Communication method and device

Abstract

The invention provides a communication method and device, which are used for reducing the scanning times of a precoding matrix of an RIS. Based on the method, the RIS receives a first signal from a sending end through a plurality of precoding matrixes in a first codebook of the RIS, and channel measurement information corresponding to the first signal can be used for determining the first precoding matrix in the plurality of precoding matrixes in the first codebook. The RIS may also reflect a second signal to the receiving end through a plurality of precoding matrices in a third codebook, the plurality of precoding matrices in the third codebook corresponding to the first precoding matrix and the plurality of precoding matrices in the second codebook, therefore, the second precoding matrix in the plurality of precoding matrixes in the second codebook can be determined according to the channel measurement information corresponding to the second signal, the first precoding matrix and the second precoding matrix correspond to one precoding matrix in the third codebook, and the precoding matrix of the RIS can be determined.

Description

Communication method and device Technical Field

[0001] The present application relates to the field of mobile communication technologies, and in particular to a communication method and device. Background Art

[0002] Currently, RIS-assisted networking, which uses reconfigurable intelligent meta-surfaces (RIS) to control channel characteristics, is considered a key enabling technology for expanding wireless communication network coverage. When a RIS participates in signal transmission between network devices and terminal devices, it reflects the signal between the two devices using the RIS's optimal precoding matrix, optimizing the channel quality between the two devices.

[0003] Referring to the current process of determining the optimal precoding matrix when a network device and a terminal device communicate, when a RIS participates in signal transmission between the network device and the terminal device, a large number of precoding matrices in the RIS codebook need to be scanned to determine the optimal precoding matrix of the RIS. There is a problem of excessive precoding matrix scanning times, which leads to increased scanning delay.

[0004] Summary of the Invention

[0005] The present application provides a communication method and apparatus for providing a method for determining a precoding matrix of RIS, so as to reduce the number of scan times of the precoding matrix of RIS.

[0006] In a first aspect, the present application provides a communication method for reducing the number of scans of a precoding matrix in a RIS. The method can be implemented by a RIS or a component in the RIS (e.g., a RIS device). The component in the present application may include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the execution entity as an example, the method can be implemented by the following steps: the RIS receives a first signal from a transmitter using multiple precoding matrices in a first codebook of the RIS, channel measurement information corresponding to the first signal is used to determine a first precoding matrix, the multiple precoding matrices in the first codebook include the first precoding matrix, the first codebook is used to adjust channel characteristics between the transmitter and the RIS, one precoding matrix in the first codebook and one precoding matrix in the second codebook of the RIS correspond to a precoding matrix in a third codebook of the RIS, the second codebook is used to adjust channel characteristics between the RIS and a receiver, and the third codebook is used to adjust channel characteristics between the transmitter, the RIS, and the receiver. The RIS may further reflect the second signal to the receiving end through multiple precoding matrices in the third codebook, where the second signal comes from the transmitting end, and channel measurement information corresponding to the second signal is used to determine a second precoding matrix. The multiple precoding matrices in the third codebook correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix.

[0007] Based on the method described in the first aspect, the RIS receives a first signal from a transmitter using multiple precoding matrices in a first codebook of the RIS. Therefore, based on channel measurement information corresponding to the first signal, a first precoding matrix from the multiple precoding matrices in the first codebook can be determined. The RIS can also reflect a second signal to a receiver using multiple precoding matrices in a third codebook. The multiple precoding matrices in the third codebook correspond to the first precoding matrix and multiple precoding matrices in the second codebook. Therefore, based on the channel measurement information corresponding to the second signal, a second precoding matrix from the multiple precoding matrices in the second codebook can be determined. Because one precoding matrix in the first codebook and one precoding matrix in the second codebook correspond to one precoding matrix in the third codebook, the RIS can determine a precoding matrix in the third codebook based on the first and second precoding matrices, and use this precoding matrix to reflect the signal between the transmitter and receiver, thereby determining the optimal precoding matrix for the RIS.

[0008] Assume that the number of precoding matrices in the first codebook is M, and the number of precoding matrices in the second codebook is N, where M and N are positive integers. Since one precoding matrix in the first codebook and one precoding matrix in the second codebook correspond to one precoding matrix in the third codebook, the third codebook includes a total of M×N precoding matrices. That is, if all precoding matrices in the third codebook are scanned, the RIS needs to scan M×N precoding matrices to determine the optimal precoding matrix. In the method shown in the first aspect, since the multiple precoding matrices in the third codebook used by the RIS when reflecting the second signal correspond to the first precoding matrix and the N precoding matrices in the second codebook, the number of precoding matrices in the third codebook is N. That is, in this method, the RIS only needs to receive the first signal through M precoding matrices and reflect the second signal through N precoding matrices. Therefore, a total of M+N precoding matrices are scanned to determine the optimal precoding matrix for the RIS. Compared to the scheme of scanning all precoding matrices in the third codebook, when M or N is greater than 2, the number of beam scans can be reduced, thereby reducing the scanning delay.

[0009] In a possible implementation manner, the RIS may further determine the first precoding matrix from multiple precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

[0010] Based on this implementation, the RIS may determine the first precoding matrix according to the channel measurement information corresponding to the received first signal, thereby achieving flexible determination of the first precoding matrix.

[0011] In a possible implementation, the RIS may further send indication information of the first precoding matrix to a network device, where the network device includes the transmitting end or the receiving end, and the indication information of the first precoding matrix is ​​used to determine the first precoding matrix.

[0012] Based on this implementation, after determining the first precoding matrix, the RIS may indicate the first precoding matrix to the network device, thereby enabling the network device to determine the first precoding matrix.

[0013] In a possible implementation, the RIS may further send channel measurement information corresponding to the first signal to a network device, where the network device includes the transmitting end or the receiving end.

[0014] Based on this implementation, the RIS can send channel measurement information corresponding to the first signal to the network device, so that the network device determines the first precoding matrix according to the channel measurement information corresponding to the first signal, thereby achieving flexible determination of the first precoding matrix.

[0015] In a possible implementation manner, the RIS may further receive indication information of the first precoding matrix from the network device, and determine the first precoding matrix according to the indication information of the first precoding matrix.

[0016] Based on this implementation, the RIS may determine the first precoding matrix according to the indication information of the first precoding matrix sent by the network device.

[0017] In a possible implementation, the RIS may receive first indication information from a network device, where the first indication information is used to instruct the RIS to receive the first signal using multiple precoding matrices in a first codebook of the RIS.

[0018] Based on this implementation, the RIS may receive the first signal through multiple precoding matrices in the first codebook based on the first indication information, so as to implement scanning of the precoding matrices in the first codebook.

[0019] In one possible implementation, the RIS may further receive indication information of the second precoding matrix from a network device, the network device including the transmitting end or the receiving end, and may further determine the second precoding matrix based on the indication information of the second precoding matrix.

[0020] Based on this implementation, the RIS may determine the second precoding matrix according to the received indication information of the second precoding matrix, thereby achieving flexible determination of the second precoding matrix.

[0021] In one possible implementation, the RIS may further receive channel measurement information corresponding to the second signal from a network device, the network device including the transmitting end or the receiving end. The RIS may also determine the second precoding matrix from a plurality of precoding matrices in the second codebook based on the received channel measurement information corresponding to the second signal.

[0022] Based on this implementation, the RIS may determine the second precoding matrix from multiple precoding matrices in the second codebook according to the channel measurement information corresponding to the received second signal, thereby achieving flexible determination of the second precoding matrix.

[0023] In a possible implementation manner, the RIS may further send indication information of the second precoding matrix to the network device, where the indication information of the second precoding matrix is ​​used to determine the second precoding matrix.

[0024] Based on this implementation, after determining the second precoding matrix, the RIS may indicate the second precoding matrix to the network device, thereby enabling the network device to determine the second precoding matrix.

[0025] In a possible implementation, the RIS may further receive second indication information from the network device, where the second indication information is used to instruct the RIS to reflect the second signal to the receiving end through multiple precoding matrices in the third codebook.

[0026] Based on this implementation, the RIS may send the second signal using multiple precoding matrices in the third codebook based on the second indication information. Optionally, the second indication information may include indication information of multiple precoding matrices in the second codebook, or the second indication information may include indication information of multiple precoding matrices in the third codebook.

[0027] In a second aspect, the present application provides a communication method for reducing the number of scans of a precoding matrix of a RIS. The method can be implemented by a first device, which can be a network device or a component in the network device (such as a chip or chip system). The component in the present application may include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the execution subject as an example, the method can be implemented by the following steps: the network device sends first indication information to the RIS, the first indication information being used to instruct the RIS to receive a first signal from a transmitter using multiple precoding matrices in a first codebook of the RIS, channel measurement information corresponding to the first signal being used to determine the first precoding matrix, the multiple precoding matrices in the first codebook including the first precoding matrix, the first codebook being used to adjust channel characteristics between the transmitter and the RIS, one precoding matrix in the first codebook and one precoding matrix in the second codebook of the RIS corresponding to a precoding matrix in a third codebook of the RIS, the second codebook being used to adjust channel characteristics between the RIS and a receiver, and the third codebook being used to adjust channel characteristics between the transmitter, the RIS, and the receiver. The network device may also send second indication information to the RIS, where the second indication information is used to instruct the RIS to reflect a second signal to the receiving end through multiple precoding matrices in the third codebook, where the second signal comes from the transmitting end, and the channel measurement information corresponding to the second signal is used to determine the second precoding matrix. The multiple precoding matrices in the third codebook correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix.

[0028] In a possible implementation, the network device may further receive indication information of the first precoding matrix from the RIS, and the network device may further determine the first precoding matrix according to the indication information of the first precoding matrix.

[0029] In one possible implementation, the network device may further receive channel measurement information corresponding to the first signal from the RIS. The network device may further determine the first precoding matrix from multiple precoding matrices in a first codebook of the RIS based on the channel measurement information corresponding to the first signal.

[0030] In a possible implementation manner, the network device may further send indication information of the first precoding matrix to the RIS, where the indication information of the first precoding matrix is ​​used to determine the first precoding matrix.

[0031] In a possible implementation manner, the network device may further send indication information of the second precoding matrix to the RIS, where the indication information of the second precoding matrix is ​​used to determine the second precoding matrix.

[0032] In one possible implementation, the network device may further transmit channel measurement information corresponding to the second signal to the RIS. The network device may further receive indication information of the second precoding matrix from the RIS. The network device may further determine the second precoding matrix based on the indication information of the second precoding matrix.

[0033] In a possible implementation manner, the network device includes the sending end or the receiving end.

[0034] In a third aspect, the present application provides a communication method for reducing the number of scans of a precoding matrix in a RIS. The method can be implemented by a RIS or a component in the RIS (e.g., a RIS device). The components in the present application can, for example, include at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the execution entity as an example, the method can be implemented by the following steps: the RIS reflects a third signal to a receiving end via a first set of precoding matrices, the third signal originating from a transmitting end, and channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix. The first set of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, the first set of precoding matrices corresponding to a plurality of precoding matrices in a fourth codebook and a precoding matrix in a fifth codebook, the plurality of precoding matrices in the fourth codebook including the fourth precoding matrix. The RIS may also reflect a fourth signal to the receiving end via a second set of precoding matrices. The second set of precoding matrices comprises multiple precoding matrices in a third codebook of the RIS. The second set of precoding matrices corresponds to the fourth precoding matrix and multiple precoding matrices in the fifth codebook. Channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix. The multiple precoding matrices in the fifth codebook include the fifth precoding matrix. The fourth codebook and the fifth codebook are respectively the first codebook and the second codebook of the RIS, and the fourth and fifth codebooks are different. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiving end.

[0035] Based on the method described in the third aspect, the RIS can reflect the third signal through the first set of precoding matrices and reflect the fourth signal through the second set of precoding matrices. The channel measurement information corresponding to the third signal and the channel measurement information corresponding to the fourth signal can be used to determine the fourth precoding matrix and the fifth precoding matrix, respectively. The fourth precoding matrix and the fifth precoding matrix can be used to determine the sixth precoding matrix, thereby enabling the determination of the precoding matrix in the third codebook of the RIS. The fourth codebook and the fifth codebook are respectively one of the first codebook and the second codebook.

[0036] Assume that the fourth codebook is the first codebook, the number of precoding matrices included therein is M, and the fifth codebook is the second codebook, the number of precoding matrices included therein is N, where M and N are positive integers. Since one precoding matrix in the first codebook and one precoding matrix in the second codebook correspond to one precoding matrix in the third codebook, the third codebook includes a total of M×N precoding matrices. That is, if all precoding matrices in the third codebook are scanned, the RIS needs to scan M×N precoding matrices to determine the optimal precoding matrix. In the method shown in the third aspect, since the first group of precoding matrices used by the RIS when reflecting the third signal corresponds to M precoding matrices in the fourth codebook and 1 precoding matrix in the fifth codebook, that is, M precoding matrices are scanned, and the second group of precoding matrices used by the RIS when reflecting the fourth signal corresponds to the fourth precoding matrix and the fifth codebook, resulting in N precoding matrices, that is, N precoding matrices are scanned. That is, in this method, the RIS scans a total of M+N precoding matrices to determine the optimal precoding matrix of the RIS. Compared with the scheme of scanning all precoding matrices in the third codebook, when M or N is greater than 2, the number of beam scanning times can be reduced and the scanning delay can be reduced.

[0037] In a possible implementation, the RIS may further receive third indication information from a network device, where the third indication information is used to instruct the RIS to reflect the third signal to the receiving end through a first set of precoding matrices.

[0038] Based on this implementation, the RIS may transmit the third signal using multiple precoding matrices in the fourth codebook based on the third indication information. Optionally, the third indication information specifically includes indication information of the multiple precoding matrices in the fourth codebook, or the third indication information specifically includes indication information of the first group of precoding matrices.

[0039] In one possible implementation, the RIS may further receive indication information of the fourth precoding matrix from a network device, the network device including the transmitting end or the receiving end, and may further determine the fourth precoding matrix based on the indication information of the fourth precoding matrix.

[0040] Based on this implementation, the network device may indicate the fourth precoding matrix to the RIS, thereby enabling flexible determination of the fourth precoding matrix.

[0041] In a possible implementation, the RIS receives fourth indication information from a network device, where the fourth indication information is used to instruct the RIS to reflect the fourth signal to the receiving end through a second set of precoding matrices.

[0042] Based on this implementation, the RIS may, based on the fourth indication information, reflect the fourth signal using multiple precoding matrices in the fifth codebook. Optionally, the fourth indication information specifically includes indication information of the multiple precoding matrices in the fifth codebook, or the fourth indication information specifically includes indication information of the second group of precoding matrices.

[0043] In one possible implementation, the RIS may further receive indication information of the fifth precoding matrix from a network device, the network device including the transmitting end or the receiving end, and may further determine the fifth precoding matrix based on the indication information of the fifth precoding matrix.

[0044] Based on this implementation, the network device may indicate the fifth precoding matrix to the RIS, thereby enabling flexible determination of the fifth precoding matrix.

[0045] In a fourth aspect, the present application provides a communication method to reduce the number of scans of a precoding matrix of a RIS. The method can be implemented by a first device, which can be a network device or a component in the network device (such as a chip or chip system). The component in the present application may include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the execution subject as an example, the method can be implemented by the following steps: the network device sends third indication information to the RIS, the third indication information is used to instruct the RIS to reflect a third signal to a receiving end through a first set of precoding matrices, the third signal originating from a transmitting end, and channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix, the first set of precoding matrices being multiple precoding matrices in the third codebook of the RIS, the first set of precoding matrices corresponding to multiple precoding matrices in the fourth codebook and one precoding matrix in the fifth codebook, the multiple precoding matrices in the fourth codebook including the fourth precoding matrix. The network device sends fourth indication information to the RIS, where the third indication information is used to instruct the RIS to reflect a fourth signal to the receiving end using a second set of precoding matrices. The second set of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, the second set of precoding matrices corresponds to the fourth precoding matrix and a plurality of precoding matrices in a fifth codebook, channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix, and the plurality of precoding matrices in the fifth codebook include the fifth precoding matrix. The fourth codebook and the fifth codebook are respectively the first codebook or the second codebook of the RIS, and the fourth and fifth codebooks are different. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiving end.

[0046] In a possible implementation manner, the third indication information specifically includes indication information of multiple precoding matrices in the fourth codebook, or the third indication information specifically includes indication information of the first group of precoding matrices.

[0047] In a possible implementation manner, the fourth indication information specifically includes indication information of multiple precoding matrices in the fifth codebook, or the fourth indication information specifically includes indication information of a second group of precoding matrices.

[0048] In a possible implementation, the network device may further send indication information of the fourth precoding matrix to the RIS, the network device includes the transmitting end or the receiving end, and the indication information of the fourth precoding matrix is ​​used to determine the fourth precoding matrix.

[0049] In a possible implementation, the network device may further send indication information of the fifth precoding matrix to the RIS, the network device includes the transmitting end or the receiving end, and the indication information of the fifth precoding matrix is ​​used to determine the fifth precoding matrix.

[0050] It can be understood that the beneficial effects of the above fourth aspect and its possible implementation methods can be found in the description of the beneficial effects of the third aspect and its corresponding possible implementation methods, and will not be repeated here.

[0051] In a fifth aspect, the present application provides a communication method for reducing the codebook feedback overhead of a RIS. The method can be implemented by a first apparatus, which can be a terminal device, a network device, a component in a terminal device (such as a chip or chip system), or a component in a network device (such as a chip or chip system). The first apparatus can be configured to receive or transmit a reference signal and / or data, or in other words, the first apparatus can be a transmitter or a receiver. The components in the present application may, for example, include at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the first apparatus as an example, the method can be implemented by the following steps: the first apparatus obtains first information, the first information being used to determine a first precoding matrix and / or a second precoding matrix, the first precoding matrix belonging to a first codebook, the second precoding matrix belonging to a second codebook, a precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS corresponding to a precoding matrix in the third codebook, the third codebook being used to adjust channel characteristics between the transmitter, the RIS, and the receiver, the first codebook being used to adjust channel characteristics between the transmitter and the RIS, and the second codebook being used to adjust channel characteristics between the RIS and the receiver. The first device may also send second information to the RIS, where the second information is used to indicate the first precoding matrix and / or the second precoding matrix.

[0052] Based on the method described in the fifth aspect, the first device may send second information to the RIS to indicate the first precoding matrix and / or the second precoding matrix. Since the first codebook and the second codebook are used to determine the third codebook, the RIS may determine the precoding matrix in the third codebook based on the first precoding matrix and / or the second precoding matrix, without the first device needing to indicate the precoding matrix in the third codebook to the RIS. It will be appreciated that the number of precoding matrices in the third codebook is the product of the number of precoding matrices in the first codebook and the number of precoding matrices in the second codebook. Therefore, the signaling overhead required to indicate a precoding matrix from the third codebook is greater than the overhead of indicating a precoding matrix from the first codebook and a precoding matrix from the second codebook.

[0053] In one possible implementation, the first information includes third information, and the third information indicates the correspondence between the precoding matrix in the first codebook, the precoding matrix in the second codebook, and the precoding matrix in the third codebook. The first device may also determine a third precoding matrix, and the third precoding matrix belongs to the third codebook. The first device may also determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information. Optionally, the first device may obtain channel measurement information through measurement, or receive channel measurement information from the second device, and determine the third precoding matrix based on the channel measurement information. Alternatively, the first device may receive indication information of the third precoding matrix from the second device, and determine the third precoding matrix based on the indication information. The first device is a transmitter, the second device is a receiver, or the first device is a receiver, and the second device is a transmitter.

[0054] Based on this implementation, the first device can determine the third precoding matrix in the first codebook based on the channel measurement information, and determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information. Thus, flexible determination of the first precoding matrix and / or the second precoding matrix is ​​achieved.

[0055] In a possible implementation, the first device may receive the third information from the RIS, thereby attempting to flexibly obtain the third information.

[0056] In a possible implementation manner, the first information is used to indicate the first precoding matrix and / or the second precoding matrix, and the first device may receive the first information from the second device.

[0057] Based on this implementation, the first device can determine the first precoding matrix and / or the second precoding matrix according to the indication information of the first precoding matrix and / or the second precoding matrix, thereby achieving flexible determination of the first precoding matrix and / or the second precoding matrix.

[0058] In one possible implementation, the first device may further send third information to the second device, where the third information indicates a correspondence between the first codebook, the second codebook, and the third codebook. Based on this implementation, the first device may send the third information to the second device, for the second device to determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information.

[0059] In a sixth aspect, the present application provides a communication method for reducing the codebook scanning time of a RIS. The method can be implemented by a RIS or a component within the RIS. The components herein may include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the RIS as an example, the method can be implemented by the following steps: the RIS sends third information to a first device, the third information indicating a correspondence between precoding matrices in a first codebook of the RIS, precoding matrices in a second codebook of the RIS, and precoding matrices in a third codebook of the RIS, wherein a precoding matrix in the first codebook and a precoding matrix in the second codebook correspond to a precoding matrix in the third codebook, the third codebook being used to adjust channel characteristics between a transmitting end, the RIS, and a receiving end, the first codebook being used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook being used to adjust channel characteristics between the RIS and the receiving end. The RIS may also receive second information from the first device, the second information indicating a first precoding matrix and / or a second precoding matrix, the first precoding matrix belonging to the first codebook and the second precoding matrix belonging to the second codebook.

[0060] It can be understood that the beneficial effects of the above sixth aspect and its possible implementation methods can be found in the description of the beneficial effects of the fifth aspect and its corresponding possible implementation methods, and will not be repeated here.

[0061] In a seventh aspect, the present application provides a communication method for reducing the codebook feedback overhead of RIS. The method can be implemented by a second device, which can be a terminal device, a network device, a component in a terminal device (such as a chip or chip system), or a component in a network device (such as a chip or chip system). The second device can be a device or a component in a device (such as a chip or chip system) that receives or sends signals and / or data for codebook scanning for RIS, or in other words, the second device can be a transmitting end or a receiving end. Exemplarily, the second device can be implemented by a terminal device, a network device, a component in a terminal device, or a component in a network device. The components in the present application may, for example, include at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the execution entity as the second device as an example, the method can be implemented by the following steps: the second device obtains third information, the third information indicating a correspondence between precoding matrices in a first codebook of the RIS, precoding matrices in a second codebook of the RIS, and precoding matrices in a third codebook of the RIS, wherein a precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook, and the third codebook is used to adjust channel characteristics between a transmitter, the RIS, and a receiver. The first codebook is used to adjust channel characteristics between the transmitter and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiver. The second device may also determine a third precoding matrix based on channel measurement information, the third precoding matrix belonging to the third codebook. The second device may also send first information to the first device, the first information indicating a first precoding matrix and / or a second precoding matrix, the first precoding matrix belonging to the first codebook, the second precoding matrix belonging to the second codebook, and the first precoding matrix and / or the second precoding matrix determined based on the third precoding matrix and the third information.

[0062] In a possible implementation, the second device may receive the third information from the first device.

[0063] It can be understood that the beneficial effects of the above seventh aspect and its possible implementation methods can be found in the description of the beneficial effects of the fifth aspect and its corresponding possible implementation methods, and will not be repeated here.

[0064] In an eighth aspect, the present application provides a communication method that can be implemented by a first device and a RIS. Taking the first device and the RIS as examples, the communication method may include the following steps: the first device obtains first information. The first information can be described in the fifth aspect. The first device may also send second information to the RIS, where the second information indicates a first precoding matrix and / or a second precoding matrix. The RIS receives the second information to determine the first precoding matrix and / or the second precoding matrix. The first precoding matrix and / or the second precoding matrix can be described in the fifth or sixth aspect.

[0065] The method of the eighth aspect may also include the method implemented by the first apparatus in any possible implementation of the fifth aspect and the method implemented by the RIS in the sixth aspect and any possible implementation thereof. Optionally, the method of the eighth aspect may also include the method implemented by the second apparatus in the seventh aspect and any possible implementation thereof.

[0066] Alternatively, the communication method may also include a method implemented by the RIS in the first aspect and any possible implementation thereof and a method implemented by the network device in the second aspect and any possible implementation thereof, or include a method implemented by the RIS in the third aspect and any possible implementation thereof and a method implemented by the network device in the fourth aspect and any possible implementation thereof.

[0067] In a ninth aspect, a data transmission device is provided. The device can implement the method performed by a RIS in the first, third, or fifth aspects, or any possible designs thereof; or can be used to implement the method performed by a network device in the second or third aspects, or any possible designs thereof; or can be used to implement the method performed by a first device in the sixth aspect, or any possible designs thereof; or can be used to implement the method performed by a second device in the seventh aspect, or any possible designs thereof. The device can be, for example, a RIS, a terminal device, a network device, a component in a RIS, a component in a terminal device, or a component in a network device.

[0068] In an optional implementation, the device may include a module that performs the methods / operations / steps / actions described in the first to seventh aspects and any possible implementations. The module may be a hardware circuit, software, or a combination of a hardware circuit and software. In an optional implementation, the device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). The transceiver unit is capable of implementing a sending function and a receiving function. When the transceiver unit implements the sending function, it may be referred to as a sending unit (sometimes also referred to as a sending module). When the transceiver unit implements the receiving function, it may be referred to as a receiving unit (sometimes also referred to as a receiving module). The sending unit and the receiving unit may be the same functional module, which is called a transceiver unit, and the functional module is capable of implementing a sending function and a receiving function; or, the sending unit and the receiving unit may be different functional modules, and the transceiver unit is a general term for these functional modules.

[0069] For another example, the apparatus includes a processor coupled to a memory, configured to execute instructions in the memory to implement the methods described in aspects 1 through 7 above and any possible implementations. Optionally, the apparatus also includes other components, such as an antenna, an input / output module, an interface, and the like. These components may be hardware, software, or a combination of hardware and software.

[0070] In a tenth aspect, a computer-readable storage medium is provided, which is used to store computer programs or instructions, which, when executed, enables the method of any one of the first to seventh aspects to be implemented.

[0071] In an eleventh aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the method described in any one of the first to seventh aspects to be implemented.

[0072] In the twelfth aspect, a chip system is provided, which includes a logic circuit (or it can be understood that the chip system includes a processor, and the processor may include a logic circuit, etc.), and may also include an input and output interface. The input and output interface can be used to receive messages or to send messages. The input and output interfaces can be the same interface, that is, the same interface can implement both the sending function and the receiving function; or, the input and output interface includes an input interface and an output interface, the input interface is used to implement the receiving function, that is, for receiving messages; the output interface is used to implement the sending function, that is, for sending messages. The logic circuit can be used to perform operations other than the sending and receiving functions in the methods described in the first to eighth aspects and any possible implementations above; the logic circuit can also be used to transmit messages to the input and output interface, or receive messages from other communication devices from the input and output interface. The chip system can be used to implement the methods described in the first to seventh aspects and any possible implementations above. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0073] Optionally, the chip system may further include a memory, which may be used to store instructions, and the logic circuit may call the instructions stored in the memory to implement corresponding functions.

[0074] In the thirteenth aspect, a communication system is provided, which may include an apparatus for implementing the first aspect and any possible design thereof and an apparatus for implementing the second aspect and any possible design thereof, or, include an apparatus for implementing the third aspect and any possible design thereof and an apparatus for implementing the fourth aspect and any possible design thereof, or, include an apparatus for implementing the fifth aspect and any possible design thereof, an apparatus for implementing the sixth aspect and any possible design thereof, and at least two of the apparatuses for implementing the seventh aspect and any possible design thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIG1 is a schematic diagram of the architecture of a wireless communication system provided in an embodiment of the present application;

[0076] FIG2 is a schematic diagram of a beam scanning process;

[0077] FIG3 is a schematic diagram of the working principle of RIS;

[0078] FIG4 is a schematic diagram of the architecture of a RIS-based communication system provided in an embodiment of the present application;

[0079] FIG5 is a schematic diagram of a decoupling method of a RIS codebook provided in an embodiment of the present application;

[0080] FIG6 is a schematic diagram showing the relationship between the codebooks of RIS before and after decoupling provided by an embodiment of the present application;

[0081] FIG7 is a schematic diagram of another decoupling method of a RIS codebook provided in an embodiment of the present application;

[0082] FIG8 is a flow chart of a communication method provided by the present application;

[0083] FIG9 is a flow chart of another communication method provided by the present application;

[0084] FIG10 is a flow chart of another communication method provided by the present application;

[0085] FIG11 is a flow chart of another communication method provided by the present application;

[0086] FIG12 is a flow chart of another communication method provided by the present application;

[0087] FIG13 is a flow chart of another communication method provided by the present application;

[0088] FIG14 is a flow chart of another communication method provided by the present application;

[0089] FIG15 is a flow chart of another communication method provided by the present application;

[0090] FIG16 is a schematic structural diagram of a communication device provided by the present application;

[0091] FIG17 is a schematic structural diagram of another communication device provided by the present application;

[0092] FIG18 is a schematic structural diagram of another communication device provided in this application. DETAILED DESCRIPTION

[0093] The embodiments of the present application provide a data transmission method and device. Among them, the method and the device are based on the same inventive concept. Since the principles of the method and the device for solving the problem are similar, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated. In the description of the embodiments of the present application, "and / or" describes the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. At least one referred to in this application refers to one or more; multiple refers to two or more. In addition, it should be understood that in the description of this application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0094] The data transmission method provided in the embodiment of the present application can be applied to a fourth generation (4G) communication system, such as a long term evolution (LTE) communication system, and can also be applied to a fifth generation (5G) communication system, such as a 5G new radio (NR) communication system, or to various future communication systems, such as a sixth generation (6G) communication system. The method provided in the embodiment of the present application can also be applied to a Bluetooth system, a wireless fidelity (Wifi) system, a long range radio (LoRa) system, or a vehicle networking system. The method provided in the embodiment of the present application can also be applied to a satellite communication system, wherein the satellite communication system can be integrated with the above-mentioned communication system.

[0095] To facilitate understanding of the embodiments of the present application, the application scenarios used in the present application are described using the communication system architecture shown in Figure 1 as an example. Referring to Figure 1, a communication system 100 includes a network device 101 and a terminal device 102. The apparatus provided in the embodiments of the present application can be applied to the network device 101 or to the terminal device 102. It will be understood that Figure 1 only illustrates one possible communication system architecture that can be applied in the embodiments of the present application. In other possible scenarios, the communication system architecture may also include other devices.

[0096] The network device 101 is a node in a radio access network (RAN), which may also be referred to as a base station or a RAN node (or device). Currently, some examples of radio access network devices include: a next-generation base station (gNodeB / gNB / NR-NB), a transmission reception point (TRP), an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wifi) access point (AP), satellite equipment, or network equipment in a 5G communication system, or network equipment in a possible future communication system. The network device 101 may also be another device having network device functions. For example, the network device 101 may also be a device that functions as a network device in device-to-device (D2D) communication, Internet of Vehicles (IoV) communication, or machine communication. The network device 101 may also be a network device in a possible future communication system.

[0097] In some deployments, a gNB may include a centralized unit (CU) and a distributed unit (DU). The gNB may also include a radio unit (RU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU implements radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions, while the DU implements radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling or PDCP layer signaling, can also be considered to be sent by the DU, or by both the DU and the RU. It is understood that a network device can be a CU node, a DU node, or a device that includes both a CU node and a DU node. In addition, the CU can be divided into a network device in the access network RAN, and the CU can also be divided into a network device in the core network CN, which is not limited here.

[0098] Terminal device 102, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), provides voice or data connectivity to users and may also be an IoT device. For example, terminal devices include handheld devices and vehicle-mounted devices with wireless connectivity. At present, terminal devices can be: mobile phones, tablet computers, laptops, PDAs, mobile internet devices (MIDs), wearable devices (such as smart watches, smart bracelets, pedometers, etc.), vehicle-mounted devices (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed railways, etc.), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, smart home devices (such as refrigerators, TVs, air conditioners, electric meters, etc.), intelligent robots, workshop equipment, wireless terminals in unmanned driving, wireless terminals in remote surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes, flight equipment (such as intelligent robots, hot air balloons, drones, airplanes), etc. The terminal device can also be other devices with terminal functions. For example, the terminal device can also be a device that serves as a terminal function in D2D communication. In this application, terminal devices with wireless transceiver functions and chips that can be set in the aforementioned terminal devices are collectively referred to as terminal devices.

[0099] The following is an introduction to the technical terms that may be involved in the embodiments of this application.

[0100] (1) Beam management. 5G NR improves on the wide-beam broadcast mechanism of the LTE era and adopts a narrow beam and polling scanning mechanism to cover the entire cell. The purpose of beam management is to rationally design narrow beams and select appropriate time-frequency resources to transmit narrow beams.

[0101] Broadcast beams are designed to consist of up to N fixed-directional narrow beams, where N is a positive integer. Broadcast beam coverage of a cell is achieved by transmitting different narrow beams at different times. Terminal devices scan each narrow beam to obtain the optimal beam, achieve synchronization, and demodulate system messages.

[0102] Compared to wide beams (such as LTE beams), narrow beams have limited coverage. A single beam cannot fully cover all users within a cell, nor can it guarantee that every user in the cell receives maximum signal energy. Therefore, beam management is introduced. Based on the different characteristics of each channel or signal, the gNB manages the beams for each channel or signal separately and selects the optimal beam for each user, improving coverage performance and user experience for each channel or signal.

[0103] As shown in Figure 2, the beam scanning technology in 5G NR can be divided into the following three stages:

[0104] In the P1 phase, coarse alignment occurs. The network device first transmits a synchronization signal block (SSB) omnidirectionally, and the terminal device scans with a wide beam. After both the terminal and network device scan once, the network device's narrow beam and the terminal device's wide beam are determined. The terminal device then transmits a physical random access channel (PRACH) for random access.

[0105] In the P2 phase, the network equipment is fine-tuned. After establishing an RRC connection between the network equipment and the terminal device, the terminal device reports the optimal SSB measurement report using a specific wide beam. The network equipment then scans near the optimal beam with a narrow beam to determine the narrow beam of the gNB.

[0106] In the P3 stage, the network device fixes the beam, and the terminal device then uses a narrow beam to scan to determine the narrow beam of the terminal device. After the P3 process is completed, both the terminal device and the network device are aligned with the narrow beam.

[0107] (2) Codebook refers to a set of precoding matrices defined by the protocol. There are two ways for network devices to obtain the precoding matrix V:

[0108] Method 1: Network equipment estimates the downlink channel matrix H based on uplink sounding reference signal (SRS) measurements and the reciprocity of the uplink and downlink channels, thereby obtaining V. However, this method is applicable only in time division duplex (TDD) systems. Method 1 is also known as SRS-based precoding.

[0109] Method 2: The terminal estimates the channel matrix H based on downlink reference signal measurements, and then obtains V, which is then fed back to the network device. Method 2 is also known as precoding based on precoding matrix indication (PMI).

[0110] For the second approach, to reduce implementation complexity and feedback overhead, the current 3GPP protocol defines a finite number of quantized precoding matrices, V. This finite set of precoding matrices is called a codebook. The precoding matrices in the codebook are numbered, and the terminal only needs to feedback the relevant codebook numbers or parameters to indicate the precoding matrix.

[0111] Table 1 shows the codebook for 2 antenna ports.

[0112] Table 1

[0113]

[0114] From the transmitter's perspective, after layer mapping and antenna port mapping, the network device weights the data of each stream using the precoding matrix (also called weights or codebook weights) in the codebook. The orthogonal frequency division multiplexing (OFDM) signal generator then forms a directional beam at the antenna port, thus achieving layer-to-beam domain conversion. That is, the data stream of each layer is carried on these beams and transmitted in space.

[0115] Taking Table 1 as an example, when the number of transmission layers is 1, the precoding matrix corresponding to index 0 is

[0116] (3) Reconfigurable intelligent meta-surface (RIS) is a digitally reconfigurable artificial electromagnetic surface, an artificial composite structure formed by a large number of sub-wavelength digitally reconfigurable artificial electromagnetic units (or reflective elements) arranged in a certain macroscopic manner (periodic or aperiodic). Depending on the specific material of the reflective elements, RIS can be divided into antenna array-based structures and metamaterial-based structures. By adjusting the phase shift of all reflective elements, the reflected signals can be configured to propagate in the desired direction. Due to the rapid development of metamaterials, the reflection coefficient of each element can be configured in real time to adapt to the dynamically fluctuating wireless propagation environment.

[0117] Because the basic units and arrangements of RIS can be arbitrarily designed, they can overcome the limitations of traditional materials, which are difficult to precisely manipulate at the atomic or molecular level. This allows the construction of extraordinary media parameters unattainable with traditional materials and technologies, such as those with both positive and negative permittivity. Materials with extraordinary media parameters are referred to as metamaterials. Because they control electromagnetic waves by varying the spatial arrangement of digitally encoded units—that is, by altering the state distribution of the basic units, the properties of the electromagnetic field at a specific spatial location can be controlled—in some embodiments, metamaterials can also be referred to as digital electromagnetic metamaterials or electromagnetically coded metamaterials.

[0118] RIS can be mounted on large flat surfaces (such as walls or ceilings indoors, buildings or signs outdoors) to reflect radio frequency (RF) energy around obstacles and create a virtual line of sight (LoS) propagation path between the communication source and destination.

[0119] For example, please refer to Figure 3, which is a schematic diagram of the operating principle of the RIS module. As shown in Figure 3, the RIS module includes multiple RIS units, each connected via diodes such as PIN diodes and varactor diodes. The RIS can reflect received radio waves. It should be understood that when radio waves propagate from one medium to another with a different refractive index, they undergo not only reflection but also refraction. Therefore, the RIS can change the reflection phase difference of the radio waves. It can also be understood that the RIS causes radio waves to follow the generalized Snell's law at reflective or refractive interfaces. In other words, the RIS can make the reflection angle of the radio wave different from the incident angle. Compared to traditional surfaces (where the reflection angle of the radio wave is reflection angle 1), the reflection angle of the radio wave can be made to be reflection angle 2. In other words, compared to traditional surfaces, the RIS has the ability to shape radio waves according to the generalized Snell's law.

[0120] Specifically, by controlling the RIS units to adjust the amplitude and / or phase of received signals, the reflection coefficient of each RIS unit can be controlled. Adjusting the amplitude and / or phase of received signals by a RIS unit can also be considered adjusting the amplitude and / or phase of the RIS unit. It should be understood that since each RIS unit has a different reflection coefficient, the reflection angle or refraction angle of the radio wave by that RIS unit also varies. In other words, by controlling multiple RIS units to adjust the amplitude and / or phase of received signals, the reflection angle or refraction angle of the radio wave by the RIS can be adjusted, thereby collaboratively achieving sophisticated three-dimensional (3D) passive beamforming for directional signal enhancement or nulling.

[0121] In some embodiments, the RIS unit can be controlled to adjust the amplitude and / or phase of a received signal by controlling the on / off state (on or off) of a PIN diode connected to the RIS unit. For example, by applying different bias voltages to the PIN diode, turning it on or off, the RIS unit connected to it is also turned on or off. The multiple RIS units within the RIS are in different states, resulting in different amplitude and / or phase adjustments to the received signal, and thus different reflection coefficients. Therefore, by controlling the states of the RIS units, the RIS module can adjust the amplitude and / or phase of the received signal. For example, by causing the phase of the RIS reflection of a radio wave to differ by 180°, the RIS reflection coefficient, i.e., the phase and / or amplitude of the RIS, can be controlled. This allows the RIS reflection angle of the radio wave to differ from the incident angle, achieving directional beamforming. This can improve wireless network coverage and system capacity, making the RIS widely applicable in communication systems. For example, in embodiments of the present application, the RIS can be installed in the source node and / or the cooperative node to implement cooperative communication. Different RIS reflection coefficients result in different reflection angles for radio waves, leading to different beam directions. Therefore, the RIS reflection coefficient can be used to adjust the RIS beam direction. From this perspective, the RIS reflection coefficient can also be called the RIS beamforming parameter (this example is used below).

[0122] Optionally, the RIS can use an intelligent controller, such as a field programmable gate array (FPGA), to control the on / off state of the PIN diode. In a typical scenario, the workflow can be as follows: the network device calculates the optimal reflection coefficient for the RIS and then sends it to the RIS controller via a dedicated feedback link. The design of the reflection coefficient depends on the channel state information (CSI), which is updated only when the CSI changes, and its duration is much longer than the data symbol duration. For example, each reflective element in the RIS panel is embedded with a PIN photodiode. By controlling the voltage on the bias line, the PIN photodiode can be switched between "on" and "off" modes, thereby achieving a phase shift difference of π radians.

[0123] By adjusting the phase shift of the RIS's reflective elements, the reflected signal can be superimposed with the signal from the direct path (or direct link, i.e., a path not reflected by the RIS) to enhance the desired signal power, or destructively combine to mitigate the harmful effects of multi-user interference. RIS thus provides an additional degree of freedom to further improve system performance, particularly for millimeter-wave (mmWave) communications. Typically, mmWave transmission suffers from high penetration losses, which cannot be easily addressed using large antenna arrays. RIS can also be deployed to create auxiliary transmission links when direct links are blocked.

[0124] It will be appreciated that the amplitude and / or phase of the RIS units can be adjusted based on instructions from the network device. For example, the RIS's adjustments to the signal's amplitude and / or phase can be mapped to multiple precoding matrices in the RIS's codebook. The network device can indicate the index of the precoding matrix in the codebook to the RIS. Based on the network device's instructions, the RIS can determine the precoding matrix with that index and use the amplitude and / or phase corresponding to that precoding matrix to control the reflection coefficients of the RIS units, so that the RIS units achieve signal reflection according to the instructions from the network device. For ease of explanation, this RIS codebook will be referred to as the RIS concatenated codebook.

[0125] It can be understood that, as shown in Figure 4, when a RIS participates in signal transmission between a network device and a terminal device, a single precoding matrix is ​​used to determine the optimal precoding matrix. Taking downlink signal transmission as an example, during the beam scanning process of RIS-assisted communication, the RIS's emission direction is related to the RIS's outgoing beam and also to the RIS's incoming beam. The combination of the RIS's incoming beam and outgoing beam corresponds to a precoding matrix in the RIS's concatenated codebook. In other words, this precoding matrix determines the incoming and outgoing beams used by the RIS. Only when the RIS's incoming beam is aligned with the network device's transmit beam, and the RIS's outgoing beam is aligned with the UE's receive beam, can downlink signal transmission performance be optimized.

[0126] Therefore, to determine the optimal precoding matrix for the RIS, it is necessary to scan all incoming and outgoing beams of the RIS. In other words, the RIS must scan all precoding matrices in the concatenated codebook, significantly increasing the RIS's beam scanning time and the number of precoding matrices that need to be scanned. For example, if the number of incoming and outgoing beams of the RIS is M and N, respectively, then the RIS's concatenated codebook contains M×N precoding matrices. Therefore, to determine the optimal precoding matrix, the RIS must perform I=M×N beam scans by switching precoding matrices (i.e., adjusting the phase and / or amplitude of the RIS unit based on the amplitude and / or phase corresponding to the precoding matrix). Each beam scan uses a precoding matrix from the codebook. Reducing the number of scans, for example, scanning only the M precoding matrices in the concatenated codebook, reduces the accuracy of the optimal precoding matrix.

[0127] For example, if the optimal precoding matrix is ​​determined based on the criterion of maximizing the received power of the UE, the precoding matrix in the concatenated codebook of the RIS can be expressed by the following formula:

[0128]

[0129] Among them, W BS and W UE Respectively represent the precoding matrices used by the network device and the terminal device, that is, when the network device and the UE communicate through RIS, they can use W BS and W UE H is the signal between the network device and RIS, F is the channel between RIS and UE, exp(jΦ i ) is the i-th precoding matrix of the RIS, i = 1, 2, ..., I. That is, if the precoding matrix of the RIS is determined by beam scanning, it is necessary to traverse I RIS precoding matrices and select the RIS precoding matrix that maximizes the UE's received power.

[0130] The present application provides a communication method for reducing the number of scans of a precoding matrix of a RIS.

[0131] In this application, based on the decoupling of the RIS codebook, the RIS concatenated codebook is decoupled into an incident side codebook and an output side codebook. Therefore, the precoding matrix in the RIS concatenated codebook can be regarded as a combination of the incident side precoding matrix and the output side precoding matrix. In other words, based on the decoupling of the RIS precoding matrix, the RIS precoding matrix is ​​decoupled into an incident side precoding matrix and an output side precoding matrix. The incident side precoding matrix is ​​included in the incident side codebook, and the output side precoding matrix is ​​included in the output side codebook.

[0132] In this application, during the transmission of downlink signals, the incident side codebook of RIS refers to the network device side codebook of RIS, and the exit side codebook of RIS refers to the terminal device side codebook of RIS. Similarly, during the transmission of uplink signals, the incident side codebook of RIS refers to the terminal device side codebook of RIS, and the exit side codebook of RIS refers to the network device side codebook of RIS. It can be understood that the incident side codebook can be used to adjust the channel characteristics of the incident side of RIS (or between the transmitting end and RIS), or in other words, the incident side codebook can be used to be responsible for the beamforming and scanning of the incident beam of RIS. The exit side codebook can be used to adjust the channel characteristics of the exit side of RIS (or between RIS and the receiving end), or in other words, the exit codebook can be used to be responsible for the beamforming and scanning of the exit beam of RIS.

[0133] Optionally, in the embodiment of the present application, the codebook of the RIS may be decoupled based on the perspective of space division.

[0134] Taking downlink communication as an example, Figure 5 is a schematic diagram of decoupling the RIS codebook based on the perspective of space division. It can be seen that with the direction perpendicular to RIS as the boundary, the precoding matrix Φ in the RIS concatenated codebook is m,n Can be decoupled into the incident side precoding matrix Φ m and the output side precoding matrix Φ n . Among them, both the incident side codebook and the outgoing side codebook contain multiple precoding matrices. Among them, m and n are the index of the incident side precoding matrix and the index of the outgoing side precoding matrix, respectively. For example, Ф0, Ф1, Ф2 and Ф3 on the network device side in Figure 5 represent the incident side precoding matrices when m is 0, 1, 2 and 3, respectively, and Ф0, Ф1, Ф2 on the terminal device side represent the outgoing side precoding matrices when n=0, 1 and 2, respectively. It can be understood that each incident beam of RIS corresponds to a precoding matrix in the incident side codebook, and each outgoing beam corresponds to a precoding matrix in the outgoing side codebook.

[0135] In addition, an example of the RIS concatenated codebook can be decomposed based on the elevation angle and azimuth angle of the incident side beam and the outgoing side beam of the RIS. For example, as shown in FIG6 , the RIS concatenated codebook Φ m,n (p,q) and the decoupled incident codebook Φ m (p,q) and the output side codebook Φ n (p,q) respectively. Where p and q are the indices of the RIS element in the horizontal and vertical dimensions of the antenna array. θ and where dx and dy are the beam's elevation and azimuth angles, respectively; dx and dy are the spacing between antenna elements; and λ is the wavelength of the antenna array's center frequency. m and n are the indices of the input and output precoding matrices, respectively.

[0136] Optionally, the RIS codebook may be decoupled based on the angle of the wide and narrow beams.

[0137] Still taking downlink communication as an example, Figure 7 is a schematic diagram of decoupling the RIS codebook based on the perspective of wide and narrow beams. For example, through algorithm design, a narrow beam can be converted into a wide beam to cover a larger scanning range and reduce the number of scans. Accordingly, the RIS precoding matrix can be decoupled into a combination of the precoding matrix corresponding to the wide beam and the precoding matrix corresponding to the wide beam, or a combination of the precoding matrix corresponding to the wide beam and the precoding matrix corresponding to the narrow beam. For example, the decoupled RIS codebook includes a combination of at least two of the following: the incident side precoding matrix corresponding to the wide beam, the outgoing side precoding matrix corresponding to the narrow beam, and the incident side precoding matrix corresponding to the narrow beam and the outgoing side precoding matrix corresponding to the wide beam. In Figure 7, m and n are the indices of the input and output precoding matrices, respectively. For example, in Figure 5, Φ0, Φ1, and Φ2 on the network device side represent the input precoding matrices when m is 0, 1, and 2, respectively. Φ0, Φ1, and Φ2 on the terminal device side represent the output precoding matrices when n = 0, 1, 2, and 2, respectively. It can be seen that the input precoding matrix Φ1 and the output precoding matrix Φ2 are wide beams. Each input beam corresponds to a precoding matrix in the input codebook, and each output beam corresponds to a precoding matrix in the output codebook.

[0138] Optionally, the RIS codebook can be decoupled based on the angle of the discrete Fourier transform (DFT) beam, where the DFT design is independent of the angle and only depends on the number of antenna elements.

[0139] For example, the incident side codebook and the output side codebook after RIS decoupling are both expressed as:

[0140]

[0141] Where N and M are the vertical and horizontal numbers of antennas, n and m are the vertical and horizontal beam indices, and l and k are the vertical and horizontal scaling factors. Represents the Kronecker product operation.

[0142] Based on the above decoupling method, the RIS concatenated codebook is decoupled into the RIS input side codebook and the RIS output side codebook. For example, if the RIS has M input beams and N output beams that need to be scanned in space, since both the input beam and the output beam affect the channel between the network device and the UE, each beam scan requires one input beam and one output beam. In other words, the RIS has a total of M×N beams to scan. Through codebook decoupling, during beam scanning, the RIS can fix a precoding matrix in the incident codebook and scan N precoding matrices in the outgoing codebook to determine the optimal precoding matrix in the outgoing codebook. Furthermore, the RIS can fix a precoding matrix in the outgoing codebook and scan M precoding matrices in the outgoing codebook to determine the optimal precoding matrix in the incident codebook. Due to the decoupling approach, it is easy to determine a precoding matrix in the RIS concatenated codebook based on a precoding matrix in the incident codebook and a precoding matrix in the outgoing codebook. Therefore, the optimal precoding matrix in the RIS can be determined based on the optimal precoding matrix in the incident codebook and the optimal precoding matrix in the outgoing codebook. This process only requires M+N precoding matrix scans. Generally, the number of precoding matrices in the RIS concatenated codebook is much greater than 2. Therefore, the method provided in the embodiments of the present application can reduce the number of beam scans from M×N to M+N, reducing the number of precoding matrix scans in the RIS and significantly shortening the scanning latency. Furthermore, the communication method does not reduce the accuracy of the optimal precoding matrix determination process, thereby ensuring communication performance.

[0143] The following describes the communication method provided in an embodiment of the present application. Optionally, the communication method can be performed by a RIS and a network device. The RIS can be used to receive and / or reflect signals toward a receiving end, where the signals may originate from a transmitting end. It will be understood that in downlink communication, the network device is the transmitting end and the terminal device is the receiving end. In uplink communication, the terminal device is the transmitting end and the network device is the receiving end. The network device can be either a transmitting end or a receiving end. If the transmitting end is a network device, the receiving end is a terminal device, and this is downlink communication. If the transmitting end is a terminal device, the receiving end is a network device, and this is uplink communication.

[0144] As shown in FIG8 , a communication method provided in an embodiment of the present application may include the following steps:

[0145] S801: The RIS receives a first signal from a transmitting end through multiple precoding matrices in a first codebook of the RIS.

[0146] In the present application, RIS receives signals through multiple precoding matrices in the code book, which means that RIS polling uses the configuration of the incident side reflective elements corresponding to the multiple precoding matrices to change the phase and / or amplitude of the RIS unit, and receives signals through RIS units with different phases and / or amplitudes of RIS units.

[0147] The channel measurement information corresponding to the first signal is used to determine a first precoding matrix. The first precoding matrix is ​​included in a plurality of precoding matrices in a first codebook used by the RIS to receive the first signal.

[0148] In this application, the precoding matrix can also be replaced by codebook weights or weights. Therefore, the first precoding matrix can be replaced by the first weight. In this application, the precoding matrix of the RIS refers to the weight matrix corresponding to the adjustable phase and / or amplitude of each RIS unit on the RIS device. Therefore, when using different precoding matrices, the phase and / or amplitude of the RIS units of the RIS will be different. The RIS can use the configuration of reflective elements corresponding to the precoding matrix to adjust the phase and / or amplitude of the RIS units. It is understood that the RIS can change the precoding matrix used when receiving or reflecting signals to change the amplitude, phase, or rank characteristics of the wireless channel.

[0149] The first codebook in this application can be used to adjust the channel characteristics between the transmitter and the RIS, and therefore, the first codebook is the input-side codebook of the RIS. Furthermore, the second codebook is used to adjust the channel characteristics between the RIS and the receiver, and therefore, the second codebook is the output-side codebook of the RIS. Optionally, the first codebook and / or the second codebook can be indicated by a network device, or can be determined by decoupling from a third codebook, or can be protocol-defined, preconfigured, or predefined, which is not specifically required by this application. The third codebook can be used to adjust the channel characteristics between the transmitter, the RIS, and the receiver, and therefore, the third codebook is a concatenated codebook of the RIS. Based on the decoupling principle of the third codebook of RIS, in this application, the precoding matrix in the first codebook is a precoding matrix used to change the phase and / or amplitude of the signal between the transmitter and the RIS, and the precoding matrix in the second codebook is a precoding matrix used to change the phase and / or amplitude of the signal between the RIS and the receiver. The third codebook is a combination of the precoding matrix in the first codebook and the precoding matrix in the second codebook, which can be used to change the phase and / or amplitude of the signal between the transmitter and the RIS and between the RIS and the receiver.

[0150] Exemplarily, the third codebook can be decoupled to obtain the first and second codebooks. For the decoupling method, refer to the description of the decoupling of the concatenated codebooks in RIS in this application and will not be repeated here. It will be understood that, in this application, a precoding matrix in the first codebook and a precoding matrix in the second codebook of RIS correspond to a precoding matrix in the third codebook of RIS. Optionally, a precoding matrix in the first codebook and a precoding matrix in the second codebook can be obtained by decoupling a precoding matrix in the third codebook, and / or a precoding matrix in the first codebook and a precoding matrix in the second codebook can be combined to obtain a precoding matrix in the third codebook. For example, any precoding matrix in the third codebook is the product of a precoding matrix in the first codebook and a precoding matrix in the second codebook.

[0151] For example, the precoding matrix with an index of 0 in the third codebook is obtained by combining the precoding matrix with an index of 0 in the first codebook and the precoding matrix with an index of 0 in the second codebook, or in other words, the precoding matrix with an index of 0 in the third codebook can be decoupled into the precoding matrix with an index of 0 in the first codebook and the precoding matrix with an index of 0 in the second codebook; the precoding matrix with an index of 1 in the third codebook is obtained by combining the precoding matrix with an index of 0 in the first codebook and the precoding matrix with an index of 1 in the second codebook, or In other words, the precoding matrix with an index of 0 in the third codebook can be decoupled into the precoding matrix with an index of 0 in the first codebook and the precoding matrix with an index of 1 in the second codebook; the precoding matrix with an index of 1 in the third codebook is obtained by combining the precoding matrix with an index of 1 in the first codebook and the precoding matrix with an index of 0 in the second codebook, or in other words, the precoding matrix with an index of 1 in the third codebook is obtained by combining the precoding matrix with an index of 0 in the first codebook and the precoding matrix with an index of 1 in the second codebook, and so on.

[0152] In the present application, the first precoding matrix may be determined based on channel measurement information corresponding to the first signal. The RIS may receive the first signal and measure the first signal to obtain the channel measurement information corresponding to the first signal. Optionally, the channel measurement information may include CSI.

[0153] For example, the channel measurement information corresponding to the first signal may include channel measurement results obtained by receiving the first signal according to multiple precoding matrices, such as reference signal received power (RSRP) or signal to interference plus noise ratio (SINR).

[0154] In addition, the channel measurement information corresponding to the first signal may include time or order indication information of the precoding matrix with the best channel quality determined based on the channel measurement result (hereinafter referred to as the time of the precoding matrix with the best channel quality is referred to as time indication information, and the order indication information of the precoding matrix with the best channel quality is referred to as order indication information). To reduce overhead, the channel measurement information may not include the channel measurement result, or may only include the channel measurement result of the precoding matrix with the best channel quality.

[0155] It will be appreciated that since the RIS receives or reflects signals using multiple precoding matrices, the channel measurement result corresponding to the signal may include multiple channel measurement values. These multiple channel measurement values ​​may correspond to different times (or time units), and the time corresponding to the channel measurement value is the time when the RIS uses the precoding matrix corresponding to the channel measurement value.

[0156] The time indication information may include, for example, an index of a time unit corresponding to the channel measurement result. In the present application, a time unit may include a time length such as a time slot or a symbol, which is not specifically limited.

[0157] The order indication information may include a time order of the corresponding channel measurement result among the multiple channel measurement results corresponding to the first signal.

[0158] Taking RSRP as an example, the RSRP values ​​of the received signals of the first signal can be numbered according to the chronological order in which the RIS uses the precoding matrix, and the number of the signal with the best RSRP value is used as the channel measurement information corresponding to the first signal. For example, if the RIS uses five precoding matrices in a poll, the channel measurement result may include five RSRP values, which are numbered 1-5 in chronological order. If RSRP value number 1 is the best, the order indication information is number 1. In addition, the time indication information may include the time slot number corresponding to the best RSRP value.

[0159] Optionally, the channel measurement information corresponding to the first signal may further include channel parameters such as a channel quality indication (CQI) of the best channel quality.

[0160] Because the amplitude and / or phase of the RIS units in the RIS are adjusted differently when the RIS uses different precoding matrices in the first codebook, the channel measurement information of the received first signal varies when the RIS uses different precoding matrices, resulting in a change in the channel of the first signal when it reaches the RIS. In other words, the channel measurement information corresponding to the first signal varies. Therefore, based on the channel measurement information corresponding to the first signal, the precoding matrix in the first codebook of the RIS that achieves the best channel quality (i.e., the first precoding matrix) can be determined to improve the input-side channel quality of the RIS.

[0161] In one possible implementation, if the RIS is capable of performing signal measurement and determining an optimal precoding matrix based on channel measurement information, then after receiving the first signal, the RIS may determine channel measurement information corresponding to the first signal through signal measurement. For example, the RIS may obtain channel measurement results for the first signal when using different precoding matrices in the first codebook through channel measurement, or determine timing indication information or sequence indication information based on the channel measurement results. Furthermore, the RIS may select, based on the channel measurement information corresponding to the first signal, a precoding matrix with the best channel quality among multiple precoding matrices as the first precoding matrix.

[0162] Optionally, the RIS may also send indication information of the first precoding matrix to a network device (e.g., a transmitter or receiver). In the present application, the indication information of the precoding matrix may include the index of the precoding matrix in the codebook. In addition, the indication information of the precoding matrix may also include the index of the beam corresponding to the precoding matrix. The mapping relationship between the precoding matrix and the beam may be indicated by the network device or the RIS, or may be determined through protocol definition, preconfiguration, or predefined means.

[0163] In another possible implementation, the RIS may send channel measurement information corresponding to the first signal to a network device (such as a transmitting end or a receiving end), and the network device may determine the first precoding matrix from multiple precoding matrices in the first codebook based on the channel measurement information corresponding to the first signal and information about multiple precoding matrices in the first codebook used by the RIS when receiving the first signal.

[0164] Optionally, the information of the precoding matrix used by the RIS when receiving the first signal may include indication information (such as index) of the multiple precoding matrices used by the RIS when receiving the first signal, or include usage time (such as time slot) or sequence information of the multiple precoding matrices.

[0165] In the present application, the RIS may send information about the precoding matrix used by the RIS when receiving the first signal to the network device. That is, after the RIS determines the multiple precoding matrices used when receiving the first signal and / or determines the time or order of the multiple precoding matrices used, the RIS indicates this to the network device. Alternatively, the network device may send information about the precoding matrix used by the RIS when receiving the first signal to the RIS. That is, after the network device determines the multiple precoding matrices used by the RIS when receiving the first signal and / or determines the time or order of the multiple precoding matrices used, the network device indicates this to the RIS. In addition, the information about the precoding matrix used when receiving the first signal may also be defined by the protocol or determined by preconfiguration or predefinition. For example, the multiple precoding matrices may default to all precoding matrices in the first codebook, and the order in which the multiple precoding matrices are used is related to the index size of the precoding matrix.

[0166] Optionally, before S801, the network device may further send first indication information to the RIS. The first indication information may be used to instruct the RIS to receive the first signal using multiple precoding matrices in the first codebook. Optionally, the first indication information may include information about the precoding matrix used by the RIS when receiving the first signal. Therefore, the network device knows information about the precoding matrix used by the RIS when receiving the first signal.

[0167] Taking the example of a channel measurement result including RSRP, when the channel measurement information corresponding to the first signal includes the channel measurement result, the network device can determine the optimal RSRP based on the RSRP corresponding to the first signal, which is the RSRP of the x-th precoding matrix used by the RIS in chronological order when receiving the first signal. Based on the information about the precoding matrix used by the RIS when receiving the first signal, the network device can determine which precoding matrices with indices in the first codebook were used by the RIS to receive the first signal, as well as the time or sequence of these precoding matrices used by the RIS. Therefore, the network device can determine the index of the x-th precoding matrix used by the RIS in chronological order in the first codebook, thereby determining the first precoding matrix. Where x is a positive integer.

[0168] When the channel measurement information corresponding to the first signal includes sequence indication information, the precoding matrices used by the RIS when receiving the first signal are the precoding matrices indexed 0, 1, 2, 3, and 4 in the first codebook, and the temporal order of use of the five precoding matrices is 5, 4, 3, 2, and 1. That is, the RIS uses the above five precoding matrices in descending order of index to receive the first signal. Accordingly, after measuring the RSRP of the first signal, the RSI sends sequence indication information determined based on the RSRP to the network device. The network device receives the sequence indication information and, based on the sequence indication information, determines the first precoding matrix from the precoding matrices indexed 0, 1, 2, 3, and 4 in the first codebook. To reduce overhead, the sequence indication information only needs to feed back the temporal sequence number of the channel measurement information with the best channel quality. For example, the temporal sequence number is n, where n=1, 2, 3, 4, or 5, indicating that the RIS has the best channel quality when using the nth precoding matrix among the five precoding matrices. For example, if the RSRP obtained by the RIS when receiving the first signal through the precoding matrix with index 0 is the best, the channel quality information of the first signal may include sequence indication information, and the value of the sequence indication information is 5. Then the network device can determine that the precoding matrix with index 0 is the first precoding matrix.

[0169] Optionally, after the network device determines the first precoding matrix, the network device may further send indication information of the first precoding matrix to the RIS, so that the RIS acquires the first precoding matrix.

[0170] Based on S801, the RIS and / or the network device may determine the incident side weight of the RIS, that is, determine the first precoding matrix. It can be understood that when the RIS uses the first precoding matrix to receive the signal from the transmitter, the channel quality between the transmitter and the RIS is optimal.

[0171] S802: The RIS reflects a second signal to a receiving end through multiple precoding matrices in a third codebook, where the second signal comes from the transmitting end.

[0172] In the present application, RIS reflects the signal to the receiving end through multiple precoding matrices in the third codebook, which means that RIS polling adopts the configuration of the reflective elements corresponding to the multiple precoding matrices to change the phase and / or amplitude of the RIS unit, and reflects the signal from the transmitting end to the receiving end through RIS units with different phases and / or amplitudes of the RIS units.

[0173] The channel measurement information corresponding to the second signal is used to determine a second precoding matrix, and the second precoding matrix belongs to the second codebook. It will be understood that the multiple precoding matrices in the third codebook used by the RIS when reflecting the second signal correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix.

[0174] Optionally, the multiple precoding matrices in the third codebook can be determined based on the first precoding matrix. As described above, any precoding matrix in the third codebook can be decoupled into a precoding matrix in the first codebook and a precoding matrix in the second codebook. In S802, the precoding matrix in the first codebook obtained after decoupling the multiple precoding matrices in the third codebook is the first precoding matrix. Alternatively, the multiple precoding matrices in the third codebook are obtained by combining the first precoding matrix with the multiple precoding matrices in the second codebook.

[0175] It can be understood that after determining the first precoding matrix through S801, the RIS in S802 can poll and use multiple precoding matrices in the third codebook to reflect the second signal. Since the multiple precoding matrices all correspond to the first precoding matrix and correspond to multiple precoding matrices in the second codebook, the second precoding matrix can be determined according to the channel measurement information corresponding to the second signal. The second precoding matrix includes multiple precoding matrices in the second codebook.

[0176] The channel measurement information corresponding to the second signal only reflects channel changes between the transmitter and the RIS. These channel changes are caused by the RIS using different precoding matrices in the third codebook to reflect the second signal. Specifically, the multiple precoding matrices in the third codebook correspond to one precoding matrix in the first codebook (i.e., the first precoding matrix) and multiple precoding matrices in the second codebook. Therefore, the incident-side phase and amplitude of the RIS corresponding to the multiple precoding matrices remain unchanged. Therefore, the channel between the transmitter and the RIS does not change due to the RIS using the phase and / or amplitude parameters corresponding to different precoding matrices in the first codebook. However, the channel between the RIS and the receiver changes because the RIS uses the phase and / or amplitude parameters corresponding to multiple precoding matrices in the second codebook. That is, the channel change is caused by changes in the RIS's output-side precoding matrix (or phase and / or amplitude parameters). Therefore, the channel measurement information corresponding to the second signal can determine the output-side precoding matrix (or phase and / or amplitude parameters) of the RIS that optimizes the channel quality between the RIS and the receiver.

[0177] The channel measurement information corresponding to the second signal may refer to the description of the channel measurement information corresponding to the first signal in S801. For example, the channel measurement information corresponding to the second signal may include the channel measurement result corresponding to the second signal, or include time indication information or sequence indication information determined based on the channel measurement result corresponding to the second signal.

[0178] In the present application, the channel measurement information corresponding to the second signal can be determined by the receiving end. For example, in downlink communication, the terminal device can receive the second signal reflected by the RIS and determine the channel measurement information corresponding to the second signal. In uplink communication, the network device can receive the second signal reflected by the RIS and determine the channel measurement information corresponding to the second signal.

[0179] Exemplarily, the receiving end may receive the second signal and obtain channel measurement information corresponding to the second signal through measurement.

[0180] Optionally, the receiving end or the transmitting end may also determine the second precoding matrix based on channel measurement information corresponding to the second signal. For example, the receiving end may determine the second precoding matrix from multiple precoding matrices in the second codebook based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook, wherein the information about the multiple precoding matrices in the second codebook and the first precoding matrix correspond to multiple precoding matrices in the third codebook. For another example, the receiving end may also send the channel measurement information corresponding to the second signal to the transmitting end, so that the transmitting end may determine the second precoding matrix from multiple precoding matrices in the second codebook based on the channel measurement information corresponding to the second signal and information about the multiple precoding matrices in the second codebook.

[0181] The information of multiple precoding matrices in the second codebook is described below with reference to Table 2.

[0182] For example, the index of the first precoding matrix in the first codebook is 0, and the indication information of the multiple precoding matrices in the second codebook includes the indices of the multiple precoding matrices in the second codebook, which are 0, 1, 2, 3, and 4, respectively. The precoding matrices with indices 0, 1, 2, 3, and 4 correspond to the precoding matrices with indices 10, 9, 8, 7, and 6 in the third codebook, respectively. The RIS uses the precoding matrices with indices 10, 9, 8, 7, and 6 in the third codebook to receive the second signal in the order of 5, 4, 3, 2, and 1. Optionally, in this example, the correspondence between the first precoding matrix, the indices of the multiple precoding matrices in the second codebook, the indices of the multiple precoding matrices in the third codebook, and the usage order information is shown in Table 2.

[0183] Table 2

[0184]

[0185]

[0186] Optionally, the information of the multiple precoding matrices in the second codebook may include indication information (such as indexes) of the multiple precoding matrices in the second codebook, such as the content of the second row shown in Table 2.

[0187] The information of the multiple precoding matrices in the second codebook may further include indication information (such as an index) of the precoding matrix in the third codebook corresponding to the first precoding matrix and the multiple precoding matrices in the second codebook, such as the content of the third row in Table 2.

[0188] The information on the multiple precoding matrices in the second codebook may further include a correspondence between the first precoding matrix and the multiple precoding matrices in the second codebook and the multiple precoding matrices in the third codebook, such as the contents of rows 1 to 3 in Table 2, or the contents of rows 2 to 3, to indicate the correspondence between the multiple precoding matrices in the second codebook and the multiple precoding matrices in the third codebook.

[0189] The information about the multiple precoding matrices in the second codebook may also include usage time information or usage order information corresponding to the multiple precoding matrices in the second codebook. Taking the usage order information as an example, the usage order information may be used to indicate the correspondence between the indexes and usage order numbers of the multiple precoding matrices in the third codebook. For example, the usage order information may include the contents of rows 2 and 4 in Table 2 to indicate the usage order numbers of the precoding matrices in the second codebook. For another example, the usage order information may include the contents of rows 3 and 4 to indicate the correspondence between the indexes and usage order numbers of the multiple precoding matrices in the second codebook, or may include the contents of rows 2 through 4.

[0190] In addition, the information of the multiple precoding matrices in the second codebook may further include a correspondence between the first precoding matrix and the multiple precoding matrices in the second codebook, such as the contents of the first and second rows shown in Table 2.

[0191] Optionally, the usage time information may be an index of a time unit in which the precoding matrix in the third codebook is used when the RIS reflects the second signal. For example, the usage sequence number in Table 2 may be replaced with a time unit index, or a row may be added to Table 2 to carry the time unit index. The usage sequence information may be determined based on the usage time information.

[0192] Exemplarily, the information of multiple precoding matrices in the second codebook may include the contents of rows 1 to 4 in Table 2, or include the contents of rows 2 to 4 in Table 2, or include the contents of rows 2 to 3 and the contents of rows 3 to 4, and so on. No further examples are given.

[0193] Taking the information of multiple precoding matrices in the second codebook including the contents of the 2nd and 4th rows in Table 2 as an example, after determining the order indication information of the optimal precoding matrix in the third codebook according to the channel measurement information corresponding to the second signal, the precoding matrix in the second codebook corresponding to the optimal precoding matrix in the third codebook can be determined according to the contents of the 2nd and 4th rows. This precoding matrix is ​​the second precoding matrix.

[0194] In the present application, the RIS may transmit information about the multiple precoding matrices in the second codebook to the network device, i.e., after the RIS determines the multiple precoding matrices to be used for reflecting the second signal and / or determines the time or order of the multiple precoding matrices to be used, the RIS may indicate this to the network device. Alternatively, the network device may transmit information about the multiple precoding matrices in the second codebook to the RIS, i.e., after the network device determines the multiple precoding matrices to be used for reflecting the second signal and / or determines the time or order of the multiple precoding matrices to be used, the network device may indicate this to the RIS. Furthermore, the information about the multiple precoding matrices in the second codebook may also be protocol-defined or determined through preconfiguration or predefined means. For example, the multiple precoding matrices may default to all precoding matrices in the second codebook, and the order of use of the multiple precoding matrices in the third codebook may be related to the index size of the precoding matrix.

[0195] Optionally, before S802, the network device may further send second indication information to the RIS. The second indication information may be used to instruct the RIS to receive the first signal using multiple precoding matrices in the third codebook. Optionally, the second indication information may include information about multiple precoding matrices in the second codebook, wherein the information about the multiple precoding matrices in the second codebook and the first precoding matrix correspond to multiple precoding matrices in the third codebook. Therefore, the network device is aware of the information about the multiple precoding matrices in the second codebook. Alternatively, the second indication information may include indication information about the multiple precoding matrices in the second codebook.

[0196] Exemplarily, the second indication information may include indication information of the first precoding matrix and / or indication information of multiple precoding matrices in the second codebook. The RIS determines the multiple precoding matrices in the third codebook based on the indication information of the first precoding matrix and the indication information of the multiple precoding matrices in the second codebook. Therefore, the RIS does not need to be pre-configured with all the precoding matrices in the third codebook. The RIS only needs to support determining the precoding matrices in the third codebook based on the precoding matrices in the first codebook and the precoding matrices in the second codebook. For example, the RIS may support determining the precoding matrices in the third codebook based on the precoding matrices in the first codebook and the precoding matrices in the second codebook through table lookup or calculation. Optionally, the multiple precoding matrices in the second codebook may be preconfigured, predefined, or protocol-defined, for example, all the precoding matrices in the second codebook. The indication information of the first precoding matrix may also be sent independently of the second indication information, without specific limitation.

[0197] In addition, the second indication information may also include indication information of the multiple precoding matrices in the third codebook, so RIS does not need to be processed, which can reduce the processing complexity of RIS.

[0198] As one possible implementation of determining the second precoding matrix, when the receiving end includes a network device, the network device may obtain information about multiple precoding matrices in the second codebook. Furthermore, when the receiving end includes a terminal device, the terminal device may obtain information about multiple precoding matrices in the second codebook from the network device.

[0199] Taking the channel measurement result including RSRP as an example, when the channel measurement information corresponding to the second signal includes the channel measurement result, the receiving end may determine, based on the RSRP corresponding to the second signal, that the optimal RSRP is the RSRP when the second signal is reflected by the precoding matrix in the yth third codebook used in chronological order by the RIS. Further, based on the contents of rows 2 to 4 in Table 2, the receiving end may determine the index of the precoding matrix in the second codebook corresponding to the precoding matrix in the yth third codebook used in chronological order, thereby determining the precoding matrix with this index in the second precoding matrix as the second precoding matrix.

[0200] Similarly, when the channel measurement information corresponding to the first signal includes sequence indication information, and the sequence indication information indicates y, this indicates that the RSRP when reflecting the second signal using the precoding matrix in the yth third codebook, which is used in chronological order by the RIS, is the optimal RSRP. Further, based on the contents of rows 2 to 4 in Table 2, the receiving end can determine the index of the precoding matrix in the second codebook corresponding to the precoding matrix in the yth third codebook, which is used in chronological order, and thereby determine that the precoding matrix with this index in the second precoding matrices is the second precoding matrix.

[0201] As another possible implementation method for determining the second precoding matrix, optionally, when the receiving end includes a terminal device, the terminal device may send channel measurement information corresponding to the second signal to the network device (i.e., the transmitting end), so that the network device determines the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook. The manner in which the network device determines the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook can refer to the manner in which the network device determines the second precoding matrix when it is the receiving end, and is not further described.

[0202] As another possible implementation method for determining the second precoding matrix, optionally, when the receiving end includes a terminal device, the network device (i.e., the transmitting end) or the RIS may also send information about multiple precoding matrices in the second codebook to the terminal device, so that the terminal device can determine the second precoding matrix based on the channel measurement information corresponding to the second signal and the information about the multiple precoding matrices in the second codebook. The manner in which the terminal device determines the second precoding matrix based on the channel measurement information corresponding to the second signal and the information about the multiple precoding matrices in the second codebook can refer to the manner in which the network device determines the second precoding matrix when the receiving end is used, and is not further described.

[0203] As another possible implementation method for determining the second precoding matrix, the receiving end may also transmit channel measurement information corresponding to the second signal to the RIS, so that the RIS determines the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook. The manner in which the RIS determines the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook can be referenced to the manner in which the network device determines the second precoding matrix as the receiving end, and is not further described.

[0204] Therefore, in the present application, the second precoding matrix can be determined by the receiving end, the transmitting end, or the RIS based on the channel measurement information corresponding to the second signal. If the second precoding matrix is ​​determined by the receiving end or the transmitting end, the receiving end or the transmitting end can send indication information of the second precoding matrix to the RIS, so that the RIS can determine the second precoding matrix based on the indication information of the second precoding matrix from the receiving end or the transmitting end. In other words, the second precoding matrix can be determined by the terminal device, the network device, or the RIS based on the channel measurement information corresponding to the second signal. If the second precoding matrix is ​​determined by the terminal device or the network device, the terminal device or the network device can also send indication information of the second precoding matrix to the RIS, so that the RIS can determine the second precoding matrix based on the indication information of the second precoding matrix from the terminal device or the network device.

[0205] Based on the process shown in Figure 8, the RIS can receive a first signal and reflect a second signal. Channel measurement information corresponding to the first signal and the second signal can be used to determine a first precoding matrix and a second precoding matrix, respectively. The first and second precoding matrices correspond to a third precoding matrix in a third codebook, thus enabling the RIS to determine the precoding matrix in the third codebook.

[0206] The method for determining the third precoding matrix based on the first and second precoding matrices corresponds to the method for decoupling the third codebook to obtain the first and second codebooks. Optionally, the third precoding matrix can be obtained by multiplying the first and second precoding matrices. In addition, for the decoupling method shown in Figure 6, the third precoding matrix can also be obtained by adding the first and second precoding matrices.

[0207] Optionally, in the present application, the RIS does not need to be configured with a third codebook. It only needs to determine the corresponding precoding matrix in the third precoding matrix according to the first precoding matrix and the second precoding matrix after knowing the first precoding matrix and the third precoding matrix.

[0208] It is understood that the process shown in Figure 8 may also include: the RIS sending RIS codebook information to the network device. The RIS codebook information includes, but is not limited to, at least one of the following: the RIS's first codebook, second codebook, third codebook, information about the method for decoupling the third codebook to obtain the first and second codebooks, and the beam scanning range corresponding to the precoding matrix. The beam scanning range may indicate the maximum range of the beam covered by the RIS after all precoding matrices are configured. For example, the beam scanning range is 120 degrees horizontally and 60 degrees vertically.

[0209] Optionally, before S801, the network device may send configuration information to at least one of the RIS, the transmitter, or the receiver to configure the RIS to perform the method shown in Figure 8. Alternatively, the RIS may be configured to perform the method shown in Figure 8 by pre-configuration, pre-definition, or protocol definition.

[0210] In addition, before S801, the transmitting end may use a beam aligned with the RIS, such as a beam whose beam direction is aligned with the position of the RIS. For example, if the transmitting end's transmission codebook includes multiple precoding matrices, the transmitting end may use the precoding matrix with the best channel quality with the RIS to send signals (including but not limited to the first signal and the second signal) to the RIS. Alternatively, in the process shown in Figure 8, the transmitting end may also use any precoding matrix in the transmission codebook. After determining the first precoding matrix and / or the second precoding matrix in the process shown in Figure 8, the optimal precoding matrix in the transmitting end's transmission codebook is determined. Similarly, before S802, the receiving end may use a beam aligned with the RIS to receive signals (including but not limited to the first signal and the second signal), or, after the process shown in Figure 8, the receiving end may use any precoding matrix in the receiving end's reception codebook to receive signals.

[0211] The following takes uplink communication and downlink communication as examples to introduce possible implementation methods based on the process shown in Figure 8.

[0212] As shown in Figure 9, in downlink communication, the transmitting end is the network device and the receiving end is the terminal device. When the RIS has channel measurement capabilities, the network device may send first indication information to the RIS, instructing the RIS to use multiple precoding matrices in a first codebook (i.e., the network device-side codebook of the RIS) to receive the first signal. The network device may also send a first signal to the RIS. The RIS receives the first signal using multiple precoding matrices in the first codebook and determines a first precoding matrix from the multiple precoding matrices based on the channel measurement information corresponding to the first signal. The RIS may also send indication information of the first precoding matrix to the network device. In response, the network device may determine the first precoding matrix based on the indication information. Furthermore, after determining the first precoding matrix, the network device may determine multiple precoding matrices in a third codebook (i.e., the concatenated codebook of the RIS) based on the first precoding matrix. These multiple precoding matrices correspond to the first precoding matrix and the multiple precoding matrices in the second codebook (i.e., the terminal device-side codebook of the RIS). The network device may further transmit second indication information to instruct the RIS to receive the first signal using multiple precoding matrices in a third codebook, where the multiple precoding matrices correspond to the first precoding matrix and the multiple precoding matrices in the second codebook. The network device may also transmit a second signal to the RIS, which reflects the second signal toward the terminal device using the multiple precoding matrices in the third codebook. The terminal device receives the second signal and determines channel measurement information corresponding to the second signal. The terminal device transmits the channel measurement information corresponding to the second signal to the network device, which determines the second precoding matrix based on the channel measurement information corresponding to the second signal and information about the multiple precoding matrices in the second codebook. Exemplarily, the information about the multiple precoding matrices in the second codebook may include the information shown in Table 2. The network device may further transmit indication information of the second precoding matrix to the RIS, and the RIS may determine the second precoding matrix based on the indication information. The network device may also transmit indication information of the first precoding matrix and indication information of the second precoding matrix to the RIS, instructing the RIS to use the precoding matrix corresponding to the first precoding matrix and the second precoding matrix (i.e., the third precoding matrix) for signal transmission between the network device and the terminal device.

[0213] Optionally, the network device may further send control information to the RIS to instruct the RIS on the timing or order of using multiple precoding matrices in the first codebook when receiving the first signal. Optionally, the network device may further send information indicating the time-frequency resources occupied by the first signal to the RIS. The RIS may determine the time-frequency resources occupied by the first signal based on the information indicating the time-frequency resources, and receive the first signal based on the time-frequency resources.

[0214] Optionally, before sending the second signal, the network device may send control information to the RIS to instruct the RIS on the timing or order of using multiple precoding matrices in the third codebook when reflecting the second signal. Optionally, the network device may also send information indicating the time-frequency resources occupied by the second signal to the RIS. The RIS may determine information indicating the time-frequency resources occupied by the second signal based on the information indicating the time-frequency resources, and reflect the second signal based on the time-frequency resources.

[0215] As shown in Figure 10, in uplink communication, the transmitting end is a terminal device and the receiving end is a network device. When the RIS has channel measurement capabilities, the network device may send first indication information to the RIS, instructing the RIS to use multiple precoding matrices in a first codebook (i.e., the terminal device-side codebook of the RIS) to receive a first signal. Optionally, the network device may also send indication information of the time-frequency resources occupied by the first signal to the terminal device, so that the terminal device may transmit the first signal using these time-frequency resources. The terminal device may send the first signal to the RIS, and the RIS may receive the first signal based on the multiple precoding matrices in the first codebook and determine the first precoding matrix from the multiple precoding matrices based on the channel measurement information corresponding to the first signal. The RIS may also send indication information of the first precoding matrix to the network device, and the network device may determine the first precoding matrix based on this indication information. Furthermore, after determining the first precoding matrix, the network device may determine multiple precoding matrices in a third codebook (i.e., the concatenated codebook of the RIS) based on the first precoding matrix. These multiple precoding matrices correspond to the first precoding matrix and the multiple precoding matrices in the second codebook (i.e., the network device codebook of the RIS). The network device may also send second indication information to the RIS, instructing the RIS to receive the first signal using multiple precoding matrices in the third codebook, where the multiple precoding matrices correspond to the first precoding matrix and the multiple precoding matrices in the second codebook. Optionally, the network device may also send indication information of the time-frequency resources occupied by the second signal to the terminal device, so that the terminal device can transmit the second signal using these time-frequency resources. The terminal device may also transmit a second signal, and the RIS reflects the second signal to the network device using the multiple precoding matrices in the third codebook. Accordingly, the network device receives the second signal and determines channel measurement information corresponding to the second signal. The network device may further determine the second precoding matrix based on the channel measurement information corresponding to the second signal and information about the multiple precoding matrices in the second codebook. Exemplarily, the information about the multiple precoding matrices in the second codebook may include the information shown in Table 2. The network device may further send indication information about the second precoding matrix to the RIS, instructing the RIS to use the precoding matrix corresponding to the first and second precoding matrices (i.e., the third precoding matrix) for transmitting signals between the network device and the terminal device.

[0216] Optionally, the network device may also send control information to the RIS to instruct the RIS on the time or order of using multiple precoding matrices in the first codebook to receive the first signal. Optionally, the network device may also send information indicating the time-frequency resources occupied by the first signal to the RIS. Based on this information, the RIS may determine the time-frequency resources occupied by the first signal and receive the first signal based on these time-frequency resources. Optionally, before the terminal device sends the second signal, the network device may also send control information to the RIS or the terminal device to instruct the RIS on the time or order of using multiple precoding matrices in the second codebook to reflect the second signal. Optionally, the network device may also send information indicating the time-frequency resources occupied by the second signal to the RIS. Based on this information, the RIS may determine the time-frequency resources occupied by the second signal and reflect the second signal based on these time-frequency resources.

[0217] Optionally, in the processes shown in FIG9 and FIG10 , the RIS may further report capability information to the network device, where the capability information may indicate that the RIS has the capability of channel measurement and / or determining a precoding matrix.

[0218] The present embodiment also provides another communication method, as shown in Figure 11. This method differs from the communication method shown in Figure 8 in that the process shown in Figure 11 does not require the RIS to have measurement capabilities, and does not require the RIS's incident-side optimal codebook to be determined first. In contrast, in the process shown in Figure 8, the first precoding matrix is ​​determined first, followed by the second precoding matrix. The first precoding matrix is ​​included in the RIS's incident-side codebook, and the second precoding matrix is ​​included in the RIS's outgoing-side codebook.

[0219] As shown in FIG11 , a communication method provided in an embodiment of the present application may include the following steps:

[0220] S1101: The RIS reflects a third signal to a receiving end through a first set of precoding matrices, where the third signal comes from a transmitting end. Channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix.

[0221] In S1101, the first group of precoding matrices is a plurality of precoding matrices in a third codebook. The first group of precoding matrices corresponds to a plurality of precoding matrices in a fourth codebook and a precoding matrix in a fifth codebook, and the plurality of precoding matrices in the fourth codebook include the fourth precoding matrix. That is, the fourth precoding matrix can be determined from the plurality of precoding matrices in the fourth codebook based on channel measurement information corresponding to the third signal.

[0222] In this application, the fourth codebook and the fifth codebook are respectively one of the first codebook and the second codebook of the RIS, and the fourth codebook is different from the fifth codebook. Therefore, the fourth precoding matrix is ​​a precoding matrix in the first codebook or a precoding matrix in the second codebook. As described in S801, the first codebook can be used to adjust the channel characteristics between the transmitter and the RIS, or it can be said that the first codebook is the input side codebook of the RIS. The second codebook is used to adjust the channel characteristics between the RIS and the receiver, or it can be said that the second codebook is the output side codebook of the RIS. The first codebook and the second codebook are used to determine the third codebook. The third codebook is used to adjust the channel characteristics between the transmitter, the RIS, and the receiver, or it can be said that the third codebook is the concatenated codebook of the RIS.

[0223] It can be understood that the first group of precoding matrices corresponds to multiple precoding matrices in the fourth codebook and one precoding matrix in the fifth codebook, which means that the multiple precoding matrices in the first group of precoding matrices correspond to one precoding matrix in the fifth codebook and one of the multiple precoding matrices in the fourth codebook, respectively.

[0224] Referring to the description of the channel measurement information corresponding to the first signal or the second signal in this application, the channel measurement information corresponding to the third signal may include the channel measurement result of the third signal, or include time indication information or sequence indication information determined based on the channel measurement result of the third signal.

[0225] In addition, the RIS, the receiving end, or the transmitting end may determine the fourth precoding matrix based on the channel measurement information corresponding to the third signal and information about multiple precoding matrices in the fourth codebook. It will be understood that the manner in which the RIS, the receiving end, or the transmitting end determines the fourth precoding matrix based on the channel measurement information corresponding to the third signal and information about multiple precoding matrices in the fourth codebook can be referred to the aforementioned description of the RIS, the receiving end, or the transmitting end determining the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook, and will not be repeated here.

[0226] With reference to the aforementioned description of the information of the multiple precoding matrices in the second codebook, the information of the multiple precoding matrices in the fourth codebook may include indication information (such as indices) of the multiple precoding matrices in the fourth codebook, the correspondence between the precoding matrix in the fifth codebook, the multiple precoding matrices in the fourth codebook, and the multiple precoding matrices in the third codebook, or usage time information or usage order information corresponding to the multiple precoding matrices in the fourth codebook. For example, the index of the first precoding matrix in Table 2 in the first codebook may be replaced with the index of the precoding matrix in the fifth codebook, and the indexes of the multiple precoding matrices in the second codebook in Table 2 may be replaced with the indexes of the multiple precoding matrices in the fourth codebook. The information of the multiple precoding matrices in the fourth codebook may include the replaced Table 2.

[0227] Optionally, if the fourth precoding matrix is ​​determined by the receiving end or the transmitting end, the network device may further send indication information of the fourth precoding matrix to the RIS, so that the RIS determines the fourth precoding matrix based on the indication information. If the fourth precoding matrix is ​​determined by the RIS, the RIS may further send indication information of the fourth precoding matrix to the network device, so that the network device determines the fourth precoding matrix based on the indication information.

[0228] Optionally, before S1101, the network device may send third indication information to the RIS, instructing the RIS to reflect the third signal to the receiving end using the first set of precoding matrices. The third indication information may include indication information of the first set of precoding matrices (e.g., the index of each precoding matrix in the first set of precoding matrices in the third codebook). Alternatively, the third indication information may include indication information of multiple precoding matrices in the fourth codebook and / or indication information of a precoding matrix in the fifth codebook. Thus, the RIS may determine the first set of precoding matrices based on the indication information of the multiple precoding matrices and the indication information of the precoding matrix in the fifth codebook. The multiple precoding matrices in the fourth codebook may also be preconfigured, predefined, or protocol-defined, for example, all precoding matrices in the fourth codebook. The precoding matrix in the fifth codebook may also be preconfigured, predefined, or protocol-defined, for example, a default precoding matrix.

[0229] S1102: The RIS reflects a fourth signal to the receiving end through the second set of precoding matrices, where the fourth signal comes from the transmitting end. Channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix.

[0230] In S1102, the second group of precoding matrices is a plurality of precoding matrices in a third codebook. The second group of precoding matrices corresponds to a fourth precoding matrix and a plurality of precoding matrices in a fifth codebook, and the plurality of precoding matrices in the fifth codebook include the fifth precoding matrix. That is, the fifth precoding matrix can be determined from the plurality of precoding matrices in the fifth codebook based on channel measurement information corresponding to the fourth signal.

[0231] It can be understood that the second group of precoding matrices corresponding to the fourth precoding matrix and multiple precoding matrices in the fifth codebook means that the multiple precoding matrices in the second group of precoding matrices correspond to one of the fourth precoding matrix and the multiple precoding matrices in the fifth codebook respectively.

[0232] Referring to the description of the channel measurement information corresponding to the first signal or the second signal in this application, the channel measurement information corresponding to the fourth signal may include the channel measurement result of the fourth signal, or include time indication information or sequence indication information determined based on the channel measurement result of the fourth signal.

[0233] In addition, the RIS, the receiving end, or the transmitting end may determine the fifth precoding matrix based on the channel measurement information corresponding to the fourth signal and information about multiple precoding matrices in the fifth codebook. It will be understood that the manner in which the RIS, the receiving end, or the transmitting end determines the fifth precoding matrix based on the channel measurement information corresponding to the fourth signal and information about multiple precoding matrices in the fifth codebook can be referred to the aforementioned description of the RIS, the receiving end, or the transmitting end determining the second precoding matrix based on the channel measurement information corresponding to the second signal and information about multiple precoding matrices in the second codebook, and will not be repeated here.

[0234] With reference to the aforementioned description of the information of the multiple precoding matrices in the second codebook, the information of the multiple precoding matrices in the fifth codebook may include indication information (such as indices) of the multiple precoding matrices in the fifth codebook, correspondences between the fourth precoding matrix and the multiple precoding matrices in the fifth codebook and the multiple precoding matrices in the third codebook, or usage time information or usage order information corresponding to the multiple precoding matrices in the fifth codebook. For example, the index of the first precoding matrix in the first codebook in Table 2 may be replaced with the index of the fourth precoding matrix in the fourth codebook, and the indexes of the multiple precoding matrices in the second codebook in Table 2 may be replaced with the indexes of the multiple precoding matrices in the fifth codebook. The information of the multiple precoding matrices in the fifth codebook may include the replaced Table 2.

[0235] Optionally, if the fifth precoding matrix is ​​determined by the receiving end or the transmitting end, the network device may further send indication information of the fifth precoding matrix to the RIS, so that the RIS determines the fifth precoding matrix based on the indication information. If the fifth precoding matrix is ​​determined by the RIS, the RIS may further send indication information of the fifth precoding matrix to the network device, so that the network device determines the fifth precoding matrix based on the indication information.

[0236] Optionally, before S1102, the network device may send fourth indication information to the RIS, instructing the RIS to reflect the fourth signal to the receiving end using the second set of precoding matrices. The fourth indication information may include indication information of the second set of precoding matrices (e.g., the index of each precoding matrix in the second set of precoding matrices in the third codebook). Alternatively, the fourth indication information may include indication information of the fourth precoding matrix and / or indication information of multiple precoding matrices in the fifth codebook. Thus, the RIS may determine the second set of precoding matrices based on the indication information of the fourth precoding matrix and the indication information of the multiple precoding matrices in the fifth codebook. The multiple precoding matrices in the fifth codebook may also be preconfigured or predefined, for example, all precoding matrices in the fifth codebook. The indication information of the fourth precoding matrix may also be sent independently of the fourth indication information, without specific limitation.

[0237] Based on the process shown in Figure 11, the RIS can reflect the third signal using the first set of precoding matrices and reflect the fourth signal using the second set of precoding matrices. The channel measurement information corresponding to the third signal and the channel measurement information corresponding to the fourth signal can be used to determine the fourth precoding matrix and the fifth precoding matrix, respectively. The fourth and fifth precoding matrices can be used to determine the sixth precoding matrix, thereby enabling the determination of the precoding matrices in the third codebook of the RIS.

[0238] The manner of determining the sixth precoding matrix according to the fourth precoding matrix and the fifth precoding matrix corresponds to the manner of decoupling the third codebook to obtain the first codebook and the second codebook.

[0239] Optionally, in the process shown in FIG11 , the network device may send information to the RIS to indicate whether the fourth codebook is the first codebook or the second codebook, or to indicate whether the fifth codebook is the first codebook or the fifth codebook. Furthermore, the RIS may also use a default method to determine whether the fourth codebook is the first codebook or the second codebook. For example, if the RIS scans the first codebook first by default, i.e., the fourth codebook is the first codebook, then the network device only needs to indicate the index in the first codebook to be scanned.

[0240] Optionally, the network device may carry information in the third indication information and / or the fourth indication information, used to indicate that the fourth codebook is the first codebook or the second codebook, or used to indicate that the fifth codebook is the first codebook or the fifth codebook.

[0241] It is understood that the process shown in FIG11 may further include: the RIS sending RIS codebook information to the network device. The RIS codebook information includes, but is not limited to, the RIS first codebook, second codebook, third codebook, information about the method for decoupling the third codebook to obtain the first codebook and the second codebook, and the scanning range of the beam.

[0242] Optionally, in the process shown in FIG11 , the network device may further indicate to the RIS which codebooks need to be scanned (or need to be repeated (repetition off)) when reflecting the third signal and / or the fourth signal, and / or indicate which codebooks do not need to be scanned (or referred to as fixed or do not need to be repeated (repetition on)). The codebook that needs to be scanned when reflecting the third signal is the fourth codebook, and the codebook that does not need to be scanned when reflecting the third signal is the fifth codebook; the codebook that needs to be scanned when reflecting the fourth signal is the fifth codebook, and the codebook that does not need to be scanned when reflecting is the fourth codebook. For example, before S1101, the network device may send information to the RIS indicating that the incident-side codebook does not need to be scanned, in which case the fourth codebook is the outgoing-side codebook, and the fifth codebook is the incident-side codebook. For another example, before S1105, the network device may send information to the RIS indicating that the outgoing-side codebook does not need to be scanned, in which case the fifth codebook is the incident-side codebook, and the fourth codebook is the outgoing-side codebook.

[0243] Furthermore, the RIS may be instructed to determine, through preconfiguration, predefinition, protocol definition, or negotiation, whether a codebook needs to be scanned or not scanned when reflecting the third signal, and / or whether a codebook needs to be scanned or not scanned when reflecting the fourth signal. It will be appreciated that the codebook that the RIS needs to scan when reflecting the third signal is different from the codebook that the RIS needs to scan when reflecting the fourth signal, and these two codebooks are respectively one of the incident-side codebook and the outgoing-side codebook of the RIS.

[0244] The following takes uplink communication as an example to introduce a method based on the process shown in Figure 11.

[0245] As shown in Figure 12, in uplink communication, the transmitting end is a terminal device, and the receiving end is a network device. The RIS can report its codebook information to the network device. The network device can send control information to the RIS, which may include third indication information instructing the RIS to reflect a third signal to the receiving end using the first set of precoding matrices. The third indication information may include information about the time or order in which the RIS uses the precoding matrices when reflecting the third signal, and / or the index of a precoding matrix that must be fixed when reflecting the third signal. The precoding matrix that must be fixed when reflecting the third signal is a precoding matrix from the fifth codebook.

[0246] Optionally, the control information may further include information indicating the order in which the incident-side codebook and the outgoing-side codebook of the RIS are scanned. The indication information may be used to indicate a fourth codebook from the first codebook and the second codebook, or to indicate a fifth codebook from the first codebook and the second codebook. For example, when the indication information indicates that the fourth codebook is the first codebook, it means that the incident-side codebook of the RIS is scanned first, followed by the outgoing-side codebook of the RIS.

[0247] Optionally, the control information may also include indication information of the time-frequency resources occupied by the third signal and / or the fourth signal. The RIS may determine the time-frequency resources occupied by the third signal and / or the fourth signal based on the indication information, so as to reflect the third signal and / or the fourth signal based on the time-frequency resources.

[0248] Optionally, before the terminal device sends the third signal, the network device may also send indication information of the time-frequency resources occupied by the third signal to the terminal device, so that the terminal device sends the third signal according to the time-frequency resources.

[0249] As shown in Figure 12, the terminal device can transmit a third signal, which is reflected by the RIS to the network device using a first set of precoding matrices, where the first set of precoding matrices corresponds to multiple precoding matrices in the fourth codebook and one precoding matrix in the fifth codebook. Accordingly, the network device can receive the third signal and determine channel measurement information corresponding to the third signal. The network device can also determine a fourth precoding matrix from multiple precoding matrices in the fourth codebook based on the channel measurement information corresponding to the third signal and information about the multiple precoding matrices in the fourth codebook.

[0250] Optionally, after determining the fourth precoding matrix, the network device may further send control information to the RIS, which may include fourth indication information. The fourth indication information may include information about the time or order of use of the precoding matrix by the RIS when reflecting the fourth signal, and / or the index of a precoding matrix that needs to be fixed when reflecting the fourth signal. For the fourth signal, the precoding matrix that needs to be fixed when reflecting the signal is the fourth precoding matrix.

[0251] Optionally, the control information may further include indication information of the time-frequency resources occupied by the fourth signal. The RIS may determine the time-frequency resources occupied by the fourth signal according to the indication information, so as to reflect the fourth signal according to the time-frequency resources.

[0252] In addition, optionally, before the terminal device sends the fourth signal, the network device may also send indication information of the time-frequency resources occupied by the fourth signal to the terminal device.

[0253] As shown in Figure 12, the terminal device may also transmit a fourth signal, and the RIS reflects the fourth signal using a second set of precoding matrices, where the second set of precoding matrices corresponds to the fourth precoding matrix and multiple precoding matrices in the fifth codebook. The network device receives the fourth signal and determines channel measurement information corresponding to the fourth signal. The network device may also determine a fifth precoding matrix from multiple precoding matrices in the fifth codebook based on the channel measurement information corresponding to the fourth signal and information about the multiple precoding matrices in the fifth codebook.

[0254] Optionally, the network device may send indication information of the fourth precoding matrix and / or indication information of the fifth precoding matrix to the RIS. The indication information of the fourth precoding matrix may be sent before the network device sends the control information including the fourth precoding matrix, or may be sent after the fifth precoding matrix is ​​determined. The indication information of the fourth precoding matrix may also be included in the control information, without specific limitation.

[0255] It can be understood that based on the processes shown in Figures 8 to 12, assuming that the number of precoding matrices in the first codebook is M and the number of precoding matrices in the second codebook is N, the number of precoding matrices in the third codebook is I = M × N. Therefore, if the RIS uses multiple precoding matrices in the third codebook to reflect signals between the transmitter and the receiver, it is necessary to use I = M × N precoding matrices to complete the scanning of the multiple precoding matrices in the third codebook. However, according to the method shown in Figures 8 or 11 above, the RIS only needs to receive the first signal using the M precoding matrices in the first codebook (i.e., use M precoding matrices) and reflect the second signal using the N precoding matrices in the second codebook (i.e., use N precoding matrices). A total of M + N precoding matrices are used, i.e., M + N precoding matrix scans are performed, without having to use I = M × N precoding matrices in the third codebook. This can greatly reduce the number of scans and the scanning time.

[0256] As shown in Table 3, taking M and N = 128 as an example, the codebook scanning method shown in Figure 8 or Figure 11 can greatly reduce the number of scanned precoding matrices and the scanning time compared to the solution of performing codebook scanning according to the third codebook.

[0257] Table 3

[0258]

[0259] Optionally, M is less than N, for example, M = Y × N, 0 < Y < 1. Since the positional relationship between the network device and the RIS is generally relatively fixed, the number of precoding matrices in the network device-side codebook of the RIS can be appropriately reduced during the decoupling of the cascaded codebook, such that the number of network device-side codebooks of the RIS is smaller than the number of terminal device-side codebooks of the RIS. Furthermore, / or the scanning range of the network device-side codebook of the RIS can be reduced, such that the scanning range of the network device-side codebook of the RIS is smaller than the scanning range of the terminal device-side codebook of the RIS.

[0260] The embodiment of the present application also provides another communication method for reducing the signaling overhead during the codebook scanning process of RIS.

[0261] The following describes the method using the example of a first device and a RIS as the execution entities. The first device can function as either a transmitter or a receiver. It is understood that, in this application, the first and second devices can communicate via the RIS. For example, the first device can function as a transmitter and the second device as a receiver, or vice versa.

[0262] As shown in FIG13 , a communication method provided in an embodiment of the present application includes the following steps:

[0263] S1301: A first device obtains first information, wherein the first information is used to determine a first precoding matrix and / or a second precoding matrix, the first precoding matrix belongs to a first codebook, and the second precoding matrix belongs to a second codebook.

[0264] As described in S801, a precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook of the RIS. The first codebook can be used to adjust the channel characteristics between the transmitter and the RIS, that is, the first codebook is the input-side codebook of the RIS. In addition, the second codebook is used to adjust the channel characteristics between the RIS and the receiver, that is, the second codebook is the output-side codebook of the RIS. Optionally, the first codebook and / or the second codebook can be indicated by the network device, or can be determined by decoupling from the third codebook, or can be protocol-defined, preconfigured, or predefined, which is not specifically required by this application. The third codebook can be used to adjust the channel characteristics between the transmitter, the RIS, and the receiver, that is, the third codebook is the concatenated codebook of the RIS.

[0265] The first precoding matrix and / or the second precoding matrix may be determined based on the third precoding matrix and the first information. The third precoding matrix is ​​a precoding matrix in the third codebook. Specifically, the RIS may use multiple precoding matrices in the third codebook to reflect signals between the transmitter and the receiver. Channel measurement information corresponding to the signals may be used to determine the third precoding matrix from the multiple precoding matrices in the third codebook.

[0266] S1302: The first device sends second information to the RIS, where the second information is used to indicate the first precoding matrix and / or the second precoding matrix.

[0267] Optionally, the second information may include indication information (such as an index) of the first precoding matrix and / or indication information (such as an index) of the second precoding matrix.

[0268] Therefore, based on the method shown in Figure 13, the RIS can determine the first precoding matrix and / or the second precoding matrix based on the second information, where the first precoding matrix is ​​the input-side precoding matrix of the RIS, and the second precoding matrix is ​​the output-side precoding matrix of the RIS. Because the second information only needs to indicate the first precoding matrix and / or the second precoding matrix, and does not need to indicate the precoding matrices in the third codebook of the RIS, signaling overhead can be reduced.

[0269] Continuing with the example of M input beams and N output beams that need to be scanned spatially, each input beam corresponds to an input-side precoding matrix of the RIS, and each output beam corresponds to an output-side precoding matrix of the RIS. Therefore, the third codebook includes I = M × N precoding matrices. Therefore, indicating a single precoding matrix in the third codebook incurs significant signaling overhead. Using the method shown in Figure 13, only the first precoding matrix needs to be indicated from the M input-side precoding matrices, and the second precoding matrix from the N precoding matrices, significantly reducing signaling overhead.

[0270] As shown in Table 4, taking M, N = 128 as an example, the method shown in Figure 13 indicates the first precoding matrix and the second precoding matrix. Compared with the precoding matrix in the concatenated codebook indicating RIS, at least 6 bits of signaling overhead can be saved, and a lower quadrature amplitude modulation (QAM) order can be used to improve communication reliability.

[0271] Table 4

[0272] M=128, N=128 indicates the concatenation of RIS. Codebook indicates the first precoding matrix and the second precoding matrix. Air interface indication. Overhead 14 bits (bits). Modulation order 8 bits. 16QAM 8QAM

[0273] Referring to the description in S802, in the method shown in Figure 13, the first device, the RIS, or the second device can determine the third precoding matrix based on the channel measurement information corresponding to the reference signal and the information of multiple precoding matrices in the third codebook used when the RIS reflects the reference signal.

[0274] In which, referring to the description of the information of multiple precoding matrices in the third codebook in S802, the information of multiple precoding matrices in the third codebook used when the RIS reflects the reference signal may include indication information (such as an index) of the precoding matrix used when the RIS reflects the reference signal and usage time information or usage order information of the multiple precoding matrices.

[0275] Taking the example of the first device determining the third precoding matrix, the first device may determine the third precoding matrix and determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information. The third precoding matrix may be determined by the first device or the second device based on the channel measurement information.

[0276] As a possible implementation of the method shown in FIG. 13 , in S1301, the first information includes third information, where the third information indicates a correspondence between the first codebook, the second codebook, and the third codebook. The first apparatus may also obtain channel measurement information and determine a third precoding matrix based on the channel measurement information, where the third precoding matrix belongs to the third codebook. The first apparatus may also determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information.

[0277] Optionally, in this implementation, the RIS or the second device may send the third information to the first device, where the second device may obtain the third information from the RIS. Alternatively, the first device may obtain the third information according to a protocol definition, preconfiguration, or predefined method. The channel measurement information may be obtained by measuring a reference signal, which is transmitted between the first and second devices via the RIS. The RIS receives and modulates the reference signal using multiple precoding matrices in the third codebook.

[0278] As described in S801, the channel measurement information may include the channel measurement results corresponding to the reference signal, such as RSRP or SINR, or the channel measurement information may include time sequence indication information of the best channel quality determined based on the channel measurement results corresponding to the reference signal.

[0279] Optionally, a reference signal may be sent by the first device, reflected by the RIS using multiple precoding matrices in the third codebook, and received by the second device. Accordingly, the first device may receive channel measurement information from the second device, the channel measurement information being obtained by the second device measuring the reference signal.

[0280] Alternatively, the reference signal may be sent by the second device, the RIS may be polled using multiple precoding matrices in the third codebook to reflect the reference signal, and the first device may receive the reference signal. Accordingly, the first device may measure the reference signal to obtain channel measurement information.

[0281] It will be appreciated that in this implementation, the third information may include the correspondence between the precoding matrix in the first codebook, the precoding matrix in the second codebook, and the precoding matrix in the third codebook. Alternatively, the third information may include information about the manner in which the first codebook and the second codebook are determined by decoupling the third codebook, for example, including the functional relationship satisfied between the first codebook, the second codebook, and the third codebook, for example, the functional relationship shown in FIG6. Alternatively, the third information may include the functional relationship satisfied between the precoding matrix in the first codebook, the precoding matrix in the second codebook, and the precoding matrix in the third codebook.

[0282] As another possible implementation of the embodiment shown in Figure 13, in S1301, the first information is used to indicate the first precoding matrix and / or the second precoding matrix. For example, the first information includes indication information (such as an index) of the first precoding matrix and / or indication information (such as an index) of the second precoding matrix.

[0283] Optionally, in this implementation, the first device may transmit a reference signal, the second device may measure the reference signal and determine channel measurement information corresponding to the reference signal, and determine the third precoding matrix based on the channel measurement information. Furthermore, the second device may determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information.

[0284] Alternatively, in this possible implementation, the second device may transmit a reference signal, the first device may measure the reference signal and determine channel measurement information corresponding to the reference signal, and the first device may transmit the channel measurement information corresponding to the reference signal to the second device. Thus, the second device may determine a third precoding matrix based on the channel measurement information, and determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information.

[0285] Optionally, in this implementation, the first device and / or the RIS may send the third information to the second device. For the third information, refer to the description in the previous possible implementation.

[0286] As an example, in the process shown in Figure 13, the first device is a network device or a device included in the network device, and the second device is a terminal device or a device included in the terminal device. Therefore, the network device can indicate the first precoding matrix and / or the second precoding matrix to the RIS.

[0287] The following takes downlink communication as an example to introduce a method based on the process shown in Figure 13.

[0288] As shown in Figure 14, in downlink communication, a reference signal is sent by a network device to a terminal device. This description is based on the example of the first device shown in Figure 13 being a network device and the second device being a terminal device. Optionally, before sending the reference signal, the RIS may send codebook information to the network device. Exemplarily, the codebook information may also include the scanning range of the beam corresponding to the precoding matrix. Corresponding to S1301, the codebook information includes third information. Furthermore, the network device may also send control information to the RIS, including information on the time or order of use of multiple precoding matrices in the concatenated codebook when the RIS reflects the reference signal. Furthermore, the RIS may also send information on the time or order of use of multiple precoding matrices in the concatenated codebook when the RIS reflects the reference signal to the network device.

[0289] The use time information or use order information of multiple precoding matrices in the concatenated codebook when the RIS reflects the reference signal includes, for example, a correspondence between the precoding matrix in the third codebook and the index of the time unit using the precoding matrix.

[0290] Taking the time unit as a time slot as an example, as shown in Table 5, it is an exemplary correspondence between the precoding matrix and the scanning time slot. It can be seen that RIS uses the third codebook Φ in time slot 0 to time slot 3. m,n A precoding matrix in reflects the reference signal.

[0291] Table 5

[0292] Time slot 0123Φ m,n 3120

[0293] Among them, Φ m,n represents the precoding matrix in the third codebook, where m and n are the incident and outgoing beam indices corresponding to the precoding matrix, respectively. Therefore, the RIS can use the precoding matrix with index 3 in the third codebook in time slot 0, the precoding matrix with index 1 in time slot 1, and so on.

[0294] Optionally, the third information may include a precoding matrix correspondence relationship as shown in Table 6, where the correspondence relationship may be used to indicate a correspondence relationship between a precoding matrix in the third codebook, a precoding matrix in the first codebook, and a precoding matrix in the second codebook.

[0295] Table 6

[0296] Φ m,n 3120Φ m ,Φ n 1,10,11,00,0

[0297] Among them, Φ m and Φ n represents the precoding matrix in the first codebook and the precoding matrix in the second codebook, respectively. m and n represent the incident beam index and the output beam index corresponding to the precoding matrix, respectively. Table 5 shows that the precoding matrix with index 3 in the third codebook corresponds to the precoding matrix with index 1 in the first codebook and the precoding matrix with index 1 in the second codebook. It can be understood that the precoding matrix in the third codebook can be decoupled into its corresponding precoding matrix in the first codebook and its corresponding precoding matrix in the second codebook.

[0298] Alternatively, Table 4 and Table 5 may be combined into one table, such as shown in Table 7.

[0299] Table 7

[0300] Scan time slot 0123Φ m，n 3120Φ m ,Φ n 1,10,11,00,0

[0301] In addition, in Figure 14, the network device may transmit a reference signal, and the RIS may reflect the reference signal to the terminal device using multiple precoding matrices in the third codebook. Accordingly, the terminal device receives the reference signal and measures the reference signal to determine channel measurement information corresponding to the reference signal. The terminal device transmits the channel measurement information corresponding to the reference signal to the network device. The network device determines a third precoding matrix for the RIS based on the received channel measurement information corresponding to the reference signal and information about the multiple precoding matrices in the third codebook. The network device further determines a first precoding matrix and / or a second precoding matrix based on the third precoding matrix and the third information. Corresponding to S1302, the network device transmits second information to the RIS indicating the first precoding matrix and / or the second precoding matrix.

[0302] As shown in Figure 15, during downlink communications, a terminal device can receive control information from a network device, which may include third information, and thus can obtain the third information. The third information can be sent to the network device by the RIS via codebook information. Therefore, the terminal device can determine the third precoding matrix of the RIS based on downlink signal measurement results. Furthermore, the terminal device can determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix of the RIS and the third information. Thus, when the terminal device feeds back channel measurement data to the network device, it can send indication information of the first precoding matrix and / or indication information of the second precoding matrix to the network device, thereby reducing signaling overhead.

[0303] In addition, the difference between the processes shown in Figure 15 and Figure 14 is that the network device or the RIS can send control information to the terminal device, including the third information, so that the terminal device can determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix of the RIS and the third information. For example, the network device can send the third information to the terminal device before, simultaneously with, or after the network device sends the reference signal.

[0304] In addition, the network device may also send control information to the terminal device to indicate information about multiple precoding matrices in the third codebook, so that after the terminal device obtains channel measurement information corresponding to the reference signal through measurement, the terminal device determines the third precoding matrix based on the channel measurement information and information about the multiple precoding matrices in the third codebook. Furthermore, the terminal device determines the first precoding matrix and / or the second precoding matrix of the RIS based on the third precoding matrix and the third information.

[0305] In FIG15 , the terminal device may also send second information to the network device.

[0306] Illustratively, in FIG15 , the network device or RIS may also send the corresponding relationships shown in Table 5 and Table 6, or the corresponding relationship shown in Table 7, to the terminal device.

[0307] It can be understood that the terminal device in Figure 15 corresponds to the first device shown in Figure 13, and the network device shown in Figure 15 corresponds to the second device shown in Figure 13. For example, in Figure 15, the action of the terminal device receiving the control information including the third information from the network device may correspond to S1301 shown in Figure 13; in Figure 15, the action of the terminal device sending the second information to the network device may correspond to S1302 shown in Figure 13.

[0308] Optionally, in this application, if the channel measurement results corresponding to multiple precoding matrices are the same, or the time indication information or sequence indication information of the best channel measurement result corresponds to multiple precoding matrices, then a precoding matrix can be selected from the multiple precoding matrices as the best precoding matrix. The selection method includes random selection, selection according to index from large to small or from small to large, etc., and no specific requirements are made. It can be understood that the best precoding matrix here includes the first precoding matrix, the second precoding matrix, the third precoding matrix, or the fourth precoding matrix in this application.

[0309] It is understandable that in order to implement the functions in the above embodiments, the embodiments of the present application also provide a communication device. The communication device may include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0310] Figures 16 to 18 are schematic diagrams of the structures of possible communication devices provided by embodiments of the present application. The communication device can be used to implement the functions of the RIS, network device, first device, or second device in the above-mentioned method embodiments, and thus can also achieve the beneficial effects possessed by the above-mentioned method embodiments. In one possible implementation, the communication device can be any network device or terminal device as shown in Figures 1, 3, 4, 5, or 7, or any RIS as shown in Figures 3 to 5 or 7, or a module (such as a chip) applied to a terminal device, network device, or RIS. For relevant details and effects, please refer to the description of the aforementioned embodiments.

[0311] As shown in Figure 16 , communication device 1600 includes a processing unit 1610 and a communication unit 1620 , where communication unit 1620 may also be a transceiver unit or an input / output interface. Communication device 1600 may be used to implement the functions of the RIS, network device, first device, or second device in the method embodiments shown in Figures 8 to 15 .

[0312] Exemplarily, when the communication device 1600 is used to implement the RIS function in the method embodiment shown in FIG8 :

[0313] The communication unit 1620 may be configured to receive a first signal from a transmitting end using multiple precoding matrices in the first codebook of the RIS and further configured to reflect the second signal to the receiving end using multiple precoding matrices in the third codebook.

[0314] In a possible implementation, the processing unit 1610 may be configured to determine the first precoding matrix from a plurality of precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

[0315] In one possible implementation, the communication unit 1620 may be further configured to receive channel measurement information corresponding to the first signal. The processing unit 1610 may be further configured to determine the first precoding matrix from multiple precoding matrices in the first codebook of the RIS based on the channel measurement information corresponding to the first signal.

[0316] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the first precoding matrix to a network device.

[0317] In a possible implementation, the communication unit 1620 may be further configured to send channel measurement information corresponding to the first signal to a network device, where the network device includes the transmitting end or the receiving end.

[0318] In a possible implementation, the communication unit 1620 may be further configured to receive indication information of the first precoding matrix from a network device, and the processing unit 1610 may be configured to determine the first precoding matrix according to the indication information of the first precoding matrix.

[0319] In a possible implementation, the communication unit 1620 may be further configured to receive first indication information from a network device.

[0320] In a possible implementation, the communication unit 1620 may be further configured to receive indication information of the second precoding matrix from the network device, and the processing unit 1610 may be configured to determine the second precoding matrix according to the indication information of the second precoding matrix.

[0321] In one possible implementation, the communication unit 1620 may be further configured to receive channel measurement information corresponding to the second signal from the network device. The processing unit 1610 may be configured to determine the second precoding matrix from a plurality of precoding matrices in the second codebook based on the received channel measurement information corresponding to the second signal.

[0322] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the second precoding matrix to the network device.

[0323] In a possible implementation, the communication unit 1620 may be further configured to receive second indication information from the network device.

[0324] When the communication device 1600 is used to implement the functions of the network device in the method embodiment shown in FIG8 :

[0325] The communication unit 1620 may be configured to send first indication information to the RIS. The communication unit 1620 may also be configured to send second indication information to the RIS.

[0326] In a possible implementation, the communication unit 1620 may be further configured to receive indication information of the first precoding matrix from the RIS.

[0327] In one possible implementation, the communication unit 1620 may be further configured to receive channel measurement information corresponding to the first signal from the RIS. The processing unit 1610 may also be configured to determine the first precoding matrix from a plurality of precoding matrices in a first codebook of the RIS based on the channel measurement information corresponding to the first signal.

[0328] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the first precoding matrix to the RIS.

[0329] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the second precoding matrix to the RIS.

[0330] In one possible implementation, communication unit 1620 may be further configured to send channel measurement information corresponding to the second signal to the RIS. Communication unit 1620 may be further configured to receive indication information of the second precoding matrix from the RIS. Processing unit 1610 may be further configured to determine the second precoding matrix based on the indication information of the second precoding matrix.

[0331] When the communication device 1600 is used to implement the function of the RIS in the method embodiment shown in FIG11 :

[0332] The communication unit 1620 may be configured to reflect the third signal to the receiving end using the first set of precoding matrices. The communication unit 1620 may also be configured to reflect the fourth signal to the receiving end using the second set of precoding matrices.

[0333] In a possible implementation, the communication unit 1620 may be further configured to receive third indication information from the network device.

[0334] In a possible implementation, the communication unit 1620 may be further configured to receive indication information of the fourth precoding matrix from a network device. The processing unit 1610 may be further configured to determine the fourth precoding matrix according to the indication information of the fourth precoding matrix.

[0335] In a possible implementation, the communication unit 1620 may be further configured to receive fourth indication information from the network device.

[0336] In a possible implementation, the communication unit 1620 may be further configured to receive indication information of the fifth precoding matrix from a network device. The processing unit 1610 may be further configured to determine the fifth precoding matrix according to the indication information of the fifth precoding matrix.

[0337] When the communication device 1600 is used to implement the functions of the network device in the method embodiment shown in FIG11 :

[0338] The communication unit 1620 may be configured to send third indication information to the RIS. The communication unit 1620 may also be configured to send fourth indication information to the RIS.

[0339] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the fourth precoding matrix to the RIS.

[0340] In a possible implementation, the communication unit 1620 may be further configured to send indication information of the fifth precoding matrix to the RIS.

[0341] When the communication device 1600 is used to implement the function of the first device in the method embodiment shown in FIG13 :

[0342] The processing unit 1610 may be configured to obtain first information. The communication unit 1620 may also be configured to send second information to the RIS.

[0343] In a possible implementation, the first information includes third information, and the processing unit 1610 may be configured to determine a third precoding matrix, and determine the first precoding matrix and / or the second precoding matrix according to the third precoding matrix and the third information.

[0344] In a possible implementation, the communication unit 1620 may be configured to receive the first information from the RIS.

[0345] In one possible implementation, the first information is used to indicate the first precoding matrix and / or the second precoding matrix, the first information comes from a second device, and the processing unit 1610 is further configured to determine the first precoding matrix and / or the second precoding matrix based on the first information. Optionally, the communication unit 1620 is configured to receive the first information from the second device.

[0346] In a possible implementation, the communication unit 1620 may be configured to receive third information from the RIS and send the third information to the second device.

[0347] When the communication device 1600 is used to implement the function of the RIS in the method embodiment shown in FIG13 :

[0348] The communication unit 1620 may be configured to send the third information to the first device and may also be configured to receive the second information from the first device.

[0349] When the communication device 1600 is used to implement the functions performed by the second device related to the method embodiment shown in FIG13 :

[0350] Communication unit 1620 may be configured to obtain third information. Processing unit 1610 may be configured to determine a third precoding matrix. Communication unit 1620 may also be configured to send first information to the first device, where the first information indicates the first precoding matrix and / or the second precoding matrix. Optionally, processing unit 1610 may also be configured to determine the first precoding matrix and / or the second precoding matrix based on the third precoding matrix and the third information.

[0351] In a possible implementation, the communication unit 1620 may be configured to receive third information from the first device.

[0352] The terms and explanations of the terms involved in the above device embodiments can be found in the description of the aforementioned method embodiments and will not be expanded here.

[0353] The division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0354] As shown in Figure 17, a communication device 1700 provided in an embodiment of the present application is used to implement the communication method provided in the present application. The communication device 1700 can be a communication device that applies the communication method, or a component in a communication device, or a device that can be used in conjunction with the communication device. The communication device 1700 can be a RIS, a network device, a first device, or a second device. Specifically, the communication device 1700 can be a chip system or a chip. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. The communication device 1700 includes at least one processor 1720 for implementing the communication method provided in the embodiment of the present application. The communication device 1700 can also include an output interface 1710, which can also be referred to as an input / output interface. In the embodiment of the present application, the output interface 1710 can be used to communicate with other devices via a transmission medium, and its functions may include sending and / or receiving. For example, when the communication device 1700 is a chip, it transmits to other chips or devices via the output interface 1710. The processor 1720 can be used to implement the method of the above method embodiment.

[0355] Exemplarily, the processor 1720 may be used to execute actions executed by the processing unit 1610 , and the output interface 1710 may be used to execute actions executed by the communication unit 1620 , which will not be described in detail.

[0356] Optionally, the communication device 1700 may further include at least one memory 1730 for storing program instructions and / or data. The memory 1730 is coupled to the processor 1720. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be electrical, mechanical, or other forms, and is used for information exchange between devices, units, or modules. The processor 1720 may operate in conjunction with the memory 1730. The processor 1720 may execute program instructions stored in the memory 1730. At least one of the at least one memory may be integrated with the processor.

[0357] In an embodiment of the present application, the memory 1730 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or may be a volatile memory (volatile memory), such as a random-access memory (RAM). A memory is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application may also be a circuit or any other device that can implement a storage function, for storing program instructions and / or data.

[0358] In the embodiments of the present application, the processor 1720 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present application may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0359] As shown in Figure 18, a communication device 1800 provided in an embodiment of the present application is used to implement the communication method provided in the present application. The communication device 1800 can be a communication device that applies the communication method shown in the embodiment of the present application, or it can be a component in a communication device, or it can be a device that can be used in combination with a communication device. The communication device 1800 can be a RIS, a network device, a first device, or a second device. Among them, the data transmission device 1800 can be a chip system or a chip. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. Part or all of the communication method using the Huygens equivalent surface provided in the above embodiment can be implemented by hardware or by software. When implemented by hardware, the data transmission device 1800 may include: an input interface circuit 1801, a logic circuit 1802, and an output interface circuit 1803.

[0360] Optionally, taking the device being used to implement the function of the receiving end as an example, the input interface circuit 1801 can be used to execute the above-mentioned receiving action performed by the communication unit 1620, the output interface circuit 1803 can be used to execute the above-mentioned sending action performed by the communication unit 1620, and the logic circuit 1802 can be used to execute the above-mentioned action performed by the processing unit 1610, which will not be repeated.

[0361] Optionally, the data transmission device 1800 may be a chip or an integrated circuit in a specific implementation.

[0362] Part or all of the operations and functions performed by the data transmission device described in the above method embodiments of the present application can be completed using a chip or an integrated circuit.

[0363] An embodiment of the present application provides a computer-readable storage medium storing a computer program, wherein the computer program includes instructions for executing the above method embodiment.

[0364] An embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the above method embodiment.

[0365] Embodiments of the present application provide a communication system. Specifically, the communication system may include at least two of a network device, a transmitter, a RIS, or a receiver for implementing the method shown in any of Figures 8 or 11, or at least two of a network device, a RIS, or a terminal device for implementing the method shown in any of Figures 9 to 10, 12, 14, or 15, or a first device and a RIS for implementing the method shown in Figure 13. For details, please refer to the relevant descriptions in the above method embodiments, which will not be repeated here. The communication system may include the structure shown in Figure 3 or 4.

[0366] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0367] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one flow chart flow or multiple flows and / or one box or multiple boxes of the block diagram.

[0368] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0369] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0370] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0371] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the embodiments and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

Claims

1. A communication method, characterized in that: include: A reconfigurable intelligent surface (RIS) receives a first signal from a transmitting end through multiple precoding matrices in a first codebook of the RIS. Channel measurement information corresponding to the first signal is used to determine a first precoding matrix. The multiple precoding matrices in the first codebook include the first precoding matrix. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in a third codebook of the RIS. The second codebook is used to adjust channel characteristics between the RIS and a receiving end. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The RIS reflects the second signal to the receiving end through multiple precoding matrices in the third codebook, where the second signal comes from the transmitting end, and channel measurement information corresponding to the second signal is used to determine a second precoding matrix. The multiple precoding matrices in the third codebook correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix.

2. The method according to claim 1, wherein The method further comprises: The RIS determines the first precoding matrix from a plurality of precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

3. The method according to claim 2, wherein The method further comprises: The RIS sends indication information of the first precoding matrix to a network device, where the network device includes the transmitting end or the receiving end, and the indication information of the first precoding matrix is ​​used to determine the first precoding matrix.

4. The method according to claim 1, wherein The method further comprises: The RIS sends channel measurement information corresponding to the first signal to a network device, where the network device includes the transmitting end or the receiving end.

5. The method according to claim 4, wherein The method further comprises: The RIS receives indication information of the first precoding matrix from the network device; The RIS determines the first precoding matrix according to indication information of the first precoding matrix.

6. The method according to any one of claims 1 to 5, wherein: The method further comprises: The RIS receives first indication information from a network device, where the first indication information is used to instruct the RIS to receive the first signal using multiple precoding matrices in a first codebook of the RIS.

7. The method according to any one of claims 1 to 6, wherein: The method further comprises: The RIS receives indication information of the second precoding matrix from a network device, where the network device includes the transmitting end or the receiving end; The RIS determines the second precoding matrix according to indication information of the second precoding matrix.

8. The method according to any one of claims 1 to 6, wherein: The method further comprises: The RIS receives channel measurement information corresponding to the second signal from a network device, where the network device includes the transmitting end or the receiving end; The RIS determines the second precoding matrix from a plurality of precoding matrices in the second codebook according to channel measurement information corresponding to the received second signal.

9. The method according to claim 8, wherein The method further comprises: The RIS sends indication information of the second precoding matrix to the network device, where the indication information of the second precoding matrix is ​​used to determine the second precoding matrix.

10. The method according to any one of claims 1 to 9, wherein: The method further comprises: The RIS receives second indication information from the network device, where the second indication information is used to instruct the RIS to reflect the second signal to the receiving end through multiple precoding matrices in the third codebook.

11. The method according to claim 10, wherein The second indication information includes indication information of multiple precoding matrices in the second codebook, or the second indication information includes indication information of multiple precoding matrices in the third codebook.

12. A communication method, characterized in that: include: A first device sends first indication information to a reconfigurable smart surface (RIS), where the first indication information is used to instruct the RIS to receive a first signal from a transmitter through multiple precoding matrices in a first codebook of the RIS, where channel measurement information corresponding to the first signal is used to determine a first precoding matrix, where the multiple precoding matrices in the first codebook include the first precoding matrix, where the first codebook is used to adjust channel characteristics between the transmitter and the RIS, where a precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in a third codebook of the RIS, where the second codebook is used to adjust channel characteristics between the RIS and a receiver, and where the third codebook is used to adjust channel characteristics between the transmitter, the RIS, and the receiver. The first device sends second indication information to the RIS, where the second indication information is used to instruct the RIS to reflect a second signal to the receiving end through multiple precoding matrices in the third codebook, where the second signal comes from the transmitting end, and channel measurement information corresponding to the second signal is used to determine a second precoding matrix. The multiple precoding matrices in the third codebook correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix.

13. The method according to claim 12, wherein: The method further comprises: The first device receives indication information of the first precoding matrix from the RIS; The first device determines the first precoding matrix according to indication information of the first precoding matrix.

14. The method according to claim 12, wherein: The method further comprises: The first device receives channel measurement information corresponding to the first signal from the RIS; The first device determines the first precoding matrix from multiple precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

15. The method according to claim 14, wherein The method further comprises: The first device sends indication information of the first precoding matrix to the RIS, where the indication information of the first precoding matrix is ​​used to determine the first precoding matrix.

16. The method according to any one of claims 12 to 15, wherein: The method further comprises: The first device sends indication information of the second precoding matrix to the RIS, where the indication information of the second precoding matrix is ​​used to determine the second precoding matrix.

17. The method according to any one of claims 12 to 16, wherein: The method further comprises: The first device sends channel measurement information corresponding to the second signal to the RIS; The first device receives indication information of the second precoding matrix from the RIS; The first device determines the second precoding matrix according to indication information of the second precoding matrix.

18. The method according to any one of claims 12 to 17, wherein: The first device includes the transmitting end or the receiving end.

19. A communication method, characterized in that: include: The reconfigurable smart surface (RIS) reflects a third signal to a receiving end through a first group of precoding matrices, where the third signal comes from a transmitting end, and channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix. The first group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, and the first group of precoding matrices corresponds to a plurality of precoding matrices in a fourth codebook and a precoding matrix in a fifth codebook, where the plurality of precoding matrices in the fourth codebook include the fourth precoding matrix. The RIS reflects a fourth signal to the receiving end through a second group of precoding matrices, where the second group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, the second group of precoding matrices corresponding to the fourth precoding matrix and a plurality of precoding matrices in the fifth codebook, and channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix, where the plurality of precoding matrices in the fifth codebook include the fifth precoding matrix. The fourth codebook and the fifth codebook are respectively the first codebook or the second codebook of the RIS, and the fourth codebook and the fifth codebook are different. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS. The second codebook is used to adjust channel characteristics between the RIS and the receiving end.

20. The method according to claim 19, wherein The method further comprises: The RIS receives third indication information from a network device, where the third indication information is used to instruct the RIS to reflect the third signal to the receiving end through a first set of precoding matrices.

21. The method according to claim 20, wherein The third indication information specifically includes indication information of multiple precoding matrices in the fourth codebook, or the third indication information specifically includes indication information of the first group of precoding matrices.

22. The method according to any one of claims 19 to 21, wherein: The method further comprises: The RIS receives indication information of the fourth precoding matrix from a network device, where the network device includes the transmitting end or the receiving end; The RIS determines the fourth precoding matrix according to indication information of the fourth precoding matrix.

23. The method according to any one of claims 19 to 22, wherein: The method further comprises: The RIS receives fourth indication information from a network device, where the fourth indication information is used to instruct the RIS to reflect the fourth signal to the receiving end through a second set of precoding matrices.

24. The method according to claim 23, wherein The fourth indication information specifically includes indication information of multiple precoding matrices in the fifth codebook, or the fourth indication information specifically includes indication information of the second group of precoding matrices.

25. The method according to any one of claims 19 to 24, wherein: The method further comprises: The RIS receives indication information of the fifth precoding matrix from a network device, where the network device includes the transmitting end or the receiving end; The RIS determines the fifth precoding matrix according to indication information of the fifth precoding matrix.

26. A communication method, characterized in that: include: A first device sends third indication information to a reconfigurable smart surface (RIS), where the third indication information is used to instruct the RIS to reflect a third signal to a receiving end through a first group of precoding matrices, where the third signal comes from a transmitting end, and channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix, where the first group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, the first group of precoding matrices corresponds to a plurality of precoding matrices in a fourth codebook and a precoding matrix in a fifth codebook, and the plurality of precoding matrices in the fourth codebook include the fourth precoding matrix; The first device sends fourth indication information to the RIS, where the third indication information is used to instruct the RIS to reflect a fourth signal to the receiving end using a second group of precoding matrices, where the second group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, where the second group of precoding matrices corresponds to the fourth precoding matrix and a plurality of precoding matrices in the fifth codebook, where the channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix, and where the plurality of precoding matrices in the fifth codebook include the fifth precoding matrix; The fourth codebook and the fifth codebook are respectively the first codebook or the second codebook of the RIS, and the fourth codebook and the fifth codebook are different. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS. The second codebook is used to adjust channel characteristics between the RIS and the receiving end.

27. The method according to claim 26, wherein The third indication information specifically includes indication information of multiple precoding matrices in the fourth codebook, or the third indication information specifically includes indication information of the first group of precoding matrices.

28. The method according to claim 26 or 27, wherein The fourth indication information specifically includes indication information of multiple precoding matrices in the fifth codebook, or the fourth indication information specifically includes indication information of a second group of precoding matrices.

29. The method according to any one of claims 26 to 28, wherein: The method further comprises: The first device sends indication information of the fourth precoding matrix to the RIS, the first device includes the transmitting end or the receiving end, and the indication information of the fourth precoding matrix is ​​used to determine the fourth precoding matrix.

30. The method according to any one of claims 26 to 29, wherein: The method further comprises: The first device sends indication information of the fifth precoding matrix to the RIS, the first device includes the transmitting end or the receiving end, and the indication information of the fifth precoding matrix is ​​used to determine the fifth precoding matrix.

31. The method according to any one of claims 26 to 30, wherein: The first device includes the transmitting end or the receiving end.

32. A communication method, characterized in that: include: A first device obtains first information, where the first information is used to determine a first precoding matrix and / or a second precoding matrix, where the first precoding matrix belongs to a first codebook of a reconfigurable intelligent surface (RIS), and the second precoding matrix belongs to a second codebook of the RIS. A precoding matrix in the first codebook and a precoding matrix in the second codebook correspond to a precoding matrix in a third codebook of the RIS, where the third codebook is used to adjust channel characteristics between a transmitting end, the RIS, and a receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiving end. The first device sends second information to the RIS, where the second information is used to indicate the first precoding matrix and / or the second precoding matrix.

33. The method of claim 32, wherein: The first information includes third information, where the third information indicates a correspondence between a precoding matrix in the first codebook, a precoding matrix in the second codebook, and a precoding matrix in the third codebook. The method further includes: The first device determines a third precoding matrix, where the third precoding matrix belongs to the third codebook; The first device determines the first precoding matrix and / or the second precoding matrix according to the third precoding matrix and the third information.

34. The method of claim 33, wherein: The first device acquiring the first information includes: The first device receives the first information from the RIS.

35. The method of claim 32, wherein: The first information is used to indicate the first precoding matrix and / or the second precoding matrix, and the first information comes from a second device. The method further includes: The first device determines the first precoding matrix and / or the second precoding matrix according to the first information; The first device is the transmitting end, and the second device is the receiving end; or The first device is the receiving end, and the second device is the sending end.

36. The method of claim 35, wherein: The method further comprises: The first device receives third information from the RIS, where the third information indicates a correspondence between a precoding matrix in the first codebook, a precoding matrix in the second codebook, and a precoding matrix in the third codebook; The first device sends the third information to the second device.

37. The method according to any one of claims 31 to 34, wherein: The first device includes the transmitting end or the receiving end.

38. A communication method, characterized in that: include: The reconfigurable intelligent surface (RIS) sends third information to the first device, where the third information is used to indicate a correspondence between a precoding matrix in a first codebook of the RIS, a precoding matrix in a second codebook of the RIS, and a precoding matrix in a third codebook of the RIS, where the third codebook is used to adjust channel characteristics between a transmitting end, the RIS, and a receiving end, the first codebook is used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiving end; The RIS receives second information, where the second information is used to indicate a first precoding matrix and / or a second precoding matrix, where the first precoding matrix belongs to the first codebook and the second precoding matrix belongs to the second codebook.

39. The method of claim 38, wherein The first device includes the transmitting end or the receiving end.

40. A communication method, characterized in that: include: The second device obtains third information, where the third information is used to indicate a correspondence between a precoding matrix in a first codebook of a reconfigurable intelligent surface (RIS), a precoding matrix in a second codebook of the RIS, and a precoding matrix in a third codebook of the RIS, where a precoding matrix in the first codebook and a precoding matrix in the second codebook correspond to a precoding matrix in the third codebook, and the third codebook is used for adjusting channel characteristics between a transmitting end, the RIS, and a receiving end; the first codebook is used for adjusting channel characteristics between the transmitting end and the RIS, and the second codebook is used for adjusting channel characteristics between the RIS and the receiving end; The second device determines a third precoding matrix according to the channel measurement information, where the third precoding matrix belongs to the third codebook; The second device sends the first information to the first device, where the first information is used to indicate a first precoding matrix and / or a second precoding matrix, the first precoding matrix belongs to the first codebook, the second precoding matrix belongs to the second codebook, and the first precoding matrix and / or the second precoding matrix are determined based on the third precoding matrix and the third information.

41. The method of claim 40, wherein The second device obtains the third information, including: The second device receives the third information from the first device.

42. The method according to claim 40 or 41, wherein The first device includes the transmitting end, and the second device includes the receiving end; or The first device includes the receiving end, and the second device includes the sending end.

43. A communication device, characterized in that include: processor; The processor is used to execute one or more computer programs stored in the memory, so that the communication device performs the method according to any one of claims 1 to 11, or the communication device performs the method according to any one of claims 12 to 18, or the communication device performs the method according to any one of claims 19 to 25, or the communication device performs the method according to any one of claims 26 to 31, or the communication device performs the method according to any one of claims 32 to 37, or the communication device performs the method according to claims 38 or 39, or the communication device performs the method according to any one of claims 40 to 42.

44. The communication device according to claim 43, wherein: The communication device further includes the memory.

45. The communication device according to claim 43 or 44, characterized in that The communication device is a chip or a chip system.

46. ​​A communication device, characterized in that comprising a module for executing the method as claimed in any one of claims 1 to 11, or comprising a module for executing the method as claimed in any one of claims 12 to 18, or comprising a module for executing the method as claimed in any one of claims 19 to 25, or comprising a module for executing the method as claimed in any one of claims 26 to 31, or comprising a module for executing the method as claimed in any one of claims 32 to 37, or comprising a module for executing the method as claimed in claim 38 or 39, or comprising a module for executing the method as claimed in any one of claims 40 to 42.

47. A chip system, characterized in that: The chip system includes a logic circuit and an input / output interface, wherein: The input and output interface is used to communicate with other communication devices outside the chip system, and the logic circuit is used to execute the method as described in any one of claims 1 to 11, or the logic circuit is used to execute the method as described in any one of claims 12 to 18, or the logic circuit is used to execute the method as described in any one of claims 19 to 25, or the logic circuit is used to execute the method as described in any one of claims 26 to 31, or the logic circuit is used to execute the method as described in any one of claims 32 to 37, or the logic circuit is used to execute the method as described in claim 38 or 39, or the logic circuit is used to execute the method as described in any one of claims 40 to 42.

48. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store a computer program. When the computer program is run on a computer, the computer executes the method according to any one of claims 1 to 11, or the method according to any one of claims 12 to 18, or the method according to any one of claims 19 to 25, or the method according to any one of claims 26 to 31, or the method according to any one of claims 32 to 37, or the method according to claims 38 or 39, or the method according to any one of claims 40 to 42.

49. A computer program product, characterized in that The computer program product comprises a computer program which, when run on a computer, causes the computer to perform the method according to any one of claims 1 to 11, or causes the computer to perform the method according to any one of claims 12 to 18, or causes the computer to perform the method according to any one of claims 19 to 25, or causes the computer to perform the method according to any one of claims 26 to 31, or causes the computer to perform the method according to any one of claims 32 to 37, or causes the computer to perform the method according to claims 38 or 39, or causes the computer to perform the method according to any one of claims 40 to 42.

50. A communication system, characterized in that comprising a communication device for executing the method according to any one of claims 1 to 11, and a communication device for executing the method according to any one of claims 12 to 18; or, comprising a communication device for executing the method according to any one of claims 19 to 25, and a communication device for executing the method according to any one of claims 26 to 31; or, comprising a communication device for performing the method according to any one of claims 32 to 37, and a communication device for performing the method according to claim 38 or 39; or The invention comprises a communication device for executing the method according to any one of claims 32 to 37, a communication device for executing the method according to claim 38 or 39, and a communication device for executing the method according to any one of claims 40 to 42.

51. A communication method, characterized in that: include: A first device sends first indication information to a reconfigurable smart surface (RIS), where the first indication information is used to instruct the RIS to receive the first signal from a transmitter through multiple precoding matrices in a first codebook of the RIS, where channel measurement information corresponding to the first signal is used to determine a first precoding matrix, where the multiple precoding matrices in the first codebook include the first precoding matrix, where the first codebook is used to adjust channel characteristics between the transmitter and the RIS, where a precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in a third codebook of the RIS, where the second codebook is used to adjust channel characteristics between the RIS and a receiver, and where the third codebook is used to adjust channel characteristics between the transmitter, the RIS, and the receiver. The RIS receives the first indication information; The RIS receives the first signal from the transmitting end through multiple precoding matrices in the first codebook; The first device sends second indication information to the RIS, where the second indication information is used to instruct the RIS to reflect a second signal to the receiving end through multiple precoding matrices in the third codebook, where the second signal comes from the transmitting end, channel measurement information corresponding to the second signal is used to determine a second precoding matrix, the multiple precoding matrices in the third codebook correspond to the first precoding matrix and the multiple precoding matrices in the second codebook, and the multiple precoding matrices in the second codebook include the second precoding matrix; The RIS receives the second indication information; The RIS reflects the second signal to the receiving end through multiple precoding matrices in the third codebook.

52. The method of claim 51, wherein The method further comprises: The RIS determines the first precoding matrix from a plurality of precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

53. The method of claim 52, wherein: The method further comprises: The RIS sends indication information of the first precoding matrix to the first device; The first device receives indication information of the first precoding matrix from the RIS; The first device determines the first precoding matrix according to indication information of the first precoding matrix.

54. The method of claim 51, wherein The method further comprises: The RIS sends channel measurement information corresponding to the first signal to the first device; The first device receives channel measurement information corresponding to the first signal from the RIS; The first device determines the first precoding matrix from multiple precoding matrices in a first codebook of the RIS according to channel measurement information corresponding to the first signal.

55. The method of claim 54, wherein: The method further comprises: The first device sends indication information of the first precoding matrix to the RIS; The RIS receives indication information of the first precoding matrix from the first device; The RIS determines the first precoding matrix according to indication information of the first precoding matrix.

56. The method according to any one of claims 51 to 55, wherein: The method further comprises: The first device sends indication information of the second precoding matrix to the RIS; The RIS receives indication information of the second precoding matrix from the first device; The RIS determines the second precoding matrix according to indication information of the second precoding matrix.

57. The method according to any one of claims 51 to 55, wherein: The method further comprises: The first device sends channel measurement information corresponding to the second signal to the RIS; The RIS receives channel measurement information corresponding to the second signal from the first device; The RIS determines the second precoding matrix from a plurality of precoding matrices in the second codebook according to channel measurement information corresponding to the received second signal.

58. The method of claim 57, wherein: The method further comprises: The RIS sends indication information of the second precoding matrix to the first device; The first device receives indication information of the second precoding matrix from the RIS; The first device determines the second precoding matrix according to indication information of the second precoding matrix.

59. The method according to any one of claims 51 to 58, wherein: The second indication information includes indication information of multiple precoding matrices in the second codebook, or the second indication information includes indication information of multiple precoding matrices in the third codebook.

60. The method according to any one of claims 51 to 59, wherein: The first device includes the transmitting end or the receiving end.

61. A communication method, characterized in that: include: A first device sends third indication information to a reconfigurable smart surface (RIS), where the third indication information is used to instruct the RIS to reflect a third signal to a receiving end through a first group of precoding matrices, where the third signal comes from a transmitting end, and channel measurement information corresponding to the third signal is used to determine a fourth precoding matrix, where the first group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, the first group of precoding matrices corresponds to a plurality of precoding matrices in a fourth codebook and a precoding matrix in a fifth codebook, and the plurality of precoding matrices in the fourth codebook include the fourth precoding matrix; The RIS receives the third indication information from the first device; The RIS reflects the third signal to the receiving end through the first group of precoding matrices; The first device sends fourth indication information to the RIS, where the third indication information is used to instruct the RIS to reflect a fourth signal to the receiving end using a second group of precoding matrices, where the second group of precoding matrices is a plurality of precoding matrices in a third codebook of the RIS, where the second group of precoding matrices corresponds to the fourth precoding matrix and a plurality of precoding matrices in the fifth codebook, where the channel measurement information corresponding to the fourth signal is used to determine a fifth precoding matrix, and where the plurality of precoding matrices in the fifth codebook include the fifth precoding matrix; The RIS receives the fourth indication information from the first device; The RIS reflects the fourth signal to the receiving end through the second set of precoding matrices; The fourth codebook and the fifth codebook are respectively the first codebook or the second codebook of the RIS, and the fourth codebook and the fifth codebook are different. A precoding matrix in the first codebook and a precoding matrix in the second codebook of the RIS correspond to a precoding matrix in the third codebook. The third codebook is used to adjust channel characteristics between the transmitting end, the RIS, and the receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS. The second codebook is used to adjust channel characteristics between the RIS and the receiving end.

62. The method of claim 61, wherein The third indication information specifically includes indication information of multiple precoding matrices in the fourth codebook, or the third indication information specifically includes indication information of the first group of precoding matrices.

63. The method according to claim 61 or 62, wherein The fourth indication information specifically includes indication information of multiple precoding matrices in the fifth codebook, or the fourth indication information specifically includes indication information of the second group of precoding matrices.

64. The method according to any one of claims 61 to 63, wherein: The method further comprises: The first device sends indication information of the fourth precoding matrix to the RIS; The RIS receives indication information of the fourth precoding matrix from the first device; The RIS determines the fourth precoding matrix according to indication information of the fourth precoding matrix.

65. The method according to any one of claims 61 to 64, wherein: The method further comprises: The first device sends indication information of the fifth precoding matrix to the RIS; The RIS receives indication information of the fifth precoding matrix from the first device; The RIS determines the fifth precoding matrix according to indication information of the fifth precoding matrix.

66. The method according to any one of claims 61 to 65, wherein: The first device includes the transmitting end or the receiving end.

67. A communication method, characterized in that: include: A first device obtains first information, where the first information is used to determine a first precoding matrix and / or a second precoding matrix, where the first precoding matrix belongs to a first codebook of a reconfigurable intelligent surface (RIS), and the second precoding matrix belongs to a second codebook of the RIS. A precoding matrix in the first codebook and a precoding matrix in the second codebook correspond to a precoding matrix in a third codebook of the RIS, where the third codebook is used to adjust channel characteristics between a transmitting end, the RIS, and a receiving end. The first codebook is used to adjust channel characteristics between the transmitting end and the RIS, and the second codebook is used to adjust channel characteristics between the RIS and the receiving end. The first device sends second information to the RIS, where the second information is used to indicate the first precoding matrix and / or the second precoding matrix; The RIS receives the second information from the first device.

68. The method of claim 67, wherein The first information includes third information, where the third information indicates a correspondence between a precoding matrix in the first codebook, a precoding matrix in the second codebook, and a precoding matrix in the third codebook. The method further includes: The first device determines a third precoding matrix, where the third precoding matrix belongs to the third codebook; The first device determines the first precoding matrix and / or the second precoding matrix according to the third precoding matrix and the third information.

69. The method of claim 68, wherein The method further comprises: The RIS sends the third information; The first device acquiring the first information includes: The first device receives the first information from the RIS.

70. The method of claim 67, wherein The first information is used to indicate the first precoding matrix and / or the second precoding matrix. The method further includes: The second device sends the first information to the first device; The first device acquiring the first information includes: The first device receives the first information from the second device; The method further comprises: The first device determines the first precoding matrix and / or the second precoding matrix according to the first information; The first device is the transmitting end, and the second device is the receiving end; or The first device is the receiving end, and the second device is the sending end.

71. The method of claim 70, wherein The method further comprises: The RIS sends the third information to the first device; The first device receives third information from the RIS, where the third information indicates a correspondence between a precoding matrix in the first codebook, a precoding matrix in the second codebook, and a precoding matrix in the third codebook; The first device sends the third information to the second device; The second device receives the third information from the first device; The second device determines a third precoding matrix according to the channel measurement information, where the third precoding matrix belongs to the third codebook; The second device determines the first precoding matrix and / or the second precoding matrix according to the third precoding matrix and the third information.

72. The method according to any one of claims 67 to 69, wherein: The first device is the transmitting end, and the second device is the receiving end; or, The first device is the receiving end, and the second device is the sending end.

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