Communication method, communication apparatus, chip, computer readable storage medium, and computer program product

Abstract

The present application discloses a communication method, a communication apparatus, a chip, a computer readable storage medium, and a computer program product. The present application can be applied to support an RIS-based communication enhancement scenario. The method comprises: repeatedly sending pilot signals to an RIS by means of N antenna ports over B time blocks; receiving the pilot signals over the B time blocks, the pilot signals received over the B time blocks comprising pilot signals reflected by the RIS over the B time blocks, and pilot signals repeatedly sent by a terminal device over the B time blocks; and on the basis of the pilot signals received over the B time blocks, determining at least one of a channel matrix between an access network device and the RIS and a channel matrix between the RIS and the terminal device. The estimation of two-segment independent channels (a BS-RIS and an RIS-UE) can be acquired so as to serve the sensing, power optimization and other scenarios.

Description

Communication method, communication device, chip, computer-readable storage medium, and computer program product

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on February 2, 2024, with application number 202410153471.X, and priority to the Chinese patent application entitled “Communication method, communication device, chip, computer-readable storage medium and computer program product”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method, a communication device, a chip, a computer-readable storage medium, and a computer program product. Background Art

[0003] Throughout the evolution of wireless communication systems, expanding the coverage of wireless communication networks has always been a goal. Recently, reconfigurable intelligent surfaces (RIS), which control channel characteristics through RIS-assisted networks, have been recognized as a key enabling technology for expanding wireless communication network coverage. Reconfigurable intelligent metasurfaces are also known as intelligent reflecting surfaces (IRS) or large intelligent surfaces (LIS).

[0004] RIS is a subwavelength, artificial two-dimensional material typically composed of metal, dielectrics, and tunable elements. Specifically, RIS manifests as a smart panel consisting of multiple arrays, each of which is a low-cost passive reflector. By flexibly configuring the amplitude and phase of each array, wireless channel fading can be controlled and a desired directional beam can be formed. RIS can be mounted on large surfaces (such as indoor walls or ceilings, outdoor buildings, or signs) to reflect radio frequency (RF) energy around obstacles and create a virtual line-of-sight path between the communication source and target. Passive RIS is a passive reflector.

[0005] In some passive RIS-assisted wireless communication systems, it is necessary to estimate the channel between the base station (BS) and the RIS (i.e., the BS-RIS channel), as well as the channel between the RIS and the user equipment (UE) (i.e., the RIS-UE channel), so that operations such as precoding, modulation order, and rank number setting can be performed based on the estimated channels. Summary of the Invention

[0006] The present application discloses a communication method, a communication device, a chip, a computer-readable storage medium, and a computer program product. By utilizing the simultaneous transmission and reception characteristics of a full-duplex base station, the independent channels of the BS-RIS and RIS-UE segments can be decoupled and calculated through the configuration of the transmitting and receiving antennas and the transmission of orthogonal pilots.

[0007] In a first aspect, an embodiment of the present application provides a communication method, comprising: transmitting a signal to a reconfigurable intelligent metasurface through N antenna ports in B time blocks; A RIS is a wireless communication system comprising: receiving pilot signals on surfaces (RIS), wherein a first antenna port and a second antenna port among the N antenna ports respectively transmit a pilot signal in T time units included in each time block, the T pilot signals successively transmitted by the first antenna port in each time block correspond to a first vector, and the T pilot signals successively transmitted by the second antenna port in each time block correspond to a second vector, the first vector and the second vector are orthogonal, B is an integer greater than 0, and N and T are integers greater than 1; receiving pilot signals in the B time blocks, the pilot signals received in the B time blocks include the pilot signals reflected by the RIS in the B time blocks and the pilot signals repeatedly transmitted by the terminal device in the B time blocks, an antenna port of the terminal device successively transmits a pilot signal in T time units included in each time block, and the T pilot signals successively transmitted by an antenna port of the terminal device in each time block correspond to a third vector that is orthogonal to the first vector; and determining at least one of a channel matrix between the access network device and the RIS and a channel matrix between the RIS and the terminal device based on the pilot signals received in the B time blocks.

[0008] In an embodiment of the present application, based on the pilot signals received in B time blocks, at least one of the channel matrices between the base station and the RIS and the channel matrix between the RIS and the terminal device is determined; estimates of two independent channels, BS-RIS and RIS-UE, can be obtained to serve scenarios such as perception and power optimization.

[0009] In one possible implementation, determining at least one of the channel matrices between the access network device and the RIS and the channel matrix between the RIS and the terminal device based on the pilot signals received in the B time blocks includes: obtaining a first signal matrix based on the pilot signals received in the B time blocks, the first signal matrix being a three-dimensional matrix of (N×T×B), and each two-dimensional matrix of (N×T) in the first signal matrix corresponding to the pilot signals received by the N antenna ports of the access network device in T time units included in one time block; obtaining a second signal matrix based on the first signal matrix, the second signal matrix representing the noise-free pilot signals received by the access network device in the B time blocks; and determining at least one of the channel matrices between the access network device and the RIS and the channel matrix between the RIS and the terminal device based on the second signal matrix.

[0010] In this implementation, estimates of two independent channels, BS-RIS and RIS-UE, can be obtained to serve scenarios such as perception and power optimization.

[0011] In one possible implementation, determining at least one of the channel matrix between the access network device and the RIS and the channel matrix between the RIS and the terminal device based on the pilot signals received in the B time blocks includes: obtaining a third signal matrix based on the pilot signals received in the B time blocks; estimating a first arrival angle set, a first departure angle set, and a first path gain set of the channel between the access network device and the RIS based on the third signal matrix; and determining the channel matrix between the access network device and the RIS based on the first arrival angle set, the first departure angle set, and the first path gain set.

[0012] In this implementation, the sparse characteristics of the channel are used to perform channel estimation. Only the angle and gain coefficient of the channel need to be estimated, and fewer pilot signals are required.

[0013] In one possible implementation, the method further includes: estimating a second angle of arrival and a second path gain set of the channel between the RIS and the terminal device based on the third signal matrix and the channel matrix between the access network device and the RIS; and determining the channel matrix between the RIS and the terminal device based on the second angle of arrival and the second path gain set.

[0014] In this implementation, the sparse characteristics of the channel are used to perform channel estimation. Only the angle and gain coefficient of the channel need to be estimated, and fewer pilot signals are required.

[0015] In a possible implementation, the method further includes: sending first indication information to the terminal device, where the first indication information is used to indicate the pilot signal that the terminal device repeatedly sends in the B time blocks.

[0016] In this implementation, first indication information is sent to the terminal device so that the terminal device sends a corresponding pilot signal.

[0017] In a possible implementation, the first indication information is used to indicate that the pilot signal repeatedly sent by the terminal device in the B time blocks satisfies an orthogonality condition with the pilot signal sent by the access network device.

[0018] In a possible implementation manner, the method further includes: sending third indication information to the RIS, where the third indication information is used to instruct the RIS to perform orthogonal reflection coefficient switching on the B time blocks.

[0019] In this implementation, third indication information is sent to the RIS so that the RIS performs orthogonal reflection coefficient switching over B time blocks.

[0020] In a possible implementation, the third indication information includes the start time of the first time block in the B time blocks, the duration of each time block, and the number B of time blocks.

[0021] In a possible implementation, the method is applied to a RIS-assisted full-duplex wireless communication scenario.

[0022] In the second aspect, an embodiment of the present application provides another communication method, which is applied to a terminal device, and the method includes: generating a pilot signal that needs to be repeatedly sent in B time blocks; repeatedly sending the generated pilot signal to the access network device in the B time blocks, an antenna port of the terminal device successively sends a pilot signal in the T time units included in each time block, and the pilot signals sent by an antenna port of the terminal device in different time blocks are the same, B is an integer greater than 0, and T is an integer greater than 1.

[0023] In an embodiment of the present application, the generated pilot signal is repeatedly sent to the access network device in B time blocks so that the access network device can estimate at least one of the channel matrix between the access network device and the RIS and the channel matrix between the RIS and the terminal device.

[0024] In one possible implementation, the method further includes: receiving first indication information from the access network device, the first indication information being used to indicate the pilot signal that the terminal device repeatedly sends in the B time blocks; generating the pilot signal that needs to be repeatedly sent in the B time blocks includes: generating the pilot signal that needs to be repeatedly sent in the B time blocks based on the first indication information.

[0025] In this implementation, based on the first indication information, a pilot signal that needs to be repeatedly sent in B time blocks is generated; and the corresponding pilot signal can be sent according to the indication of the access network device.

[0026] In one possible implementation, the vector corresponding to the pilot signal repeatedly sent by the terminal device in the B time blocks indicated by the first indication information is orthogonal to the vector corresponding to the pilot signal repeatedly sent by any antenna port of the access network device in the B time blocks.

[0027] In a possible implementation, the first indication information is used to indicate that the pilot signal repeatedly sent by the terminal device in the B time blocks satisfies an orthogonality condition with the pilot signal sent by the access network device.

[0028] In a third aspect, an embodiment of the present application provides another communication method, which includes: receiving third indication information, wherein the third indication information is used to instruct the configurable intelligent metasurface RIS to perform orthogonal reflection coefficient switching on B time blocks, where B is an integer greater than 1; based on the third indication information, performing orthogonal reflection coefficient switching on the B time blocks.

[0029] In the embodiment of the present application, based on the third indication information, orthogonal reflection coefficient switching is performed on B time blocks so that the access network device can independently estimate the channel matrix between the access network device and the RIS and the channel matrix between the RIS and the terminal device.

[0030] In a possible implementation, the third indication information includes the start time of the first time block in the B time blocks, the duration of each time block, and the number B of time blocks.

[0031] In a fourth aspect, an embodiment of the present application provides another communication method, which is applied to an access network device, the method comprising: repeatedly sending a first pilot signal to a RIS through a first antenna port in B1 time blocks, where B1 is an integer greater than 1; receiving the first pilot signal reflected by the RIS through (N-1) antenna ports in the B1 time blocks, where the (N-1) antenna ports do not include the first antenna port; obtaining a fourth signal matrix based on the received first pilot signal reflected by the RIS; repeatedly sending a second pilot signal to the RIS through a second antenna port in B2 time blocks, where B2 is an integer greater than 1, where the second antenna port is different from the first antenna port; receiving the second pilot signal reflected by the RIS through (N-2) antenna ports in the B2 time blocks, where the (N-2) antenna ports are included in the (N-1) antenna ports and do not include the first antenna port and the second antenna port; obtaining a fifth signal matrix based on the received second pilot signal reflected by the RIS; and determining a channel matrix between the access network device and the RIS based on the fourth signal matrix and the fifth signal matrix.

[0032] In the embodiment of the present application, the channel matrix between the access network device and the RIS is determined based on the fourth signal matrix and the fifth signal matrix; the channel matrix between the base station and the RIS can be determined to serve scenarios such as perception and power optimization.

[0033] In one possible implementation, the method further includes: receiving, through N antenna ports, a pilot signal repeatedly sent by a terminal device in B3 time blocks, the N antenna ports including the first antenna port and the (N-1) antenna ports; and determining a channel matrix between the RIS and the terminal device based on the pilot signal repeatedly sent by the terminal device in the B3 time blocks received through the N antenna ports.

[0034] In this implementation, the channel matrix between the base station and the RIS and the channel matrix between the RIS and the terminal device are determined to serve scenarios such as perception and power optimization.

[0035] In a possible implementation, the method further includes: sending second indication information to the terminal device, where the second indication information is used to instruct the terminal device to repeatedly send a pilot signal in the B3 time blocks.

[0036] In this implementation, second indication information is sent to the terminal device so that the terminal device sends a corresponding pilot signal.

[0037] In a possible implementation, the second indication information is used to indicate that the pilot signal repeatedly sent by the terminal device in the B3 time blocks satisfies an orthogonality condition with the pilot signal sent by the access network device.

[0038] In a possible implementation manner, the method further includes: sending fourth indication information to the RIS, where the fourth indication information is used to instruct the RIS to perform orthogonal reflection coefficient switching on the B1 time blocks.

[0039] In this implementation, fourth indication information is sent to the RIS so that the RIS performs orthogonal reflection coefficient switching over B1 time blocks.

[0040] In a possible implementation, the method is applied to a RIS-assisted full-duplex wireless communication scenario.

[0041] In the fifth aspect, an embodiment of the present application provides another communication method, which is applied to a terminal device, and the method includes: generating a pilot signal that needs to be repeatedly sent in B3 time blocks; repeatedly sending the generated pilot signal to the access network device in the B3 time blocks, an antenna port of the terminal device successively sends a pilot signal in the T time units included in each time block, and the pilot signals sent by an antenna port of the terminal device in different time blocks are the same, B3 is an integer greater than 0, and T is an integer greater than 1.

[0042] In the embodiment of the present application, the generated pilot signal is repeatedly sent to the access network device in B3 time blocks so that the access network device can estimate the channel matrix between the RIS and the terminal device.

[0043] In one possible implementation, the method further includes: receiving second indication information from the access network device, the second indication information being used to indicate the pilot signal that the terminal device repeatedly sends in the B3 time blocks; generating the pilot signal that needs to be repeatedly sent in the B3 time blocks includes: generating the pilot signal that needs to be repeatedly sent in the B3 time blocks based on the second indication information.

[0044] In this implementation, based on the second indication information, a pilot signal that needs to be repeatedly sent in B3 time blocks is generated; the corresponding pilot signal can be sent according to the indication of the access network device.

[0045] In a possible implementation, the second indication information is used to indicate that the pilot signal repeatedly sent by the terminal device in the B3 time blocks satisfies an orthogonality condition with the pilot signal sent by the access network device.

[0046] In a sixth aspect, an embodiment of the present application provides another communication method, which includes: receiving fourth indication information, wherein the fourth indication information is used to instruct the configurable intelligent metasurface RIS to perform orthogonal reflection coefficient switching on B1 time blocks, where B1 is an integer greater than 1; based on the fourth indication information, performing orthogonal reflection coefficient switching on the B1 time blocks.

[0047] In the embodiment of the present application, based on the fourth indication information, orthogonal reflection coefficient switching is performed on B1 time blocks so that the access network device can independently estimate the channel matrix between the access network device and the RIS and the channel matrix between the RIS and the terminal device.

[0048] In a possible implementation, the fourth indication information includes the start time of the first time block in the B1 time blocks, the duration of each time block, and the number of time blocks B1.

[0049] In a seventh aspect, an embodiment of the present application provides a communication system, which includes: an access network device, a RIS, and a terminal device; the access network device is used to repeatedly send a pilot signal to the RIS through N antenna ports in B time blocks, and the first antenna port and the second antenna port of the N antenna ports respectively send a pilot signal in the T time units included in each time block, the T pilot signals sent successively by the first antenna port in each time block correspond to a first vector, and the T pilot signals sent successively by the second antenna port in each time block correspond to a second vector, the first vector and the second vector are orthogonal, B is an integer greater than 0, and N and T are integers greater than 1; the terminal device is used to repeatedly send a pilot signal to the access network device in the B time blocks, and one antenna port of the terminal device sends a pilot signal in each time block. The T time units included in the block successively send a pilot signal, the pilot signals sent by an antenna port of the terminal device in different time blocks are the same, and the T pilot signals sent successively by an antenna port of the terminal device in each time block correspond to a third vector that is orthogonal to the first vector; the RIS is used to perform orthogonal reflection coefficient switching on the B time blocks; the access network device is further used to receive pilot signals in the B time blocks, and the pilot signals received by the access network device in the B time blocks include the pilot signals reflected by the RIS in the B time blocks and the pilot signals repeatedly sent by the terminal device in the B time blocks; based on the pilot signals received in the B time blocks, at least one of the channel matrix between the access network device and the RIS and the channel matrix between the RIS and the terminal device is determined.

[0050] In an embodiment of the present application, based on the pilot signals received in B time blocks, at least one of the channel matrices between the base station and the RIS and the channel matrix between the RIS and the terminal device is determined; estimates of two independent channels, BS-RIS and RIS-UE, can be obtained to serve scenarios such as perception and power optimization.

[0051] In an eighth aspect, an embodiment of the present application provides a communication system, comprising: an access network device, a RIS, and a terminal device; the access network device is configured to repeatedly send a first pilot signal to the RIS through a first antenna port in B1 time blocks, where B1 is an integer greater than 1; receive the first pilot signal reflected by the RIS through (N-1) antenna ports in the B1 time block, where the (N-1) antenna ports do not include the first antenna port; obtain a fourth signal matrix based on the first pilot signal reflected by the received RIS; repeatedly send a second pilot signal to the RIS through a second antenna port in B2 time blocks, where B2 is an integer greater than 1, where the second antenna port is different from the first antenna port; receive the second pilot signal reflected by the RIS through an (N-2) antenna port in the B2 time block, where the (N-2) antenna port is included in the (N-1 ) antenna ports, excluding the first antenna port and the second antenna port; obtaining a fifth signal matrix based on the received second pilot signal reflected by the RIS; determining a channel matrix between the access network device and the RIS based on the fourth signal matrix and the fifth signal matrix; the RIS is used to perform orthogonal reflection coefficient switching on the B1 time blocks and the B2 time blocks; the terminal device is used to repeatedly send pilot signals to the access network device in B3 time blocks; the access network device is further used to receive, through N antenna ports, the pilot signals repeatedly sent by the terminal device in the B3 time blocks, the N antenna ports including the first antenna port and the (N-1) antenna ports; determining the channel matrix between the RIS and the terminal device based on the pilot signals repeatedly sent by the terminal device in the B3 time blocks received through the N antenna ports.

[0052] In this embodiment of the present application, the channel matrix between the base station and the RIS, as well as the channel matrix between the RIS and the terminal device, can be determined to serve scenarios such as perception and power optimization. This embodiment of the present application is applicable to dual-station full-duplex channel estimation in non-geometric models. The hardware architecture of dual-station full-duplex is easier to implement, and the self-interference within the base station is also lower.

[0053] In a ninth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the method embodiment of the first aspect above. The communication device can be a network device, or a component of a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the network device. The functions of the communication device can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to repeatedly send pilot signals to the RIS through N antenna ports in B time blocks, and the first antenna port and the second antenna port of the N antenna ports respectively send a pilot signal in the T time units included in each time block. The T pilot signals sent successively by the first antenna port in each time block correspond to a first vector, and the T pilot signals sent successively by the second antenna port in each time block correspond to a second vector. The first vector and the second vector are orthogonal, B is an integer greater than 0, and N and T are integers greater than 1; receiving pilot signals, where the pilot signals received in the B time blocks include the pilot signals reflected by the RIS in the B time blocks and the pilot signals repeatedly transmitted by the terminal device in the B time blocks, one antenna port of the terminal device successively transmits a pilot signal in T time units included in each time block, and the T pilot signals successively transmitted by the antenna port of the terminal device in each time block correspond to a third vector that is orthogonal to the first vector; and the processing module is configured to determine at least one of a channel matrix between the access network device and the RIS and a channel matrix between the RIS and the terminal device based on the pilot signals received in the B time blocks.

[0054] In one possible implementation, the processing module is specifically configured to obtain a first signal matrix based on the pilot signals received in the B time blocks, where the first signal matrix is ​​a three-dimensional matrix of (N×T×B), and each two-dimensional matrix of (N×T) in the first signal matrix corresponds to the pilot signals received by the N antenna ports of the access network device in the T time units included in one time block; obtain a second signal matrix based on the first signal matrix, where the second signal matrix represents the noise-free pilot signals received by the access network device in the B time blocks; and determine at least one of the channel matrices between the access network device and the RIS and the channel matrix between the RIS and the terminal device based on the second signal matrix.

[0055] In one possible implementation, the processing module is specifically configured to obtain a third signal matrix based on the pilot signals received in the B time blocks; estimate a first arrival angle set, a first departure angle set, and a first path gain set of the channel between the access network device and the RIS based on the third signal matrix; and determine a channel matrix between the access network device and the RIS based on the first arrival angle set, the first departure angle set, and the first path gain set.

[0056] In one possible implementation, the processing module is further used to estimate a second angle of arrival and a second path gain set of the channel between the RIS and the terminal device based on the third signal matrix and the channel matrix between the access network device and the RIS; and determine the channel matrix between the RIS and the terminal device based on the second angle of arrival and the second path gain set.

[0057] In a possible implementation, the transceiver module is further used to send first indication information to the terminal device, where the first indication information is used to instruct the terminal device to repeatedly send a pilot signal in the B time blocks.

[0058] Possible implementations of the communication device of the ninth aspect can refer to the various possible implementations of the first aspect.

[0059] For the technical effects brought about by various possible implementation methods of the ninth aspect, reference may be made to the introduction to the technical effects of the first aspect or various possible implementation methods of the first aspect.

[0060] In a tenth aspect, an embodiment of the present application provides a communication device having the function of implementing the behavior in the method embodiment of the second aspect above. The communication device can be a terminal device, or a component of a terminal device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the terminal device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software implementations, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a pilot signal that needs to be repeatedly sent in B time blocks; the transceiver module is used to repeatedly send the generated pilot signal to the access network device in the B time blocks, and an antenna port of the terminal device successively sends a pilot signal in T time units included in each time block, and the pilot signals sent by an antenna port of the terminal device in different time blocks are the same, B is an integer greater than 0, and T is an integer greater than 1.

[0061] In one possible implementation, the transceiver module is also used to receive a first indication information from the access network device, where the first indication information is used to indicate the pilot signal that the terminal device repeatedly sends in the B time blocks; the processing module is specifically used to generate a pilot signal that needs to be repeatedly sent in the B time blocks based on the first indication information.

[0062] Possible implementations of the communication device of the tenth aspect can refer to the various possible implementations of the second aspect.

[0063] For the technical effects brought about by various possible implementation methods of the tenth aspect, reference may be made to the introduction to the technical effects of the second aspect or various possible implementation methods of the second aspect.

[0064] In the eleventh aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the method embodiment of the third aspect above. The communication device can be a network device, or a component of a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the network device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software implementations, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a third indication information, and the third indication information is used to instruct the configurable intelligent metasurface RIS to perform orthogonal reflection coefficient switching on B time blocks, where B is an integer greater than 1; the processing module is used to perform orthogonal reflection coefficient switching on the B time blocks based on the third indication information.

[0065] Possible implementations of the communication device of the eleventh aspect may refer to the various possible implementations of the third aspect.

[0066] For the technical effects brought about by various possible implementation methods of the eleventh aspect, reference may be made to the introduction to the technical effects of the third aspect or various possible implementation methods of the third aspect.

[0067] In a twelfth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the method embodiment of the fourth aspect above. The communication device can be a network device, or a component of a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the network device. The functions of the communication device can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to repeatedly send a first pilot signal to the RIS through the first antenna port in B1 time blocks, where B1 is an integer greater than 1; the first pilot signal reflected by the RIS is received through (N-1) antenna ports in the B1 time block, and the (N-1) antenna ports do not include the first antenna port; the processing module is used to obtain a fourth signal matrix based on the first pilot signal reflected by the received RIS; the transceiver module is also used to send a first pilot signal to the RI through the second antenna port in B2 time blocks. S repeatedly transmits a second pilot signal, B2 is an integer greater than 1, and the second antenna port is different from the first antenna port; the second pilot signal reflected by the RIS is received through (N-2) antenna ports in the B2 time blocks, and the (N-2) antenna ports are included in the (N-1) antenna ports and do not include the first antenna port and the second antenna port; the processing module is further used to obtain a fifth signal matrix based on the received second pilot signal reflected by the RIS; and determine a channel matrix between the access network device and the RIS based on the fourth signal matrix and the fifth signal matrix.

[0068] In one possible implementation, the transceiver module is further used to receive, through N antenna ports, a pilot signal repeatedly sent by the terminal device in B3 time blocks, where the N antenna ports include the first antenna port and the (N-1) antenna ports; the processing module is further used to determine the channel matrix between the RIS and the terminal device based on the pilot signal repeatedly sent by the terminal device in the B3 time blocks and received through the N antenna ports.

[0069] In a possible implementation, the transceiver module is further used to send second indication information to the terminal device, where the second indication information is used to instruct the terminal device to repeatedly send the pilot signal in the B3 time blocks.

[0070] In a possible implementation, the transceiver module is further configured to send fourth indication information to the RIS, where the fourth indication information is used to instruct the RIS to perform orthogonal reflection coefficient switching on the B1 time blocks.

[0071] For possible implementations of the communication device of the twelfth aspect, reference may be made to various possible implementations of the fourth aspect.

[0072] For the technical effects brought about by various possible implementation methods of the twelfth aspect, reference may be made to the introduction to the technical effects of the fourth aspect or various possible implementation methods of the fourth aspect.

[0073] In a thirteenth aspect, an embodiment of the present application provides a communication device having the function of implementing the behavior in the method embodiment of the fifth aspect above. The communication device can be a terminal device, or a component of the terminal device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the terminal device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software implementations, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a pilot signal that needs to be repeatedly transmitted in B3 time blocks; the transceiver module is used to repeatedly transmit the generated pilot signal to the access network device in the B3 time blocks, and an antenna port of the terminal device transmits a pilot signal successively in T time units included in each time block, and the pilot signals transmitted by an antenna port of the terminal device in different time blocks are the same, B3 is an integer greater than 0, and T is an integer greater than 1.

[0074] In one possible implementation, the transceiver module is also used to receive a second indication information from the access network device, and the second indication information is used to instruct the terminal device to repeatedly send the pilot signal in the B3 time blocks; the processing module is specifically used to generate the pilot signal that needs to be repeatedly sent in the B3 time blocks based on the second indication information.

[0075] For possible implementations of the communication device of the thirteenth aspect, reference may be made to various possible implementations of the fifth aspect.

[0076] For the technical effects brought about by various possible implementation methods of the third aspect, reference may be made to the introduction to the technical effects of the fifth aspect or various possible implementation methods of the fifth aspect.

[0077] In the fourteenth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the method embodiment of the sixth aspect above. The communication device can be a network device, or a component of a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the network device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software implementations, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive fourth indication information, and the fourth indication information is used to instruct the configurable intelligent metasurface RIS to perform orthogonal reflection coefficient switching on B1 time blocks, where B1 is an integer greater than 1; the processing module is used to perform orthogonal reflection coefficient switching on the B1 time blocks based on the fourth indication information.

[0078] In the fifteenth aspect, an embodiment of the present application provides another communication device, which includes one or more processors, and the one or more processors are used to process data and / or signaling so that the method of any one of the above-mentioned aspects 1 to 6 is implemented.

[0079] Optionally, the communication device further includes a memory storing a computer program or instruction. When the computer program or instruction is executed by the processor, the communication device performs the method of any one of the first to sixth aspects described above. Exemplarily, the communication device may be a chip, the processor may be a processing unit in the chip, and the memory may be a random access memory or cache in the chip.

[0080] In the embodiment of the present application, during the execution of the above method, the process of sending information (or signal) in the above method can be understood as the process of outputting information based on the computer program or instructions of the processor. When outputting information, the processor outputs the information to the transceiver so that it can be transmitted by the transceiver. After being output by the processor, the information may undergo other processing before reaching the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may undergo other processing before being input into the processor.

[0081] For operations such as sending and / or receiving involved by the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant description, they can be generally understood as computer programs or instruction outputs based on the processor.

[0082] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer programs or instructions in a memory to execute these methods, such as a general-purpose processor. For example, the processor may also be configured to execute a program stored in a memory. When the program is executed, the communication device performs the method described in the first aspect or any possible implementation of the first aspect.

[0083] In a possible implementation, the memory is located outside the communication device. In a possible implementation, the memory is located inside the communication device.

[0084] In a possible implementation, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0085] In a possible implementation, the communication device further includes a transceiver, and the transceiver is used to receive signals or send signals.

[0086] In the sixteenth aspect, the present application provides another communication device, which includes a processing circuit and an interface circuit, the interface circuit is used to obtain data or output data; the processing circuit is used to execute the method of any one of the first to sixth aspects above.

[0087] In the seventeenth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method of any one of the first to sixth aspects mentioned above.

[0088] In the eighteenth aspect, the present application provides a computer program product, which includes a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method of any one of the above-mentioned first to sixth aspects.

[0089] In the nineteenth aspect, the present application provides a chip comprising a communication interface and a processor; the communication interface is used for transmitting and receiving signals of the chip; the processor is used for executing computer programs or instructions so that a communication device comprising the chip executes a method as in any one of the first to sixth aspects above. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] FIG1 shows a schematic diagram of the working mode of the emission type RIS;

[0091] FIG2 shows a schematic diagram of a RIS-assisted full-duplex wireless communication system;

[0092] FIG3 is an example of a channel estimation scenario in which the technical solution of the present application is applied;

[0093] FIG4 is a schematic diagram of the architecture of a communication system to which an embodiment of the present application may be applied;

[0094] FIG5 is a flow chart of a communication method provided in an embodiment of the present application;

[0095] FIG6 is a flow chart of another communication method provided in an embodiment of the present application;

[0096] FIG7 is a flow chart of another communication method provided in an embodiment of the present application;

[0097] FIG8 is a flow chart of another communication method provided in an embodiment of the present application;

[0098] FIG9 is a flow chart of another communication method provided in an embodiment of the present application;

[0099] FIG10 is a flow chart of another communication method provided in an embodiment of the present application;

[0100] FIG11 is a schematic structural diagram of a communication device 1100 provided in an embodiment of the present application;

[0101] FIG12 shows a simplified schematic diagram of a base station structure;

[0102] FIG13 shows a simplified schematic structural diagram of a terminal device. DETAILED DESCRIPTION

[0103] The terms "first" and "second" in the specification, claims and drawings of the present application are only used to distinguish different objects, rather than to describe a specific order. It will be understood that the various digital numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0104] The "embodiment" mentioned in this document means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments. In this application, the naming of messages is only used to distinguish different messages and should not be understood as a limitation. In other words, the name of any message in this application can be replaced with other names, and this application is not limited.

[0105] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification of the present application and the appended claims, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear contrary indication in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The term "multiple" used in the present application refers to two or more. In the textual description of the present application, the character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0106] It is understood that in each embodiment of the present application, "A corresponds to B" means that there is a corresponding relationship between A and B, and B can be determined according to A. However, it should also be understood that determining (or generating) B according to (or based on) A does not mean that B is determined (or generated) only according to (or based on) A, and B can also be determined (or generated) according to (or based on) A and / or other information.

[0107] It should be understood that, in this application, indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication of information A refers to including information A; implicit indication of information A refers to indicating information A through the correspondence between information A and information B and the direct indication of information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0108] It should be understood that, in this application, information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0109] In addition, in each embodiment of the present application, "network element A sends information A to network element B" can be understood as the destination end of the information A or the intermediate network element in the transmission path between the destination end and the network element B, which may include directly or indirectly sending information to network element B. "Network element B receives information A from network element A" can be understood as the source end of the information A or the intermediate network element in the transmission path between the source end and the network element A, which may include directly or indirectly receiving information from network element A. The information may be processed as necessary between the source end and the destination end of the information transmission, such as format changes, but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0110] To facilitate understanding of the solutions of the present application, the following first introduces the terms and technical solutions involved in the embodiments of the present application.

[0111] Reconfigurable intelligent surface (RIS): A RIS is a subwavelength artificial material typically composed of metal, dielectric, and tunable elements. It can be represented as an equivalent RLC circuit. An RLC circuit is a circuit structure consisting of resistance (R), inductance (L), and capacitance (C). RIS generates desired electromagnetic behavior by controlling the bias voltage of varactor diodes, PIN switches, diodes, micro-electromechanical system (MEMS) switches, liquid crystals, graphene, and other materials. Specifically, a RIS is a smart panel consisting of multiple arrays (called elements), each of which is a low-cost passive reflector. By flexibly configuring the amplitude and phase of each element, wireless channel fading can be controlled and a desired directional beam can be formed. RIS can be mounted on large surfaces (such as indoor walls or ceilings, outdoor buildings, or signs) to reflect radio frequency (RF) energy around obstacles and create a virtual line-of-sight path between the communication source and target. Compared to the transmitter and receiver in existing wireless networks, the advantages of RIS can be summarized as follows: 1) Enhanced Spectral Efficiency: RIS provides a new degree of flexibility. Through intelligent array control, it can further improve the communication quality of wireless links, enhance the useful signal strength at the receiver, and reduce the intensity of channel interference. This provides a starting point for the realization of future intelligent networks. 2) Reduced Energy Consumption and Equipment Complexity: Because RIS can only passively reflect received signals, meaning that no transmitting and receiving units or data encoding and decoding are required on the RIS side, the actual hardware complexity of RIS can be significantly reduced compared to existing base stations and terminals, thereby reducing the system energy consumption of wireless networks. 3) Ease of Deployment: Because RIS consists only of passive electromagnetic reflection components, it can be easily deployed on various building surfaces, indoor walls, platforms, roadside billboards, highway signs, car windows, and other devices. It can be removed and redeployed at any time according to network needs. 4) Compatibility: RIS can be considered a supplementary device to existing networks, thus having no impact on existing protocols and requiring no modifications to existing equipment, ensuring compatibility. 5) Full-duplex: Compared with relay devices that operate in half-duplex mode, RIS only performs passive reflection and can therefore operate in full-duplex mode, thereby improving spectrum efficiency.

[0112] The application scenarios of RIS are coverage enhancement and blind spot filling. For example, deploying one or more RIS at the edge of a cell, or in a coverage blind spot caused by obstruction or deep attenuation, can achieve the effect of extending coverage and filling blind spots. Figure 1 shows a schematic diagram of the working mode of a transmitting RIS. As shown in Figure 1, the uplink signal sent by the terminal device is transmitted to the base station through the reflection of the RIS. The channel between the terminal device (communication source) and the base station (target) includes the channel between the terminal device and the RIS (i.e., the channel between the UE and the RIS) and the channel between the RIS and the base station (BS) (i.e., the channel between the RIS and the BS). The channel quality between the base station and the terminal device is poor, that is, the direct link between the base station and the terminal device cannot guarantee the communication quality between the base station and the terminal device. Referring to Figure 1, when the direct link between the base station and the terminal device cannot guarantee the communication quality between the base station and the terminal device, by deploying the RIS, the communication quality between the terminal device and the base station can be improved, and the coverage of the base station can be enhanced.

[0113] In future 6G scenarios, to achieve higher array gain, large-scale RIS arrays, such as those consisting of 1024 or more elements, are generally considered. To achieve more precise phase control, current RIS architectures typically employ phase shifters behind each element. Because phase shifters consume power, RIS power consumption and cost are critical issues in such architectures.

[0114] Full-duplex base station: Full-duplex radio enables communication devices (including base stations) to transmit (or send) and receive at the same time and in the same frequency band, thereby improving spectrum efficiency. This lays the foundation for the dual-link channel estimation strategy we will propose next. In addition, in order to reduce the self-interference caused by the leakage of the transmission signal (or the sending signal) to the receiver, this application considers two common full-duplex base station antenna configuration schemes, namely single-station and dual-station, see Figure 2. Figure 2 shows a schematic diagram of a RIS-assisted full-duplex wireless communication system. Referring to Figure 2, the base station may be a dual-station full-duplex base station or a single-station full-duplex base station. The dual-station full-duplex base station (or dual-station system) uses different antennas for the transmitter and receiver (i.e., dual-antenna configuration) to provide spatial isolation to reduce radio self-interference; the single-station full-duplex base station (or single-station system) uses a single antenna for the transmitter and receiver (i.e., single-antenna configuration), and uses a circulator-based circuit isolation technology to isolate the transmitter and receiver branches to different circuit ports. In Figure 2, terminal devices (e.g., terminal device #1 and terminal device #2) can transmit signals to a base station via the RIS. The base station can then transmit signals to the RIS and receive signals transmitted and / or transmitted by the RIS. Dual-station base stations are easier to implement because typically only a subset of antennas transmit signals, while the remaining antennas receive signals. A single-station base station can fully exploit the available spatial diversity for accurate channel estimation, but the required electronics are complex and challenging to implement.

[0115] Definition of mathematical symbols: Table 1 shows the description of some mathematical symbols involved in this application.

[0116] Table 1

[0117] System model of the technical solution provided by this application: The technical solution of this application can be applied to a RIS-assisted wireless communication system, in which K (an integer greater than 0) single-antenna users (can be multi-antenna users) communicate with a base station equipped with N (an integer greater than 0) antennas via a RIS equipped with M (an integer greater than 0) reflection units. In this application, w = [w1, ..., w M ] T Expressed as the reflection coefficient vector of RIS, where ∠w m and |w m | respectively represent the phase shift and reflection gain of the mth (integer greater than or equal to 0) reflection unit. For a passive RIS, its reflection unit can only reflect signals by adjusting the phase shift. Therefore, the reflection gain of the mth reflection unit of the passive RIS is |w m | 2= 1. For active RIS, each reflective element is integrated with an amplifier to overcome the multiplicative fading existing in the passive RIS auxiliary system, which makes the reflection gain of the mth reflective unit of the active RIS satisfy |w m | 2 ≥ 1. In this application, user can be replaced by terminal device or user equipment (UE).

[0118] For simplicity, this application assumes that due to the presence of physical obstacles or severe attenuation, the direct link between the base station and the user can be ignored and and The channels between the base station and the RIS and between the RIS and the kth user are represented, respectively. In typical narrowband time division duplex (TDD) RIS-assisted wireless communication systems, the uplink channel is often used for channel estimation, as this significantly reduces the estimation pilot overhead when the number of base station antennas is large. In this application, the term "time slot" refers to a time duration. A time slot can be replaced by a probability of a time duration, such as a mini-slot.

[0119] For a passive RIS-assisted wireless communication system, the uplink signal received by the base station in the tth time slot can be expressed as:

[0120] In formula (1.1), s u,k (t) represents the pilot signal transmitted by the kth user, and the corresponding signal power can be expressed as |s u，k (t)| 2 =p,w=[w1,...,w M ] T It is expressed as the reflection coefficient vector of RIS, and D(w) represents the diagonal matrix of vector w. n(t) can be expressed as The distributed additive Gaussian white noise, the corresponding noise power is δ 2 , I N Represents the (N×N)-dimensional identity matrix. Most of the existing literature focuses on the cascade channel This is sufficient for most wireless communication scenarios using passive RIS. However, in some scenarios, the base station needs to separately obtain the channel matrix between the base station and RIS and the channel matrix between the RIS and the user. We will list some application scenarios below to illustrate this.

[0121] RIS-assisted user tracking: In vehicular networks, the channel state information (CSI) of highly mobile users is rapidly time-varying. Therefore, high-speed user tracking techniques are required to obtain the latest directional information for these users. Since the locations of the base station and RIS are usually fixed, if the CSI of the base station-RIS link is available, fewer pilots are needed to estimate h. u，k The angle information contained in .

[0122] RIS-assisted sensing: In sensor networks, RIS is often used when the direct link between the base station and the target for sensing is blocked. In this application, x(t) is represented as the waveform received by the base station in the tth time slot. The echo signal received at the base station can be expressed as:

[0123] In equation (1.2), Q represents the response matrix of the target to be estimated. In addition, it can be noted that the useful echo signal directly reflected by the RIS is and echo interference They all depend on the channel matrix H of the base station-RIS link. Therefore, the information of H can be used to eliminate echo interference, thereby improving the estimation accuracy of the target response matrix.

[0124] Active RIS: In an active RIS-assisted wireless communication system, since the components on the RIS are integrated with amplifiers, the uplink signal received by the corresponding base station in the tth time slot should be expressed as:

[0125] In formula (1.3), n R (t) means follow The distributed additive Gaussian white noise, the corresponding noise power is I M It is noted that to calculate the noise power amplified by the active RIS and the transmit power of the active RIS, it is necessary to know the channel matrix of the base station-RIS link and the channel matrix of the RIS-user link respectively.

[0126] Therefore, for the wireless communication scenario using passive RIS, it is crucial to obtain the channel matrix of the base station-RIS link and the channel matrix of the RIS-user link respectively. However, due to ambiguity, the base station cannot extract the channel matrices of both from the estimated cascade channel, that is, for any reversible diagonal matrix Λ, Note that Λ must be a diagonal matrix, since the resulting equivalent channel matrix It must be a diagonal matrix. In order to solve this problem, the present application provides a RIS channel estimation scheme design based on a full-duplex system. Through the configuration of the transmitting and receiving antennas and the transmission of orthogonal pilots, the channel matrix between BS-RIS and the channel matrix between RIS-UE can be independently estimated. The technical solution of the present application is aimed at full-duplex systems based on single stations and dual stations. On this basis, a non-geometric channel estimation method and a geometric channel estimation method are established. Figure 3 is an example of a channel estimation scenario applied to the technical solution of the present application. As shown in Figure 3, the base station communicates in full-duplex mode, that is, the base station transmits (or sends) and receives at the same time and on the same frequency band. K single-antenna users send signals (such as pilot signals) to the base station through RIS. H represents the channel between BS-RIS, and H u Including channels between K users and RIS, RIS is deployed with M arrays (or elements).

[0127] Non-geometric channel models: Unstructured or non-parametric channel models (non-geometric channel models) are often used to characterize propagation environments with rich multipath scattering (e.g., for sub-6 GHz systems). Each channel gain can be represented by a complex number and needs to be estimated.

[0128] Geometric channel model (i.e., geometric channel model): The pilot overhead required for channel estimation based on non-geometric channel models is proportional to the number of RIS reflection elements, which is unacceptable for systems assisted by a large number of RIS. This has prompted those skilled in the art to study geometric channel models (or geometric channel models) involving fewer parameters. This channel model is suitable for millimeter wave (mmWave) systems and higher carrier frequencies, where multipath is sparse and characterized by gain, angle of arrival (AoA) and angle of departure (AoD). The geometric channel model can be parameterized by the steering vector of the transmit and receive signals according to the underlying structure of the array. For example, for M deployed in the xz plane and antenna spacing d x ×M z Uniform planar array (UPA) with elevation AoAφ el and azimuth AoAφ az The steering vector of the incident signal is composed of a Given, where the horizontal array response vector By spatial frequency Definition, and the vertical array response vector By spatial frequency Definition, λ cis the carrier wavelength. Vector ω=[ω x ,ω z ] T From the two-dimensional (2D) space angle {φ el ,φ az} parameterized. For x The uniform linear array (ULA) of antennas has a Depend on Give the steering vector.

[0129] In this application, we assume that the base station and RIS are ULA and UPA respectively. The generalization to arbitrary array geometry is very simple. BR Base station-RIS link of space path and L RU,k The geometric channel models of the RIS-user link with k spatial paths are as follows:

[0130] In formula (3.1), the diagonal matrix Complex path gain including base station-RIS link vector Contains the complex path gain between RIS and user k. The columns are spatial frequencies The base station AoA steering vector. In addition, and The spatial frequencies are AoD steering vector and spatial frequency Here, the vector ω RH，l =[ω RH，l，x ,ω RH，l，z ] T and ω Rh，k，i =[ω Rh，k，i，x ,ω Rh，k，i，z ] T are the 2D AoD and AoA spatial frequencies of RIS, respectively.

[0131] Under the geometric channel model, channel estimation involves recovering the sparse parameters {ω BH ,ω RH , α}, and restore b u，k The sparsity parameter {ω Rh，k , β k}.

[0132] In some wireless communication scenarios using passive RIS, the base station needs to obtain the channel matrices for both the base station-RIS link and the RIS-user link. This application provides a RIS channel estimation solution designed for a full-duplex system. By configuring transmit and receive antennas and transmitting orthogonal pilot signals, it can independently estimate the channel matrix between the base station and RIS, and the channel matrix between the RIS and the user equipment (UE). The following describes the communication system to which this application's technical solution is applicable.

[0133] Figure 4 is a schematic diagram of the architecture of a communication system applicable to embodiments of the present application. As shown in Figure 4, the communication system includes a network device 110, a terminal device 120, and a RIS 130. A communication system applicable to embodiments of the present application includes one or more terminal devices and multiple RISs. Terminal device 120 is used as an example of a terminal device in the communication system, and RIS 130 is used as an example of a RIS in the communication system. Figure 4 is merely a schematic diagram, and embodiments of the present application do not limit the number of network devices, terminal devices, and RISs included in the communication system. Terminal device 120 can access and communicate with network device 110. The terminal device can connect to network device 110 wirelessly. The terminal device sends signals to a base station via the RIS and / or sends signals to the base station via a direct link with the base station. The base station can send signals to the RIS and receive signals transmitted and / or transmitted by the RIS. Network device 110 can connect to the core network wirelessly or wiredly. The core network device and network device 110 can be independent, distinct physical devices, or the core network device's functions and the network device's logical functions can be integrated into the same physical device. Alternatively, a single physical device can integrate some of the core network device's functions and some of the network device's functions. Terminal devices and network devices can be connected to each other via wired or wireless means. Figure 4 is merely a schematic diagram; the communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 4.

[0134] Figure 4 is only an example of a communication system to which embodiments of the present application can be applied. Embodiments of the present application can also be applied to other communication systems including network devices, terminal devices, and RIS. Embodiments of the present application can be applied to support RIS-based communication enhancement scenarios, such as scenarios where RIS is used to reduce coverage blind spots in existing networks, scenarios where RIS is used to enhance communication quality in certain areas, and so on.

[0135] In the embodiments of the present application, terminal equipment may also be referred to as user equipment (UE), access terminal, subscriber unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0136] The terminal device may be a device that provides wireless communication functions, such as a handheld device or a vehicle-mounted device with a wireless connection function. At present, some examples of terminal devices are: mobile phones, cellular phones, smart phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, machine type communications (MTCs), and other similar terminal devices. Communication, MTC) terminal, terminal equipment in a 5G network, or terminal equipment in a future evolved public land mobile communication network (public land mobile network, PLMN), etc., and the embodiments of the present application are not limited to this.

[0137] As an example but not a limitation, in the embodiment of the present application, the terminal device may also be a mobile terminal (mobile termination, MT) in an integrated access & backhaul (IAB) node.

[0138] As an example and not a limitation, in the embodiment of the present application, the terminal device may also be a wearable device. Wearable devices may also be called wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0139] In the embodiments of the present application, the device for realizing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to realize the function, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the embodiments of the present application, only the terminal device is used as an example for description, and the embodiments of the present application are not limited to the solutions of the embodiments of the present application.

[0140] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. The term "base station" may broadly cover the following names or be replaced with the following names, such as RAN node, NodeB, evolved NodeB (eNB), next generation NodeB (gNB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home NodeB, HNB), baseband unit (BBU), wireless relay node, wireless backhaul node, relay station, transmitting and receiving point (TRP), IAB node, transmitting point (TP), master station, auxiliary station, multi-standard radio (motor slide retainer, MSR) node, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CNU), etc. unit (CU), distributed unit (DU), radio unit (RU), positioning node, one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, etc.

[0141] An IAB node integrates a mobile termination (MT) and a distributed unit (DU). An IAB node may include an MT, a DU, and a central unit (CU). A central unit may be referred to as a central unit. An IAB node may include one CU and one or more DUs. When an IAB node includes a CU, the IAB node is an IAB donor node, and the CU in the IAB donor node accesses the core network through a next-generation application protocol (NG) interface. When an IAB node faces its parent node, it can be considered a terminal, in which case the IAB node plays the role of an MT. When an IAB node faces its child node (the child node may be a terminal or the MT of another IAB node), the IAB node can be considered a network device. An IAB node can establish a backhaul connection with at least one parent node of the IAB node through the MT part. The DU part of an IAB node can provide access services to the MT part of a terminal or another IAB node.

[0142] The base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The base station can also refer to a communication module, a modem or a chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs the base station function in device to device (D2D), vehicle to everything (V2X), and machine to machine (M2M) communications, a network side device in a 6G network, and a device that performs the base station function in future communication systems. The base station can support networks with the same or different access technologies. Optionally, the RAN node can also be a server, a wearable device, a vehicle or an on-board device, etc. For example, the access network device in the V2X technology can be a road side unit (RSU). The embodiments of the present application do not limit the specific technology and specific device form adopted by the network equipment.

[0143] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0144] In some deployments, the network devices mentioned in the embodiments of the present application may include a CU, a DU, or both a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)), a user plane CU node (central unit-user plane (CU-UP)), and a DU node. For example, the network devices may include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0145] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of the base station's functionality. For example, a RAN node can be a CU, DU, CU-CP, CU-UP, or RU. The CU and DU can be separate or included in the same network element, such as the BBU. The RU can be included in radio frequency equipment, such as the RRU, AAU, or RRH.

[0146] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (ORAN) system, CU may also be referred to as O-CU (open CU), DU may also be referred to as O-DU, CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. Any of the CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0147] In the embodiments of the present application, the device for implementing the functions of the network device can be a network device; it can also be a device that can support the network device to implement the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit and a software module. The device can be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the device for implementing the functions of the network device is used as an example to illustrate, and does not constitute a limitation on the solutions of the embodiments of the present application.

[0148] The network device and / or terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface; it can also be deployed on aircraft, balloons and satellites in the air. The embodiments of this application do not limit the scenarios in which the network device and the terminal device are located. In addition, the terminal device and the network device can be hardware devices, or they can be software functions running on dedicated hardware, software functions running on general-purpose hardware, such as virtualization functions instantiated on a platform (e.g., a cloud platform), or entities including dedicated or general-purpose hardware devices and software functions. This application does not limit the specific forms of the terminal device and the network device.

[0149] In one possible implementation, the RIS may only need to passively reflect received signals. This means that no transmitting or receiving units are required on the RIS side, and no data encoding or decoding is required. In other words, the RIS may only include passively reflecting electromagnetic components. In one possible implementation, the RIS may be capable of transmitting or receiving signals or information. This application does not limit the structure of the RIS; the RIS may be replaced with other relay devices capable of reflecting and / or transmitting signals, or with other devices capable of beamforming signals.

[0150] It should be noted that the network architecture described in the embodiment of the present application is to more clearly illustrate the technical solutions of the embodiment of the present application, and does not constitute a limitation on the technical solutions provided in the embodiment of the present application. Those skilled in the art will appreciate that, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiment of the present application are equally applicable to similar technical problems. In the following embodiments, the technical solutions provided in the embodiment of the present application are described by taking the device for implementing the functions of the network device as a network device and the network device as a base station as an example.

[0151] It is understood that this application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the application. As long as it is possible to communicate according to the method provided in the embodiment of the application by running a program that records the code of the method provided in the embodiment of the application. The method provided in the embodiment of the application can be applied to communication between a sending end and a receiving end. The interaction between the sending end and the receiving end is used as an example for explanation below.

[0152] To facilitate understanding of the technical solution provided by this application, the following first introduces the geometric / non-geometric channel estimation method and theoretical support based on single-station and dual-station full-duplex base stations provided by this application.

[0153] The main idea of ​​the technical solution of this application is to utilize the simultaneous transmission and reception characteristics of the full-duplex base station, decouple and estimate the independent channels of the BS-RIS (i.e., the channel between the base station and the RIS) and the RIS-UE (i.e., the channel between the RIS and the terminal device) through the configuration of the transmitting and receiving antennas and the transmission of orthogonal pilots.

[0154] 1) Non-geometric channel estimation method for full-duplex base stations based on single-station antenna configuration.

[0155] Assume that a full-duplex base station (hereinafter referred to as the base station) is equipped with a single-station antenna, that is, the N antenna transmitters (or antenna ports) on the base station and K users simultaneously send pilot signals to the RIS, and the N antenna receivers (or antenna ports) on the base station receive the signals reflected from the RIS, as shown in Figure 3. In this embodiment of the present application, the training time slot (which can be named as a measurement time slot or other names) is divided into B pilot time blocks (which can be named as sub-time blocks or other names) containing T time slots. In the B pilot time blocks, the base station and the kth user respectively repeatedly send the pilot signal matrix and vector The reflection coefficient vector w of RIS b In B pilot time blocks, the base station repeatedly sends the pilot signal matrix Each antenna port of the base station sends a pilot signal in each T time slot contained in each pilot time block. The (N*T) pilot signals sent by the base station in one pilot time block are the pilot signal matrix The base station repeatedly sends the pilot signal, which means that the base station sends the same pilot signal in different pilot time blocks. In B pilot time blocks, the kth user (terminal device) repeatedly sends vector The kth user may send a pilot signal in each of the T time slots contained in each pilot time block. The T pilot signals sent by the kth user in each pilot time block are vectors The reflection coefficient vector w of RIS b The difference between time blocks may be that RIS performs orthogonal reflection coefficient switching on B time blocks, and the reflection coefficient vector of RIS remains unchanged within the same time block.

[0156] Assume that W is a matrix of dimension B×M, whose bth (integer greater than or equal to 0) row is And assume that the system is synchronized. W represents the RIS training matrix, that is, the RIS reflection coefficient vector w b Therefore, the signal received by the base station in the bth pilot time block can be expressed as:

[0157] Since the pilot signal from the base station can be reflected at the same frequency within a very short time interval, the propagation environment does not change, so the channel reciprocity holds. The effective noise samples are included in the passive RIS-assisted system, including the residual self-interference and additive white Gaussian noise after the self-interference cancellation technology is used. For the active RIS-assisted system, the corresponding received signal contains the residual self-interference, the noise generated by the active RIS, and the additive white Gaussian noise at the base station. Equation (2.1) can be rewritten as follows:

[0158] The relevant variables in formula (2.2) are defined as follows: and

[0159] Based on equation (2.2), the base station can obtain a three-dimensional tensor based on the signal matrix received in B pilot time blocks Should Each element in can be a complex number representing the pilot signal received by the base station, and each pilot time block corresponds to a (N×T) two-dimensional matrix. With Y b Satisfies the following relationship: Then, we can further Defined as Among them, the tensor and They represent the noise-free measurement value (i.e., useful signal) and the corresponding noise respectively. The (n, t, b)th element of can be expressed as:

[0160] Equation (2.3) is the sum of M rank-1 triple products, called Trilinear decomposition or parallel factor (PARAFAC) analysis of . Based on PARAFAC decomposition, can be re-expressed as:

[0161] In formula (2.4), Represents the identity tensor of shape (M×M×M).

[0162] Since the RIS training matrix W is known to the base station, let B = M, and the following least square (LS) problem can be constructed to obtain The estimated factor matrix H and (GX) T :

[0163] In formula (2.5), Express The mode 3 expansion can also be expressed as Y (3) =[vec(Y1),...,vec(Y B )] T . N (3) represents the corresponding noise matrix.

[0164] Problem (2.5) can be decomposed into M rank-1 approximation problems using the Khatri-Rao decomposition algorithm. Specifically, we can first -1 Y (3) ) T , H and (GX) T The mth column is respectively and Then, when 1≤m≤M, the following problem can be constructed:

[0165] In formula (2.6), we have Among them, unvec N×T (·) means that the vector formed by column stacking is restored to a matrix with dimension (N×T). According to the Eckart-Young theorem, by m Performing singular value decomposition (SVD) can obtain the best rank-1 approximation of the problem (2.5), but this solution is not unique. Therefore, we define h m =ρ m f 1,m / λ m and g m =λ m f 2,m , where λ m represents the unknown complex scaling factor, ρ m It is C m The maximum singular value of f 1,m and are the corresponding left and right singular vectors respectively. We further define the complex scaling vector λ = [λ1, ..., λ M ] T and Thus H and (GX) T Rewritten as: H=F1Λ -1 , (2.7); X T G T =F2Λ. (2.8);

[0166] F1 and F2 in formulas (2.7) and (2.8) are defined as: F1 = [ρ1f1，1 ,...,ρ M f 1，M ] and F2=[f 2，1 ,...,f 2，M ].

[0167] To determine the unknown Λ, we need to use H, which exists in both equations (2.7) and (2.8). To do this, we first use the orthogonality of the pilot matrix to eliminate the channel matrix H in equation (2.8). u , that is, using the relation X * X T =pTI K+N This orthogonality imposes the necessary condition T ≥ K + N and yields and Therefore, when using this method to u When eliminated from formula (2.8), formula (2.8) can be rewritten as:

[0168] Then, according to equations (2.7) and (2.9), we can obtain the following relationship:

[0169] Formula (2.11) is derived from equation We get, and the definition of λ2 in formula (2.11) is: λ2=diag(Λ 2 ). Before proceeding with the explanation, we introduce the following lemma.

[0170] Lemma 1 (column rank property of Khatri-Rao product matrix): For a Khatri-Rao product matrix in when When the Khatri-Rao product matrix The columns of are full rank and have rank M.

[0171] According to Lemma 1, we can deduce that min(N,M)+M≥M+1, which means The column of is always full rank M, because N ≥ 1 always holds. Then, we can further derive an expression for λ2:

[0172] Since λ2 satisfies λ2=diag(Λ 2 )=diag((-Λ 2 ), we choose As an estimate of Λ. Therefore, we can derive the following relationship: where e ΛEach value of belongs to the set {1, -1}. We note that There is a square root operation, and the result obtained has two possibilities: positive and negative. This application calls it sign ambiguity. Λ is called the symbol fuzzy vector. We will prove below that The symbol ambiguity in the [1] does not affect the application scenarios where it is necessary to obtain each channel matrix.

[0173] By assuming To estimate the obtained Λ, we can give H and H based on Equations (2.7) and (2.8) u The estimated value of is as follows:

[0174] Then, the actual channels H and H u The expression is as follows:

[0175] A related note on symbolic ambiguity: We will prove below that and The symbol ambiguity of has no effect on the application scenario where the matrix of each channel needs to be obtained. and HΛ x H H and Here we assume that Λ x is an arbitrary diagonal matrix. First, substitute the result of formula (2.15) into HΛ x H H In this case, we can get:

[0176] Formula (2.17) shows that the symbol fuzzy vector e Λ In this case, there is no effect. Next, we let in, Indicates h u，k Similarly, Substitute into In the above example, we can get:

[0177] Equation (2.18) shows that the symbol ambiguity vector e Λ There is no impact in this case either.

[0178] It should be noted that the unstructured channel model considered in this application is not relevant to the sensing and user tracking tasks. For sensing and tracking, high carrier frequency is preferred so that angular information can be exploited and geometric channel models can be applied.

[0179] 2) Non-geometric channel estimation method for full-duplex base stations based on dual-station antenna configuration.

[0180] The complex circuitry required for a single-station full-duplex base station makes hardware implementation challenging, prompting those skilled in the art to investigate channel estimation algorithms for dual-station full-duplex base stations. Since single-station full-duplex base stations utilize simpler circuitry, they are more suitable for practical applications. Since dual-station full-duplex base stations use different antennas for transmission and reception, the reciprocity of the uplink and downlink base station-RIS links no longer holds. Therefore, directly applying the estimation algorithm proposed above is impossible. This application proposes a channel estimation method for the base station-RIS channel. The key idea is to select a base station antenna for reception in the first phase and transmission in the second phase. This process creates a pair of interacting channels to aid in estimating the entire base station-RIS link. Next, using the estimated base station-RIS link, a least squares (LS) method can be used to estimate the RIS-user link, requiring only a low pilot overhead.

[0181] 2.1) Estimate the channel matrix H of the base station-RIS link.

[0182] In the first stage, it is assumed that a base station receiver with (N-1) antennas (e.g., including the 1st to (N-1)th antennas of the base station) is responsible for receiving the pilot signal transmitted by a single-antenna base station transmitter (e.g., including the Nth antenna of the base station). The base station transmitter can repeatedly send the pilot signal for B1 time blocks. In the b1th (1≤b1≤B1) time block, the signal received by the base station through the base station-RIS-base station link can be expressed as:

[0183] In formula (2.19), and Represent the first (N-1) rows and the last row of H, that is, is the beamforming phase shift matrix at the RIS, is a valid noise vector. The base station can collect B1 observations And stack them in a matrix of dimension (N-1)×B1, which is expressed as follows:

[0184] In formula (2.20), we have

[0185] In the second phase, the Nth base station antenna is turned off and the (N-1)th antenna starts transmitting. According to equation (2.20), the new single-antenna base station transmitter repeatedly transmits the pilot signal for B2 time blocks. The signal received by the base station can be expressed as:

[0186] In formula (2.21) and Respectively represent the first N-2 rows and the last row of H1, that is is the beamforming phase shift matrix of RIS, and the equivalent noise matrix Definition and similar.

[0187] Please note that in the above description, h N-1 It acts as a downlink channel in equation (2.20) and as an uplink channel in equation (2.21). N Before, the base station can first estimate h by combining equations (2.20) and (2.21). N-1 If B1≥M and B2≥M, we can deduce that:

[0188] P1 in formula (2.22) and P1 in formula (2.23) The definitions are as follows:

[0189] Next, by combining P1 and Can eliminate h N . Based on this, we can get the following relationship:

[0190] In Equation (2.26), Z1 includes all noise terms. By combining Equations (2.23) and (2.26) to eliminate H2, we can derive:

[0191] In formula (2.27), h x =h N-1 ⊙h N-1 and We have discussed before that the matrix According to Lemma 1, it is column-full rank. Therefore, we get the following estimates:

[0192] Let x 1 / 2 Represents the square root operation performed on a vector x element by element. Then, we can get Get h N-1 Therefore, we have where the symbol ambiguity vector e h Every value of exists in the set {1, -1}.

[0193] Next, given the estimated value H2 and h NThey can be estimated from equations (2.23) and (2.25) as follows:

[0194] This led to Finally, the estimate of the channel matrix H is given by:

[0195] Then, the actual channel matrix H can be expressed as

[0196] As in Equation (2.15), the unknown symbol ambiguity vector e h This has no impact on application scenarios that require obtaining matrices of each channel.

[0197] 2.2) Estimate the channel matrix H of the RIS-user link u .

[0198] According to the estimation results of the base station-RIS link in 2.1) The estimated channel matrix H of the RIS-user link can be reduced u In particular, K users simultaneously transmit B3 time blocks of orthogonal pilot symbols repeatedly. Right now All base station antennas are used to receive pilot signals. In the b3th time block (1≤b3≤B3), the received signal can be expressed as:

[0199] In formula (2.33), we have We then collect observations and b3 = {1, ..., B3}, to obtain:

[0200] It can be estimated from formula (2.34). This method requires and are all full rank. Then, The estimated value of can be given by:

[0201] The actual channel matrix H u It can be expressed as follows:

[0202] As in Equation (2.16), the unknown symbol ambiguity vector e h Need to know The application has no effect.

[0203] 3) Geometric channel estimation method for full-duplex base stations based on single-station antenna configuration.

[0204] The following introduces the channel matrix H of the base station-RIS link and the channel vector h of the RIS-user link of a single-station full-duplex base station system based on the geometric channel model. u，k To this end, first according to equation (3.1), the base station received signal in the bth pilot time block represented in equation (2.2) can be rewritten as follows:

[0205] In formula (3.3), we have as well as

[0206] Estimate ω from formula (3.3) BH is a typical angle estimation problem. Existing angle estimation methods can be divided into two categories, grid estimation methods (including matched filters) and gridless estimation methods (including multiple signal classification (MUSIC), which estimates signal parameters with the help of rotation invariance technology. The grid method establishes a discrete grid covering the entire angle range at a given resolution. The goal is to find the grid point closest to the angle to be estimated and use its value as the estimated angle. Therefore, an inherent disadvantage of the gridding method is the angle mismatch. This mismatch error can be reduced by increasing the grid resolution, but this also expands the search space, thereby increasing the complexity of the algorithm. The gridless estimation method can provide extremely high estimation accuracy, but at the cost of higher computational complexity. It should be noted that estimating ω BH The error of may seriously affect the estimation accuracy of the subsequent estimation steps. Therefore, in the embodiment of the present application, ω BH The high-precision estimation of ω is used to reduce the negative impact on subsequent parameter estimation. BH The base station can use any method to estimate ω BH .

[0207] Assume that the base station obtains ω BH Accurate estimation of T≥L BR + K, we can get:

[0208] In formula (3.5), we have and Please note that Y B,b The front L BR The columns contain the angle and gain information of H, which will be used to estimate the sparse parameters ω of H. RH and ω BR , and Y B,b The last K columns will be used to estimate H u The sparsity parameter ω Rh,k and β k .

[0209] 3.1) Estimate the channel matrix H of the base station-RIS link:

[0210] For any 1≤l1,l2≤L BR , Y B，b The (l1, l2)th element of can be expressed as:

[0211] By aggregating B time blocks We can get:

[0212] In formula (3.7) Definition and Similarly, Equation (3.7) can be transformed into a two-dimensional angle estimation problem. Therefore, the cascaded spatial frequency and cascade gain The estimated value of can be given by:

[0213] in, for An estimated value of . and Therefore, the search range of ω in formula (3.8) is and

[0214] After solving the problem that for any 1≤l1=l2≤L BR L BR After solving the two-dimensional angle estimation problem, we further obtain and Estimated value of and Therefore, ω RH The final estimate of can be written as: However, each All have symbol ambiguity. In order to reduce the symbol ambiguity, we can further solve A two-dimensional angle estimation problem, which leads to the following conclusion: BR Estimated value of If the estimate is error-free, we can obtain the following relationship:

[0215] In the presence of estimation errors, Equation (3.10) only holds approximately. Therefore, we estimate α based on SVD. The steps for estimating α are summarized in Algorithm 1.

[0216] It should be noted that, because αα T=(-α)(-α) T , so the α estimation based on Algorithm 1 will have sign ambiguity, so we have Finally, the estimate of H can be constructed as Therefore, there are also

[0217] 3.2) Estimate the channel vector h of the RIS-user link u，k :

[0218] Given an estimated value We can start from Y B，b L BR +k columns estimate h u,k , combined with formula (3.2), its geometric form can be written as:

[0219] In this application, you can stack Into a (BL BR ×1) vector, that is It can also be written as follows:

[0220] n in formula (3.12) B,k Definition and y B,k Similar. When BL BR <M, E(α, ω) in formula (3.12) RH ) is an overcomplete perception matrix. Then, the vector g k =A R (ω Rh,k )β k Only through compressive sensing (CS) technology can we measure y B,k Parameter ω Rh，k and β k can be estimated to solve for an L RU，k dimensional angle estimation problem. BR ≥M, E(α,ω RH ) is an overdetermined sensor matrix with full column rank, the LS method can be used to directly estimate g k ,Right now However, B，k is a single measurement vector (SMV), g k Each element of is estimated independently, which leads to poor estimation performance. Therefore, even if the observation value is uncertain, the CS technique can still further improve the estimation accuracy of the geometric channel model. BH Similar to the estimation of g, we propose two different g in Appendix B. kEstimation methods: OMP-based grid method and 2D ANM-based gridless method.

[0221] Will and Respectively expressed as ω Rh，k and β k The estimated value of h u，k The estimated value of Note that the sign ambiguity generated by estimating H is propagated to h u，k In the estimation of

[0222] Relevant explanation of symbol ambiguity: Similar to the unstructured channel model, H and h u，k The symbol ambiguity in the estimation of does not affect the application of the geometric channel model mentioned above.

[0223] 4) Geometric channel estimation method for full-duplex base stations based on dual-station antenna configuration.

[0224] For a dual-station full-duplex base station, the base station antenna can be divided into two parts, that is, N = N1 + N2, where N1 antennas send signals to RIS and N2 antennas receive signals reflected from RIS at the same time. Denotes the channel between the N1 antenna base station transmitter and the RIS, let Denote the channel between the N2-antenna base station receiver and the RIS. Then, in the b-th time block (1≤b≤B) with T time slots, the signal received by the base station transmitter and all users can be expressed as:

[0225] In formula (3.13), we have and

[0226] For full-duplex communication, due to channel reciprocity, we assume that the downlink channel and the uplink channel H2 share the same propagation path. The structures of and H2 are respectively and Here, and Represent the steering vectors of the N1 antenna transmitter and N2 antenna receiver on the base station respectively. and H2, Equation (3.13) can be rewritten as:

[0227] In formula (3.14), and Φ b The definition of is in formula (3.4). Since N>>L BRFor high frequency systems, we can choose appropriate values ​​of N1 and N2 so that N1>L BR and N2>>L BR Then, using the existing method, the base station AoA spatial frequency ω can be estimated according to formula (3.14) BH .

[0228] Based on ω BH Accurate estimation of T≥L BR + K, we can get:

[0229] In formula (3.15), we have We can notice that Y B1，b With Y B，b With the same structure, it can be used for denoising. Therefore, the sparse parameter ω RH and α can be estimated using the method described in Section 2.1) to estimate the channel matrix H of the base station-RIS link. In addition, the method proposed in Section 2.2) can estimate the RIS-user channel H u .

[0230] The following introduces the pilot overhead of different channel estimation methods.

[0231] Pilot overhead analysis for non-geometric channels: For a single-station full-duplex base station, at least B = M time blocks of the Khatri-Rao decomposition algorithm are required to solve the problem expressed in Equation (2.6). In order to design the pilot signals sent by the base station and the user in each pilot time block as orthogonal pilot signals, T = N + K is required. Therefore, the minimum pilot overhead is BT = M(N + K). For a dual-station full-duplex base station, 2M pilots are required to estimate H, which requires at least The pilot is used to estimate the channel between the RIS and each user. Therefore, the total pilot overhead required is

[0232] Pilot overhead analysis for geometric channels: n measurements are required to determine an l-sparse complex signal (vector) with dimension m, and its pilot overhead is For the estimation of H, BH The number of measurements required for sparse estimation is given by BT, where T ≥ L BR +K. If T is large enough, B can be reduced to B = 1. In addition, based on formula (3.8) Estimated need For h u，k The estimated number of measurements is BL BR , which results in its pilot overhead being Therefore, the minimum pilot overhead required is The above pilot overhead is summarized in Table 2 below.

[0233] Table 2

[0234] Where M represents the number of RIS arrays; N represents the number of BS antennas; K represents the number of UEs; L BR Indicates: the multipath number of BS-RIS channel; L RU Indicates the multipath number of the RIS-UE channel.

[0235] The foregoing describes the geometric / non-geometric channel estimation method and theoretical support based on single-station and dual-station full-duplex base stations provided by this application.

[0236] FIG5 is a flow chart of a communication method provided by an embodiment of the present application. The method in FIG5 can be applied to single-station full-duplex channel estimation in a non-geometric model, and can also be applied to single / dual-station full-duplex channel estimation in a geometric model. As shown in FIG5, the method includes:

[0237] 501. The base station repeatedly sends a pilot signal to the RIS via N antenna ports in B time blocks.

[0238] Accordingly, the RIS reflects the pilot signal that the base station repeatedly transmits to the RIS via N antenna ports in B time blocks. For example, the RIS reflects the pilot signal that the base station repeatedly transmits to the RIS via N antenna ports in B time blocks to the base station. In one possible implementation, the RIS switches orthogonal reflection coefficients over the B time blocks, and the reflection coefficient vector of the RIS remains unchanged within the same time block.

[0239] The first antenna port and the second antenna port among the N antenna ports respectively transmit a pilot signal in the T time units included in each time block. The T pilot signals successively transmitted by the first antenna port in each time block correspond to a first vector. The T pilot signals successively transmitted by the second antenna port in each time block correspond to a second vector. The first vector and the second vector are orthogonal. B is an integer greater than 0. N and T are integers greater than 1. In one possible implementation, each antenna port of the base station respectively transmits a pilot signal in the T time units included in each time block, that is, each antenna port successively transmits T pilot signals in each time block, and the T pilot signals successively transmitted by each antenna port in each time block correspond to a vector, and the vectors corresponding to different antenna ports are orthogonal, for example, the first vector and the second vector are orthogonal.

[0240] The base station repeatedly sends pilot signals to the RIS through N antenna ports in B time blocks: each antenna port of the base station sends a pilot signal in each T time slot contained in each pilot time block. The (N*T) pilot signals sent by the base station in one pilot time block can be regarded as a pilot signal matrix Since the vectors corresponding to different antenna ports of the base station are orthogonal, the pilot signal matrix is an orthogonal matrix, the pilot signal matrix It can be called an orthogonal pilot signal matrix. Another description of step 501 is that the base station repeatedly sends an orthogonal pilot signal matrix of B time blocks to the RIS.

[0241] 502. The terminal device repeatedly sends a pilot signal to the base station in B time blocks.

[0242] An antenna port of the above-mentioned terminal device sends a pilot signal successively in the T time units included in each time block. The pilot signals sent by an antenna port of the above-mentioned terminal device in different time blocks are the same. The third vector corresponding to the T pilot signals sent successively in each time block by an antenna port of the above-mentioned terminal device is orthogonal to the above-mentioned first vector. The third vector corresponding to the T pilot signals sent successively in each time block by an antenna port of the terminal device can be orthogonal to the vectors corresponding to each antenna port of the base station. The terminal device repeatedly sends pilot signals to the base station in B time blocks, which can be that the terminal device sends a pilot signal in each T time slot included in each pilot time block, and the T pilot signals sent by the terminal device (taking the kth user as an example) in each pilot time block are vectors. The method flow in FIG5 may include K terminal devices, and the operations performed by each terminal device are similar to those of the terminal device. The method flow in FIG5 is described by taking one terminal device as an example.

[0243] In one possible implementation, step 502 is replaced by: K terminal devices (i.e., the first user to the kth user) repeatedly send an orthogonal pilot signal matrix Su of B time blocks to the BS, where one column in the orthogonal pilot signal matrix is ​​a vector corresponding to T pilot signals sent successively by a terminal device in the same time block. For example, the T pilot signals sent by the kth user in each pilot time block are vectors. The vectors corresponding to the T pilot signals sent successively by different terminal devices in the same time block are orthogonal. In other words, the vectors corresponding to the pilot signals sent by K terminal devices in the T time slots contained in the same pilot time block correspond to an orthogonal pilot signal matrix.

[0244] It should be noted that the measurement pilot sent by the base station, that is, the pilot signal matrix The measurement pilots sent by the terminal device (i.e., the orthogonal pilot signal matrix Su) satisfy the orthogonal condition, which has the following mathematical characteristics: and / or, Step 502 can be understood as: the terminal device side sends a pilot signal that satisfies the orthogonal condition with the base station, that is, the orthogonal pilot signal matrix Su.

[0245] In one possible implementation, the base station instructs the UE to send a measurement pilot based on different channel forms. The measurement pilot may last for B time blocks, where each time block may be T in length, for example, including T time slots. In different scenarios, there are no restrictions on the length of the measurement pilot, the number of base station antennas, the number of RIS antennas, the number of users (i.e., the number of terminal devices), the number of multipaths in the BS-RIS channel, and the number of multipaths in the RIS-UE channel.

[0246] 503. The base station receives a pilot signal in B time blocks.

[0247] The pilot signals received by the base station in the B time blocks include the pilot signals reflected by the RIS in the B time blocks and the pilot signals repeatedly sent by the terminal device in the B time blocks.

[0248] Steps 501 to 503 belong to the air interface measurement phase, and step 504 belongs to the calculation phase.

[0249] 504. Determine at least one of a channel matrix between the base station and the RIS and a channel matrix between the RIS and the terminal device based on the pilot signals received in the B time blocks.

[0250] In this application, the channel matrix may be the CSI of the channel.

[0251] In an embodiment of the present application, based on the pilot signals received in B time blocks, at least one of the channel matrices between the base station and the RIS and the channel matrix between the RIS and the terminal device is determined; estimates of two independent channels, BS-RIS and RIS-UE, can be obtained to serve scenarios such as perception and power optimization.

[0252] FIG6 is a flow chart of another communication method provided by an embodiment of the present application. The method flow in FIG6 is a possible implementation of the method described in FIG5. The method in FIG5 can be applied to single-station full-duplex channel estimation in a non-geometric model. As shown in FIG6, the method includes:

[0253] 601. The base station sends first indication information to the terminal device.

[0254] Correspondingly, the terminal device receives the first indication information from the base station. The first indication information is used to indicate the pilot signal that the above-mentioned terminal device repeatedly sends in the above-mentioned B time blocks. Exemplarily, the first indication information may carry the start time of the first time block in the above-mentioned B time blocks, the length of each time block, the number of time blocks (i.e., B), and the pilot signal (or measurement pilot) that the terminal device needs to send. In a possible implementation, the vectors corresponding to the pilot signals repeatedly sent by the terminal device indicated by the first indication information in the above-mentioned B time blocks are orthogonal to the vectors corresponding to the pilot signals repeatedly sent by each antenna port of the base station in the above-mentioned B time blocks.

[0255] Step 601 can be replaced by: the base station sends different indication information to K terminal devices (i.e., terminal device #1 to terminal device #K) respectively, wherein the base station sends indication information #1 to terminal device #1, and indication information #1 is used to indicate that terminal device #1 repeatedly sends pilot signal #1 in the above-mentioned B time blocks; the base station sends indication information #2 to terminal device #2, and indication information #2 is used to indicate that terminal device #2 repeatedly sends pilot signal #2 in the above-mentioned B time blocks; and so on, the base station sends indication information #K to terminal device #K, and indication information #K is used to indicate that terminal device #K repeatedly sends pilot signal #K in the above-mentioned B time blocks; the vector corresponding to pilot signal #1, the vector corresponding to pilot signal #2, ..., the vector corresponding to pilot signal #K can form an orthogonal pilot signal matrix Su, and the vector corresponding to each pilot signal is a row in the orthogonal pilot signal matrix Su. The orthogonal pilot signal matrix Su and the measurement pilot sent by the base station, i.e., the pilot signal matrix Satisfy the orthogonality condition: The base station sending different indication information to K terminal devices (i.e., terminal device #1 to terminal device #K) can be understood as the base station instructing the terminal device to send measurement pilot Su, i.e., orthogonal pilot signal matrix Su. The first indication information is an example of indication information #1, indication information #2, ..., indication information #K. For ease of description, the present embodiment is described using a single terminal device as an example.

[0256] 602. Based on the first indication information, the terminal device generates a pilot signal that needs to be repeatedly sent in B time blocks.

[0257] 603. The terminal device repeatedly sends the pilot signal to the base station in B time blocks.

[0258] Step 603 may refer to step 502 in FIG. 5 .

[0259] 604. The base station sends third indication information to the RIS.

[0260] In response, the RIS receives third instruction information from the base station. The third instruction information is used to instruct the RIS to perform orthogonal reflection coefficient switching in the B time blocks and maintain the transmission system unchanged within each time block. Exemplarily, the third instruction information includes the start time of the first time block in the B time blocks, the duration of each time block, and the number of time blocks (B).

[0261] 605. The RIS performs orthogonal reflection coefficient switching on the B time blocks based on the third indication information.

[0262] RIS keeps the reflection coefficient constant within the same time block.

[0263] 606. The base station repeatedly sends a pilot signal to the RIS via N antenna ports in B time blocks.

[0264] Accordingly, the RIS reflects the pilot signal that the base station repeatedly sends to the RIS through the N antenna ports in B time blocks.

[0265] For step 606 , please refer to step 501 in FIG. 5 .

[0266] 607. The base station receives the pilot signal in B time blocks.

[0267] For step 607 , please refer to step 503 in FIG. 5 .

[0268] 608. The base station obtains a first signal matrix based on the pilot signals received in B time blocks.

[0269] The first signal matrix is ​​a three-dimensional matrix of (N×T×B), and each two-dimensional matrix of (N×T) in the first signal matrix corresponds to the pilot signal received by the N antenna ports of the access network device in T time units included in a time block. The first signal matrix can be the three-dimensional tensor Should Each element in can be a complex number representing the pilot signal received by the base station, and each pilot time block corresponds to a (N×T) two-dimensional matrix. With Y b Satisfies the following relationship: Y b is the signal received by the base station in the bth pilot time block.

[0270] 609. The base station obtains a second signal matrix based on the first signal matrix.

[0271] The second signal matrix represents the noise-free pilot signal received by the base station in the B time blocks. The second signal matrix can be the tensor in formula (2.3) Based on the first signal matrix, the base station can obtain the second signal matrix using the following formula:

[0272] First signal matrix:

[0273] Based on PARAFAC decomposition, Can be re-expressed as: The second signal matrix: in, Represents the identity tensor of dimension M×M×M.

[0274] 610. Determine at least one of a channel matrix between the base station and the RIS and a channel matrix between the RIS and the terminal device based on the second signal matrix.

[0275] A possible implementation of step 610 is as follows: Since the RIS training matrix W is known to the base station, let B = M, the following least square (LS) problem can be constructed to obtain The estimated factor matrix H and (GX) T :

[0276] In formula (2.5), Express The mode 3 expansion can also be expressed as Y (3) =[vec(Y1),...,vec(Y B )] T . N (3) represents the corresponding noise matrix.

[0277] Problem (2.5) can be decomposed into M rank-1 approximation problems using the Khatri-Rao decomposition algorithm. Specifically, we can first -1 Y (3) ) T , H and (GX) T The mth column of and Then, when 1≤m≤M, the following problem can be constructed:

[0278] In formula (2.6), we have Among them, unvec N×T (·) means that the vector formed by column stacking is restored to a matrix with dimension (N×T). We define h m =ρ m f 1,m / λ m and g m =λm f 2,m , where λ m represents the unknown complex scaling factor, ρ m It is C m The maximum singular value of f 1,m and are the corresponding left and right singular vectors respectively. We further define the complex scaling vector λ=[λ1,...,λ M ] T and Thus H and (GX) T Rewritten as: H=F1 Λ- 1, (2.7); X T G T =F2Λ. (2.8);

[0279] F1 and F2 in formulas (2.7) and (2.8) are defined as: F1 = [ρ1f 1，1 ,...,ρ M f 1，M ] and F2=[f 2，1 ,...,f 2，M ].

[0280] To determine the unknown Λ, we need to use H, which exists in both equations (2.7) and (2.8). To do this, we first use the orthogonality of the pilot matrix to eliminate the channel matrix H in equation (2.8). u , that is, using the relation X * X T =pTI K+N This orthogonality imposes the necessary condition T ≥ K + N and yields and Therefore, when using this method to u When eliminated from formula (2.8), formula (2.8) can be rewritten as:

[0281] Then, according to equations (2.7) and (2.9), we can obtain the following relationship:

[0282] Formula (2.11) is derived from equation We get, and the definition of λ2 in formula (2.11) is: λ2=diag(Λ 2 ).

[0283] We can deduce that min(N,M)+M≥M+1, which means The column of is always full rank M, because N ≥ 1 always holds. Then, we can further derive an expression for λ2:

[0284] Since λ2 satisfies λ2=diag(Λ 2 )=diag((-Λ) 2 ), we choose As an estimate of Λ. Therefore, we can derive the following relationship: where e Λ Every value of belongs to the set {1,-1}.

[0285] By assuming To estimate the obtained Λ, we can give the channel matrix H between the base station and RIS and the channel matrix H between the RIS and the terminal device based on Equations (2.7) and (2.8): u The estimated value of is as follows:

[0286] Then, the actual channel matrix H between the base station and RIS and the channel matrix H between the RIS and the terminal device are u The expression is as follows:

[0287] In this embodiment of the present application, based on the pilot signals received in the above-mentioned B time blocks, at least one of the channel matrices between the base station and the RIS and the channel matrix between the RIS and the terminal device is determined; and estimates of two independent channels, BS-RIS and RIS-UE, are obtained to serve scenarios such as perception and power optimization.

[0288] FIG7 is a flow chart of a communication method provided by an embodiment of the present application. The method in FIG7 is a full-duplex channel estimation method based on a geometric model and can be applied to a single-station full-duplex base station. As shown in FIG7 , the method includes:

[0289] 701. The base station sends first indication information to the terminal device.

[0290] Correspondingly, the terminal device receives the first indication information from the base station.

[0291] 702. Based on the first indication information, the terminal device generates a pilot signal that needs to be repeatedly sent in B time blocks.

[0292] Steps 701 to 702 may refer to steps 601 to 602 in FIG. 6 .

[0293] 703. The terminal device repeatedly sends the pilot signal to the base station in B time blocks.

[0294] For step 703 , please refer to step 502 in FIG. 5 .

[0295] 704. The base station sends third indication information to the RIS.

[0296] Correspondingly, the RIS receives the third indication information from the base station.

[0297] 705. The RIS performs orthogonal reflection coefficient switching on the B time blocks based on the third indication information.

[0298] Steps 704 to 705 may refer to steps 604 to 605 in FIG. 6 .

[0299] 706. The base station repeatedly sends a pilot signal to the RIS via N antenna ports in B time blocks.

[0300] Accordingly, the RIS reflects the pilot signal that the base station repeatedly sends to the RIS via N antenna ports in B time blocks. In one possible implementation, the RIS performs orthogonal reflection coefficient switching in the B time blocks, and the reflection coefficient vector of the RIS remains unchanged within the same time block.

[0301] Step 706 may refer to step 501 in FIG. 5 .

[0302] 707. The base station receives pilot signals through N antenna ports in B time blocks.

[0303] For step 707 , please refer to step 503 in FIG. 5 .

[0304] 708. The base station obtains a third signal matrix based on the pilot signals received in the B time blocks.

[0305] The third signal matrix can be Y in the above formula (3.5) B，b .

[0306] 709. The base station estimates a first set of arrival angles, a first set of departure angles, and a first set of path gains of a channel between the base station and the RIS based on the third signal matrix.

[0307] A possible implementation of step 709 is as follows: Assume that the base station obtains ω BH Accurate estimation of T≥L BR + K, we can get:

[0308] In formula (3.5), we have and Please note that Y B,b The front L BR The columns contain the angle and gain information of H, which will be used to estimate the sparse parameters ω of H. BH and ω BR , and Y B，b The last K columns will be used to estimate Hu The sparsity parameter ω Rh，k and β k .

[0309] For any 1≤l1,l2≤L BR , Y B，b The (l1, l2)th element of can be expressed as:

[0310] By aggregating B time blocks We can get:

[0311] In formula (3.7) Definition and Similarly, Equation (3.7) can be transformed into a two-dimensional angle estimation problem. Therefore, the cascaded spatial frequency and cascade gain The estimated value of can be given by:

[0312] in, for An estimated value of . and Therefore, the search range of ω in formula (3.8) is and

[0313] After solving the problem that for any 1≤l1=l2≤L BR L BR After solving the two-dimensional angle estimation problem, we further obtain and Estimated value of and Therefore, ω RH The final estimate of can be written as: However, each All have symbol ambiguity. In order to reduce the symbol ambiguity, we can further solve A two-dimensional angle estimation problem, which leads to the following conclusion: BR Estimated value of If the estimate is error-free, we can obtain the following relationship:

[0314] In the presence of estimation errors, Equation (3.10) only holds approximately. Therefore, we estimate α based on SVD. The steps for estimating α are summarized in Algorithm 1.

[0315] So far, we have successfully obtained the first arrival angle set ω BR , the first departure angle set ω RH and an estimated value of the first path gain set α.

[0316] 710. The base station determines a channel matrix between the base station and the RIS based on a first set of arrival angles, a first set of departure angles, and a first set of path gains.

[0317] In one possible implementation, the estimate of H can be constructed as Since the α estimate may have sign ambiguity, there is also

[0318] 711. The base station estimates a second arrival angle and a second path gain set of a channel between the RIS and the terminal device based on the third signal matrix and the channel matrix between the base station and the RIS.

[0319] A possible implementation of step 711 is as follows: From step 710, obtain the estimated value We can start from Y B，b L BR +k columns estimate h u，k , combined with formula (3.2), its geometric form can be written as:

[0320] In this application, you can stack Into a (BL BR ×1) vector, that is It can also be written as follows:

[0321] n in formula (3.12) B，k Definition and y B，k Similar. When BL BR <M, E(α, ω) in formula (3.12) RH ) is an overcomplete perception matrix. Then, the vector g k =A R (ω Rh，k )β k Only CS technology can be used to measure y B,k Parameter ω Rh,k and β k can be estimated to solve for an L RU,k dimensional angle estimation problem. BR ≥M, E(α,ω RH ) is an overdetermined sensor matrix with full column rank, the LS method can be used to directly estimate g k ,Right now With ω BHSimilar to the estimation of g, we propose two different g in Appendix B. k Estimation method: OMP-based grid method and 2D ANM-based gridless method are used to estimate the second arrival angle ω Rh，k and the second path gain set β k Estimate the estimates and get their estimated values and

[0322] 712. The base station determines a channel matrix between the RIS and the terminal device based on the second arrival angle and the second path gain set.

[0323] Obtained through step 711 and Then h u，k The estimated value of Note that the sign ambiguity generated by estimating H is propagated to h u，k In the estimation of

[0324] In the embodiment of the present application, the sparse characteristics of the channel are used to perform channel estimation, and only the angle and gain coefficient of the channel need to be estimated, which requires fewer pilot signals.

[0325] FIG8 is a flow chart of a communication method provided by an embodiment of the present application. The method in FIG8 is a full-duplex channel estimation method based on a geometric model and can be applied to a dual-station full-duplex base station. As shown in FIG8 , the method includes:

[0326] 801. The base station sends first indication information to the terminal device.

[0327] Correspondingly, the terminal device receives the first indication information from the base station.

[0328] 802. Based on the first indication information, the terminal device generates a pilot signal that needs to be repeatedly sent in B time blocks.

[0329] Steps 801 to 802 may refer to steps 601 to 602 in FIG. 6 .

[0330] 803. The terminal device repeatedly sends a pilot signal to the base station in B time blocks.

[0331] For step 803 , please refer to step 502 in FIG. 5 .

[0332] 804. The base station sends third indication information to the RIS.

[0333] Correspondingly, the RIS receives the third indication information from the base station.

[0334] 805. The RIS performs orthogonal reflection coefficient switching on the B time blocks based on the third indication information.

[0335] Steps 804 to 805 may refer to steps 604 to 605 in FIG. 6 .

[0336] 806. The base station repeatedly sends the pilot signal to the RIS via N1 antenna ports in B time blocks.

[0337] Accordingly, the RIS reflects the pilot signal that the base station repeatedly sends to the RIS through N1 antenna ports in B time blocks.

[0338] The base station can be a dual-station full-duplex base station. Its N antenna ports are divided into two parts: N = N1 + N2. The N1 antenna port transmits signals to the RIS, while the N2 antenna ports simultaneously receive signals reflected from the RIS. In one possible implementation, the RIS performs orthogonal reflection coefficient switching over the B time blocks, and the RIS reflection coefficient vector remains unchanged within the same time block.

[0339] 807. The base station receives pilot signals through N2 antenna ports in B time blocks.

[0340] Step 807 may refer to step 503 in Figure 5. In one possible implementation, N2 antenna ports of the base station simultaneously receive the signal reflected from the RIS and the signal sent by the terminal device in B time blocks.

[0341] 808. The base station obtains a third signal matrix based on the pilot signals received in the B time blocks.

[0342] The third signal matrix can be Y in the above formula (3.13) 1，b .

[0343] 809. The base station estimates a first set of arrival angles, a first set of departure angles, and a first set of path gains of a channel between the base station and the RIS based on the third signal matrix.

[0344] For step 809 , please refer to step 709 in FIG. 7 .

[0345] 810. The base station determines a channel matrix between the base station and the RIS based on a first set of arrival angles, a first set of departure angles, and a first set of path gains.

[0346] In one possible implementation, in the b-th time block (1≤b≤B) with T time slots, the signals received by the base station transmitter and all users can be expressed as:

[0347] In formula (3.13), we have and

[0348] For full-duplex communication, due to channel reciprocity, we assume that the downlink channel Shares the same propagation path as the uplink channel H2, and Represent the steering vectors of the N1 antenna transmitter and N2 antenna receiver on the base station respectively. and H2, Equation (3.13) can be rewritten as:

[0349] In formula (3.14), and Φ b The definition of is in formula (3.4). Since N>>L BR For high frequency systems, we can choose appropriate values ​​of N1 and N2 so that N1>L BR and N2>>L BR Then, using the existing method, the base station AoA spatial frequency ω can be estimated according to formula (3.14) BH .

[0350] Based on ω BH Accurate estimation of T≥L BR + K, we can get:

[0351] In formula (3.15), we have We can notice that Y B1，b With Y B，b With the same structure, it can be used for denoising. Therefore, the sparse parameter ω RH and α can be estimated using the method in step 707 .

[0352] So far, we have successfully obtained the first arrival angle set ω BR , the first departure angle set ω RH and the estimated value of the first path gain set α, thereby obtaining the estimated value of the channel between the base station and the RIS

[0353] 811. The base station estimates a second arrival angle and a second path gain set of a channel between the RIS and the terminal device based on the third signal matrix and the channel matrix between the base station and the RIS.

[0354] For step 811 , please refer to step 711 in FIG. 7 .

[0355] 812. The base station determines a channel matrix between the RIS and the terminal device based on the second arrival angle and the second path gain set.

[0356] Step 801 may be step 712 in FIG. 7 .

[0357] In the embodiment of the present application, the sparse characteristics of the channel are used to perform channel estimation, and only the angle and gain coefficient of the channel need to be estimated, which requires fewer pilot signals.

[0358] FIG9 is a flow chart of another communication method provided by an embodiment of the present application. The method in FIG9 can be applied to dual-station full-duplex channel estimation based on a non-geometric model. As shown in FIG9 , the method includes:

[0359] 901. The base station sends fourth indication information to the RIS.

[0360] In response, the RIS receives fourth instruction information from the base station. The fourth instruction information is used to instruct the RIS to perform orthogonal reflection coefficient switching in the B1 time blocks, while maintaining the transmission system unchanged within each time block. Exemplarily, the fourth instruction information includes the start time of the first time block in the B1 time blocks, the duration of each time block, and the number of time blocks (B1).

[0361] 902. The RIS performs orthogonal reflection coefficient switching on the B1 time blocks based on the fourth indication information.

[0362] 903. The base station repeatedly sends a first pilot signal to the RIS through the first antenna port in B1 time blocks.

[0363] B1 is an integer greater than 1. The first antenna port can be any of the N antenna ports of the base station. Before executing step 901, the base station can select the first antenna port as a transmitter and the remaining (N-1) antenna ports as receivers. In one possible implementation, the RIS performs orthogonal reflection coefficient switching over the B1 time blocks, and the reflection coefficient vector of the RIS remains unchanged within the same time block.

[0364] 904. The base station receives the first pilot signal reflected by the RIS through (N-1) antenna ports in the B1 time blocks.

[0365] The above (N-1) antenna ports do not include the above first antenna port. The first pilot signal reflected by the RIS received by the base station through the (N-1) antenna ports in a time block can be expressed as the above formula (2.24). The first pilot signal can be

[0366] 905. The base station obtains a fourth signal matrix based on the received first pilot signal reflected by the RIS.

[0367] The fourth signal matrix can be expressed as the above formula (2.25).

[0368] 906. The base station sends fifth indication information to the RIS.

[0369] In response, the RIS receives fifth instruction information from the base station. The fifth instruction information is used to instruct the RIS to perform orthogonal reflection coefficient switching in the B2 time blocks, while maintaining the transmission system unchanged within each time block. Exemplarily, the fifth instruction information includes the start time of the first time block in the B2 time blocks, the duration of each time block, and the number of time blocks (B2).

[0370] 907. The RIS performs orthogonal reflection coefficient switching on the B2 time blocks based on the fifth indication information.

[0371] 908. The base station repeatedly sends the second pilot signal to the RIS through the second antenna port in B2 time blocks.

[0372] B2 is an integer greater than 1, and the second antenna port is different from the first antenna port. In one possible implementation, before executing step 904, the base station turns off the first antenna port, selects the second antenna port as a transmitter, and uses the remaining (N-2) antenna ports as receivers. The second pilot signal can be In a possible implementation, the RIS performs orthogonal reflection coefficient switching on the B2 time blocks, and the reflection coefficient vector of the RIS remains unchanged within the same time block.

[0373] 909. The base station receives the second pilot signal reflected by the RIS through (N-2) antenna ports in the B2 time blocks.

[0374] The (N-2) antenna ports are included in the (N-1) antenna ports and do not include the first antenna port and the second antenna port. The second pilot signal reflected by the RIS received by the base station through the (N-2) antenna ports in a time block can be expressed as the above equation (2.26).

[0375] 910. The base station obtains a fifth signal matrix based on the received second pilot signal reflected by the RIS.

[0376] The fifth signal matrix can be expressed as the above formula (2.26).

[0377] 911. The base station determines a channel matrix H between the base station and the RIS based on the fourth signal matrix and the fifth signal matrix.

[0378] A possible implementation of step 911 is as follows: In the first stage, it is assumed that a base station receiver with (N-1) antennas (e.g., including the 1st to (N-1)th antennas of the base station) is responsible for receiving the pilot signal transmitted by a single-antenna base station transmitter (e.g., including the Nth antenna of the base station). The base station transmitter can repeatedly transmit the pilot signal for B1 time blocks. In the b1th (1≤b1≤B1) time block, the signal received by the base station through the base station-RIS-base station link can be expressed as:

[0379] In formula (2.19), and Represent the first (N-1) rows and the last row of H, that is, is the beamforming phase shift matrix at the RIS, is a valid noise vector. The base station can collect B1 observations And stack them in a matrix of dimension (N-1)×B1, which is expressed as follows:

[0380] Fourth signal matrix

[0381] In formula (2.20), we have

[0382] In the second phase, the Nth base station antenna is turned off and the (N-1)th antenna starts transmitting. According to equation (2.20), the new single-antenna base station transmitter repeatedly transmits the pilot signal for B2 time blocks. The signal received by the base station can be expressed as:

[0383] Fifth signal matrix

[0384] In formula (2.21) and Respectively represent the first N-2 rows and the last row of H1, that is is the beamforming phase shift matrix of RIS, and the equivalent noise matrix Definition and similar.

[0385] Please note that in the above description, h N-1 It acts as a downlink channel in equation (2.20) and as an uplink channel in equation (2.21). N Before, the base station can first estimate h by combining equations (2.20) and (2.21). N-1 If B1≥M and B2≥M, we can deduce that:

[0386] P1 in formula (2.22) and P1 in formula (2.23) The definitions are as follows:

[0387] Next, by combining P1 and Can eliminate h N . Based on this, we can get the following relationship:

[0388] In Equation (2.26), Z1 includes all noise terms. By combining Equations (2.23) and (2.26) to eliminate H2, we can derive:

[0389] In formula (2.27), h x =h N-1 ⊙h N-1 and h x The estimated value of can be expressed as follows:

[0390] Let x 1 / 2 Represents the square root operation performed on a vector x element by element. Then, we can get Get h N-1 Therefore, we have where the symbol ambiguity vector e h Every value of exists in the set {1, -1}.

[0391] Next, given the estimated value H2 and h N They can be estimated from equations (2.23) and (2.25) as follows:

[0392] Finally, the estimated value of the channel matrix H between the base station and the RIS is given by:

[0393] Then, the actual channel matrix H between the base station and RIS can be expressed as

[0394] In this embodiment of the present application, the channel matrix between the base station and the RIS can be determined to serve scenarios such as perception and power optimization. This embodiment of the present application is applicable to channel estimation for dual-station full-duplex in non-geometric models. The hardware architecture of dual-station full-duplex is easier to implement, and the self-interference within the base station is also lower.

[0395] FIG10 is a flow chart of another communication method provided by an embodiment of the present application. The method flow in FIG10 is based on FIG9 and further estimates the channel matrix between the RIS and the terminal device. As shown in FIG7, the method includes:

[0396] 1001. The base station sends fourth indication information to the RIS.

[0397] 1002. The RIS performs orthogonal reflection coefficient switching on the B1 time blocks based on the fourth indication information.

[0398] 1003. The base station repeatedly sends a first pilot signal to the RIS through the first antenna port in B1 time blocks.

[0399] 1004. The base station receives the first pilot signal reflected by the RIS through (N-1) antenna ports in the B1 time blocks.

[0400] 1005. The base station obtains a fourth signal matrix based on the received first pilot signal reflected by the RIS.

[0401] 1006. The base station sends fifth indication information to the RIS.

[0402] 1007. The RIS performs orthogonal reflection coefficient switching on the B2 time blocks based on the fifth indication information.

[0403] 1008. The base station repeatedly sends the second pilot signal to the RIS through the second antenna port in B2 time blocks.

[0404] 1009. The base station receives the second pilot signal reflected by the RIS through (N-2) antenna ports in the B2 time blocks.

[0405] 1010. The base station obtains a fifth signal matrix based on the received second pilot signal reflected by the RIS.

[0406] 1011. The base station determines a channel matrix between the base station and the RIS based on the fourth signal matrix and the fifth signal matrix.

[0407] Steps 1001 to 1011 may refer to steps 901 to 911 in FIG. 9 .

[0408] 1012. The base station sends second indication information to the terminal device.

[0409] The second indication information is used to indicate the pilot signal that the above-mentioned terminal device repeatedly sends in the above-mentioned B3 time blocks. Exemplarily, the second indication information may carry the start time of the first time block in the above-mentioned B3 time blocks, the length of each time block, and the pilot signal (or measurement pilot) that the terminal device needs to send. Figure 10 shows only one terminal device. In actual applications, the base station can send different indication information to multiple terminal devices to indicate the pilot signals that different terminal devices repeatedly send in the above-mentioned B3 time blocks. For ease of description, the embodiment of the present application is described using a terminal device as an example.

[0410] 1013. Based on the second indication information, the terminal device generates a pilot signal that needs to be repeatedly sent in the above-mentioned B3 time blocks.

[0411] 1014. The terminal device repeatedly sends the pilot signal to the base station in B3 time blocks.

[0412] In one possible implementation, multiple terminal devices repeatedly send pilot signals, i.e., measurement pilots, to the base station in B3 time blocks. The measurement pilots sent by different terminal devices are orthogonal in the time domain. The number of pilot signals sent by the terminal device can meet Where A is a predefined threshold, M is the number of RIS arrays, N is the number of antennas of the base station, and B3 is the number of time blocks for sending pilot signals on the terminal device side.

[0413] 1015. The base station receives the pilot signal repeatedly sent by the terminal device in B3 time blocks through N antenna ports.

[0414] The N antenna ports include the first antenna port and the (N-1) antenna ports. In one possible implementation, before executing step 907, the base station turns on the first antenna port and uses the N antenna ports as receivers.

[0415] 1016. The base station obtains a sixth signal matrix based on the pilot signals repeatedly sent by the terminal device in the above B3 time blocks and received through the N antenna ports.

[0416] The sixth signal matrix can be expressed by the above formula (2.39).

[0417] 1017. The base station determines a channel matrix between the RIS and the terminal device based on the sixth signal matrix.

[0418] A possible implementation of step 1017 is as follows: the channel estimation result of the base station-RIS link in step 1011 The estimated channel matrix H of the RIS-user link can be reduced uIn particular, K users simultaneously transmit B3 time blocks of orthogonal pilot symbols repeatedly. Right now All base station antennas are used to receive pilot signals. In the b3th time block (1≤b3≤B3), the received signal can be expressed as:

[0419] In formula (2.33), we have We then collect observations and b3 = {1, ..., B3}, to obtain:

[0420] It can be estimated from formula (2.34). This method requires and are all full rank. Then, The estimated value of can be given by:

[0421] The actual channel matrix H u It can be expressed as follows:

[0422] In this embodiment of the present application, the channel matrix between the base station and the RIS, as well as the channel matrix between the RIS and the terminal device, can be determined to serve scenarios such as perception and power optimization. This embodiment of the present application is applicable to dual-station full-duplex channel estimation in non-geometric models. The hardware architecture of dual-station full-duplex is easier to implement, and the self-interference within the base station is also lower.

[0423] The following describes the structure of a communication device that can implement the communication method provided in the embodiment of the present application in conjunction with the accompanying drawings. The following only briefly describes the communication device. For details on the implementation of the solution, please refer to the description of the method embodiment above, which will not be repeated below.

[0424] Figure 11 is a schematic diagram of the structure of a communication device 1100 provided in an embodiment of the present application. The communication device 1100 can implement the functions or steps implemented by the base station in each of the above-mentioned method embodiments, or can also implement the functions or steps implemented by the terminal device in each of the above-mentioned method embodiments. The communication device may include a processing module 1110 and a transceiver module 1120. In one possible implementation, it may also include a storage unit, which can be used to store instructions (code or program) and / or data. The processing module 1110 and the transceiver module 1120 can be coupled to the storage unit. For example, the processing module 1110 can read the instructions (code or program) and / or data in the storage unit to implement the corresponding method. The above-mentioned units can be provided independently or partially or fully integrated. For example, the transceiver module 1120 may include a transmitting module and a receiving module. The transmitting module may be a transmitter, and the receiving module may be a receiver. The entity corresponding to the transceiver module 1120 may be a transceiver circuit, such as a transceiver or a communication interface.

[0425] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the base station in the above-described method embodiments. For example, the communication device 1100 can be a base station, or a component (e.g., a chip or circuit) used in a base station. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the base station in the embodiments of Figures 5 to 10. The processing module 1110 can, for example, be used to perform all operations performed by the base station in the embodiments of Figures 5 to 10 except for the transmitting and receiving operations.

[0426] In some possible implementations, the communication device 1100 can implement the behaviors and functions of the terminal device in the above-described method embodiments. For example, the communication device 1100 can be a terminal device, or a component (such as a chip or circuit) used in the terminal device. The transceiver module 1120 can be used to perform all receiving or sending operations performed by the terminal device in the embodiments of Figures 5 to 10. The processing module 1110 can be used to perform all operations performed by the terminal device in the embodiments of Figures 5 to 10 except for the receiving and sending operations.

[0427] The present application further provides an apparatus 1200, which may be a network device (eg, a base station) or a chip. The apparatus 1200 may be configured to execute the operations executed by the base station in the embodiments shown in FIG. 5 to FIG. 10 .

[0428] When the apparatus 1200 is a network device, for example, a base station, FIG12 shows a simplified schematic diagram of a base station structure. The base station includes parts 1210, 1220, and 1230.

[0429] Part 1210 is mainly used for baseband processing, base station control, etc.; Part 1210 is usually the control center of the base station, which can usually be called a processor, used to control the base station to perform the processing operations of the base station in the above method embodiment.

[0430] Part 1220 is mainly used to store computer program code and data.

[0431] Part 1230 is primarily used for receiving and transmitting radio frequency signals and converting radio frequency signals into baseband signals. Part 1230 can generally be referred to as a transceiver module, transceiver, transceiver circuit, or transceiver. The transceiver module in part 1230, which can also be referred to as a transceiver or transceiver, includes an antenna 1233 and a radio frequency circuit (not shown in the figure), wherein the radio frequency circuit is primarily used for radio frequency processing. Optionally, the device used to implement the receiving function in part 1230 can be considered a receiver, and the device used to implement the transmitting function can be considered a transmitter, that is, part 1230 includes a receiver 1232 and a transmitter 1231. A receiver can also be referred to as a receiving module, a receiver, or a receiving circuit, and a transmitter can be referred to as a transmitting module, a transmitter, or a transmitting circuit.

[0432] Sections 1210 and 1220 may include one or more boards, each of which may include one or more processors and one or more memories. The processor is used to read and execute programs in the memory to implement baseband processing functions and control the base station. If multiple boards are present, the boards may be interconnected to enhance processing capabilities. As an optional implementation, multiple boards may share one or more processors, multiple boards may share one or more memories, or multiple boards may simultaneously share one or more processors.

[0433] For example, in one implementation, the transceiver module in section 1230 is used to execute the transceiver-related processes performed by the base station in the embodiments shown in Figures 5 to 10. The processor in section 1210 is used to execute the processing-related processes performed by the base station in the embodiments shown in Figures 5 to 10.

[0434] It should be understood that FIG12 is merely an example and not a limitation, and the network device including the processor, memory, and transceiver may not rely on the structure shown in FIG12 .

[0435] When device 1200 is a chip, the chip includes a transceiver, memory, and a processor. The transceiver may be an input / output circuit or a communication interface; the processor may be a processor, microprocessor, or integrated circuit integrated on the chip. The base station's transmission operations in the above method embodiments can be understood as chip outputs, and the base station's reception operations in the above method embodiments can be understood as chip inputs.

[0436] The present application further provides an apparatus 1300, which may be a terminal device, a processor in the terminal device, or a chip. The apparatus 1300 may be used to execute the operations executed by the terminal device in the above method embodiment.

[0437] When apparatus 1300 is a terminal device, FIG13 shows a simplified schematic diagram of the terminal device structure. As shown in FIG13 , the terminal device includes a processor, a memory, and a transceiver. The memory can store computer program code, and the transceiver includes a transmitter 1331, a receiver 1332, a radio frequency circuit (not shown), an antenna 1333, and input / output devices (not shown).

[0438] The processor is mainly used to process communication protocols and communication data; control terminal devices, execute software programs and process software program data, etc.

[0439] Memory is mainly used to store software programs and data.

[0440] Radio frequency circuits are mainly used for conversion between baseband signals and radio frequency signals and for processing radio frequency signals.

[0441] Antennas are mainly used to send and receive radio frequency signals in the form of electromagnetic waves.

[0442] The input and output device may include a touch screen, a display screen, or a keyboard. The input and output device is mainly used to receive data input by the user and output data to the user. It should be noted that some types of terminal devices may not have input and output devices.

[0443] When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs the baseband signal to the RF circuit. The RF circuit then performs RF processing on the baseband signal and transmits the RF signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the RF circuit receives the RF signal through the antenna. The RF circuit converts the RF signal into a baseband signal and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. For ease of explanation, Figure 13 shows only one memory, processor, and transceiver. In actual terminal device products, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or storage device, etc. The memory may be set independently of the processor or integrated with the processor, and this embodiment of the application does not limit this.

[0444] In the embodiment of the present application, the antenna and radio frequency circuit with transceiver functions can be regarded as the transceiver module of the terminal device, and the processor with processing function can be regarded as the processing module of the terminal device.

[0445] As shown in FIG13 , the terminal device includes a processor 1310, a memory 1320, and a transceiver 1330. The processor 1310 may also be referred to as a processing unit, a processing board, a processing module, or a processing device. The transceiver 1330 may also be referred to as a transceiver unit, a transceiver, or a transceiver device.

[0446] Optionally, the device used to implement the receiving function in transceiver 1330 is considered a receiving module, and the device used to implement the transmitting function in transceiver 1330 is considered a transmitting module. That is, transceiver 1330 includes a receiver and a transmitter. A transceiver may also be sometimes referred to as a transceiver, a transceiver module, or a transceiver circuit. A receiver may also be sometimes referred to as a receiver, a receiving module, or a receiving circuit. A transmitter may also be sometimes referred to as a transmitter, a transmitting module, or a transmitting circuit.

[0447] In one possible implementation, the processor 1310 is configured to execute the processing actions of the terminal device in the embodiments shown in Figures 5 to 10. The transceiver 1330 is configured to execute the transceiver actions of the terminal device in the embodiments shown in Figures 5 to 10.

[0448] It should be understood that FIG13 is merely an example and not a limitation, and the terminal device including the transceiver module and the processing module may not rely on the structure shown in FIG13 .

[0449] When the device 1300 is a chip, the chip includes a processor, a memory, and a transceiver. The transceiver may be an input / output circuit or a communication interface. The processor may be a processing module, a microprocessor, or an integrated circuit integrated on the chip. The sending operation of the terminal device in the above method embodiment can be understood as the output of the chip, and the receiving operation of the terminal device in the above method embodiment can be understood as the input of the chip.

[0450] The present application also provides a computer-readable storage medium storing a computer program or instructions. When the computer program or instructions are executed on a computer, the computer executes the method of the above embodiment. For example, when the computer program is executed by a computer, the computer can implement the method performed by the base station or terminal device in the above method embodiment.

[0451] The present application also provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are run on a computer, the method in the above embodiment is executed.

[0452] The present application also provides a communication system, comprising the above-mentioned base station, RIS and the above-mentioned terminal device.

[0453] The present application also provides a chip, which includes: a communication interface and a processor; the communication interface is used for sending and receiving signals of the above-mentioned chip; the processor is used for executing computer programs or instructions so that the communication device including the above-mentioned chip executes the method in the above-mentioned embodiment.

[0454] An embodiment of the present application also provides a chip device, including a processor, for calling a computer program or computer instruction stored in the memory so that the processor executes the method provided in the embodiment shown in the above-mentioned terminal device.

[0455] In one possible implementation, the input of the chip device corresponds to the receiving operation in any one of the embodiments shown in the above-mentioned terminal device, and the output of the chip device corresponds to the sending operation in any one of the embodiments shown in the above-mentioned terminal device.

[0456] Optionally, the processor is coupled to the memory via an interface.

[0457] Optionally, the chip device further includes a memory, in which a computer program or computer instructions are stored.

[0458] The processor mentioned in any of the above may be a general-purpose central processing unit, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the method provided in any of the embodiments shown in the terminal device. The memory mentioned in any of the above may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), etc.

[0459] Those skilled in the art can clearly understand that, for the sake of convenience and brevity of description, the explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can refer to the corresponding method embodiments provided above, and will not be repeated here.

[0460] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0461] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0462] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0463] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the part that essentially contributes to the technical solution of the present application or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several computer programs or instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the above-mentioned methods of each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks or optical disks.

[0464] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0465] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0466] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

Claims

1. A communication method, characterized in that: include: Repeatedly sending pilot signals to the configurable smart metasurface RIS through N antenna ports in B time blocks, wherein the first antenna port and the second antenna port of the N antenna ports respectively send a pilot signal in the T time units included in each time block, the T pilot signals successively sent by the first antenna port in each time block correspond to a first vector, and the T pilot signals successively sent by the second antenna port in each time block correspond to a second vector, the first vector and the second vector are orthogonal, B is an integer greater than 0, and N and T are integers greater than 1; receiving pilot signals in the B time blocks, where the pilot signals received in the B time blocks include pilot signals reflected by the RIS in the B time blocks and pilot signals repeatedly sent by the terminal device in the B time blocks, one antenna port of the terminal device successively sending one pilot signal in T time units included in each time block, and a third vector corresponding to the T pilot signals successively sent by one antenna port of the terminal device in each time block is orthogonal to the first vector; At least one of a channel matrix between an access network device and the RIS and a channel matrix between the RIS and the terminal device is determined based on the pilot signals received in the B time blocks.

2. The method according to claim 1, characterized in that The determining, based on the pilot signals received in the B time blocks, at least one of a channel matrix between the access network device and the RIS and a channel matrix between the RIS and the terminal device comprises: Obtaining a first signal matrix based on the pilot signals received in the B time blocks, where the first signal matrix is a three-dimensional matrix of (N×T×B), and each two-dimensional matrix of (N×T) in the first signal matrix corresponds to a pilot signal received by the N antenna ports of the access network device in T time units included in one time block; Obtaining a second signal matrix based on the first signal matrix, where the second signal matrix represents noise-free pilot signals received by the access network device in the B time blocks; Based on the second signal matrix, at least one of a channel matrix between the access network device and the RIS and a channel matrix between the RIS and the terminal device is determined.

3. The method according to claim 1, characterized in that The determining, based on the pilot signals received in the B time blocks, at least one of a channel matrix between the access network device and the RIS and a channel matrix between the RIS and the terminal device comprises: obtaining a third signal matrix based on the pilot signals received in the B time blocks; estimating, based on the third signal matrix, a first set of arrival angles, a first set of departure angles, and a first set of path gains of a channel between the access network device and the RIS; A channel matrix between the access network device and the RIS is determined based on the first arrival angle set, the first departure angle set, and the first path gain set.

4. The method according to claim 3, characterized in that The method further comprises: estimating a second angle of arrival and a second set of path gains of a channel between the RIS and the terminal device based on the third signal matrix and a channel matrix between the access network device and the RIS; A channel matrix between the RIS and the terminal device is determined based on the second angle of arrival and the second set of path gains.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: Send first indication information to the terminal device, where the first indication information is used to instruct the terminal device to repeatedly send a pilot signal in the B time blocks.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: Send third indication information to the RIS, where the third indication information is used to instruct the RIS to perform orthogonal reflection coefficient switching on the B time blocks.

7. A communication method, characterized in that: Applied to a terminal device, the method includes: Generate a pilot signal that needs to be repeatedly sent in B time blocks; The generated pilot signal is repeatedly sent to the access network device in the B time blocks, and an antenna port of the terminal device successively sends a pilot signal in the T time units included in each time block. The pilot signals sent by an antenna port of the terminal device in different time blocks are the same, B is an integer greater than 0, and T is an integer greater than 1.

8. The method according to claim 7, characterized in that The method further comprises: receiving first indication information from the access network device, where the first indication information is used to instruct the terminal device to repeatedly send a pilot signal in the B time blocks; Generating a pilot signal that needs to be repeatedly sent in B time blocks includes: Based on the first indication information, a pilot signal that needs to be repeatedly sent in the B time blocks is generated.

9. The method according to claim 8, characterized in that The vector corresponding to the pilot signal repeatedly sent by the terminal device in the B time blocks indicated by the first indication information is orthogonal to the vector corresponding to the pilot signal repeatedly sent by any antenna port of the access network device in the B time blocks.

10. A communication method, characterized in that: include: receiving third indication information, where the third indication information is used to instruct the configurable intelligent metasurface RIS to perform orthogonal reflection coefficient switching over B time blocks, where B is an integer greater than 1; Based on the third indication information, orthogonal reflection coefficient switching is performed on the B time blocks.

11. A communication method, characterized in that: The method is applied to an access network device, and includes: Repeatedly sending a first pilot signal to the configurable smart metasurface RIS through the first antenna port in B1 time blocks, where B1 is an integer greater than 1; receiving the first pilot signal reflected by the RIS through (N-1) antenna ports in the B1 time blocks, the (N-1) antenna ports excluding the first antenna port; Obtaining a fourth signal matrix based on the received first pilot signal reflected by the RIS; repeatedly sending a second pilot signal to the RIS through a second antenna port in B2 time blocks, where B2 is an integer greater than 1, and the second antenna port is different from the first antenna port; receiving the second pilot signal reflected by the RIS through (N-2) antenna ports in the B2 time blocks, where the (N-2) antenna ports are included in the (N-1) antenna port and do not include the first antenna port and the second antenna port; obtaining a fifth signal matrix based on the received second pilot signal reflected by the RIS; A channel matrix between the access network device and the RIS is determined based on the fourth signal matrix and the fifth signal matrix.

12. The method according to claim 11, characterized in that The method further comprises: Receiving, through N antenna ports, a pilot signal repeatedly sent by a terminal device in B3 time blocks, where the N antenna ports include the first antenna port and the (N-1) antenna port; A channel matrix between the RIS and the terminal device is determined based on the pilot signal repeatedly transmitted by the terminal device in the B3 time blocks and received through the N antenna ports.

13. The method according to claim 11 or 12, characterized in that The method further comprises: Send second indication information to the terminal device, where the second indication information is used to instruct the terminal device to repeatedly send the pilot signal in the B3 time blocks.

14. The method according to any one of claims 11 to 13, characterized in that The method further comprises: Send fourth indication information to the RIS, where the fourth indication information is used to instruct the RIS to perform orthogonal reflection coefficient switching on the B1 time blocks.

15. A communication system, characterized in that: include: Access network equipment, configurable intelligent metasurface RIS and terminal equipment; The access network device is configured to repeatedly send pilot signals to the RIS through N antenna ports in B time blocks, where a first antenna port and a second antenna port among the N antenna ports respectively send a pilot signal in T time units included in each time block, the T pilot signals successively sent by the first antenna port in each time block correspond to a first vector, and the T pilot signals successively sent by the second antenna port in each time block correspond to a second vector, the first vector and the second vector are orthogonal, B is an integer greater than 0, and N and T are integers greater than 1; The terminal device is configured to repeatedly send a pilot signal to the access network device in the B time blocks, wherein an antenna port of the terminal device successively sends a pilot signal in T time units included in each time block, the pilot signals sent by the antenna port of the terminal device in different time blocks are the same, and a third vector corresponding to the T pilot signals successively sent by the antenna port of the terminal device in each time block is orthogonal to the first vector; The RIS is configured to perform orthogonal reflection coefficient switching on the B time blocks; The access network device is further configured to receive a pilot signal in the B time blocks, where the pilot signal received by the access network device in the B time blocks includes a pilot signal reflected by the RIS in the B time blocks and a pilot signal repeatedly sent by the terminal device in the B time blocks; At least one of a channel matrix between an access network device and the RIS and a channel matrix between the RIS and the terminal device is determined based on the pilot signals received in the B time blocks.

16. A communication system, characterized in that: include: Access network equipment, configurable intelligent metasurface RIS and terminal equipment; The access network device is configured to repeatedly send a first pilot signal to the RIS through a first antenna port during B1 time blocks, where B1 is an integer greater than 1; receive the first pilot signal reflected by the RIS through (N-1) antenna ports during the B1 time blocks, where the (N-1) antenna ports do not include the first antenna port; obtain a fourth signal matrix based on the received first pilot signal reflected by the RIS; repeatedly send a second pilot signal to the RIS through a second antenna port during B2 time blocks, where B2 is an integer greater than 1, where the second antenna port is different from the first antenna port; and receive the second pilot signal reflected by the RIS through (N-2) antenna ports during the B2 time blocks, where the (N-2) antenna ports are included in the (N-1) antenna ports and do not include the first antenna port and the second antenna port. obtaining a fifth signal matrix based on the received second pilot signal reflected by the RIS; and determining a channel matrix between the access network device and the RIS based on the fourth signal matrix and the fifth signal matrix; The RIS is configured to perform orthogonal reflection coefficient switching on the B1 time blocks and the B2 time blocks; The terminal device is configured to repeatedly send a pilot signal to the access network device in B3 time blocks; The access network device is further used to receive, through N antenna ports, the pilot signal repeatedly sent by the terminal device in the B3 time blocks, where the N antenna ports include the first antenna port and the (N-1) antenna ports; and determine the channel matrix between the RIS and the terminal device based on the pilot signal repeatedly sent by the terminal device in the B3 time blocks received through the N antenna ports.

17. A communication device, characterized in that: The method comprises a module for implementing the method according to any one of claims 1 to 14.

18. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, wherein the computer program includes program instructions. When the program instructions are executed by a processor, the method according to any one of claims 1 to 14 is executed.

19. A communication device, characterized in that: The device comprises a processor, wherein when executing instructions, the processor causes the communication device to perform the method according to any one of claims 1 to 14.

20. A chip, characterized in that: include: A communication interface, used for sending and receiving signals from the chip; A processor, configured to execute computer program instructions so that a communication device comprising the chip performs the method according to any one of claims 1 to 14.

21. A computer program product, comprising a computer program, wherein the computer program comprises program instructions, and when the program instructions are executed, the computer is caused to perform the method according to any one of claims 1 to 14.

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