Method and apparatus for determining channel state information

Abstract

Provided are a method and apparatus for determining channel state information, which can reduce the overheads of sending uplink reference signals and improve the accuracy of determined channel state information. The method comprises: a network device sending a first reference signal to a terminal device; the network device receiving first information from the terminal device, wherein the first information is used to indicate first spatial-domain statistical information determined on the basis of the first reference signal; the network device sending second information to the terminal device, wherein the second information is used to instruct the terminal device to send by means of N1 antenna ports a second reference signal precoded using N1 first precoding vectors, wherein the N1 first precoding vectors are determined on the basis of the first spatial-domain statistical information; and the network device receiving the second reference signal from the terminal device that is precoded using the N1 first precoding vectors, and determining channel state information between the network device and N antenna ports of the terminal device on the basis of the precoded second reference signal and the N1 first precoding vectors.

Description

Method and device for determining channel state information

[0001] This application claims priority to the Chinese patent application filed with the Intellectual Property Office of the People's Republic of China on September 28, 2023, with application number 202311294488.9 and invention name "Method and Apparatus for Determining Channel State Information", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and more particularly, to a method and apparatus for determining channel state information. Background Art

[0003] 5G communication systems have higher requirements for system capacity and spectral efficiency. In 5G communication systems, the application of massive multiple input multiple output (Massive MIMO) technology plays a crucial role in improving the system's spectral efficiency. When using MIMO technology, the base station needs to precode the data before sending it to the terminal device. The precoding method relies on channel state information (CSI) fed back by the terminal device to the base station. Therefore, accurate CSI information is a key factor affecting system performance.

[0004] In a time division duplex (TDD) system, because uplink and downlink channels use the same frequency band, the CSI of the uplink and downlink channels is reciprocal. The base station can leverage this reciprocity to obtain the uplink CSI using the uplink sounding reference signal (SRS), thereby precoding the data to be transmitted to the terminal device.

[0005] Currently, when a terminal device sends an SRS to a base station, it can send one SRS to each antenna port without precoding the transmitted SRS. This method of sending uplink SRSs results in a large uplink SRS overhead and low accuracy of the determined channel state information. Alternatively, the terminal device can send a precoded SRS to the base station. The SRS precoding method is determined by the terminal device based on the CSI measurement results, and the base station is unaware of this precoding method. This method of sending uplink SRSs can reduce the uplink SRS overhead, but because the base station does not know the precoding method of the received SRS, it cannot obtain the true channel state information, resulting in low accuracy of the determined channel state information.

[0006] Summary of the Invention

[0007] The present application provides a method and apparatus for determining channel state information, which can reduce the overhead of sending uplink reference signals while improving the accuracy of the determined channel state information.

[0008] In a first aspect, a method for determining channel state information is provided, which can be performed by a network device or a chip or chip system in the network device. The method includes: the network device sends a first reference signal to a terminal device; the network device receives first information from the terminal device, the first information indicating first spatial statistical information, the first spatial statistical information being determined based on the first reference signal; the network device sends second information to the terminal device, the second information instructing the terminal device to send a second reference signal precoded using N1 first precoding vectors through N1 antenna ports, the N1 antenna ports corresponding one-to-one to the N1 first precoding vectors, the N1 first precoding vectors being determined based on the first spatial statistical information, N1 being less than or equal to N, wherein the terminal device includes N antenna ports; the network device receives the second reference signal precoded using the N1 first precoding vectors from the terminal device; the network device determines first channel state information based on the precoded second reference signal and the N1 first precoding vectors, the first channel state information including channel state information between the network device and the N antenna ports of the terminal device.

[0009] Based on the above technical solution, the terminal device determines the first spatial domain statistical information on the terminal device side based on the first reference signal from the network device, and sends the first spatial domain statistical information to the network device; the network device instructs the terminal device to send the second reference signal precoded using N1 first precoding vectors through N1 antenna ports, and the N1 first precoding vectors are determined based on the first spatial domain statistical information; the network device determines the channel state information (first channel state information) between the network device and the N antenna ports of the terminal device based on the second reference signal precoded using N1 first precoding vectors and the N1 first precoding vectors from the terminal device. Since the second reference signal sent by the terminal device to the network device is precoded, the overhead occupied by the second reference signal (uplink reference signal) can be saved; in addition, since the N1 first precoding vectors are known to the network device, the network device can determine the true channel state information between the network device and the terminal device based on the second reference signal precoded using N1 first precoding vectors and the N1 first precoding vectors, thereby improving the accuracy of the determined channel state information.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the network device determines the first channel state information based on the precoded second reference signal and the N1 first precoding vectors, including: the network device determines the second channel state information based on the precoded second reference signal, the second channel state information including the channel state information between the network device and the N1 antenna ports of the terminal device; the network device determines the first channel state information based on the second channel state information and the N1 first precoding vectors.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0012] In combination with the first aspect, in some implementations of the first aspect, the N1 first precoding vectors are respectively the N2 column vectors of the first matrix, N1=N2; or the N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。

[0013] In combination with the first aspect, in some implementations of the first aspect, a transmission period of the first reference signal is greater than a transmission period of the second reference signal.

[0014] Based on this optional implementation, the first reference signal is used to obtain the first spatial domain statistical information. Since the time variation of the first spatial domain statistical information is slow, sending the first reference signal using a longer period can reduce the pilot overhead.

[0015] In a second aspect, a method for determining channel state information is provided, which can be performed by a terminal device or a chip or chip system in the terminal device. The method includes: the terminal device receives a first reference signal from a network device; the terminal device sends first information to the network device, the first information is used to indicate first spatial statistical information, and the first spatial statistical information is determined based on the first reference signal; the terminal device receives second information from the network device, the second information is used to instruct the terminal device to send a second reference signal precoded using N1 first precoding vectors through N1 antenna ports, the N1 antenna ports and the N1 first precoding vectors are in one-to-one correspondence, the N1 first precoding vectors are determined based on the first spatial statistical information, and N1 is less than or equal to N, wherein the terminal device includes N antenna ports; the terminal device sends the second reference signal precoded using the N1 first precoding vector to the network device through the N1 antenna port.

[0016] The method provided in the second aspect is a terminal device side method corresponding to the first aspect, and its beneficial effects can refer to the first aspect.

[0017] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: the terminal device determines third channel state information based on the first reference signal, the third channel state information including channel state information between the network device and the N antenna ports of the terminal device; the terminal device determines the first spatial domain statistical information based on the third channel state information.

[0018] In combination with the second aspect, in certain implementations of the second aspect, the first spatial statistical information includes a first matrix, which is composed of spatial eigenvectors determined by the terminal device based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0019] In combination with the second aspect, in some implementations of the second aspect, the N1 first precoding vectors are respectively the N2 column vectors of the first matrix, N1=N2; or the N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。

[0020] In combination with the second aspect, in certain implementations of the second aspect, a transmission period of the first reference signal is greater than a transmission period of the second reference signal.

[0021] According to a third aspect, a method for determining channel state information is provided, which can be executed by a network device or a chip or chip system in the network device. The method includes: the network device obtains first spatial domain statistical information of a terminal device, second spatial domain statistical information of the network device and first channel state information, the first channel state information including historical channel state information between the network device and the N antenna ports of the terminal device; the network device sends third information to the terminal device, the third information is used to instruct the terminal device to send a third reference signal precoded with N3 second precoding vectors through N3 antenna ports, the N3 antenna ports and the N3 second precoding vectors are one-to-one corresponding, and the N3 second precoding vectors are based on the first spatial domain statistical information, the second spatial domain statistical information and the signal The position information of the zero elements in the channel weighting coefficient matrix is ​​determined according to the first spatial domain statistical information, the second spatial domain statistical information and the first channel state information, wherein N3 is less than N; the network device receives a third reference signal precoded by the N3 second precoding vectors from the terminal device; the network device determines fourth channel state information according to the precoded third reference signal, the N3 second precoding vectors and the channel weighting coefficient matrix, wherein the fourth channel state information includes the current channel state information between the network device and the N antenna ports of the terminal device.

[0022] Based on the above technical solution, the network device can instruct the terminal device to send a third reference signal precoded with N3 second precoding vectors through N3 antenna ports based on the historical first channel state information between the network device and the N antenna ports of the terminal device, the first spatial domain statistical information of the terminal device, and the second spatial domain statistical information of the network device; and according to the third reference signal precoded with N3 second precoding vectors from the terminal device, the N3 second precoding vectors and the channel weighting coefficient matrix, the channel state information (fourth channel state information) between the current network device and the N antenna ports of the terminal device can be determined. Since the third reference signal sent by the terminal device to the network device is precoded, the overhead occupied by the third reference signal (uplink reference signal) can be saved; in addition, since the N3 second precoding vectors are known to the network device, the network device can determine the true channel state information between the current network device and the terminal device based on the third reference signal precoded with N3 second precoding vectors, the N3 second precoding vectors and the channel weighting coefficient matrix, thereby improving the accuracy of the determined channel state information.

[0023] In combination with the third aspect, in certain implementations of the third aspect, the network device determines the fourth channel state information based on the precoded third reference signal, the N3 second precoding vectors and the channel weighting coefficient matrix, including: the network device determines the third spatial domain statistical information of the network device based on the precoded third reference signal; the network device determines the fourth channel state information based on the N3 second precoding vectors, the channel weighting coefficient matrix and the third spatial domain statistical information.

[0024] In combination with the third aspect, in certain implementations of the third aspect, the network device obtains first spatial domain statistical information of the terminal device, second spatial domain statistical information of the network device, and first channel state information, including: the network device sends a first reference signal to the terminal device; the network device receives first information from the terminal device, the first information is used to indicate the first spatial domain statistical information, and the first spatial domain statistical information is determined based on the first reference signal; the network device sends second information to the terminal device, the second information is used to instruct the terminal device to send a second reference signal precoded using N1 first precoding vectors through N1 antenna ports, the N1 antenna ports and the N1 first precoding vectors are one-to-one corresponding, the N1 first precoding vectors are determined based on the first spatial domain statistical information, and N1 is less than N; the network device receives a second reference signal precoded using the N1 first precoding vectors from the terminal device; the network device determines the second spatial domain statistical information based on the precoded second reference signal; the network device determines the first channel state information based on the precoded second reference signal and the N1 first precoding vectors.

[0025] In combination with the third aspect, in certain implementations of the third aspect, the network device determines the first channel state information based on the precoded second reference signal and the N1 first precoding vectors, including: the network device determines the second channel state information based on the precoded second reference signal, the second channel state information including the channel state information between the network device and the N1 antenna ports of the terminal device; the network device determines the first channel state information based on the second channel state information and the N1 first precoding vectors.

[0026] In combination with the third aspect, in certain implementations of the third aspect, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0027] In combination with the third aspect, in some implementation manners of the third aspect, the N3 second precoding vectors are respectively weighted sums of N2 column vectors of the first matrix, where N3 < N2.

[0028] Compared with an implementation manner of instructing the terminal device to send a second reference signal precoded by using N1 first precoding vectors through N1 antenna ports, where N1 = N2, in this optional implementation manner, N3 < N2, which can further reduce the number of antenna ports used by the terminal device when sending an uplink reference signal (third reference signal). Therefore, the overhead of sending the uplink reference signal (third reference signal) can be further saved.

[0029] In combination with the third aspect, in some implementation manners of the third aspect, the transmission period of the first reference signal is greater than the transmission period of the second reference signal; the transmission period of the first reference signal is greater than the transmission period of the third reference signal.

[0030] Based on this optional implementation manner, the first reference signal is used to obtain first spatial domain statistical information. Since the time variation of the first spatial domain statistical information is relatively slow, using a longer period to send the first reference signal can reduce the pilot overhead.

[0031] In a fourth aspect, a method for determining channel state information is provided. This method can be executed by a terminal device or a chip or chip system in the terminal device. The method includes: the terminal device receives third information from a network device, where the third information is used to instruct the terminal device to send a third reference signal precoded by using N3 second precoding vectors through N3 antenna ports, the N3 antenna ports and the N3 second precoding vectors are in one-to-one correspondence, the N3 second precoding vectors are determined according to the first spatial domain statistical information of the terminal device, the second spatial domain statistical information of the network device, and the position information of zero elements in a channel weighting coefficient matrix, the position information of zero elements in the channel weighting coefficient matrix is determined according to the first spatial domain statistical information, the second spatial domain statistical information, and first channel state information, the first channel state information includes historical channel state information between N antenna ports of the network device and the terminal device, where N3 is less than N; the terminal device sends the third reference signal precoded by using the N3 second precoding vectors to the network device through the N3 antenna ports.

[0032] The method provided in the fourth aspect is a method on the terminal device side corresponding to the third aspect, and its beneficial effects can be referred to the third aspect.

[0033] In combination with the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the terminal device receives a first reference signal from the network device; the terminal device sends first information to the network device, the first information being used to indicate the first spatial domain statistical information, and the first spatial domain statistical information being determined based on the first reference signal; the terminal device receives second information from the network device, the second information being used to indicate that the terminal device sends a second reference signal precoded using N1 first precoding vectors through N1 antenna ports, the N1 antenna ports and the N1 first precoding vectors being one-to-one corresponding, the N1 first precoding vectors being determined based on the first spatial domain statistical information, and N1 being less than or equal to N; the terminal device sends the second reference signal precoded using the N1 first precoding vector to the network device through the N1 antenna port.

[0034] In combination with the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the terminal device determines third channel state information based on the first reference signal, the third channel state information including channel state information between the network device and the N antenna ports of the terminal device; the terminal device determines the first spatial domain statistical information based on the third channel state information.

[0035] In combination with the fourth aspect, in certain implementations of the fourth aspect, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined by the terminal device based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0036] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the N3 second precoding vectors are weighted sums of the N2 column vectors of the first matrix, and the N3 <N2。

[0037] In combination with the fourth aspect, in certain implementations of the fourth aspect, the transmission period of the first reference signal is greater than the transmission period of the second reference signal; and the transmission period of the first reference signal is greater than the transmission period of the third reference signal.

[0038] In the fifth aspect, a communication device is provided, which can be applied to the network equipment described in the first aspect, and the device includes: a transceiver unit for implementing the receiving and sending functions of the method described in the first aspect; a processing unit for implementing the processing functions of the method described in the first aspect, such as determining the first channel state information and determining the second channel state information.

[0039] In the sixth aspect, a communication device is provided, which can be applied to the terminal equipment described in the second aspect, and the device includes: a transceiver unit for implementing the receiving and sending functions of the method described in the second aspect; a processing unit for implementing the processing functions of the method described in the second aspect, such as determining the third channel state information and determining the first spatial domain statistical information.

[0040] In the seventh aspect, a communication device is provided, which can be applied to the network equipment described in the third aspect. The device includes: a transceiver unit for implementing the receiving and sending functions of the method described in the third aspect; and a processing unit for implementing the processing functions such as determining the fourth channel state information of the method described in the third aspect.

[0041] In the eighth aspect, a communication device is provided, which can be applied to the terminal equipment described in the fourth aspect, and the device includes: a transceiver unit for implementing the receiving and sending functions of the method described in the fourth aspect; a processing unit for implementing the processing functions of the method described in the fourth aspect, such as determining the third channel state information and determining the first spatial domain statistical information.

[0042] In the ninth aspect, a communication device is provided, comprising: a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices and transmit them to the processor or send signals from the processor to other communication devices, and the processor implements the method in any possible implementation of the first to fourth aspects or the first to fourth aspects through a logic circuit or by executing code instructions.

[0043] In the tenth aspect, a communication system is provided, comprising: the network device in the method described in the first aspect and other communication devices that communicate with the network device; the terminal device in the method described in the second aspect and other communication devices that communicate with the terminal device.

[0044] In the eleventh aspect, a communication system is provided, comprising: the network device in the method described in the third aspect and other communication devices that communicate with the network device; the terminal device in the method described in the fourth aspect and other communication devices that communicate with the terminal device.

[0045] In the twelfth aspect, a computer-readable storage medium is provided, which stores a computer program; when the computer program is run on a computer, the method in the above-mentioned first to fourth aspects and any possible implementation of the first to fourth aspects is executed.

[0046] In a thirteenth aspect, a computer program product is provided, comprising a computer program, which, when executed, enables the communication method in the above-mentioned first to fourth aspects and any possible implementation method of the first to fourth aspects to be implemented.

[0047] The solutions provided in the above-mentioned fifth to thirteenth aspects are used to implement or cooperate with the methods provided in the above-mentioned first to fourth aspects, and therefore can achieve the same or corresponding beneficial effects as the first to fourth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG1 is a schematic diagram of the architecture of a communication system to which an embodiment of the present application is applicable.

[0049] FIG2 is a schematic diagram of the structure of a network element involved in an embodiment of the present application.

[0050] FIG3 is a schematic diagram of a basic process for a base station to obtain CSI in a TDD system.

[0051] FIG4 is a schematic flow chart of an interaction method for determining channel state information according to an embodiment of the present application.

[0052] FIG5 is a schematic flow chart of another method for determining channel state information according to an embodiment of the present application.

[0053] FIG6 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0054] FIG7 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0055] FIG8 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0056] FIG9 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0057] FIG10 is a schematic block diagram of another communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0058] The technical solution in this application will be described below with reference to the accompanying drawings.

[0059] The embodiments of the present application can be applied to various communication systems, such as wireless local area network (WLAN), narrowband Internet of Things (NB-IoT), global system for mobile communications (GSM), enhanced data rate for GSM evolution (EDGE), wideband code division multiple access (WCDMA), code division multiple access 2000 (CDMA2000), time division-synchronization code division multiple access (TD-SCDMA), LTE, satellite communication, 5G communication system, sixth-generation (6G) communication system or new communication systems that will appear in the future.

[0060] The terminal device involved in the embodiments of the present application is a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on water, such as on ships; can also be deployed in the air, such as on airplanes, balloons, and satellites. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical care, a wireless terminal device in smart grids, a wireless terminal in transportation safety, a wireless terminal device in smart cities, a wireless terminal in smart homes, and can also include user equipment (UE), etc.

[0061] The network devices involved in the embodiments of the present application are devices in a wireless network, such as radio access network (RAN) nodes that connect terminal devices to the wireless network. At present, some examples of RAN nodes are: gNB, transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home Node B (HNB), base band unit (BBU), or wireless fidelity (Wifi) access point (AP), integrated access and backhaul (IAB), etc. In a network structure, the network device can also refer to a centralized unit (CU) or a distributed unit (DU), or the network device can also be composed of a CU and a DU. CU and DU can be understood as the division of the base station from the perspective of logical function. Among them, CU and DU can be physically separated or deployed together, and this embodiment of the present application does not specifically limit this. A CU can be connected to a DU, or multiple DUs can share a CU, which can save costs and facilitate network expansion. The division of CU and DU can be based on the protocol stack. One possible way is to deploy the radio resource control (RRC), service data adaptation protocol stack (SDAP) and packet data convergence protocol (PDCP) layer in the CU, and the remaining radio link control (RLC) layer, media access control (MAC) layer and physical layer in the DU. The above-mentioned protocol stack division method is not fully limited in the embodiment of the present application, and there may be other division methods.

[0062] Figure 1 shows the CU-DU architecture. The CU and DU are connected via the F1 interface. The CU, representing the gNB, is connected to the core network via the Ng interface.

[0063] The network device in the embodiments of the present application may also refer to a centralized unit control plane (CU-CP) node or a centralized unit user plane (CU-UP) node, or the network device may also be a CU-CP and a CU-UP. The CU-CP is responsible for control plane functions, mainly including radio resource control (RRC) and packet data convergence protocol (PDCP)-C. PDCP-C is mainly responsible for encryption and decryption of control plane data, integrity protection, and determination of channel state information. The CU-UP is responsible for user plane functions, mainly including service data adaptation protocol (SDAP) and PDCP-U. SDAP is mainly responsible for processing core network data and mapping flows to bearers. PDCP-U is mainly responsible for encryption and decryption, integrity protection, header compression, sequence number maintenance, and determination of channel state information on the data plane. The CU-CP and CU-UP are connected via the E1 interface. The CU-CP represents the gNB and is connected to the core network via the Ng interface. It is connected to the DU via F1-C (control plane). The CU-UP is connected to the DU via F1-U (user plane). Of course, another possible implementation is that PDCP-C is also in CU-UP.

[0064] The network device mentioned in the embodiments of the present application may be a device including a CU, or a DU, or a device including a CU and a DU, or a device including a control plane CU node (CU-CP node) and a user plane CU node (CU-UP node) and a DU node.

[0065] The network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water; and can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the network equipment and terminal equipment.

[0066] Network devices and terminal devices, as well as terminal devices and terminal devices, can communicate through licensed spectrum (licensed spectrum), can communicate through unlicensed spectrum (unlicensed spectrum), or can communicate through both licensed spectrum and unlicensed spectrum at the same time. Network devices and terminal devices, as well as terminal devices and terminal devices, can communicate through spectrum below 6 gigahertz (GHz), can communicate through spectrum above 6G, or can communicate using spectrum below 6G and spectrum above 6G at the same time. The embodiments of the present application do not limit the spectrum resources used between network devices and terminal devices.

[0067] Figure 1 is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application. The architecture includes a base station and multiple terminal devices, and the multiple terminal devices include terminal device 1, terminal device 2, terminal device 3, terminal device 4, terminal device 5, and terminal device 6. The base station can transmit data or control information to terminal device 1 to terminal device 6, and terminal device 1 to terminal device 6 can also transmit data or control information to the base station. In addition, terminal device 4, terminal device 5, and terminal device 6 can form a communication system, in which the base station can transmit data or control information to terminal device 5; terminal device 5 can also send the data or control information to terminal device 4 and terminal device 6; and terminal device 5 can perform sidelink (SL) communication with terminal device 4 and terminal device 6.

[0068] The network device in the embodiment of the present application includes: an entity for transmitting or receiving signals on the network side, such as a base station. The terminal device in the embodiment of the present application includes: an entity for receiving or transmitting signals on the user side, such as a terminal device. Figure 2 is a structural diagram of the network element involved in the embodiment of the present application. The base station and the terminal device both include a radio resource control (RRC) signaling interaction module, a media access control (MAC) signaling interaction module, and a physical layer (PHY) signaling and data interaction module. The RRC signaling interaction module is a module used by the base station and the terminal device to send and receive RRC signaling; the MAC signaling interaction module is a module used by the base station and the terminal device to send and receive MAC control element (CE) signaling; the PHY signaling and data interaction module is a module used by the base station and the terminal device to send uplink / downlink control signaling, receive uplink / downlink control signaling, and send and receive uplink / downlink data. Specifically, the base station can send downlink control signaling to the terminal device through the physical downlink control channel (PDCCH), the terminal device can send uplink control signaling to the base station through the physical uplink control channel (PUCCH), the base station can send downlink data to the terminal device through the physical downlink shared channel (PDSCH), and the terminal device can send uplink data to the terminal device through the physical uplink shared channel (PUSCH).

[0069] It can be understood that in the embodiments of the present application, PDCCH is only an example of a downlink control channel, PUCCH is only an example of an uplink control channel, PDSCH is only an example of a downlink data channel, and PUSCH is only an example of an uplink data channel. In different systems and different scenarios, data channels and control channels may have different names, and the embodiments of the present application do not limit this.

[0070] To facilitate understanding of the embodiments of the present application, the following briefly introduces the technical solutions related to the embodiments of the present application.

[0071] 5G communication systems have higher requirements for system capacity and spectral efficiency. The application of Massive MIMO technology plays a crucial role in improving spectral efficiency in 5G communication systems. When using MIMO technology, base stations must precode data before transmitting it to terminal devices. The precoding method relies on the CSI (Channel Information Score) that terminal devices provide to the base station. Therefore, accurate CSI information is a crucial factor affecting system performance.

[0072] In a TDD system, because the uplink and downlink channels use the same frequency band, the CSI of the uplink and downlink channels is reciprocal. The base station can leverage this reciprocity to obtain the uplink CSI using the uplink SRS, thereby precoding the data to be transmitted to the terminal device. Figure 3 illustrates the basic process for a base station to obtain CSI in a TDD system. The specific steps include: 310, the base station needs to send signaling to the terminal device, indicating the configuration information corresponding to CSI estimation; 320, the terminal device, based on this configuration information, sends an SRS to the base station for estimating the uplink CSI; 330, the base station measures the SRS transmitted by the terminal device and estimates the uplink CSI based on the measured SRS; 340, the base station precodes the data based on the estimated CSI and transmits the precoded data. Specifically, the base station determines the precoding method for the data to be transmitted to the terminal device based on the estimated CSI.

[0073] Currently, when a terminal device sends an SRS to a base station, it can send one SRS to each antenna port without precoding the sent SRS. This method of sending uplink SRS results in a large overhead occupied by the uplink SRS. In addition, when the overhead is limited, the period at which the terminal device sends SRS to the base station is relatively long. Since the channel state is constantly changing, the accuracy of the determined channel state information is low.

[0074] The terminal device can also send precoded SRS to the base station. The precoding method of SRS is determined by the terminal device based on the measurement result of CSI, and the base station is unaware of the precoding method. This method of sending uplink SRS can reduce the overhead occupied by uplink SRS. However, since the base station does not know the precoding method of the received SRS, it is unable to obtain the true channel state information and can only obtain equivalent channel state information. There is a loss of transmission performance in multi-user transmission scenarios.

[0075] To this end, embodiments of the present application provide a method for determining channel state information that can reduce the overhead of transmitting uplink reference signals while improving the accuracy of the determined channel state information. Figure 4 is a schematic flow diagram of a method 400 for determining channel state information according to an embodiment of the present application. In embodiments of the present application, the network device may be a base station or an access network device.

[0076] At 410, a network device sends a first reference signal to a terminal device; correspondingly, the terminal device receives the first reference signal from the network device. The terminal device includes N antenna ports. Optionally, the first reference signal may be a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), or a tracking reference signal (TRS).

[0077] 420. The terminal device sends first information to the network device, where the first information is used to indicate first spatial statistical information, where the first spatial statistical information is determined by the terminal device based on a first reference signal. Correspondingly, the network device receives the first information from the terminal device.

[0078] Optionally, the first spatial statistical information includes a first matrix U, where the first matrix U is composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2. Exemplarily, the first spatial statistical information is a statistic that characterizes channel variation characteristics on N antenna ports of the terminal device; the spatial eigenvector is a vector that characterizes channel variation characteristics on multiple antenna ports of the terminal device.

[0079] Optionally, before the terminal device sends the first information to the network device, the terminal device determines third channel state information based on the received first reference signal, where the third channel state information includes channel state information between the network device and the N antenna ports of the terminal device; and determines the first spatial domain statistical information based on the third channel state information.

[0080] Exemplarily, the network device sends the first reference signal to the terminal device multiple times, and correspondingly, the terminal device receives / measures the first reference signal from the network device multiple times. The third channel state information determined by the terminal device based on the first reference signal obtained by the t-th measurement is H 1,t , the terminal device obtains T third channel state information through T measurements, and the spatial statistical covariance matrix of the terminal device side composed of T third channel state information is Terminal device pair Perform singular value decomposition (SVD) to obtain the first spatial domain statistical information (first matrix U) on the terminal device side. U is a matrix of size N×N2, N2 is a matrix The number of non-zero eigenvalues ​​of S is the matrix The non-zero eigenvalues ​​of are the diagonal matrix formed by the diagonal elements, 1≤t≤T, T is a positive integer.

[0081] It should be noted that the third channel state information is determined by the terminal device according to the first reference signal from the network device. The first reference signal may be precoded or not precoded.

[0082] 430. The network device sends second information to the terminal device. The second information is used to instruct the terminal device to send a second reference signal precoded using N1 first precoding vectors through N1 antenna ports. The N1 antenna ports and the N1 first precoding vectors are in a one-to-one correspondence. The N1 first precoding vectors are determined by the network device based on the first spatial statistical information (first matrix U), and N1 is less than or equal to N. Correspondingly, the terminal device receives the second information from the network device.

[0083] Optionally, the N1 first precoding vectors are respectively N2 column vectors of the first matrix U, where N1=N2. For example, are the N2 column vectors of the first matrix U, then the N1 first precoding vectors are The matrix composed of N1 first precoding vectors is U H .

[0084] Optionally, the N1 first precoding vectors are weighted sums of the N2 column vectors of the first matrix U, and N1 <N2。

[0085] 440. The terminal device transmits a second reference signal precoded using N1 first precoding vectors to the network device via N1 antenna ports. For example, the terminal device transmits a second reference signal precoded using the first first precoding vector to the network device via antenna port 1; the terminal device transmits a second reference signal precoded using the second first precoding vector to the network device via antenna port 2; and the terminal device transmits a second reference signal precoded using the N1th first precoding vector to the network device via antenna port N1. Correspondingly, the network device receives the second reference signal precoded using the N1 first precoding vectors from the terminal device. Optionally, the second reference signal may be an SRS, a DMRS, or the like.

[0086] 450. The network device determines first channel state information based on the precoded second reference signal and N1 first precoding vectors. The first channel state information includes channel state information between the network device and N antenna ports of the terminal device.

[0087] Optionally, the network device determines second channel state information based on the precoded second reference signal, where the second channel state information includes channel state information between N1 antenna ports of the network device and the terminal device; and determines first channel state information based on the second channel state information and N1 first precoding vectors.

[0088] The first channel state information may be understood as the real channel state information between the network device and the terminal device; the second channel state information may be understood as the equivalent channel state information between the network device and the terminal device.

[0089] Exemplarily, when N1 first precoding vectors are respectively N2 column vectors of the first matrix U and N1=N2, the matrix U consisting of the first channel state information H and the second channel state information H2 and the N1 first precoding vectors is H The relationship between can be expressed by the following formula (1):

[0090] H2=U H H (1)

[0091] The network device can determine the first channel state information H=UH2 according to formula (1).

[0092] It should be noted that the first channel state information is determined by the network device based on the received second reference signal and N1 first precoding vectors precoded using N1 first precoding vectors, and the precoding matrix of the second reference signal is known to the network device; the network device obtains the first channel state information for transmitting downlink data to the terminal device.

[0093] Optionally, the transmission period of the first reference signal is greater than the transmission period of the second reference signal. For example, the transmission period of the first reference signal is T1, and the transmission period of the second reference signal is T2, where T1 is greater than T2. ​​The first reference signal is used to obtain the first spatial domain statistical information. Because the time variation of the first spatial domain statistical information is slow, using a longer period to transmit the first reference signal can reduce pilot overhead.

[0094] In the technical solution provided in the embodiment of the present application, the terminal device determines the first spatial domain statistical information on the terminal device side based on the first reference signal from the network device, and sends the first spatial domain statistical information to the network device; the network device instructs the terminal device to send the second reference signal precoded using N1 first precoding vectors through N1 antenna ports, and the N1 first precoding vectors are determined based on the first spatial domain statistical information; the network device determines the channel state information (first channel state information) between the network device and the N antenna ports of the terminal device based on the second reference signal precoded using N1 first precoding vectors and the N1 first precoding vectors from the terminal device. Since the second reference signal sent by the terminal device to the network device is precoded, the overhead occupied by the second reference signal (uplink reference signal) can be saved; in addition, since the N1 first precoding vectors are known to the network device, the network device can determine the true channel state information between the network device and the terminal device based on the second reference signal precoded using N1 first precoding vectors and the N1 first precoding vectors, thereby improving the accuracy of the determined channel state information.

[0095] This embodiment of the present application proposes another method for determining channel state information, which can reduce the overhead of sending uplink reference signals while improving the accuracy of the determined channel state information. Figure 5 is a schematic flow diagram of another method 500 for determining channel state information according to an embodiment of the present application. In this embodiment of the present application, the network device can be a base station or an access network device.

[0096] At step 510, the network device obtains first spatial domain statistical information of a terminal device, second spatial domain statistical information of the network device, and first channel state information, where the first channel state information includes historical channel state information between the network device and N antenna ports of the terminal device. The terminal device includes N antenna ports, and the network device includes M antenna ports.

[0097] Optionally, the network device obtains the first spatial domain statistical information and the first channel state information of the terminal device through the method for determining the channel state information provided in Figure 4. For details, please refer directly to the description of Figure 4 and will not be repeated here; and the network device determines the second spatial domain statistical information of the network device based on the second reference signal precoded by the N1 first precoding vectors received in the method embodiment of Figure 4.

[0098] Optionally, the second spatial domain statistical information includes a second matrix, the second matrix is ​​composed of spatial domain eigenvectors determined according to the precoded second reference signal, and the number of columns of the second matrix is ​​M1.

[0099] Exemplarily, the terminal device may send the precoded second reference signal to the network device multiple times, and correspondingly, the network device may receive / measure the precoded second reference signal from the terminal device multiple times. The second channel state information determined by the network device based on the precoded second reference signal obtained in the t-th measurement is H 2,t , the network device obtains T second channel state information through T measurements, and the spatial statistical covariance matrix of the network device side composed of T second channel state information is Network device pair Perform singular value decomposition to obtain the second spatial domain statistical information (second matrix V) on the network device side. V is an M×M1 matrix, M1 is a matrix The number of non-zero eigenvalues ​​of is the M1 column vector of V; S' is the matrix The non-zero eigenvalues ​​of are the diagonal matrix formed by the diagonal elements, 1≤t≤T, T is a positive integer.

[0100] Optionally, the network device may also obtain historical spatial statistical information of the terminal device (first spatial statistical information), historical spatial statistical information of the network device (second spatial statistical information), and historical channel state information (first channel state information) between the network device and the N antenna ports of the terminal device through other means. This application is not limited to this.

[0101] At 520, the network device sends the third information to the terminal device. The third information is used to instruct the terminal device to send the third reference signal precoded by N3 second precoding vectors via N3 antenna ports. The N3 antenna ports and the N3 second precoding vectors are in one-to-one correspondence. The N3 second precoding vectors are determined according to the first spatial domain statistical information, the second spatial domain statistical information, and the position information of the zero elements in the channel weighting coefficient matrix. The position information of the zero elements in the channel weighting coefficient matrix is determined according to the first spatial domain statistical information, the second spatial domain statistical information, and the first channel state information. Here, N3 is less than N. Correspondingly, the terminal device receives the third information from the network device.

[0102] Exemplarily, the network device determines the position information of the zero elements in the channel weighting coefficient matrix C according to the obtained first spatial domain statistical information (the first matrix U), the second spatial domain statistical information (the second matrix V), and the first channel state information H, where C = U H HV H ; the element in the i-th row and j-th column of the channel weighting coefficient matrix C is c i,j , the network device determines the set Φ0 of the binary tuples corresponding to the zero elements in the channel weighting coefficient matrix C, so that for any (i, j) ∈ Φ0, c i,j = 0. The network device determines N3 second precoding vectors according to the first spatial domain statistical information, the second spatial domain statistical information, and the position information of the zero elements in the channel weighting coefficient matrix.

[0103] Optionally, the N3 second precoding vectors are respectively the weighted sums of N2 column vectors of the first matrix U, and N3 < N2. Compared with the scheme of instructing the terminal device to send the second reference signal precoded by N1 first precoding vectors via N1 antenna ports, and N1 = N2, in this optional scheme, N3 < N1, which can further reduce the number of antenna ports used by the terminal device when sending the uplink reference signal (the third reference signal). Therefore, the overhead of sending the uplink reference signal (the third reference signal) can be further saved.

[0104] For example, the network device makes the following system of equations have a unique solution according to the first matrix U, the second matrix V, and the position information of the zero elements in the channel weighting coefficient matrix:

[0105] The obtained N3 second precoding vectors are The matrix composed of the N3 second precoding vectors is Optionally, the network device can exhaustively search for the N3 second precoding vectors until there is a unique solution for c in the above system of equations. If no combination that makes the above system of equations have a unique solution can be found, the value of N3 can be increased and the attempt to make the above system of equations have a unique solution can be continued.

[0106] 530. The terminal device sends a third reference signal precoded using N3 second precoding vectors to the network device through N3 antenna ports. For example, the terminal device sends a third reference signal precoded using the first second precoding vector to the network device through antenna port 1; the terminal device sends a third reference signal precoded using the second second precoding vector to the network device through antenna port 2; and the terminal device sends a third reference signal precoded using the N3th second precoding vector to the network device through antenna port N3. Correspondingly, the network device receives the third reference signal precoded using the N3 second precoding vectors from the terminal device. Optionally, the third reference signal is an SRS. Correspondingly, the network device receives a third reference signal precoded using the N3 second precoding vectors from the terminal device. Optionally, the third reference signal may be an SRS, a DMRS, or the like.

[0107] At 540, the network device determines fourth channel state information based on the received precoded third reference signal, the N3 second precoding vectors, and the channel weighting coefficient matrix C. The fourth channel state information includes channel state information between the current network device and the N antenna ports of the terminal device. The fourth channel state information can be understood as the most recently determined channel state information between the network device and the N antenna ports of the terminal device.

[0108] Optionally, the network device determines third spatial statistical information of the network device based on the precoded third reference signal; and determines fourth channel state information based on the N3 second precoding vectors, the channel weighting coefficient matrix, and the third spatial statistical information. Optionally, the third spatial statistical information includes a third matrix V1, which is composed of spatial eigenvectors determined based on the precoded third reference signal, and the number of columns of the third matrix is ​​M2.

[0109] Exemplarily, the terminal device may send a precoded third reference signal to the network device multiple times; correspondingly, the network device may receive / measure the precoded third reference signal from the terminal device multiple times, and the network device may determine fifth channel state information based on the precoded third reference signal. The fifth channel state information includes channel state information between the network device and the N3 antenna ports of the terminal device, wherein the fifth channel state information may be understood as equivalent channel state information between the network device and the terminal device. The fifth channel state information determined by the network device based on the precoded third reference signal obtained in the tth measurement is H 3,t , the network device obtains T fifth channel state information through T measurements, and the spatial statistical covariance matrix of the network device side composed of T fifth channel state information is Network device pair Perform singular value decomposition to obtain the third spatial domain statistical information (third matrix V1) on the network device side. V1 is a matrix of M×M2, M2 is a matrix The number of non-zero eigenvalues ​​of M is the number of antenna ports of the network device; S" is the matrix The non-zero eigenvalues ​​of are diagonal matrices formed by diagonal elements, 1≤t≤T, and T is a positive integer. Finally, the network device determines the fourth channel state information H' according to the N3 second precoding vectors, the channel weight coefficient matrix C, and the third spatial domain statistical information (third matrix V1) using the following formula (2):

[0110] H'=U1CV1 (2)

[0111] Optionally, the transmission period of the first reference signal is greater than the transmission period of the second reference signal; the transmission period of the first reference signal is greater than the transmission period of the third reference signal. For example, the transmission period of the first reference signal is T1, the transmission period of the second reference signal is T2, and the transmission period of the third reference signal is T3, where T1 is greater than T2, and T1 is greater than T3. The first reference signal is used to obtain first spatial domain statistical information. Because the time variation of the first spatial domain statistical information is slow, using a longer period to transmit the first reference signal can reduce pilot overhead.

[0112] In the technical solution provided in the embodiment of the present application, the network device can instruct the terminal device to send a third reference signal precoded with N3 second precoding vectors through N3 antenna ports based on the historical first channel state information between the network device and the N antenna ports of the terminal device, the first spatial statistical information of the terminal device, and the second spatial statistical information of the network device; and according to the third reference signal precoded with N3 second precoding vectors from the terminal device, the N3 second precoding vectors and the channel weighting coefficient matrix, the channel state information (fourth channel state information) between the current network device and the N antenna ports of the terminal device can be determined. Since the third reference signal sent by the terminal device to the network device is precoded, the overhead occupied by the third reference signal (uplink reference signal) can be saved; in addition, since the N3 second precoding vectors are known to the network device, the network device can determine the true channel state information between the current network device and the terminal device based on the third reference signal precoded with N3 second precoding vectors, the N3 second precoding vectors and the channel weighting coefficient matrix, thereby improving the accuracy of the determined channel state information.

[0113] The above describes the method for determining channel state information provided in an embodiment of the present application. The following describes an execution entity for executing the above method for determining channel state information.

[0114] FIG6 is a schematic block diagram of a communication device 600 according to an embodiment of the present application. The device can be applied to or deployed in the network device in the method embodiment of FIG4. The communication device 600 includes:

[0115] The transceiver unit 610 is configured to send a first reference signal to a terminal device;

[0116] The transceiver unit 610 is further configured to receive first information from the terminal device, where the first information is used to indicate first spatial domain statistical information, where the first spatial domain statistical information is determined based on the first reference signal;

[0117] The transceiver unit 610 is further configured to send second information to the terminal device, where the second information is used to instruct the terminal device to send a second reference signal precoded using N1 first precoding vectors through N1 antenna ports, where the N1 antenna ports and the N1 first precoding vectors are in a one-to-one correspondence, and the N1 first precoding vectors are determined based on the first spatial domain statistical information, where N1 is less than or equal to N, and the terminal device includes N antenna ports;

[0118] The transceiver unit 610 is further configured to receive a second reference signal precoded by the N1 first precoding vectors from the terminal device;

[0119] The processing unit 620 is used to determine first channel state information based on the precoded second reference signal and the N1 first precoding vectors, where the first channel state information includes channel state information between the communication device and the N antenna ports of the terminal equipment.

[0120] Optionally, the processing unit 620 is specifically configured to:

[0121] Determining second channel state information according to the precoded second reference signal, where the second channel state information includes channel state information between the communication apparatus and N1 antenna ports of the terminal device;

[0122] The first channel state information is determined according to the second channel state information and the N1 first precoding vectors.

[0123] Optionally, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0124] Optionally, the N1 first precoding vectors are respectively N2 column vectors of the first matrix, N1=N2; or,

[0125] The N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。

[0126] Optionally, the sending period of the first reference signal is greater than the sending period of the second reference signal.

[0127] FIG7 is a schematic block diagram of another communication device 700 according to an embodiment of the present application. The device can be applied to or deployed in the terminal device in the method embodiment of FIG4. The communication device 700 includes:

[0128] The transceiver unit 710 is configured to receive a first reference signal from a network device;

[0129] The transceiver unit 710 is further configured to send first information to the network device, where the first information is used to indicate first spatial domain statistical information, where the first spatial domain statistical information is determined based on the first reference signal;

[0130] The transceiver unit 710 is further configured to receive second information from the network device, where the second information is used to instruct that a second reference signal precoded using N1 first precoding vectors be transmitted through N1 antenna ports, where the N1 antenna ports are in a one-to-one correspondence with the N1 first precoding vectors, where the N1 first precoding vectors are determined based on the first spatial domain statistical information, and N1 is less than or equal to N, wherein the communication apparatus includes N antenna ports;

[0131] The transceiver unit 710 is further configured to send, through N1 antenna ports, a second reference signal precoded by using the N1 first precoding vectors to the network device.

[0132] Optionally, the communication device 700 further includes a processing unit 720, wherein the processing unit 720 is configured to:

[0133] determining third channel state information according to the first reference signal, where the third channel state information includes channel state information between the network device and N antenna ports of the communication apparatus;

[0134] The first spatial domain statistical information is determined according to the third channel state information.

[0135] Optionally, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0136] Optionally, the N1 first precoding vectors are respectively N2 column vectors of the first matrix, N1=N2; or,

[0137] The N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。

[0138] Optionally, the sending period of the first reference signal is greater than the sending period of the second reference signal.

[0139] FIG8 is a schematic block diagram of another communication device 800 according to an embodiment of the present application. The device can be applied to or deployed in the network device in the method embodiment of FIG5. The communication device 800 includes:

[0140] A processing unit 810 is configured to obtain first spatial domain statistical information of a terminal device, second spatial domain statistical information of the communication device, and first channel state information, where the first channel state information includes historical channel state information between the communication device and N antenna ports of the terminal device;

[0141] a transceiver unit 820, configured to send third information to the terminal device, where the third information is used to instruct the terminal device to send a third reference signal precoded using N3 second precoding vectors through N3 antenna ports, where the N3 antenna ports and the N3 second precoding vectors are in a one-to-one correspondence, and the N3 second precoding vectors are determined based on the first spatial domain statistical information, the second spatial domain statistical information, and position information of zero elements in a channel weighting coefficient matrix, where the position information of zero elements in the channel weighting coefficient matrix is ​​determined based on the first spatial domain statistical information, the second spatial domain statistical information, and the first channel state information, where N3 is less than N;

[0142] The transceiver unit 820 is further configured to receive a third reference signal precoded by the N3 second precoding vectors from the terminal device;

[0143] The processing unit 810 is also used to determine fourth channel state information based on the precoded third reference signal, the N3 second precoding vectors and the channel weighting coefficient matrix, where the fourth channel state information includes the current channel state information between the communication device and the N antenna ports of the terminal equipment.

[0144] Optionally, the processing unit 810 is specifically used to: determine the third spatial domain statistical information of the communication device based on the precoded third reference signal; determine the fourth channel state information based on the N3 second precoding vectors, the channel weighting coefficient matrix and the third spatial domain statistical information.

[0145] Optionally, the transceiver unit 820 is further configured to send a first reference signal to the terminal device;

[0146] The transceiver unit 820 is further configured to receive first information from the terminal device, where the first information is used to indicate the first spatial domain statistical information, where the first spatial domain statistical information is determined based on the first reference signal;

[0147] The transceiver unit 820 is further configured to send second information to the terminal device, where the second information is used to instruct the terminal device to send a second reference signal precoded by using N1 first precoding vectors through N1 antenna ports, where the N1 antenna ports and the N1 first precoding vectors are in a one-to-one correspondence, the N1 first precoding vectors are determined based on the first spatial domain statistical information, and N1 is less than N;

[0148] The transceiver unit 820 is further configured to receive a second reference signal precoded by the N1 first precoding vectors from the terminal device;

[0149] The processing unit 810 is further configured to determine the second spatial domain statistical information according to the precoded second reference signal;

[0150] The processing unit 810 is further configured to determine the first channel state information according to the precoded second reference signal and the N1 first precoding vectors.

[0151] Optionally, the processing unit 810 is specifically configured to:

[0152] Determining second channel state information according to the precoded second reference signal, where the second channel state information includes channel state information between the communication apparatus and N1 antenna ports of the terminal device;

[0153] The first channel state information is determined according to the second channel state information and the N1 first precoding vectors.

[0154] Optionally, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0155] Optionally, the N3 second precoding vectors are weighted sums of the N2 column vectors of the first matrix, and N3 <N2。

[0156] Optionally, the sending period of the first reference signal is greater than the sending period of the second reference signal; the sending period of the first reference signal is greater than the sending period of the third reference signal.

[0157] FIG9 is a schematic block diagram of another communication device 900 according to an embodiment of the present application. The device can be applied to or deployed in the terminal device in the method embodiment of FIG5. The communication device 900 includes:

[0158] The transceiver unit 910 is configured to receive third information from a network device, where the third information is used to indicate that a third reference signal precoded using N3 second precoding vectors is transmitted through N3 antenna ports, where the N3 antenna ports correspond one-to-one to the N3 second precoding vectors, and the N3 second precoding vectors are determined based on first spatial domain statistical information of the communication device, second spatial domain statistical information of the network device, and position information of zero elements in a channel weighting coefficient matrix, where the position information of zero elements in the channel weighting coefficient matrix is ​​determined based on the first spatial domain statistical information, the second spatial domain statistical information, and first channel state information, where the first channel state information includes historical channel state information between the network device and the N antenna ports of the communication device, where N3 is less than N.

[0159] The transceiver unit 910 is further configured to send, to the network device through N3 antenna ports, a third reference signal precoded by using the N3 second precoding vectors.

[0160] Optionally, the transceiver unit 910 is further configured to:

[0161] receiving a first reference signal from the network device;

[0162] Sending first information to the network device, where the first information is used to indicate the first spatial domain statistical information, where the first spatial domain statistical information is determined according to the first reference signal;

[0163] receiving second information from the network device, the second information being used to instruct that a second reference signal precoded using N1 first precoding vectors be transmitted through N1 antenna ports, the N1 antenna ports being in a one-to-one correspondence with the N1 first precoding vectors, the N1 first precoding vectors being determined based on the first spatial domain statistical information, and N1 being less than or equal to N;

[0164] The second reference signal precoded by using the N1 first precoding vectors is sent to the network device through the N1 antenna ports.

[0165] Optionally, the communication device 900 further includes a processing unit 920, wherein the processing unit 920 is configured to:

[0166] determining third channel state information according to the first reference signal, where the third channel state information includes channel state information between the network device and N antenna ports of the communication apparatus;

[0167] The first spatial domain statistical information is determined according to the third channel state information.

[0168] Optionally, the first spatial statistical information includes a first matrix, the first matrix is ​​composed of spatial eigenvectors determined based on the first reference signal, and the number of columns of the first matrix is ​​N2.

[0169] Optionally, the N3 second precoding vectors are weighted sums of the N2 column vectors of the first matrix, and N3 <N2。

[0170] Optionally, the sending period of the first reference signal is greater than the sending period of the second reference signal; the sending period of the first reference signal is greater than the sending period of the third reference signal.

[0171] Figure 10 is a schematic block diagram of another communication device 1000 provided in an embodiment of the present application. The communication device 1000 includes a processor 1010 and an interface circuit 1020. The processor 1010 and the interface circuit 1020 are coupled to each other. It is understood that the interface circuit 1020 may be a transceiver or an input / output interface. Optionally, the communication device 1000 may further include a memory 1030 for storing instructions executed by the processor 1010, input data required by the processor 1010 to execute instructions, or data generated after the processor 1010 executes instructions.

[0172] When the communication device 1000 is applied to a network device, the communication device 1000 can implement the functions of the network device in the above method embodiment. When the communication device 1000 is applied to a terminal device, the communication device 1000 can implement the functions of the terminal device in the above method embodiment.

[0173] The processor 1010 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the method embodiment described above may be completed by hardware integrated logic circuits within the processor or by software instructions. The processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component. The methods, steps, and logic block diagrams disclosed in the embodiments of this application may be implemented or executed. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this application may be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules within the decoding processor. The software module may be located in a storage medium known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. The storage medium is located in a memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the method described above.

[0174] An embodiment of the present application also provides a communication system, including the network device in the method for determining channel state information provided in the embodiment of the present application, and other communication devices communicating with the network device, terminal devices, and other communication devices communicating with the terminal device.

[0175] The present application also provides a computer-readable storage medium storing a computer program for implementing the method in the above method embodiment. When the computer program is executed on a computer, the computer can implement the method in the above method embodiment.

[0176] An embodiment of the present application further provides a computer program product, which includes a computer program. When the computer program runs on a computer, the method in the above method embodiment is executed.

[0177] An embodiment of the present application also provides a chip, including a processor, wherein the processor is connected to a memory, the memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory, so that the chip executes the method in the above method embodiment.

[0178] In addition, the term "and / or" in this application is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship; the term "at least one" in this application can mean "one" and "two or more". For example, A, B and C can represent seven situations: A exists alone, B exists alone, C exists alone, A and B exist at the same time, A and C exist at the same time, C and B exist at the same time, and A, B and C exist at the same time.

[0179] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0180] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0181] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0182] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0183] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0184] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0185] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for determining channel state information, characterized in that: include: Sending a first reference signal to a terminal device; receiving first information from the terminal device, where the first information is used to indicate first spatial domain statistical information, where the first spatial domain statistical information is determined according to the first reference signal; Sending second information to the terminal device, where the second information is used to instruct the terminal device to send a second reference signal precoded by using N1 first precoding vectors through N1 antenna ports, where the N1 antenna ports correspond to the N1 first precoding vectors in a one-to-one manner, and the N1 first precoding vectors are determined according to the first spatial domain statistical information, where N1 is less than or equal to N, and the terminal device includes N antenna ports; Receiving a second reference signal precoded by using the N1 first precoding vectors from the terminal device; First channel state information is determined according to the precoded second reference signal and the N1 first precoding vectors, where the first channel state information includes channel state information between a network device and N antenna ports of the terminal device.

2. The method according to claim 1, characterized in that The determining, according to the precoded second reference signal and the N1 first precoding vectors, first channel state information includes: Determine second channel state information according to the precoded second reference signal, where the second channel state information includes channel state information between N1 antenna ports of the terminal device; The first channel state information is determined according to the second channel state information and the N1 first precoding vectors.

3. The method according to claim 1 or 2, characterized in that: The first spatial domain statistical information includes a first matrix, the first matrix is ​​composed of spatial domain eigenvectors determined according to the first reference signal, and the number of columns of the first matrix is ​​N2.

4. The method according to claim 3, characterized in that The N1 first precoding vectors are respectively N2 column vectors of the first matrix, N1=N2; or, The N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。 5. The method according to any one of claims 1 to 4, characterized in that A sending period of the first reference signal is greater than a sending period of the second reference signal.

6. A method for determining channel state information, characterized in that: include: receiving a first reference signal from a network device; Sending first information to the network device, where the first information is used to indicate first spatial domain statistical information, where the first spatial domain statistical information is determined according to the first reference signal; receiving second information from the network device, the second information being used to indicate that a second reference signal precoded by using N1 first precoding vectors is sent through N1 antenna ports, the N1 antenna ports being in one-to-one correspondence with the N1 first precoding vectors, the N1 first precoding vectors being determined according to the first spatial domain statistical information, N1 being less than or equal to N, wherein the terminal device includes N antenna ports; A second reference signal precoded by using the N1 first precoding vectors is sent to the network device through the N1 antenna ports.

7. The method according to claim 6, characterized in that The method further comprises: Determine third channel state information according to the first reference signal, where the third channel state information includes channel state information between the network device and N antenna ports; The first spatial domain statistical information is determined according to the third channel state information.

8. The method according to claim 6 or 7, characterized in that: The first spatial domain statistical information includes a first matrix, the first matrix is ​​composed of spatial domain eigenvectors determined according to the first reference signal, and the number of columns of the first matrix is ​​N2.

9. The method according to claim 8, characterized in that The N1 first precoding vectors are respectively N2 column vectors of the first matrix, N1=N2; or, The N1 first precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N1 <N2。 10. The method according to any one of claims 6 to 9, characterized in that A sending period of the first reference signal is greater than a sending period of the second reference signal.

11. A method for determining channel state information, characterized in that: include: Acquire first spatial domain statistical information of the terminal device, second spatial domain statistical information of the network device, and first channel state information, wherein the first information The channel state information includes historical channel state information between the network device and the N antenna ports of the terminal device; Sending third information to the terminal device, where the third information is used to instruct the terminal device to send a third reference signal precoded by using N3 second precoding vectors through N3 antenna ports, where the N3 antenna ports correspond to the N3 second precoding vectors one-to-one, and the N3 second precoding vectors are determined according to the first spatial domain statistical information, the second spatial domain statistical information, and position information of zero elements in a channel weighting coefficient matrix, and the position information of zero elements in the channel weighting coefficient matrix is ​​determined according to the first spatial domain statistical information, the second spatial domain statistical information, and the first channel state information, where N3 is less than N; Receiving a third reference signal precoded by using the N3 second precoding vectors from the terminal device; Fourth channel state information is determined based on the precoded third reference signal, the N3 second precoding vectors and the channel weighting coefficient matrix, and the fourth channel state information includes the current channel state information between the network device and the N antenna ports of the terminal device.

12. The method according to claim 11, characterized in that The determining, according to the precoded third reference signal, the N3 second precoding vectors and the channel weighting coefficient matrix, fourth channel state information includes: Determining third spatial domain statistical information of the network device according to the precoded third reference signal; The fourth channel state information is determined according to the N3 second precoding vectors, the channel weighting coefficient matrix and the third spatial domain statistical information.

13. The method according to claim 11 or 12, characterized in that: The acquiring the first spatial domain statistical information of the terminal device, the second spatial domain statistical information of the network device, and the first channel state information includes: Sending a first reference signal to the terminal device; receiving first information from the terminal device, where the first information is used to indicate the first spatial domain statistical information, where the first spatial domain statistical information is determined according to the first reference signal; Sending second information to the terminal device, where the second information is used to instruct the terminal device to send a second reference signal precoded by using N1 first precoding vectors through N1 antenna ports, where the N1 antenna ports correspond one-to-one to the N1 first precoding vectors, where the N1 first precoding vectors are determined according to the first spatial domain statistical information, and N1 is less than N; Receiving a second reference signal precoded by using the N1 first precoding vectors from the terminal device; Determining the second spatial domain statistical information according to the precoded second reference signal; The first channel state information is determined according to the precoded second reference signal and the N1 first precoding vectors.

14. The method according to claim 13, characterized in that The determining the first channel state information according to the precoded second reference signal and the N1 first precoding vectors includes: Determine second channel state information according to the precoded second reference signal, where the second channel state information includes channel state information between the network device and N1 antenna ports of the terminal device; The first channel state information is determined according to the second channel state information and the N1 first precoding vectors.

15. The method according to claim 13 or 14, characterized in that The first spatial domain statistical information includes a first matrix, the first matrix is ​​composed of spatial domain eigenvectors determined according to the first reference signal, and the number of columns of the first matrix is ​​N2.

16. The method according to claim 15, characterized in that The N3 second precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N3 <N2。 17. The method according to any one of claims 13 to 16, characterized in that A sending period of the first reference signal is greater than a sending period of the second reference signal; A sending period of the first reference signal is greater than a sending period of the third reference signal.

18. A method for determining channel state information, characterized in that: include: Receive third information from a network device, the third information being used to indicate that a third reference signal precoded by using N3 second precoding vectors is sent through N3 antenna ports, the N3 antenna ports are in one-to-one correspondence with the N3 second precoding vectors, the N3 second precoding vectors are determined according to first spatial domain statistical information of a terminal device, second spatial domain statistical information of the network device, and position information of zero elements in a channel weighting coefficient matrix, the position information of zero elements in the channel weighting coefficient matrix is ​​determined according to the first spatial domain statistical information, the second spatial domain statistical information, and first channel state information, the first channel state information including historical channel state information between the network device and the N antenna ports of the terminal device, wherein N3 is less than N; A third reference signal precoded by using the N3 second precoding vectors is sent to the network device through the N3 antenna ports.

19. The method according to claim 18, characterized in that The method further comprises: receiving a first reference signal from the network device; Sending first information to the network device, where the first information is used to indicate the first spatial domain statistical information, where the first spatial domain statistical information is determined according to the first reference signal; receiving second information from the network device, where the second information is used to indicate that a second reference signal precoded by using N1 first precoding vectors is sent through N1 antenna ports, where the N1 antenna ports correspond to the N1 first precoding vectors in a one-to-one manner, where the N1 first precoding vectors are determined according to the first spatial domain statistical information, and N1 is less than or equal to N; A second reference signal precoded by using the N1 first precoding vectors is sent to the network device through the N1 antenna ports.

20. The method according to claim 19, characterized in that The method further comprises: Determine third channel state information according to the first reference signal, where the third channel state information includes channel state information between the network device and N antenna ports of the terminal device; The first spatial domain statistical information is determined according to the third channel state information.

21. The method according to claim 19 or 20, characterized in that The first spatial domain statistical information includes a first matrix, the first matrix is ​​composed of spatial domain eigenvectors determined according to the first reference signal, and the number of columns of the first matrix is ​​N2.

22. The method according to claim 21, characterized in that The N3 second precoding vectors are respectively the weighted sum of the N2 column vectors of the first matrix, N3 <N2。 23. The method according to any one of claims 19 to 22, characterized in that A sending period of the first reference signal is greater than a sending period of the second reference signal; A sending period of the first reference signal is greater than a sending period of the third reference signal.

24. A communication device, characterized in that: Comprising means for performing the method as claimed in any one of claims 1 to 23.

25. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices and transmit them to the processor or send signals from the processor to other communication devices, and the processor is used to implement the method as described in any one of claims 1 to 23 through a logic circuit or executing code instructions.

26. A computer-readable storage medium, characterized in that: include: The computer readable medium stores a computer program; When the computer program is executed by a processor, the method according to any one of claims 1 to 23 is performed.

27. A computer program product, characterized in that A computer program is included which, when executed, causes the method according to any one of claims 1 to 23 to be implemented.

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