodiments of this application:

[0080] 1. Channel information and channel map.

[0081] Channel information can be used to characterize channel characteristics or features. For example, the channel information can be channel matrix information, and / or CSI, and / or channel eigenvectors. Alternatively, the channel information can be a CSI report. Alternatively, the channel information can be time domain information, frequency domain information, spatial domain information, time-frequency domain information, space-frequency domain information, delay-Doppler domain information, or time-frequency-space domain information of the channel, without specific limitation.

[0082] Among them, CSI can be used to describe information related to channel quality. For example, CSI describes the propagation process of wireless signals between the transmitter and the receiver, including the effects of distance, scattering, fading, etc. on the signal. For downlink transmission, CSI can be used by the terminal device to feedback the downlink channel quality to the network device so that the network device can perform downlink transmission based on the CSI. The CSI sent by the terminal device to the network device can be carried in the CSI report. For example, CSI can also include at least one of the following: channel state information-reference signal resource indicator index (CRI), rank indicator index (RI), channel quality indicator index (CQI), precoding matrix indicator index (PMI), layer indicator index (LI), layer 1-reference signal receiving power layer indicator (L1-RSRP), layer 1-signal to interference plus noise ratio (L1-SINR), capability index (capability index), time-domain channel properties (TDCP), etc.

[0083] The terminal device can perform channel measurement through the downlink reference signal to obtain channel information. Measurement can also be described as evaluation, detection or estimation, etc. Among them, the downlink reference signal may include but is not limited to the channel state information-reference signal (CSI-RS), synchronization signal and physical broadcast channel block (SSB) or physical broadcast channel demodulation reference signal (PBCH DMRS). For example, the terminal device can perform downlink channel measurement based on the CSI-RS to obtain CSI.

[0084] A channel map can be understood as a database that stores / indicates channel characteristics based on a location area. These channel characteristics include the channel statistical covariance matrix, angle spectrum, delay spectrum, path loss, and characteristic basis vectors. A channel map can be pre-determined and managed by core network equipment, access network equipment, 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 shown in Figure 3, the channel map can divide the physical cell into a two-dimensional grid, with each two-dimensional grid point storing several channel characteristics of the location area in the form of a matrix, vector, or scalar.

[0085] 2. The changing characteristics of the channel.

[0086] Channel variation characteristics include spatial, frequency, and time domain variations. The physical parameter corresponding to spatial channel variation is angle, the physical parameter corresponding to frequency channel variation is multipath delay, and the physical parameter corresponding to time channel variation is Doppler shift. Terminal devices can use the angle, multipath delay, and Doppler of a finite transmission path to provide compressed feedback on the channel, allowing network devices to obtain the channel's variation characteristics.

[0087] Furthermore, if the time-domain channel is projected into the Doppler domain, the channel's characteristics in the Doppler domain can be used to equivalently describe its changing trend. Therefore, the Doppler signature can characterize the time-varying characteristics of the channel. The Doppler information of a time-varying channel changes slowly compared to the time domain, and network devices can reconstruct the channel's time-varying characteristics based on this Doppler information.

[0088] In summary, channels can be characterized using three dimensions: Doppler domain, angle, and delay. For example, Figure 4 shows a three-dimensional space-time-frequency diagram. The angle, Doppler domain, and delay shown in Figure 4 represent the three dimensions of a channel: space, time, and frequency. Furthermore, multiple space-frequency matrices in time can be aggregated into a single three-dimensional space-time-frequency matrix.

[0089] Massive MIMO technology in 5G communication systems plays a crucial role in enhancing the system's spectral efficiency. In Massive MIMO, network equipment relies on CSI (Current Signal Indicator) feedback from terminal devices to transmit downlink data. Therefore, the accuracy of CSI is crucial to system performance.

[0090] Please refer to Figure 5, which illustrates an interaction between a network device and a terminal device to obtain CSI. As shown in Figure 5, the network device sends channel measurement configuration information to the terminal device to inform the terminal device of the time and behavior for channel measurement. The network device sends a pilot signal to the terminal device, which is used to measure the channel. The terminal device provides CSI feedback to the network device based on the pilot measurement results. The network device then sends data based on the CSI feedback provided by the terminal device. The terminal device can provide CSI feedback using a Type II codebook, which includes parameters such as RI, CQI, and PMI. The Type II codebook uses weighted superposition of multiple discrete Fourier transform (DFT) beams to represent the channel direction. The network device sends data based on the CSI feedback provided by the terminal device, including: determining the number of data streams to be transmitted to the terminal device based on the RI feedback provided by the terminal device; determining the modulation order and channel coding rate for data transmission to the terminal device based on the CQI feedback provided by the terminal device; and determining the precoding matrix for data transmission to the terminal device based on the PMI feedback provided by the terminal device.

[0091] The PMI feedback mechanism can be based on the selection and reporting of a specific codebook. Specifically, the information bits reported by the terminal device indicate the position of the selected codeword within the overall codebook set. Thus, the network device determines the PMI for downlink data transmission based on the known overall codebook and the codebook position reported by the terminal device.

[0092] However, the CSI fed back by the terminal device usually has a time delay, which may cause the CSI obtained by the network device to be outdated, thereby affecting 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 is a schematic diagram of a multi-user mobile scenario. As shown in Figure 6, terminal device 1, terminal device 2 and terminal device 3 move in the corresponding arrow directions at speeds V1, V2 and V3 respectively. In the multi-user mobile scenario shown in Figure 6, the expiration of CSI of multiple terminal devices will cause the precoding of multiple users to be unable to match the actual channel conditions, thereby introducing more multi-user interference, which will lead to a significant decline in system performance.

[0093] For example, Figure 7 is a schematic diagram of CSI measurement and feedback. As shown in Figure 7, during the t1 time period, the network device sends a CSI-RS to the terminal; the terminal device performs channel estimation based on the received CSI-RS, obtains CSI, and feeds the CSI back to the network device via uplink. In addition, before the terminal device reports CSI again, the network device uses the terminal device's most recently reported CSI to send downlink data. In other words, during the t2 time period, the network device uses the CSI reported by the terminal device during the t1 time period to send downlink data.

[0094] For the CSI feedback process shown in Figure 7, the delays that cause CSI expiration include the CSI validation delay t1 and the channel time-varying delay t2. As shown in Figure 7, t1 is the time between the network device sending the CSI-RS, the terminal device receiving the CSI-RS and estimating the channel, the terminal device quantizing the estimated channel and providing feedback, the network device receiving the terminal device's uplink CSI feedback, and the network device calculating the precoding matrix based on the feedback from the terminal device for downlink data transmission. The presence of t1 results in a delay between the channel H1 when the network device sends the CSI-RS and the H2 determined based on the terminal device's reported CSI. This means that the reported CSI is delayed from the actual channel CSI. In static scenarios, t1 has a minimal impact on system performance. However, when the channel varies rapidly over time, t1 can significantly degrade system performance. Furthermore, t1 is determined by the hardware capabilities of both the network and terminal devices and cannot be addressed through network device configuration.

[0095] Furthermore, CSI is fixed within time t2, meaning the network assumes the channel remains unchanged during the CSI feedback cycle. However, when the channel is time-varying, such as in mobile scenarios, the channel can also change dramatically within time t2, resulting in a time-varying channel delay t2. This can cause the precoding matrix calculated by the network based on the CSI reported during time t1 to mismatch the actual channel, resulting in performance degradation. The length of t2 is typically configurable by the network, but a shorter CSI feedback cycle increases CSI feedback overhead.

[0096] For example, Figure 8 shows a comparative diagram of CSI in a time-varying scenario. Specifically, Figure 8 was obtained under a time-varying channel at 30 km / h. As shown in Figure 8, the correlation between the CSI reported by the terminal device and the actual channel CSI shows a significant downward trend over time. Therefore, if network equipment continues to use the most recently reported CSI from the terminal device for data transmission over a prolonged period of time, system performance will degrade.

[0097] In another embodiment, the network device may also determine the future CSI based on an autoregressive model (AR) and historical channel information. That is, the network device determines the CSI for a period of time in the future based on the CSI reported historically by the terminal device and the AR. The AR model may be, for example: h(n+1)=h(n)w1+h(n-1)w2+h(n-2)w3 (1)

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

[0099] However, as a terminal device moves, the channel may experience sudden changes in time-domain multipath. For example, Figure 9 illustrates a sudden change in time-domain multipath. As shown in Figure 9, when the terminal device is at position A, the subpath disappears, meaning there is no time-domain subpath at position A. When the terminal device is at position B, the subpath appears, meaning there is a time-domain subpath at position B. Both the Doppler effect and sudden changes in multipath over time can affect CSI prediction performance. The way network devices determine future CSI based on historical channel information and AR cannot capture future sudden changes, causing the predicted channel to mismatch with the actual channel, resulting in performance degradation.

[0100] The present embodiment provides a method 100 for determining channel state information. FIG10 is an interactive diagram of the method 100. The method 100 is described from the perspective of the interaction between a network device and a terminal device. The 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 terminal device's mobility status information and channel map. Each row of the N rows of basis vectors includes X basis vectors. The channel map is used to indicate channel characteristics based on the location area.

[0102] The channel map includes channel information of the area where the terminal device is located, such as a full-dimensional channel characteristic basis vector 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 optional embodiment, the mobile state information of the terminal device includes one or more of the following: moving speed, moving direction and location area information. Among them, the moving speed of the terminal device includes at least one of the following: absolute speed based on geographical location, relative speed relative to network equipment or other reference objects. The moving direction of the terminal device includes whether the terminal device moves in a straight line in a certain direction, the angle of movement relative 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 point in time. For example, the location area information of the terminal device can be the x-coordinate, y-coordinate and z-coordinate of the terminal device at a certain point in time. For another example, the location area information of the terminal device can be the global positioning system (GPS) location information of the terminal device at a certain point in time.

[0104] In an optional embodiment, the network device receives the terminal device's mobility status information before determining the N rows of basis vectors corresponding to the N time units based on the terminal device's mobility status information and the channel map. In other words, the terminal device can report its mobility status information to the network device. The terminal device can proactively report its mobility status information to the network device. Alternatively, the network device requests the terminal device to obtain its mobility status information via a request message. After receiving the request message from the network device, the terminal device reports its mobility status information to the network device.

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

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

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

[0108] Optionally, the network device may determine the mobile state information of the terminal device on its own. For example, the network device may determine the mobile state information of the terminal device in the future based on the historical movement trajectory of the terminal device.

[0109] In addition, the N time units are partial time units of the terminal device during the movement process. All the time units of the terminal device during the movement process may be determined by the network device based on the movement status information of the terminal device, or may be pre-negotiated between the network device and the terminal device. For example, the network device determines that all the time units of the terminal device during the movement process include 10 time units based on the movement status information of the terminal device, and the N time units may be partial time units of the 10 time units. The interval between each two adjacent time units in the N time units may be a plurality of time slots, 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 each two adjacent time units in the N time units is 5 time slots, or 5s, or 10ms.

[0110] In an optional implementation, the network device determines N rows of basis vectors corresponding to N time units based on the terminal device's mobility state information and channel map. This may be accomplished by determining, based on the terminal device's mobility state information and channel map, a row of basis vectors corresponding to each of the N time units. For example, if the N time units are five time slots, the network device determines, based on the terminal device's mobility state information and channel map, a row of basis vectors corresponding to each of the five time slots. Thus, the five rows of basis vectors determined by the network device correspond one-to-one to the five time slots.

[0111] Based on the characteristics of the channel map, it is shown that the channel map can provide multiple basis vectors for each of the multiple location areas. Then, the network device can characterize the channel time variation of the terminal device during movement by using the N rows of basis vectors corresponding to the N time units determined based on the mobile state information of the terminal device and the channel map. In other words, a row of basis vectors corresponding to the n-th time unit in the N time units can characterize the channel time variation information within the n-th time unit, where n is a positive integer less than or equal to N. Each row of the N rows of basis vectors includes X basis vectors, indicating that each of the N time units corresponds to X basis vectors. Then, each of the N time units has X basis vectors for characterizing the channel time variation of the time unit.

[0112] It can be seen that the network device can determine the channel time variation of each of the N time units by determining the N rows of basis vectors corresponding to the N time units of the terminal device based on the mobility status information and channel map of the terminal device.

[0113] In an optional embodiment, 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 of the combination of time domain, frequency domain, and space domain.

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

[0115] Among them, 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. They are spatial domain basis vectors, frequency domain basis vectors and time domain basis vectors respectively, N s 、N f 、N t are their lengths respectively. In addition, N s Can be equal to the number of spatial antennas; N f It can be equal to the number of frequency domain resources, such as N f Equal to the number of subbands / resource blocks (RBs) / resource block groups (RBGs); N t It can be equal to the number of time domain resources, such as N t Equal to the number of slots / mini-slots / symbols.

[0116] Optionally, the basis vectors include time domain basis vectors Spatial basis vectors and frequency domain basis vectors Optionally, the basis vectors may be combined basis vectors of the time domain, frequency domain, and spatial domain. For example, the basis vectors may be vectors obtained by performing singular value decomposition (SVD) decomposition on the channel information H, and used to characterize the time domain channel characteristics, frequency domain channel characteristics, and spatial domain channel characteristics. For another example, the basis vectors may be basis vectors obtained by performing a Kronecker operation on the time domain basis vectors, the frequency domain basis vectors, and the spatial domain basis vectors.

[0117] In another optional implementation, the basis vector is a Doppler basis vector, wherein the Doppler basis vector is a basis vector of the space-frequency coefficient projected into the Doppler domain, and the space-frequency coefficient is determined based on the channel characteristics and the space-frequency basis vector.

[0118] Exemplarily, the channel information H and the basis vector satisfy formula (3):

[0119] Among them, c m is the coefficient of the space-frequency coefficient of a certain time unit on the Doppler basis vector, V N×1 is the space-frequency coefficient.

[0120] in addition:

[0121] Where C is the c of different time units m The collection of d s,f,t Denotes the weight coefficient of the space-frequency basis vector under the projection of the Doppler basis vector, D * is the basis vector of the space-frequency coefficient projected into the Doppler domain, that is, D * is the Doppler basis vector.

[0122] As can be seen from formula (3), the network device can determine the space-frequency coefficient c of a time unit based on the channel characteristics and space-frequency vector of the time unit. m , and then the Doppler domain basis vector D corresponding to the time unit can be determined based on the space-frequency coefficient * .

[0123] Optionally, the basis vectors may also be in other forms and may be used to represent basis vectors of time domain channel characteristics, frequency domain channel characteristics, and spatial domain channel characteristics, which is not limited in the embodiments of the present application.

[0124] Optionally, the Doppler codebook or the time-frequency domain codebook can be an N×N matrix agreed upon by the network device and the terminal, such as a DFT matrix or a wavelet matrix. For example, for the DFT form, the pth basis vector in the Doppler codebook satisfies formula (5):

[0125] Wherein, p=0,…,N-1, N is a positive integer, and T represents a time unit. Optionally, the representation of the pth basis vector in the time-frequency domain basis vector can also refer to formula (5). The embodiment of the present application does not limit the representation of the basis vector.

[0126] Optionally, when the entity managing the channel map is a core network device, the network device in S101 may refer to the core network device or the access network device. When the entity managing 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; accordingly, the core network device sends the channel map it manages to the access network device, so that the access network device can execute S101.

[0127] Optionally, when the entity that manages the channel map is an access network device, the access network device may directly execute S101.

[0128] Optionally, when the entity managing 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 managing the channel map to obtain the channel map, so that the core network device or the access network device can execute S101.

[0129] S102: The network device sends first indication information, where the first indication information is used to indicate N rows of basis vectors. Correspondingly, the terminal device receives the first indication information.

[0130] The network device indicates the N rows of basis vectors corresponding to the 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.

[0131] In an optional implementation, the network device may indicate 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, which includes N rows of basis vectors, and each row of the N rows of basis vectors includes X basis vectors. For example, if N is 9 and X is 10, the vector group included in the first indication information is:

[0132] Among them, w 1,1 ,...,w 1,10 is a row of basis vectors corresponding to the first time unit, w 9,1 ,...,w 9,10 is a row of basis vectors corresponding to the first time unit.

[0133] 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).

[0134] Optionally, the network device may also indicate N rows of basis vectors to the terminal device in other forms, that is, the first indication information may also be in other forms, which is not limited in this embodiment of the present application.

[0135] S103: The network device sends pilot signals in N time units respectively. Correspondingly, the terminal device receives pilot signals in N time units respectively.

[0136] Among them, the pilot signal can be CSI-RS, SSB and DMRS, etc., which is not limited in the embodiments of the present application.

[0137] The network device indicates N rows of basis vectors corresponding to N time units to the terminal device at step S102. Then, in order for the terminal device to feed back multiple basis vectors among the X basis vectors corresponding to each of the N time units, the network device sends pilot signals in each of the N time units.

[0138] The network device sends the pilot signal in each of the N time units, which means that the network device sends the pilot signal in each of the N time units. Correspondingly, the terminal device receives the pilot signal in each of the N time units and measures the received pilot signal.

[0139] Optionally, before executing S103, the network device further sends measurement configuration information to the terminal device, where the measurement configuration information is used to configure the terminal device to receive and measure pilot signals in N time units respectively.

[0140] S104. The terminal device sends second indication information, where the second indication information is used to indicate weight coefficients of Y basis vectors among the X basis vectors, where the weight coefficients of the Y basis vectors are determined by the terminal device based on the pilot signal. Accordingly, the network device receives the second indication information.

[0141] Wherein, Y is an integer greater than 1 and less than or equal to X.

[0142] After receiving a pilot signal in each of the N time units, the terminal device measures the received pilot signal to obtain channel information for that time unit. Based on the channel information measured in each of the N time units and the X basis vectors corresponding to that time unit, the terminal device determines Y basis vectors from the X basis vectors and their weighting coefficients.

[0143] For example, when the basis vector is a time-frequency domain basis vector, for each time unit in N time units, the terminal device can obtain the channel information H based on the measurement. N×1 And the above formula (2) determines the Y basis vectors among the X basis vectors corresponding to the time unit, and the weighting coefficient α of the Y basis vectors m .

[0144] For another example, the basis vector is the Doppler basis vector D *When, for each time unit in N time units, it can be known from the above formula (3) that the terminal device can obtain H based on the measurement N×1 and V N×1 , determine the c corresponding to the time unit m , where V N×1 It is pre-negotiated between the network device and the terminal device. The terminal device then calculates the time based on the c corresponding to multiple time units. m (i.e. C) and formula (4), the Y Doppler basis vectors among the X Doppler basis vectors corresponding to each time unit in the multiple time units and the weighting coefficient d of the Y Doppler basis vectors can be determined. s,f,t Among them, the weight coefficients d of the Y Doppler basis vectors are s,f,t is the weighting coefficient of the space-frequency basis vector under the projection of the Doppler basis vector.

[0145] 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 through the second indication information are applicable to the determination of the channel information corresponding to the N time units.

[0146] In an optional implementation, the second indication information includes the indexes of 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), and the basis vectors determined by the terminal device based on the received pilot signal are the basis vectors with indices 1 to 8 among the 10 basis vectors, then the second indication information includes indices 1 to 8 and the weighting coefficients, which are the weighting coefficients of the basis vectors with indices 1 to 8, for example, the second indication information includes w 1,1 、w 1,2 、...、w 1,10 Middle w 1,1 、w 1,2 、...、w 1,8 The index of w 1,1 、w 1,2 、...、w 1,8 The weighting coefficient of .

[0147] 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. Therefore, the second indication information including the indexes of the Y basis vectors facilitates the network device determining Y basis vectors among the X basis vectors based on the indexes of the Y basis vectors.

[0148] In another optional embodiment, the second indication information includes weighting coefficients of Y basis vectors and indices of the weighting coefficients of the Y basis vectors. 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 the Y basis vectors among the X basis vectors based on the indices of the weighting coefficients of the Y basis vectors.

[0149] For example, if the indexes of the weighting coefficients included in the second indication information are 1 to 6, then the second indication information indicates the weighting coefficients of the basis vectors with indexes 1 to 6.

[0150] Optionally, the weight coefficients of the Y basis vectors are the Y weight coefficients with the largest values ​​among the weight coefficients of the X basis vectors, where Y is configured by the network device or pre-negotiated between the network device and the terminal device.

[0151] Exemplarily, N time units are N time slots, and each of the N time slots corresponds to 10 basis vectors. A terminal device receives a pilot signal in the nth time slot and measures the received pilot signal to obtain channel information for the nth time slot. Based on the measured channel information for the nth time slot and the 10 basis vectors corresponding to the nth time slot, the terminal device determines a weighting coefficient for each of the 10 basis vectors and feeds back the Y largest weighting coefficients among the 10 weighting coefficients to the network device. Here, n is a positive integer less than N.

[0152] S105. The network device determines the channel state information corresponding to the M time units based on the weight coefficients of the Y basis vectors and the N rows of basis vectors.

[0153] Here, M is an integer greater than N, and the M time units include N time units.

[0154] Optionally, the network device determines the CSI corresponding to M time units based on the weighted coefficients of Y basis vectors and N rows of basis vectors, including: determining the CSI corresponding to M time units based on the weighted coefficients of Y basis vectors and M rows of basis vectors. Among them, the M rows of basis vectors are basis vectors corresponding to the M time units respectively, 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 and channel spectrum of the terminal device, and the M rows of basis vectors include N rows of basis vectors. The method for determining the M rows of basis vectors can be referred to S101 and will not be repeated here.

[0155] 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 in 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, where m is a positive integer less than or equal to M.

[0156] As can be seen, the network device determines the CSI corresponding to each of the M time units based on the CSI information and M rows of basis vectors fed back by the terminal device in N of the M time units. The M rows of basis vectors are determined by the network device based on the prior information provided by the channel map and the mobility status information of the terminal device. This more accurately reconstructs the channel time variation, making the determined CSI more accurate and helping to improve transmission performance.

[0157] In this embodiment of the present application, the N rows of basis vectors corresponding to the N time periods indicated by the network device to the terminal device are determined based on the terminal device's mobility status information and channel map. Thus, the N rows of basis vectors can characterize the time-varying channel conditions of the terminal device during its mobility. The network device then determines the CSI corresponding to each of the M time units based on the weighted coefficients of the Y basis vectors and the N rows of basis vectors fed back by the terminal device during the N time units. This improves the accuracy of the CSI and, in turn, transmission performance.

[0158] In addition, N time units are part of M time units. The network device determines the CSI corresponding to the M time units based on the weighted coefficients of the Y basis vectors and the N rows of basis vectors fed back by the terminal device in the N time units, thereby reducing signaling overhead.

[0159] The following uses M=64, N=9, X=10, and Y=8 as an example to illustrate the channel state information determination method 100.

[0160] Please refer to Figure 11, which is a schematic diagram of a terminal device moving. As shown in Figure 11, the terminal device moves from position A to position B based on the movement direction indicated by the arrow. Furthermore, the movement of the terminal device from position A to position B corresponds to 64 time units, represented by t1 to t64. Alternatively, the network device may divide the movement of the terminal device into 64 time units based on the terminal device's mobile location information, represented by t1 to t64.

[0161] Based on the mobile location information and channel map of the terminal device, the network device determines a row of basis vectors corresponding to each time unit from t1 to t9 during the process of the terminal device moving from position A to position B. Each row of basis vectors includes 10 basis vectors. As shown in Figure 11, the row of basis vectors corresponding to t1 is [w 1,1 ,…,w1,10 ]. Similarly, the row of basis vectors corresponding to t2 is [w 2,1 ,…,w 2,10 ]. In addition, the representation of a row of basis vectors corresponding to each time unit from t3 to t9 is similar and will not be repeated here.

[0162] Optionally, the terminal device further determines a 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 a row of basis vectors corresponding to each time unit from t10 to t64 is similar to the representation of a row of basis vectors corresponding to t1. For example, a 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 during the movement of the terminal device determined by the network device are shown in Figure 11. Each of 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 of the time-frequency-space basis vectors and the Doppler basis vectors can be found in the above-mentioned channel state information determination method 100 and will not be repeated here.

[0163] In addition, a row of basis vectors corresponding to each time unit from t1 to t64 is used to characterize the channel changes within the time unit. For example, [w 1,1 ,…,w 1,10 ] is used to characterize the channel change at t1. For example, the [w 64,1 ,…,w 64,10 ] is used to characterize the channel changes at t64.

[0164] The network device indicates to the terminal device, through the first indication information, nine rows of basis vectors corresponding to t1 to t9, where each row of basis vectors includes 10 basis vectors. As shown in FIG11 , the nine rows of basis vectors corresponding to t1 to t9 indicated by the first indication information are the basis vectors within the dotted box in FIG11 .

[0165] The network device transmits pilot signals at time intervals t1 to t9. Correspondingly, the terminal device receives the pilot signals at time intervals t1 to t9 and measures the received pilot signals to obtain channel information. Based on the channel information measured for each time unit from t1 to t9 and the 10 basis vectors corresponding to that time unit, the terminal device determines the weighting coefficients for the 10 basis vectors corresponding to that time unit and provides feedback on the weighting coefficients for some or all of the 10 basis vectors.

[0166] For example, the terminal device measures the channel information h1 and [w 1,1 ,…,w 1,10 ], confirm [w 1,1 ,…,w 1,10The 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.

[0167] Exemplarily, the network device configures the terminal device to feed back the weighting coefficients of 8 of the 10 basis vectors. The terminal device 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. That is, 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. As shown in Figure 12, the terminal device feeds back the weighting coefficients of the 8 basis vectors indexed from 1 to 8 in each row of basis vectors from t1 to t9 in Figure 12 through the second indication message. 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].

[0168] Thus, the network device determines the CSI corresponding to t1 to t64 based on the second indication information. Specifically, for the CSI corresponding to each time unit, the network device determines the CSI corresponding to the time unit based on the basis vectors indexed from 1 to 8 corresponding to the time unit and the weighting coefficient C. Figure 13 is a schematic diagram of CSI determination, where C = [c1, ..., c8]. As shown in Figure 13, for the channel information h1 = [w 1,1 ,…,w 1,8 ]C; for the channel information corresponding to t9 h9 = [w 9,1 ,…,w 9,8 ]C; for the channel information h corresponding to t10 10 =[w 10,1 ,…,w10,8 ]C; for the channel information h corresponding to t64 64 =[w 64,1 ,…,w 64,8 In addition, the CSI corresponding to t2 to t8, and the CSI corresponding to t11 to t63, are determined in a similar manner and are not described in detail herein.

[0169] Among them, the network device determines the CSI corresponding to t1 to t9 respectively based on the measurement and feedback of the pilot signals received by the terminal device for t1 to t9. Therefore, the CSI corresponding to t1 to t9 determined by the network device can be understood as being obtained by the network device measurement. The network device determines the CSI corresponding to t10 to t64 respectively based on the index feedback of the basis vectors for t1 to t9 by the terminal device. Therefore, the CSI corresponding to t1 to t9 respectively determined by the network device can be understood as the CSI predicted by the network device. For example, Figure 14 is a schematic diagram of another CSI determination. As shown in Figure 14, the CSI corresponding to t1 to t9 respectively is the CSI fed back by the terminal device based on the CSI-RS, and the CSI corresponding to t10 to t64 respectively is the CSI predicted by the network device.

[0170] It can be seen that the network device determines the 64 rows of basis vectors corresponding to t1 to t64 during the movement of the terminal device based on the mobile state information and channel map of the terminal device, and each row of basis vectors includes 10 basis vectors. The network device sends 9 rows of basis vectors corresponding to t1 to t9 to the terminal device, and sends pilot signals from t1 to t9. Thus, the terminal device performs measurements based on the pilot signals received from t1 to t9, obtains the channel information corresponding to t1 to t9, and feeds back the channel information through the weighting coefficients of the basis vectors indexed from 0 to 8 in the 10 basis vectors. Furthermore, for each time unit from t1 to t64, the network device determines the CSI corresponding to the time unit based on the basis vectors indexed from 0 to 8 in the basis vectors corresponding to the time unit, and the weighting coefficient fed back by the terminal device.

[0171] The nine rows of basis vectors corresponding to times t1 to t9 sent by the network device to the terminal device are determined based on the terminal device's mobility status information and channel map. Thus, the basis vectors corresponding to each time unit from t1 to t9 can characterize the channel time variation of the terminal device during its mobility. The network device then determines the CSI corresponding to times t1 to t64 based on the weighting coefficients of the basis vectors indexed 0 to 8 fed back by the terminal device from t1 to t9 and the nine rows of basis vectors corresponding to times t1 to t9. This improves CSI accuracy and, in turn, transmission performance.

[0172] With respect to the technical solutions described above, the corresponding device implementation solutions are further described below.

[0173] It is understood that in order to implement the functions in the above embodiments, the network devices and terminal devices include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0174] Figures 15 and 16 are schematic diagrams of the structures of possible communication devices provided in embodiments of the present application. These communication devices can be used to implement the functions of the network device or terminal device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In the embodiments of the present application, the communication device can be the terminal device 120 as shown in Figure 1, or the base station 110a as shown in Figure 1, or a module (such as a chip) applied to the terminal device or base station.

[0175] As shown in Figure 15 , a 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 terminal device in the method embodiment shown in Figure 10 above.

[0176] When the communication device 1500 is used to implement the functions of the network device in the method embodiment shown in FIG10 :

[0177] A processing unit 1510 is configured to determine, based on mobility state information of a terminal device and a channel map, N rows of basis vectors corresponding to N time units, where each row of the N rows of basis vectors includes X basis vectors, and the channel map is configured to indicate channel characteristics based on a location area.

[0178] The transceiver unit 1520 is configured to send first indication information, where the first indication information is used to indicate the N rows of basis vectors;

[0179] The transceiver unit 1520 is further configured to send a pilot signal in each of the N time units;

[0180] The transceiver unit 1520 is further configured to receive second indication information, where the second indication information is used to indicate 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;

[0181] The processing unit 1510 is further configured to determine channel state information corresponding to M time units based on the weight coefficients of the Y basis vectors and the N rows of basis vectors, where the M time units include the N time unit;

[0182] 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.

[0183] When the communication device 1500 is used to implement the functions of the terminal device in the method embodiment shown in FIG10 :

[0184] The transceiver unit 1520 is configured to receive first indication information, where the first indication information is used to indicate N rows of basis vectors;

[0185] The transceiver unit 1520 is further configured to receive pilot signals respectively in the N time units;

[0186] The transceiver unit 1520 is further configured to send second indication information, where the second indication information is used to indicate 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.

[0187] For a more detailed description of the processing unit 1510 and the transceiver unit 1520 , please refer to the relevant description in the method embodiment shown in FIG. 10 .

[0188] As shown in Figure 16, communication device 1600 includes a processor 1610 and an interface circuit 1620. Processor 1610 and interface circuit 1620 are coupled to each other. It is understood that interface circuit 1620 can be a transceiver or an input / output interface. Optionally, communication device 1600 may also include a memory 1630 for storing instructions executed by processor 1610, or storing input data required by processor 1610 to execute instructions, or storing data generated after processor 1610 executes instructions. Sometimes, interface circuit 1620 can also be understood as part of processor 1610, in which case communication device 1600 includes processor 1610.

[0189] When the communication device 1600 is used to implement the method shown in FIG10 , the processor 1610 is used to implement the functions of the processing unit 1510 , and the interface circuit 1620 is used to implement the functions of the transceiver unit 1520 .

[0190] When the communication device is a chip used in a network device, the network device chip implements the functions of the network device in the above method embodiments. When the network device chip receives information from a terminal device, it can be understood that the information is first received by other modules in the network device (such as a radio frequency module or antenna) and then sent to the network device chip by these modules. When the network device chip sends information to a terminal device, it can be understood that the information is sent to other modules in the network device (such as a radio frequency module or antenna) and then sent to the terminal device by these modules.

[0191] When the above-mentioned communication device is a chip applied to a terminal device, the terminal device chip implements the functions of the terminal device in the above-mentioned method embodiment. When the terminal device chip receives information from the network device, it can be understood that the information is first received by other modules in the terminal device (such as a radio frequency module or antenna) and then sent to the terminal device chip by these modules. When the terminal device chip sends information to the network device, it can be understood that the information is first sent to other modules in the terminal device (such as a radio frequency module or antenna) and then sent to the network device by these modules.

[0192] The embodiment of the present application further provides a communication system, which may include a terminal device and a network device. In another possible design, the system may also include other devices / functional network elements that interact with the terminal device and the network device.

[0193] An embodiment of the present application further provides a computer-readable storage medium for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0194] An embodiment of the present application also provides a computer program product for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0195] The embodiments of the present application also provide a computer program that, when executed on a computer, implements the functions of any of the above method embodiments.

[0196] In the present application, when entity A sends information to entity B, it can be that A sends it directly to B, or that A sends it indirectly 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 that entity B indirectly receives the information sent by entity A through other entities. Entities A and B here can be network devices or terminal devices, or modules within the network devices or terminal devices. The sending and receiving of information can be information interaction between a network device and a terminal device, for example, information interaction between a base station and a terminal device; the sending and receiving of information can also be information interaction between two network devices, for example, information interaction between a CU and a DU; the sending and receiving of information can also be information interaction between different modules within a device, for example, information interaction between a terminal device chip and other modules of the terminal device, or information interaction between a network device chip and other modules in the network device.

[0197] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0198] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory (ROM), programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, mobile hard disks, 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 so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a terminal device. The processor and the storage medium can also be present in a network device or a terminal device as discrete components.

[0199] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented 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 performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0200] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0201] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of this application, the character " / " indicates that the previous and next associated objects 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.

[0202] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A method for determining channel state information, characterized in that: The method comprises: Determine, based on the mobility state information and the channel spectrum of the terminal device, N rows of basis vectors corresponding to N time units, where each row of the N rows of basis vectors includes X basis vectors, and the channel spectrum is used to indicate 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 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; Determining channel state information corresponding to M time units based on weighted 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, characterized in that The basis vectors are time-frequency space basis vectors; 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 of the combination of time domain, frequency domain and space domain.

3. The method according to claim 1, characterized in that The basis vectors are Doppler basis vectors; The Doppler basis vector is a basis vector of the space-frequency coefficient projected into the Doppler domain, and the space-frequency coefficient is determined based on the channel characteristics and the space-frequency basis vector.

4. The method according to claim 3, characterized in that The weighting coefficients of the Y basis vectors are weighting coefficients of the space-frequency basis vectors under the projection of the Doppler basis vectors.

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

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

7. The method according to claim 6, characterized in that The 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 N rows of basis vectors corresponding to N time units based on the mobility state information and the channel map of the terminal device, the method further includes: Receive movement status information of a terminal device, where the movement status information includes one or more of the following: movement speed, movement direction, and location area information.

9. A communication device, characterized in that: The communication device comprises means for performing the method according to any one of claims 1 to 8.

10. A communication device, characterized in that: The communication device comprises a processor configured to execute the method according to any one of claims 1 to 8.

11. A chip, characterized in that: The device comprises a processor, wherein the processor calls a computer program stored in a memory to enable the communication device comprising 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, and when the computer-readable storage medium is run on a computer, the method according to any one of claims 1 to 8 is executed.

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

Images