Communication method and device applying Huygens equivalent surface

Abstract

The invention provides a communication method and device applying a Huygens equivalent surface, which are used for improving the energy of useful signals and the degree of freedom of a space channel and improving the communication performance. The method comprises the following steps: a receiving end receives a first receiving signal according to a first Huygens equivalent surface; the receiving end can also send first indication information. The first indication information comprises indication information of at least one Huygens equivalent surface, the indication information of the at least one Huygens equivalent surface is determined according to a second Huygens equivalent surface, and the second Huygens equivalent surface corresponds to the first receiving signal.

Description

A communication method and device using Huygens equivalent surface Technical Field

[0001] The present application relates to the field of mobile communication technology, and in particular to a communication method and device using a Huygens equivalent surface. Background Art

[0002] Multi-input multi-output (MIMO)-orthogonal frequency division multiplexing (OFDM) technology, exemplified by the 4th / 5th generation mobile communications (4G) of the 3rd Generation Partnership Project (3GPP), utilizes phased array antennas as its hardware foundation and implements wireless communication systems in the time, frequency, and space dimensions through unified and rational scheduling and signal processing algorithms at the base station. 4G / 5G utilizes the time-frequency resource blocks (RBs) of orthogonal frequency division multiplexing access (OFDMA) and the zero forcing (ZF) beamforming strategy of phased arrays at different angles to achieve flexible and efficient multi-user access and multiple-access communications.

[0003] However, the current multi-user access process cannot fully utilize all useful signal energy and spatial channel degrees of freedom, and the communication performance needs to be further improved.

[0004] Summary of the Invention

[0005] The present application provides a communication method and device using a Huygens equivalent surface to fully utilize useful signal energy and spatial channel degrees of freedom to improve communication performance.

[0006] In a first aspect, the present application provides a communication method utilizing Huygens equivalent surfaces to increase useful signal energy and spatial channel degrees of freedom, thereby enhancing communication performance. The method can be implemented by a receiving end, which can be a device or apparatus that receives reference signals and / or data, performs channel measurements, and sends feedback information. Exemplarily, the receiving end can be a terminal device, a network device, a component within a terminal device, or a component within a network device. The components herein can include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. For example, the method can be implemented by the following steps: the receiving end receives a first received signal based on a first Huygens equivalent surface. The receiving end can also send first indication information. The first indication information includes indication information of at least one Huygens equivalent surface, determined based on a second Huygens equivalent surface corresponding to the first received signal. Therefore, the first indication information, as feedback information, can be used to indicate the channel measurement results determined by the receiving end. For example, the transmitting end can determine the transmit antenna configuration and / or receive antenna configuration for subsequent transmission processes based on the first indication information. It can be understood that the method provided in the first aspect does not rely on beam selection, that is, the channel measurement process will not abandon the energy of the unselected beam direction. Therefore, this method can improve the utilization of useful signal energy and the spatial channel freedom, thereby improving communication performance.

[0007] In one possible design, the second Huygens equivalent surface is the electric field vector and / or magnetic field vector of the three-dimensional closed surface where the receiving antenna is located. The receiving end may also receive second indication information, and the second indication information is used to indicate that the first Huygens equivalent surface is the electric field vector and / or magnetic field vector of the three-dimensional closed surface where the receiving antenna is located. Among them, the first Huygens equivalent surface can be understood as the electric field vector and / or magnetic field vector in the space near the receiving antenna itself when the antenna of the receiving end sets the antenna configuration parameters (or is called the receiving antenna configuration) according to the guidance of the second indication information and then transmits electromagnetic waves outward through the receiving antenna. The second Huygens equivalent surface can be understood as the electric field vector and / or magnetic field vector formed by the radio electromagnetic wave emitted by the transmitting antenna through the propagation process of the wireless channel when it reaches the space near the receiving antenna, which can represent the effect of the first received signal being affected by the transmitting antenna configuration, wireless channel propagation and receiving antenna configuration. It can be understood that the first Huygens equivalent surface and the second Huygens equivalent surface are both the electric field vector of the three-dimensional closed surface where the receiving antenna is located, or the first Huygens equivalent surface and the second Huygens equivalent surface are both the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located, or the first Huygens equivalent surface and the second Huygens equivalent surface are both the electric field vector and the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located. In other words, the receiving end can determine, based on the second indication information, that the second Huygens equivalent surface is the electric field vector and / or the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located.

[0008] In one possible design, the indication information for any of the Huygens equivalent surfaces includes an index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: a normalized cross-correlation coefficient, a compression ratio, and a spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface. With this implementation, the receiving end can provide feedback based on the correspondence between the index and at least one of the normalized cross-correlation coefficient, the compression ratio, and the spatial angular range, thereby improving feedback flexibility.

[0009] In one possible design, the larger the absolute value of the normalized cross-correlation coefficient, the higher the transmission priority of the information indicating the Huygens equivalent surface. With this design, when feedback resources are limited, information about the Huygens equivalent surface with a larger absolute value of the normalized cross-correlation coefficient can be fed back to the transmitter. This Huygens equivalent surface can more accurately describe the second Huygens equivalent surface, allowing the transmitter to more accurately determine the configuration or parameters for subsequent transmissions. This improves channel measurement and feedback accuracy, thereby enhancing transmission performance.

[0010] In one possible design, the receiving end can determine the three-dimensional Huygens equivalent surface corresponding to the first received signal based on the first received signal, and use the two-dimensional Huygens equivalent surface obtained by projecting the three-dimensional Huygens equivalent surface as the second Huygens equivalent surface. Data processing using the two-dimensional Huygens equivalent surface can reduce data processing difficulty, thus improving channel measurement and feedback efficiency.

[0011] In one possible design, the receiving end may further obtain the second Huygens equivalent surface based on a first compression ratio corresponding to the first Huygens equivalent surface, where the first compression ratio is related to the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1. This design reduces the amount of data processing and thus improves channel measurement and feedback efficiency.

[0012] In one possible design, the first received signal is the signal received during the nth transmission cycle within the coherence time, where the coherence time includes N transmission cycles, where 1≤n≤N, and n is an integer. Therefore, the receiving end can perform multiple measurements and feedback within the coherence time, allowing the transmitting end to predict the optimal region of interest (i.e., spatial angular range) of the Huygens equivalent surface for the next period of time, thereby reducing the degradation of received signal quality caused by changes in the relative position between the receiving end and the transmitting end.

[0013] In one possible design, the receiving end may further receive second information indicating N and / or the time interval between the N transmission cycles; or the receiving end may further send third information indicating N and / or the time interval between the N transmission cycles. With this design, the receiving end and the transmitting end can negotiate the number of measurements or the interval between the measurements within the coherence time, thereby improving sampling flexibility.

[0014] In one possible design, the first indication information includes a parameter change of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time. Using this design, the amount of feedback information data can be reduced, thereby reducing the air interface overhead of the feedback information.

[0015] In one possible design, the first received signal includes a first reference signal, which is a default reference signal when RIS is enabled; or the first received signal includes a second reference signal, which is a default reference signal when RIS is disabled. This method enables accurate channel measurement and feedback in scenarios where the transmitter and receiver communicate via RIS.

[0016] In a second aspect, the present application provides a communication method using Huygens equivalent surfaces to increase useful signal energy and spatial channel freedom, thereby enhancing communication performance. The method can be implemented by a transmitting end, which can be a device or apparatus that transmits reference signals and / or data, and the reference signals and / or data can be used for channel measurement. Exemplarily, the receiving end can be implemented by a terminal device, a network device, a component in a terminal device, or a component in a network device. The components in the present application may include, for example, at least one of a processor, a transceiver, a processing unit, or a transceiver unit. Taking the example of the executing subject being the transmitting end, the method can be implemented by the following steps: sending a first received signal. Receive first indication information, the first indication information including indication information of at least one Huygens equivalent surface, the indication information of the at least one Huygens equivalent surface being determined based on a second Huygens equivalent surface, and the second Huygens equivalent surface corresponding to the first received signal.

[0017] In one possible design, the second Huygens equivalent surface is the electric field vector and / or magnetic field vector of the three-dimensional closed surface where the receiving antenna is located, and the transmitting end may also send second indication information, where the second indication information is used to indicate that the first Huygens equivalent surface is the electric field vector and / or the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located.

[0018] In one possible design, the indication information of any of the Huygens equivalent surfaces includes the index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: the normalized correlation coefficient, compression rate and spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface.

[0019] In a possible design, the larger the absolute value of the normalized cross-correlation coefficient is, the higher the transmission priority of the indication information of the Huygens equivalent surface is.

[0020] In one possible design, the second Huygens equivalent surface is obtained according to a first compression ratio, the first compression ratio is related to the size of the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1.

[0021] In one possible design, the first received signal is a received signal received in the nth transmission period in a coherence time, where the coherence time includes N transmission periods, 1≤n≤N, and n is an integer.

[0022] In one possible design, the sending end may also send second information, where the second information is used to indicate N and / or the time interval between the N transmission cycles; or, the sending end may also receive third information, where the second information is used to indicate N and / or the time interval between the N transmission cycles.

[0023] In one possible design, the first indication information includes the parameter change of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time.

[0024] In one possible design, the first received signal includes a first reference signal, which is a default reference signal when the reconfigurable smart surface RIS is in the on state; or, the first received signal includes a second reference signal, which is a default reference signal when the RIS is in the off state.

[0025] In a third aspect, a communication device utilizing a Huygens equivalent surface is provided. The device can implement the method described in any possible design of the first aspect. The device has the functionality of the aforementioned receiving end. For example, the device is a receiving end, or a functional module within the receiving end.

[0026] Alternatively, the device may implement the method described in the second aspect and any possible design thereof. The device has the functions of the above-mentioned transmitter. The device is, for example, a transmitter or a functional module in the transmitter.

[0027] In an optional implementation, the device may include a module that performs the method / operation / step / action described in the first aspect or the second aspect. The module may be a hardware circuit, software, or a combination of a hardware circuit and software. In an optional implementation, the device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). The transceiver unit is capable of implementing a sending function and a receiving function. When the transceiver unit implements the sending function, it may be referred to as a sending unit (sometimes also referred to as a sending module). When the transceiver unit implements the receiving function, it may be referred to as a receiving unit (sometimes also referred to as a receiving module). The sending unit and the receiving unit may be the same functional module, which is called a transceiver unit, and the functional module is capable of implementing a sending function and a receiving function; or, the sending unit and the receiving unit may be different functional modules, and the transceiver unit is a general term for these functional modules.

[0028] Exemplarily, when the apparatus is used to perform the method described in the first aspect, the apparatus may include a receiving unit and a sending unit. The receiving unit may be configured to receive a first received signal based on a first Huygens equivalent surface. The sending unit may be configured to send first indication information. The first received signal and the first indication information may be described in the first aspect.

[0029] In addition, optionally, the receiving unit may be configured to receive second indication information.

[0030] Optionally, the apparatus may further include a processing unit configured to obtain a second Huygens equivalent surface. For example, the processing unit may be configured to obtain the second Huygens equivalent surface based on a first compressibility corresponding to the first Huygens equivalent surface. The first compressibility may be determined by referring to the description of the first aspect.

[0031] Optionally, the receiving unit may be further configured to receive second information, or the sending unit may be further configured to send third information.

[0032] Exemplarily, when the apparatus is used to perform the method described in the second aspect, the apparatus may include a receiving unit and a sending unit. The sending unit may be configured to send a first received signal. The receiving unit may be configured to receive first indication information. The first received signal and the first indication information may be described in the second aspect.

[0033] In addition, optionally, the sending unit may be configured to send second indication information.

[0034] Optionally, the sending unit may be further configured to send second information, or the receiving unit may be further configured to receive third information.

[0035] For another example, the apparatus may include a processor coupled to a memory, configured to execute instructions in the memory to implement the method of the first or second aspect described above. Optionally, the apparatus may also include other components, such as an antenna, an input / output module, or an interface. These components may be hardware, software, or a combination of software and hardware.

[0036] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium is used to store a computer program or instruction, which, when executed, enables the method of any one of the first to second aspects to be implemented.

[0037] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the method described in any one of the first to second aspects to be implemented.

[0038] In a sixth aspect, a chip system is provided, comprising a logic circuit (or, understood as, the chip system comprising a processor, which may include logic circuits, etc.), and an input / output interface. The input / output interface can be used to receive messages or to send messages. For example, when the chip system is used to implement the function of a receiving end, the input / output interface can be used to receive a first received signal based on a first Huygens equivalent surface and / or to send first indication information. The input / output interface can be the same interface, that is, the same interface can implement both a sending and a receiving function. Alternatively, the input / output interface includes an input interface and an output interface, the input interface being used to implement a receiving function, that is, for receiving messages. The output interface being used to implement a sending function, that is, for sending messages. The logic circuit can be used to perform the operations described in the first and second aspects above, except for the sending and receiving functions. The logic circuit can also be used to transmit messages to the input / output interface, or to receive messages from other communication devices via the input / output interface. The chip system can be used to implement the method described in any of the first and second aspects above. The chip system can be composed of a chip, or it can include a chip and other discrete components.

[0039] Optionally, the chip system may further include a memory, which may be used to store instructions, and the logic circuit may call the instructions stored in the memory to implement corresponding functions.

[0040] In a seventh aspect, a communication system is provided. The communication system may include a receiving end and a transmitting end. The receiving end may be configured to execute the method performed by the receiving end in the first aspect, and the transmitting end may be configured to execute the method performed by the transmitting end in the second aspect. Alternatively, the communication system may include an apparatus for executing the method described in the first aspect, and an apparatus for executing the method described in the second aspect.

[0041] The technical effects brought about by the above second to seventh aspects can be found in the description of the above first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic diagram of the architecture of a wireless communication system provided by the present application;

[0043] FIG2 is a schematic diagram of a PMI codebook feedback method;

[0044] FIG3 is a schematic diagram of a channel measurement method based on beam selection;

[0045] FIG4 is a schematic diagram of a multi-layer antenna array structure;

[0046] FIG5 is a schematic diagram of the structure of the communication system provided by this application;

[0047] FIG6 is a schematic diagram of a Huygens equivalent surface;

[0048] FIG7 is a schematic diagram of an antenna array element distribution method provided by the present application;

[0049] FIG8 is a schematic diagram of a Huygens equivalent surface blueprint storage method provided by the present application;

[0050] FIG9( a ) is a schematic diagram of the geometric topology of an antenna array corresponding to a Huygens equivalent surface blueprint provided by the present application;

[0051] FIG9( b ) is a schematic diagram of a Huygens pattern on a three-dimensional spherical surface provided by the present application;

[0052] FIG9( c ) is an intention of a three-dimensional Huygens equivalent surface provided by this application;

[0053] FIG9( d ) is an intention of a two-dimensional Huygens equivalent surface provided by this application;

[0054] FIG10( a ) is a schematic diagram of a three-dimensional Huygens equivalent surface and a corresponding two-dimensional Huygens equivalent surface provided by the present application;

[0055] FIG10( b ) is a schematic diagram of another three-dimensional Huygens equivalent surface and a corresponding two-dimensional Huygens equivalent surface provided by the present application;

[0056] FIG10( c ) is a schematic diagram of another three-dimensional Huygens equivalent surface and a corresponding two-dimensional Huygens equivalent surface provided by the present application;

[0057] FIG11 is a flow chart of a communication method provided by the present application;

[0058] FIG12 is a schematic diagram showing the changes in the Huygens equivalent surface under the RIS scenario provided by this application;

[0059] FIG13 is a flow chart of another communication method provided by the present application;

[0060] FIG14 is a schematic structural diagram of a communication device provided by the present application;

[0061] FIG15 is a schematic structural diagram of another communication device provided by the present application;

[0062] FIG16 is a schematic structural diagram of another communication device provided in this application. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Among them, in the description of the present application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship. For example, A / B can represent A or B; "and / or" in the present application is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple. In addition, to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0064] In addition, the network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field can know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0065] To facilitate understanding of the embodiments of the present application, the communication system shown in Figure 1 is first used as an example to illustrate a communication system applicable to the embodiments of the present application. Figure 1 shows the architecture of a possible communication system applicable to the method provided in the embodiments of the present application, and the architecture of the communication system includes a network device 101 and at least one terminal device 102. Wherein: the network device can establish a communication link with at least one terminal device (for example, terminal device 1 and terminal device 2 shown in the figure) through beams in different directions. The network device can provide wireless access-related services for the at least one terminal device, and implement one or more of the following functions: wireless physical layer functions, resource scheduling and wireless resource management, quality of service (QoS) management, wireless access control, and mobility management functions. The at least one terminal device can also form a beam to transmit data between the network device. In this embodiment, the network device and at least one terminal device can communicate through a beam.

[0066] It should be understood that the network device involved in the embodiments of the present application can be any device with a wireless transceiver function or a chip that can be set in the device, including but not limited to: evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (for example, home evolved Node B (home evolved Node B, or home node B (HNB)), base band unit (BBU), access point (AP) in a wireless fidelity (WIFI) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP / TP) or remote radio head (RTR) The network device may be a wireless controller in a cloud radio access network (CRAN) scenario, or the network device may be a relay station, an access point, an in-vehicle device, a wearable device, an access network device in a future 5G network (such as a gNB), or an access network device in a future evolved PLMN network, etc., and the embodiments of the present application are not limited thereto.

[0067] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that a network device can be a device that includes one or more of a CU node, a DU node, or an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or may be classified as a network device in a core network (core network, CN), which is not limited in this application.

[0068] For example, the network device can serve as a scheduling device. In this case, the network device may include, but is not limited to, an LTE base station eNB, an NR base station gNB, an operator, etc., and its functions may include, for example, configuring uplink and downlink resources, sending downlink control information (DCI) in a base station scheduling mode. For example, the network device may also serve as a sending device. In this case, the network device may include, but is not limited to, a TRP and an RRH, and its functions may include, for example, sending downlink signals and receiving uplink signals.

[0069] The terminal devices involved in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device may also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved public land mobile network (PLMN), etc., and the embodiments of the present application are not limited to this. The terminal devices in the embodiments of the present application may be mobile phones, tablet computers, computers with wireless transceiver functions, wearable devices, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, drones, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, etc. The embodiments of the present application do not limit the application scenarios. In this application, the aforementioned terminal devices and chips that can be set in the aforementioned terminal devices are collectively referred to as terminal devices.

[0070] The functions of the terminal device may include, but are not limited to: receiving downlink / sidelink signals, and / or sending uplink / sidelink signals.

[0071] Exemplarily, the network device and the terminal device may include: an RRC signaling interaction module, a MAC signaling interaction module, and a PHY signaling interaction module. The RRC signaling interaction module may be a module used by the network device and the terminal device to send and receive RRC signaling. The MAC signaling interaction module may be a module used by the network device and the terminal device to send and receive MAC control elements (CEs). PHY signaling and data may be a module used by the network device and the terminal device to send and receive uplink control signaling or downlink control signaling, uplink and downlink data, or downlink data.

[0072] During transmission, communication systems typically use different types of reference signals: one type of reference signal is used to estimate the channel, enabling coherent demodulation of received signals containing control information or data; another type is used to measure the channel state or channel quality, thereby enabling scheduling of the user equipment (UE). Based on the channel quality measurement of the channel state information reference signal (CSI-RS), the UE can obtain channel state information (CSI). The CSI includes at least one of the following: rank indicator (RI), precoding matrix indicator (PMI), and channel quality indicator (CQI). This CSI information can be sent by the user equipment to the base station via the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH).

[0073] The wireless communication systems mentioned in the embodiments of the present application include, but are not limited to: global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, advanced long term evolution (LTE-Advanced, LTE-A) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), world wide interoperability for microwave access (WiMAX) communication system, 5G, a converged system of multiple access systems or an evolved system, and three major application scenarios of 5G mobile communication system: enhanced mobile broadband (eMBB), ultra reliable and low-latency communication (URLLC) and enhanced machine type communication (EMC). communication, eMTC) or new communication systems that will appear in the future.

[0074] It will be understood that the transmitting end in this application refers to a device that transmits a reference signal and / or data, and the receiving end refers to a device that receives the reference signal and / or data, performs channel measurement, and transmits channel information (or feedback information). Accordingly, the transmitting end may also receive channel information from the receiving end. As an example, the transmitting end may be a network device, such as a base station, and the receiving end may be a terminal device. Alternatively, as another example, the transmitting end may be a terminal device, and the receiving end may be a network device, such as a base station. In addition, as needed, both the transmitting end and the receiving end may be terminal devices or network devices.

[0075] It should be noted that the architecture of the communication system shown in FIG1 is not limited to including only the devices shown in the figure, but may also include other devices not shown in the figure, which will not be listed one by one in this application.

[0076] The following describes the PMI codebook feedback method in the multi-user MIMO wireless transmission process in conjunction with the system shown in Figure 1. As shown in Figure 2, the PMI codebook is designed to represent the dominant channel eigenvectors of multiple subband blocks (SB) with high resolution. In matrix form, the subband block corresponds to an N×K channel matrix shown in Figure 2, represented as H N,K Where K represents the number of SBs and N represents the number of dominant channel eigenvectors. N,K The K-th column vector of represents the channel eigenvector of the K-th SB.

[0077] One feedback method is type II channel state feedback (type II CSI), which is based on compressing the channel H in the spatial domain (SD) by performing a linear combination of the basis vectors of the matrix W1 in the SD. N,K In particular, the channel eigenvector e is represented as a linear combination of L discrete Fourier transform (DFT) vectors As shown in Figure 2.

[0078] In summary, Type II channel state feedback may include the following steps: First, a certain number (no more than 4) of beams are selected from all beam directions. For example, the selected 4 beams are represented as b0, b1, b2, and b3 in Figure 3. Second, dual polarization is considered in each beam direction (for example, p2 and p6 in direction b2). Finally, the weight coefficient w describing the channel is the weighted sum of (no more than) 8 complex responses, expressed as Here b i Indicates the beam direction, p i Indicates the polarization component, a i Indicates the complex response of the channel in a specific beam and selected polarization. The so-called complex response means that it has both amplitude and phase.

[0079] As an improved method based on Type II channel state feedback, in order to compress the signaling overhead of feedback, the DFT basis vector W in the frequency domain (FD) can be further utilized. f For the channel matrix H N,K Compress and get the matrix From the matrix Select K0 relatively largest elements from all elements of , and set the remaining elements to 0. Select the element with the largest value from K0 elements and set it to 1. Normalize the remaining K0-1 elements by scaling them proportionally based on the element with the largest value. Finally, the normalized The PMI is fed back from the receiving end to the transmitting end. The transmitting end determines the precoding matrix for the user data transmission process based on the PMI and then sends the user data to the receiving end.

[0080] For the measurement and feedback method of the above example, it is not possible to fully utilize all the useful signal energy and spatial channel degrees of freedom, and the communication performance needs to be further improved. On the one hand, in the above method, a certain number of beams are determined by beam selection (or selection), and zero-forcing (ZF) processing is performed in the unselected beam directions (such as b5, b6, etc., not shown in Figure 3, referring to beams other than b0 to b3), that is, the energy in other directions is abandoned. If the energy in other directions is not much different from the energy in the selected beam direction, or the energy in each direction is uniformly incident, the above scheme does not fully utilize all the useful signal energy and spatial channel degrees of freedom, and there is a certain channel capacity loss. On the other hand, the measurement and feedback method of the above example cannot accurately reflect the channel response of the antenna array that is blocked or has significant scattering effects or coupling effects in a three-dimensional geometric structure. Therefore, it can only be applied to the array deployment scheme of a planar geometric structure. For the antenna array of a non-planar geometric structure, it cannot fully utilize all the useful signal energy and spatial channel degrees of freedom.

[0081] In the post-5G era (beyond 5G, B5G), researchers are exploring new technologies to improve and advance MIMO-OFDM to further enhance the channel capacity and spectrum efficiency of wireless communication systems, enabling telecom operators to better utilize limited spectrum resources and provide users with higher data rates. Among these technologies, multi-layer antenna stacking and smart reflector technology are two promising new technologies.

[0082] Under the premise of a given wireless channel, the degree of freedom of the antenna fundamentally determines the channel capacity and spectrum efficiency of the wireless communication system. Under the premise of a given radio electromagnetic wave frequency, the physical size (length, width, thickness) of the antenna fundamentally determines the degree of freedom of the antenna. Given the physical area (length, width) of the antenna, appropriately increasing the thickness of the antenna (for example, multi-layer superposition) can significantly increase the degree of freedom of the antenna, sometimes also called depth gain. For example, without loss of generality, in order to further increase the degree of freedom of the antenna, in the typical system architecture diagram shown in Figure 3, each base station includes 3 sectors, and the antenna array of each sector is composed of 3 layers of superposition. The antenna of each layer evenly distributes multiple antenna elements on a rectangular plane, which is equivalent to increasing the thickness of the antenna array. It is easy to know that the present application can include multiple sectors, multiple layers of antenna superposition, and each layer of antenna can adopt any shape, and any number of antenna elements can be evenly or non-uniformly distributed. The shape, layout, and number of elements of antennas in different layers can be the same or different.

[0083] Therefore, there is reason to improve the channel measurement and feedback method exemplified above to fully utilize all useful signal energy and spatial channel degrees of freedom.

[0084] The method to be provided in the embodiment of the present application is described below in conjunction with the communication system shown in Figure 1. As an example, the wireless system of the present invention is composed of at least one base station and several terminals. Among them, the base station is composed of an antenna tower and a plurality of multi-layer antennas of cell sectors. The multi-layer antenna of each cell sector is composed of several layers of antenna arrays in the form of multi-layer geometric space superposition. The terminal types served by the base station include but are not limited to drones, smart phones, smart cars, and the like. The application scenario of the present invention is preferably for the wireless communication scenario of the base station macrocell. It is scalable and can also be applied to the scenario of indoor microcells, as well as other scenarios such as direct interconnection between vehicles and direct interconnection between drones. In order to better reflect the performance advantages of the solution of the present invention, ideally, the richer the propagation path of the spatial channel, the better, the richer the direction of leaving or arriving at the antenna, the better, and the more uniform the distribution of signal energy in different directions, the better.

[0085] Optionally, the base station includes a multi-layer antenna array structure, such as the array structure shown in FIG4 , or other structures, which are not within the scope of the present application.

[0086] Illustratively, the transmitting end and the receiving end in this application may have the structure shown in FIG5 .

[0087] The functional modules of the first embodiment of the present invention are shown in FIG5 , and include three entities: a transmitting end, a wireless channel, and a receiving end.

[0088] The transmitter consists of five subsystems: the signal source, baseband processor, RF link, antenna configuration module, and antenna. The baseband processor also includes a storage unit module and a computing unit module. The RF link consists of amplifier 1, mixer 1, oscillator 1, filter 1, and amplifier 2.

[0089] A wireless channel refers to the entire propagation environment of radio electromagnetic waves between the transmitting antenna and the receiving antenna.

[0090] The receiving end consists of five subsystems: antenna, antenna configuration module, RF link, baseband processor, and sink. The baseband processor also includes a storage unit module and a computing unit module. The RF link consists of amplifier 3, filter 2, mixer 2, oscillator 2, filter 3, and amplifier 4.

[0091] The center frequency of the oscillator at the transmitting end and the receiving end is f0, and the corresponding wavelength is λ0. The storage unit modules at the transmitting end and the receiving end can store some typical Huygens equivalent surfaces (or Huygens surface, Huygens equivalent surface pattern or pattern, etc.) known a priori as reference blueprints (or Huygens equivalent surface blueprints or simply blueprints). In addition, the storage unit module can dynamically refresh the locally stored reference blueprint database according to instructions. The computing unit module is responsible for completing the Huygens surface generation algorithm, the pattern index generation algorithm, and (optionally) the pattern index compression algorithm.

[0092] It can be understood that the antennas at the transmitting end and / or the receiving end shown in FIG. 5 have a multi-layer array structure as shown in FIG. 4 or other structures.

[0093] Huygens' principle states that every point on the wave front is a secondary source of the external wave. As shown in Figure 6, the electromagnetic fields in two regions are separated by a closed surface S that provides electric and magnetic surface currents. The electromagnetic fields in regions I and II are defined independently of each other, and the Huygens surface equivalence principle is used to find the virtual current element that satisfies the boundary conditions. and magnetic flux element Excitation field in region I Target field in area II outside surface S The effect of the surface current on the closed surface S can be completely determined by Here, represents the electric field, represents the magnetic field. On the Huygens surface, the following relationship is satisfied:

[0094]

[0095]

[0096] in, represents the normal unit vector pointing from region I to region II perpendicular to the closed surface S.

[0097] Assume that either the transmitting antenna or the receiving antenna in Figure 5 is a multi-layer superimposed antenna array as shown in Figure 4, or that both antennas are multi-layer superimposed antenna arrays as shown in Figure 4. The antenna configuration module allows you to configure options including the spatial position of the active element in the antenna array, the polarization mode of the element, the amplitude attenuator of the element, the phase offset of the element, the time delay of the element, and the excitation current mode of the element.

[0098] As shown in Table 1, there are four different combinations of antenna capabilities. The solution of the present invention is applicable to all four combinations. Unless otherwise specified, Example 1 will be described below based on the most complex combination 4. Other relatively simple combinations can be simplified from combination 4 and will not be repeated. Optionally, a simple and universal multi-layer superimposed antenna geometric topology is shown in Figure 7, including L layers, each layer including M rows and N columns of vibrator coordinates, and the spatial distance between each vibrator coordinate and the coordinate of the most adjacent neighbor vibrator is recorded as dx, dy, and dz, respectively. Any antenna vibrator can be marked as (m, n, l, p) representing the vibrator in the mth row, nth column, lth layer, and pth polarization direction. Among them, the value range of the polarization direction is p = {1, 2, 3}, p = 1, p = 2, and p = 3 respectively represent three polarization directions perpendicular to each other in three-dimensional space.

[0099] Table 1: Four combinations of antenna capabilities

[0100] Combination 1Combination 2Combination 3Combination 4 Transmitting antenna Single-layer antenna Single-layer antenna Multi-layer antenna Multi-layer antenna Receiving antenna Single-layer antenna Multi-layer antenna Single-layer antenna Multi-layer antenna

[0101] Considering the geometric topology shown in Figure 7, the traversal space of the antenna element's switch selectable (activation / inactivation) is 2 M×N×L×3 Assuming M=8, N=8, L=3, the traversal space is 2 M×N×L×3 =2 384 >10 96 Due to the sheer number of elements in space, it is, in principle, impossible to completely traverse the entire space using a one-to-one Huygens surface calculation within a finite timeframe. Therefore, the reference blueprint database for the storage unit module stores Huygens surface patterns for typical geometric topologies under typical excitations, as shown in Figure 8. The differently shaded antenna elements in Figure 8 represent antenna elements belonging to different antenna layers.

[0102] Taking the eighth typical geometric topology in Figure 8 as an example, as shown in Figure 9(a), a virtual three-dimensional sphere is used to wrap around it. Electromagnetic waves are emitted into the external space or incident on the antenna through this virtual sphere. The distribution of the current element (Js) on its Huygens surface on the three-dimensional sphere is shown in Figure 9(b). After normalization according to a certain quantization accuracy, the schematic diagram of the Huygens surface on the three-dimensional sphere is shown in Figure 9(c). Furthermore, according to the Mollweide projection method (also known as the world map drawing method), the schematic diagram of the Huygens surface unfolded from the three-dimensional sphere into a two-dimensional plane is shown in Figure 9(d). It can be understood that in the Huygens surface schematics shown in Figures 9(c) or 9(d), the areas enclosed by the curves represent pixel coordinate positions with the same or similar values. For example, the coordinates in different areas correspond to different numerical ranges. It can also be understood that the regions shown in Figure 9(c) correspond one-to-one with the regions shown in Figure 9(d). For example, region 1 shown in Figure 9(c) corresponds to region 1 shown in Figure 9(d), and region 2 shown in Figure 9(c) corresponds to region 2 shown in Figure 9(d). It can be understood that the schematic diagrams of Huygens surfaces shown in other figures of this application can refer to the description here.

[0103] The pixel coordinates of a Huygens pattern can be expressed using longitude and latitude. For example, longitude and latitude can be expressed as N, S, W, and E, corresponding to north latitude, south latitude, west longitude, and east longitude, respectively. The Mollweide projection method can be used to convert (x, y, z) coordinates on a surface into (longitude, latitude, altitude) according to certain rules. Globes and world maps are typical applications of this method. This method allows for reversible and equivalent graphical conversion between three-dimensional and two-dimensional Huygens surfaces.

[0104] [Corrected 09 / 08 / 2022 in accordance with Rule 91] A set of pattern blueprints for Huygens surfaces in typical geometric topologies and polarization configurations are shown in Figures 10(a) and 10(b). The three-dimensional and two-dimensional Huygens equivalent surface schematics shown in Figure 10(a) correspond to the straight line in the oz direction, which can be referred to as the coordinate system in Figure 9(a). The three-dimensional and two-dimensional Huygens equivalent surface schematics shown in Figure 10(b) correspond to a single-layer array antenna structure parallel to the ozy plane. In an actual system, the storage unit modules at both the transmitter and receiver record and update their own blueprint databases. Furthermore, the three-dimensional and two-dimensional Huygens equivalent surface schematics shown in Figure 10(c) are, for example, Huygens equivalent surfaces determined by the receiver. Exemplarily, the Huygens equivalent surface schematic diagram shown in Figure 10(c) is a linear superposition of the Huygens equivalent surface schematic diagram shown in Figure 10(a) and the Huygens equivalent surface schematic diagram shown in Figure 10(b). Based on the antenna array structures corresponding to Figure 10(a) and Figure 10(b) respectively, the antenna array structure adopted by the transmitting end when the actual measurement result is the Huygens equivalent surface schematic diagram shown in Figure 10(c) can be determined.

[0105] A communication method using a Huygens equivalent surface provided by an embodiment of the present application is described below in conjunction with the accompanying drawings. In the method provided by the present application, since the transmission process and the receiving process of any antenna are reversible, the roles of the transmitter and the receiver can be interchanged. For example, in an uplink communication link, the terminal device can serve as a transmitter, and the network device (such as a base station) or a multi-layer antenna of a network device can serve as a receiver. It can be understood that in some scenarios, a network device such as a base station can be used as a transmitter, and a terminal device can be used as a receiver. For example, in a downlink communication link, the network device can serve as a transmitter, and the terminal device or a multi-layer antenna of the terminal device can serve as a receiver. The network device and the terminal device can be described in Figure 1.

[0106] In summary, in a communication method using a Huygens equivalent surface provided in the present application, the transmitting end can be used to send a reference signal or data (such as 0 / 1 bit data), so that the receiving end obtains the Huygens equivalent surface of the incident electromagnetic wave at the time of reception based on the reference signal and using an estimation algorithm. In addition, the receiving end can also receive data (such as 0 / 1 bit data) and use a blind signal detection algorithm to obtain the Huygens equivalent surface of the incident electromagnetic wave. The receiving end can further determine at least one Huygens equivalent surface based on the similarity between the Huygens equivalent surface of the incident electromagnetic wave and the known Huygens equivalent surface. The feedback information sent by the receiving end can be called the first indication information, and the first indication information may include indication information of at least one Huygens equivalent surface, that is, the feedback information of the receiving end is used to indicate at least one Huygens equivalent surface. The transmitting end can calculate the relationship between the Huygens equivalent surface corresponding to the first received signal of the receiving end and at least one known Huygens equivalent surface based on the indication information of at least one Huygens equivalent surface received, and then determine the transmitting end configuration parameters used for subsequent sending signals or data based on the configuration parameters corresponding to the at least one known Huygens equivalent surface, thereby realizing configuration based on channel measurement and feedback.

[0107] As shown in FIG11 , the method may include steps S101 and S102:

[0108] S101: A receiving end receives a first received signal according to a first Huygens equivalent surface.

[0109] With reference to the foregoing description, the first received signal in the present application may include a reference signal and / or data, etc., without specific requirements.

[0110] In the present application, the Huygens equivalent surface is the electric field vector and / or magnetic field vector of the closed surface in the three-dimensional space where the receiving antenna is located.

[0111] Specifically, in S101 , the receiving end may receive the first received signal according to the first Huygens equivalent surface.

[0112] Optionally, the first Huygens equivalent surface may be indicated by the transmitting end, or may be determined by negotiation between the transmitting end and the receiving end, or may be determined by the receiving end through pre-configuration, protocol definition, or pre-defined manner.

[0113] Exemplarily, the receiving end may agree with the transmitting end through negotiation that the receiving end receives the first received signal according to the first Huygens equivalent surface. Alternatively, the receiving end may determine to receive the first received signal according to the first Huygens equivalent surface based on pre-configuration or according to protocol definition. For example, if determined through negotiation, the receiving end may receive indication information from the transmitting end (which may be referred to as second indication information in this application), and the indication information may be used to instruct the receiving end to receive the first received signal with the first Huygens equivalent surface, or the indication information may be used to indicate the first Huygens equivalent surface. Specifically, the indication information may be used to indicate that the first Huygens equivalent surface is the electric field vector, magnetic field vector, or electric field vector and magnetic field vector of the three-dimensional closed surface where the receiving antenna of the receiving end is located.

[0114] Here, S101 is described by taking as an example a scenario where the first received signal is determined based on a reference signal sent by a transmitting end. The reference signal may be a channel sounding reference signal (SRS) or a pilot signal, etc., and no specific requirements are imposed.

[0115] Optionally, the second indication information may be used to indicate an antenna configuration of the receiving end, and the receiving end may configure the receiving antenna according to the antenna configuration to form a first Huygens equivalent surface.

[0116] In addition, the second indication information can also be used to indicate information about the reference signal. For example, in a scenario where the first received signal is determined based on a reference signal sent by the transmitting end, the second indication information can also be used to indicate information such as the type and / or time-frequency resources of the reference signal. The receiving end can receive the reference signal based on information such as the type and / or time-frequency resources of the reference signal to obtain the first received signal. It can be understood that information such as the type and / or time-frequency resources of the reference signal can also be pre-configured or protocol-defined, and this application does not make specific requirements. Alternatively, other indication information can also indicate information such as the type and / or time-frequency resources of the reference signal.

[0117] As an example, the transmitting end shown in Figure 5 can configure the transmitting antenna so that the activated vibrator of the transmitting antenna is set to include certain geometric topology basic units. Specifically, the antenna configuration module (antenna configuration module 1 as shown in Figure 5) sequentially sets the antenna to the geometric topology basic unit. The vibrator on the selected vibrator coordinate is activated, and the other unselected vibrators are in a silent state. The transmitting end combines the vibrator coordinates and polarization mode set by the local antenna and records them as an excitation configuration (F). It can be understood that the combination of the geometric topology and polarization mode of each antenna element of the transmitting end can correspond to an excitation configuration (F).

[0118] As another example, the receiving end shown in FIG5 may configure the receiving antenna according to the second indication information or according to the local default strategy, so that the activated vibrator of the receiving antenna is set to include a certain geometric topology basic unit. Specifically, the antenna configuration module (antenna configuration module 2 as shown in FIG5 ) sequentially sets the antenna to a geometric topology basic unit. The vibrator on the selected vibrator coordinate is activated, and the other unselected vibrators are in a silent state. It can be understood that the combination of the geometric topology and polarization mode of each antenna array of the receiving end may correspond to a receiving configuration (W). According to the local default strategy, the receiving end can set the local antenna to the full vibrator activation mode according to the default receiving configuration, and listen to the detection signal from the transmitting end with maximum receiving capability. If any receiving configuration of the receiving antenna of the receiving end is used as the transmitting configuration of the transmitting antenna, it is used to emit radio electromagnetic waves. The electric field vector and / or magnetic field vector formed by this electromagnetic wave in the space near the receiving end is called the first Huygens equivalent surface. It is understandable that this electromagnetic wave emission process does not necessarily require the real existence of a physical process, because the first Huygens equivalent surface can be obtained in advance through mathematical calculations and then saved. The saved first Huygens equivalent surface can be read when executing the process of this application.

[0119] Then, based on a specific geometric topology, the transmitter sends a pre-agreed pilot signal to the receiver in polarizations p=1, p=2, and p=3 in different time windows. s , allowing up to S different types of detection signals. The radio electromagnetic wave signal carrying the sth detection signal is incident on the receiving antenna of the receiving end, and then passes through the amplifier 3, filter 2, mixer 2, filter 3 and amplifier 4 shown in Figure 5. The receiving end records the received signal or signal sequence input from amplifier 4 to baseband processor 2 at one or several instants, recorded as R s . R s The electric field vector and / or magnetic field vector formed by the radio electromagnetic wave signal from the transmitting end in the space near the receiving end is called the second Huygens equivalent surface.

[0120] Optionally, the first Huygens equivalent surface and the second Huygens equivalent surface are both the electric field vector of the three-dimensional closed surface where the receiving antenna is located, or the first Huygens equivalent surface and the second Huygens equivalent surface are both the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located, or the first Huygens equivalent surface and the second Huygens equivalent surface are both the electric field vector and magnetic field vector of the three-dimensional closed surface where the receiving antenna is located.

[0121] In the present application, the second Huygens equivalent surface can be used for channel measurement and feedback. It can be understood that the second Huygens equivalent surface can be the electromagnetic field distribution on the three-dimensional closed surface near the receiving antenna when the receiving end receives the first received signal using the first Huygens equivalent surface. The "closed surface" here specifically refers to an air interface that wraps around the physical antenna and is within a range of 1 to 10 carrier wavelengths from the physical antenna. Optionally, the geometric topological center point of the physical antenna at the receiving end is used as the center of the closed surface. The shape of the closed surface can be any closed surface, including but not limited to a sphere, a cube, a cuboid, and the like. The "electromagnetic field distribution" here specifically refers to the electric field vector, magnetic field vector, or electric field vector and magnetic field vector of the electromagnetic wave projected on the air interface.

[0122] The following describes a method in which the receiving end determines the second Huygens equivalent surface based on the first received signal.

[0123] The receiving end can use the first received signal as the transmitted signal and, using an electromagnetic algorithm, determine the Huygens surface formed by the transmitted signal in the space near the receiving antenna. This surface is called the Huygens equivalent surface corresponding to the first received signal. This Huygens equivalent surface is a three-dimensional Huygens equivalent surface. For example, the finite element method (FEM) is a feasible algorithm for determining the Huygens surface based on the transmitted signal.

[0124] Still taking FIG5 as an example, in the process of determining the second Huygens equivalent surface, the calculation unit module 2 at the receiving end can receive the signal R s As the transmission signal T s , and obtain the transmission signal T locally through computational electromagnetic algorithms (such as finite element method) s The Huygens equivalent surface formed in the nearby space when all the oscillators of the receiving antenna are activated is denoted as Hyg3D.

[0125] It can be understood that the second Huygens equivalent surface may be the Huygens equivalent surface corresponding to the first received signal, or may be the Huygens equivalent surface obtained by further processing the Huygens equivalent surface corresponding to the first received signal.

[0126] Optionally, the first Huygens equivalent surface and the second Huygens equivalent surface have the same electromagnetic field distribution. For example, the first Huygens equivalent surface and the second Huygens equivalent surface are the electric field vectors of the three-dimensional closed surface where the receiving antenna of the receiving end is located. Alternatively, the first Huygens equivalent surface and the second Huygens equivalent surface are the magnetic field vectors of the three-dimensional closed surface where the receiving antenna of the receiving end is located. Alternatively, the first Huygens equivalent surface and the second Huygens equivalent surface are the electric field vectors and magnetic field vectors of the three-dimensional closed surface where the receiving antenna of the receiving end is located.

[0127] Optionally, further processing according to the Huygens equivalent surface corresponding to the first received signal may include compressing the Huygens equivalent surface to reduce data processing overhead.

[0128] [Corrected 09.08.2022 according to Rule 91] In this application, the method of compressing the Huygens equivalent surface includes but is not limited to: projecting the three-dimensional Huygens equivalent surface into a two-dimensional space to obtain a two-dimensional Huygens equivalent surface. For example, the receiving end may project the three-dimensional Huygens equivalent surface into a two-dimensional space according to the Mollweide projection method (also known as the world map drawing method) to obtain a two-dimensional Huygens equivalent surface. For another example, the three-dimensional Huygens equivalent surface is the image shown in Figure 9(c), and the two-dimensional Huygens equivalent surface obtained by the Mollweide projection is the image shown in Figure 9(d).

[0129] Still taking FIG. 5 as an example, the computing unit module 2 at the receiving end can use Mollweide projection to unfold the Huygens equivalent surface Hyg3D from a three-dimensional curved surface into a two-dimensional planar Huygens surface, which is recorded as Hyg2D.

[0130] In addition, optionally, the method of compressing the Huygens equivalent surface includes but is not limited to: adjusting the size of the angular granularity of the three-dimensional Huygens equivalent surface and / or the three-dimensional Huygens equivalent surface to reduce the amount of data or increase the resolution. In this application, the size of the spatial angular granularity of the Huygens equivalent surface can represent the resolution (or precision) of the Huygens equivalent surface. The spatial angular granularity can represent the size of the spatial angular granularity (or unit) of the incident angle (or exit angle) of the electromagnetic wave to the antenna. The spatial angular granularity can be understood as the spatial range of the geometric topological center point of the receiving (or transmitting) antenna array diverging outward, represented by a combination of horizontal angle and vertical angle. The larger the spatial angular granularity, the lower the resolution of the Huygens equivalent surface and the higher the data compression rate. For example, the spherical surface of a regular sphere with a radius of 1 (unit not required) is divided into 8 regions, each region being a spatial angular granularity, and the horizontal angle of a spatial angular granularity is 90° (degrees) and the vertical angle is 90°. If the sphere is divided into 64 regions, the horizontal angle of a spatial angle particle is 45° and the vertical angle is 45°. It can be understood that the spatial angle granularity when the Huygens equivalent surface is divided into 8 regions is greater than the spatial angle granularity when the Huygens equivalent surface is divided into 64 regions, but the resolution of the Huygens equivalent surface of the former is lower than that of the latter, or in other words, the compression rate when the Huygens equivalent surface is divided into 64 regions is less than the compression rate when the Huygens equivalent surface is divided into 8 regions. It can be understood that in the Huygens equivalent surface schematic diagrams shown in Figures 9(c), 9(d), 10(a), 10(b) or 10(c), the spatial angle particle is the smallest unit for determining the size of a numerical value (such as the electric field amplitude).

[0131] The receiving end can obtain the second Huygens equivalent surface according to the first compression rate. Exemplarily, the value of the first compression rate is greater than 0 and less than or equal to 1. One characterization strategy for the first compression rate is to specify the number of spatial angular particles included in the Huygens equivalent surface at a given size. The larger the number, the smaller the spatial angular granularity and the higher the resolution of the Huygens equivalent surface. It can be understood that the higher the resolution of the Huygens surface, the higher the resolution of the spatial angular granularity of the wireless channel, and the higher the accuracy of the channel measurement result obtained according to the Huygens equivalent surface. The first compression rate can be understood as being related to the size of the spatial angular granularity. For example, the first compression rate is inversely proportional to the spatial angular granularity.

[0132] In addition, the first compression rate can also be understood as the compression rate for the amount of data. For example, when the amount of data of the Huygens equivalent surface corresponding to the first received signal is large, the amount of data is compressed according to the first compression rate. The compression method can be to increase the size of the spatial angular granularity. For example, when η=1, it means that the Huygens equivalent surface is uncompressed, and when η=1 / 2, it means that the amount of data of the compressed Huygens equivalent surface is 1 / 2 of the original, or in other words, the original two spatial angular granules are merged into one spatial angular granule of the compressed Huygens equivalent surface. It can be understood that data refers to the magnitude and direction information of the electric field vector and / or magnetic field vector.

[0133] As shown in FIG5 , during compression, the computing unit module 2 can compress the two-dimensional Huygens equivalent surface Hyg2D into a two-dimensional Huygens equivalent surface of a specified resolution according to a first compression ratio. The compressed Huygens equivalent surface is recorded as Hyg2D-Compress. The first compression ratio is recorded as η∈[0,1], so the Huygens equivalent surface Hyg2D-Compress can also be recorded as Hyg2D(η). It can be understood that η=0 can indicate that the amount of data is 0. η=1 can indicate that the amount of data has not been compressed.

[0134] Optionally, in order to further reduce data processing overhead, a dynamic compression method may be considered when compressing the Huygens equivalent surface.

[0135] In an example of dynamic compression, the receiving end can compress data in a certain area of ​​the Huygens equivalent surface (called the region of interest) at a higher resolution, such as compressing it according to a first compression rate, and compress data in other areas at a lower resolution, such as compressing the data in other areas at a higher compression rate than the first compression rate. For example, the region of interest can be defined by the spatial angular range. Indicates that the spatial angles of other areas do not belong to the spatial angle range Θ. Optionally, in order to further reduce the data flow, the receiving end can set the data of other areas outside the area of ​​interest to 0. For example, the spatial angle range Θ is based on the geometric topological center point of the receiving antenna array as the origin of the local coordinate system (0,0,0), with the global unified directionality of the three-dimensional space agreed in advance by the transmitting end and the receiving end. Determined by the benchmark, where the global unified directionality It is a reference direction negotiated between the sender and the receiver, indicated by the sender, indicated by the receiver, pre-configured, pre-defined, or defined by a protocol.

[0136] In another example of dynamic compression, the receiving end can compress the data of the Huygens equivalent surface obtained at a certain time or instantaneous time (which can be called the moment of interest) at a higher resolution, and compress the data of the Huygens equivalent surface obtained at other times at a lower resolution, that is, the resolution of the Huygens equivalent surface at other times is lower.

[0137] Therefore, the receiving end may use a higher resolution for the region of interest of the Huygens equivalent surface and a lower resolution for the region of no interest, or set the data to 0. And / or, the receiving end may use a higher resolution for the Huygens equivalent surface obtained at the time of interest and a lower resolution for the Huygens equivalent surface obtained at the time of no interest, or set the data to 0. It is understood that the region of interest of the Huygens equivalent surface at the time of interest may use a higher resolution, while other regions may use a lower resolution, or set the data to 0.

[0138] Optionally, the receiving end and the sending end can determine at least one of the first compression rate, the spatial angular range or the moment of interest through negotiation. For example, before S101, the receiving end and the sending end can send information indicating at least one of the first compression rate, the spatial angular range or the moment of interest.

[0139] As a possible implementation, the second indication information may indicate at least one of the first compression ratio, the spatial angular range, or the time of interest. For example, the second indication information may indicate the first compression ratio corresponding to the first Huygens equivalent surface, and the receiving end may obtain the second Huygens equivalent surface based on the first compression ratio. Alternatively, the transmitting end may indicate at least one of the first compression ratio, the spatial angular range, or the time of interest to the receiving end through other signaling.

[0140] As another possible implementation, the first indication information may include at least one of the first compression ratio, the spatial angular range, or the moment of interest. Alternatively, the receiving end may indicate at least one of the first compression ratio, the spatial angular range, or the moment of interest to the transmitting end through other signaling.

[0141] In addition, at least one of the first compression rate, the spatial aperture angle range, or the time of interest may also be determined by the transmitting end and / or the receiving end in a predefined, preconfigured, or protocol-defined manner.

[0142] It is understood that if the receiving end and the transmitting end have not determined the spatial angular range or the time of interest through negotiation, pre-definition, pre-configuration, or protocol definition, the full spatial angular range, i.e., Θ = ([0, 2π], [0, π]), can be used. In this case, the same compression rate, such as the first compression rate, is used across the entire spatial angular range of the Huygens equivalent surface determined by the receiving end to improve channel measurement accuracy.

[0143] [Corrected 09.08.2022 in accordance with Rule 91] In addition, if the transmitter and receiver communicate via a reconfigurable intelligent surface (RIS), the network device may determine the spatial angular range of the receiver based on the relative orientation of the RIS and the receiver. For example, the spatial angular range is consistent with the positional relationship of the RIS relative to the receiver, which can improve the measurement accuracy of the RIS relative to the receiver, thereby improving communication performance.

[0144] S102: The receiving end sends first indication information to the transmitting end. The first indication information includes indication information of at least one Huygens equivalent surface. The indication information of the at least one Huygens equivalent surface is determined based on a second Huygens equivalent surface corresponding to the first received signal.

[0145] Correspondingly, the transmitting end receives the first indication information and can determine the transmitting end configuration parameters used for subsequent signal or data transmission based on the first indication information.

[0146] The following introduces the content of the first indication information and the way in which the receiving end determines the first indication information.

[0147] The receiving end may determine the indication information of the at least one Huygens equivalent surface based on the second Huygens equivalent surface. The indication information of the at least one Huygens equivalent surface may include an index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: a mutual correlation coefficient (such as a normalized mutual correlation coefficient) between the Huygens equivalent surface and the second Huygens equivalent surface, a compression ratio, and a spatial angular range.

[0148] Exemplarily, the receiving end can determine the Huygens equivalent surface (hereinafter referred to as the Huygens equivalent surface blueprint) of the typical geometric topology stored locally under the typical excitation configuration, and the normalized cross correlation coefficient (NCC) between the second Huygens equivalent surface, and use the top R Huygens equivalent surface blueprints with the highest normalized cross correlation coefficient as at least one Huygens equivalent surface in S102, where R is a positive integer. Optionally, the receiving end can store a Huygens reference blueprint database including Huygens equivalent surface blueprint information as shown in Figure 8, wherein the Huygens equivalent surface blueprint information includes the index of the Huygens equivalent surface blueprint. It can be understood that in the present application, the indication information of the Huygens equivalent surface may include the index of the Huygens equivalent surface blueprint. Furthermore, it's understandable that the receiver doesn't necessarily need to know the correspondence between the Huygens equivalent surface blueprint and typical geometric topologies or excitation configurations. The receiver only needs to store the Huygens equivalent surface blueprint and its index, without having to know the specific array geometric topologies or excitation configurations to which the Huygens equivalent surface blueprint corresponds. As previously explained, the excitation configuration is a combination of the antenna array geometric topology and polarization.

[0149] Here, we introduce a method for determining the normalized cross-correlation coefficient. Taking the second Huygens equivalent surface with a compression rate of η as Hyg2D(η), the receiving end's computing unit module 2 retrieves K Huygens equivalent surface blueprints from the storage unit module 2 one by one. The kth Huygens equivalent surface blueprint is denoted as Hyg(k), where k and K are positive integers and 1≤k≤K. For example, Hyg(k) is any one of the geometric diagrams in Figure 8.

[0150] The normalized mutual correlation coefficient between Hyg(k) and Hyg2D(η) is denoted as ρ(k,η), which satisfies the following formula:

[0151]

[0152] Among them, X i represents the projection value of the i-th element vector of the Huygens equivalent surface X in the oz direction, Represents the average value of the projection values ​​of all element vectors of the Huygens equivalent surface X in the oz direction. The Huygens equivalent surface X is Hyg(k) and Hyg2D(η). The data of the Huygens equivalent surface refers to the magnitude and direction information of the electric field vector and / or magnetic field vector. Among them, it is easy to see that the NCC value range of Hyg(k) and Hyg2D(η) is -1≤ρ≤1. When the two Huygens equivalent surfaces are exactly the same, the NCC coefficient is 1; when the two Huygens equivalent surfaces are completely opposite, the NCC coefficient is -1; when the two Huygens equivalent surfaces are completely unrelated, the NCC coefficient is 0.

[0153] It is understandable that those skilled in the art may make appropriate changes to the above formula or the concept embodied in the above formula to obtain other similar methods for determining the normalized cross-correlation coefficient, which will not be described in detail here.

[0154] Alternatively, other modified methods for calculating the correlation coefficient include but are not limited to:

[0155]

[0156] or,

[0157]

[0158] The receiving end can select the first R NCCs whose absolute values ​​are closest to 1 from a set of ρ(k,η), that is, 1≥|ρ1|≥|ρ2|≥…≥|ρ R |, using the corresponding R Huygens equivalent surface blueprints as at least one Huygens equivalent surface in S102.

[0159] For example, the receiving end may obtain the index code of the Huygens surface shown in Table 2, which is an example of indication information of a possible Huygens equivalent surface. For example, when the full space angle range is used, the first indication information is a matrix W including the content shown in Table 2, where the elements of the four columns of matrix W are the values ​​of the contents of the four columns in Table 2.

[0160] Table 2: Example of indication information for a Huygens surface

[0161] Sorting r blueprint serial number k compression ratio η normalized correlation coefficient ρ(k,η)1k1η1ρ12k2η2ρ2............Rk R η R ρ R

[0162] The optional order r in Table 2 is the serial number of the R Huygens equivalent surface blueprints in descending order of the absolute value of the normalized cross-correlation coefficient ρ(k,η). The order r is optional in the first indication information, and it can be assumed that the absolute value of the normalized cross-correlation coefficient of the Huygens equivalent surface blueprint in the previous order is larger. The blueprint serial number k can represent the index of the Huygens equivalent surface blueprint in the Huygens reference blueprint database shown in Figure 8. Therefore, the blueprint serial number is the index of the Huygens equivalent surface. η1, η2...η R , respectively represent the compression ratio of R Huygens equivalent surface blueprints. For example, η1, η2...η R The first compressibility may be the same as or close to the first compressibility of the second Huygens equivalent surface.

[0163] It can be understood that the elements in a row of Table 2 correspond to each other.

[0164] For another example, when considering a spatial angle range, that is, when the spatial angle range does not cover the entire spatial angle range, the first indication information may be as shown in Table 3. For example, the first indication information is a matrix W including the contents shown in Table 3, where the five columns of matrix W are the values ​​of the five columns in Table 2. Θ1, Θ2, etc. in Table 3 each correspond to a spatial angle range. It is understood that Table 3 may contain at least one spatial angle range. According to the description in this application, the spatial angle range can be determined based on the location of the RIS to improve communication performance in RIS scenarios.

[0165] Table 3: Example of indication information for a Huygens surface

[0166]

[0167]

[0168] Among them, the ranking r, the blueprint number k, the compression rate η, and the normalized correlation coefficient ρ(k,η) can be seen in the description of Table 2. It can be understood that k1, k2...k R , k1', k2'...k R The index of the Huygens equivalent surface model in the Huygens reference model database shown in Figure 8. k1, k2...k R Some or all of the blueprint numbers in can be the same as k1', k2'...k R 'Some or all of the blueprint serial numbers are the same or different. η1, η2...η R Some or all of the compression ratios in η1', η2', ... η R ' have the same or different compression rates for some or all of them.

[0169] Optionally, in Table 3, it can be assumed that among the Huygens equivalent surface blueprints corresponding to the same spatial angular range, the Huygens equivalent surface blueprint with the earlier sorting position has a larger absolute value of the normalized mutual correlation coefficient, for example, ρ1, ρ2...ρ R In descending order, ρ1', ρ2'... ρ R 'Sort in descending order.

[0170] As shown in Table 2 or Table 3, when the feedback resources corresponding to the first indication information are limited, the receiving end can provide limited feedback to the sending end on the information of R Huygens equivalent surface blueprints, so that the sending end can determine the sending configuration or parameters based on the information of the R Huygens equivalent surface blueprints with larger absolute values ​​of the normalized mutual correlation coefficients to improve the transmission performance.

[0171] It is understandable that the first indication information may also include only the blueprint sequence number, thereby reducing feedback overhead. For example, the receiving end may default to only feeding back the blueprint sequence number whose normalized mutual correlation coefficient meets certain conditions. For example, the normalized mutual correlation coefficient of the blueprint sequence number fed back by the receiving end is not less than 0.95 or not greater than -0.95. Accordingly, the receiving end uses 0.95 or -0.95 as the normalized mutual correlation coefficient corresponding to the received blueprint sequence number. Alternatively, the first indication information may also include only the blueprint sequence number and the normalized mutual correlation coefficient. If the first indication information only includes the blueprint sequence number or only includes the blueprint sequence number and the normalized mutual correlation coefficient, the compression rate and / or spatial angular range may use a default value, or may be exchanged by the receiving end and the sending end through other signaling, or may be determined by the receiving end and the sending end through pre-configuration, pre-definition or protocol definition. If the first indication information includes multiple blueprint serial numbers, a default sorting may be used between the multiple blueprint serial numbers. For example, referring to the description of Table 2 or Table 3, the sorting from small to large may correspond to the absolute value of the normalized correlation coefficient from large to small.

[0172] The following describes a method in which the transmitting end determines the configuration parameters (or antenna excitation scheme) used for sending signals or data according to the first indication information.

[0173] Based on the above description, the first indication information may include at least one of the index of the Huygens equivalent surface, the normalized cross-correlation coefficient, the compression ratio, and the spatial angular range. For example, if the first indication information includes the content shown in Table 2 or Table 3, the transmitting end can accordingly find the antenna excitation scheme corresponding to the first indication information through offline table lookup or real-time calculation, and use it for subsequent signal or data transmission.

[0174] The transmitting end forms a set of configuration records by combining the matrix W of the first indication information fed back by the receiving end each time and the transmitting antenna excitation configuration (F) when transmitting the sth detection signal, which is recorded as<F,W> s , s∈[1,S], and stores the configuration record in the local storage unit module 1 of the transmitting end as shown in Figure 5. After receiving the first indication information, the transmitting end can find (or determine) the antenna excitation scheme corresponding to the first indication information based on the configuration record through offline table lookup or real-time calculation, for subsequent signal or data transmission.

[0175] For example, the first indication information may include a blueprint serial number, and the transmitting end may determine the Huygens equivalent surface blueprint according to the blueprint serial number, and determine the antenna excitation scheme according to information such as the antenna element topology and polarization mode corresponding to the Huygens equivalent surface blueprint. Taking the first indication information including Table 2 as an example, the transmitting end may determine the antenna excitation scheme according to k1, k2...k R Search the blueprint database to obtain the excitation configuration corresponding to the corresponding Huygens equivalent surface blueprint.

[0176] For example, for a multi-layer antenna array with L layers, M rows and N columns, it contains J=L×M×N elements. The excitation configuration of the Huygens equivalent surface template with template number k may include the jth element coordinate {e j,k} and polarization mode {p j,k The Huygens equivalent surface blueprint can select all or part of the oscillators in the active state from all J arrays. Different Huygens equivalent surface blueprints k1, k2...k R It may include oscillators having all or some of the same coordinates.

[0177] For example, the incentive scheme F corresponding to the k1th Huygens blueprint is k1 , including: oscillator coordinates {e 1,k1 ,e 2,k1 ,…,e j,k1}, polarization mode {p 1,k1 ,p 2,k1 ,…,p j,k1} and the excitation signal {s 1,k1 ,s 2,k1 ,…,s j,k1}. In particular, when s j,k1 = 0, it means that the j-th array has not been selected by the k1-th Huygens blueprint and is in an inactive state.

[0178] Among them, e j,k =(x j,k ,y j,k ,z j,k );x j,k is the X-axis space coordinate of the j-th oscillator selected by the k-th blueprint, y j,k is the Y-axis space coordinate, z j,k is the Z-axis space coordinate.

[0179] a j,k is the X-polarization weight coefficient of the j-th oscillator selected by the k-th blueprint, b j,k is the Y polarization direction weight coefficient, c j,k is the Z-polarization direction weight coefficient. is the unit direction vector of the X polarization direction, is the unit direction vector of the Y polarization direction, is the unit direction vector of the Z polarization direction.

[0180] s j,k =d j,k +i·f j,k , is the imaginary number symbol. j,k is the real part of the excitation signal of the jth oscillator selected by the kth blueprint, fj,k is the real part of the excitation signal.

[0181] Similarly, the transmitter can determine the excitation configuration of other Huygens equivalent surface blueprints. For example, the excitation configurations of R Huygens equivalent surface blueprints are calculated as

[0182] Furthermore, if the first indication information includes indication information of multiple Huygens equivalent surfaces, the sending end can perform weighted summation of the excitation schemes of multiple Huygens blueprints and use the calculation result as the precoding scheme for subsequent sending of useful user data, thereby further improving the reliability of determining the precoding scheme.

[0183] Exemplarily, the precoding scheme is represented by G, which satisfies the following formula 1:

[0184]

[0185] in, Indicates s j,k Take the complex conjugate, that is

[0186] to s j,k The advantage of taking conjugate is spatial filtering, which can be used to offset the adverse effects caused by the lower-layer oscillator waveform of the incident or outgoing signal being blocked or scattered by the upper-layer oscillator after passing through multi-layer antennas.

[0187] After determining the precoding scheme G, the transmitting end may configure the transmitting antenna according to the precoding scheme G and transmit signals and / or data to the receiving end via the configured transmitting antenna. Optionally, the transmitting end may indicate the precoding scheme G to the receiving end so that the receiving end receives the signal and / or data according to the precoding scheme, thereby improving signal reception efficiency and communication reliability. It is understood that the manner in which the precoding scheme G is indicated is not within the scope of this application.

[0188] Based on the method shown in FIG11 , it can be understood that the first received signal is affected by the transmit antenna configuration, wireless channel propagation, and receive antenna configuration. The first Huygens equivalent surface corresponds to the receive antenna configuration at the receiver, meaning the receive antenna configuration is known to the receiver. After obtaining the second Huygens equivalent surface, the receiver now knows the combined effect of these three factors, which is the second Huygens equivalent surface. Furthermore, since the receiver knows the receive antenna configuration, it can determine the combined effect of the transmit antenna configuration and wireless channel propagation. Furthermore, in step S102 , the receiver can send first indication information to the transmitter. The first indication information indicates the combined effect of the transmit antenna configuration and wireless channel propagation. Because the transmitter knows the transmit antenna configuration, it can determine the effect of wireless channel propagation, i.e., obtain channel information, thereby better adapting to wireless channel characteristics and fully utilizing the channel's degrees of freedom and the energy of electromagnetic waves in all directions. For example, optionally, the transmitting end (such as a base station) can determine the receiving antenna configuration and the transmitting antenna configuration that more fully utilize the degrees of freedom of the channel and the energy of electromagnetic waves in all directions based on the channel information, and adjust the local next transmitting antenna configuration, and / or indicate to the receiving end through a second indication information the next receiving antenna configuration that the receiving end hopes to adopt.

[0189] As an implementation method of the present application, the receiving end can receive multiple received signals at multiple instants, determine multiple second Huygens equivalent surfaces when receiving the multiple received signals, and send feedback information multiple times based on the multiple second Huygens equivalent surfaces at the multiple instants. It can be understood that the first received signal in S101 is one of the multiple received signals received at the multiple instants, the first indication information in S102 is one of the feedback information sent multiple times, and the second Huygens equivalent surface corresponding to the first indication information is one of the multiple second Huygens equivalent surfaces of the multiple received signals. It can also be understood that the way the receiving end obtains multiple second Huygens equivalent surfaces can refer to the description of the receiving end determining the second Huygens equivalent surface in this application, and the multiple feedback information can refer to the description of the first indication information.

[0190] In this application, the purpose of the receiving end sending feedback information multiple times is to take into account the significant changes in the wireless channel over time, and to reflect the time-varying characteristics of the wireless channel over a period of time through multiple feedback, so as to predict the wireless channel for the next period of time based on the time-varying characteristics, and further improve the accuracy of the precoding scheme used when sending application data subsequently. Among them, the reasons why the wireless channel changes significantly over time include but are not limited to changes in the surrounding environment, and the movement of the terminal device relative to the network device, etc. The impact of the time-varying wireless channel causes the virtual current element on the Huygens surface of the receiving end to change. and magnetic flux element The Huygens equivalent surface also varies with time and space. Therefore, the time-varying characteristics of a wireless channel can be characterized by the information provided by the Huygens equivalent surface, which is fed back multiple times over a period of time. Theoretically, while the Huygens equivalent surface varies within the coherence time and coherence space of a time-varying wireless channel, it exhibits strong similarities and correlations between preceding and following times or nearby spaces, and exhibits a theoretically calculable pattern of variation.

[0191] Optionally, the receiving end can determine N received signals within the coherence time, where N is a positive integer greater than 1, and determine a second Huygens equivalent surface based on each received signal. The receiving end can also determine feedback information based on each second Huygens equivalent surface. Exemplarily, the feedback information corresponding to each second post-transmission equivalent surface is as shown in the aforementioned first indication information. For example, each feedback information includes at least one index of the Huygens equivalent surface and at least one of the mutual correlation coefficient, compression ratio, and spatial angular range corresponding to the index. Therefore, it can be understood that the first received signal is the received signal received by the receiving end in the nth transmission period within the coherence time, 1≤n≤N, and n is a positive integer.

[0192] Optionally, the receiving end can predict the spatial angular range of the Huygens equivalent surface at the next sampling moment or the next period of time based on the changing trends of m consecutive spatial angular ranges within the spatial angular ranges corresponding to the N second Huygens equivalent surfaces, so as to improve the efficiency and reliability of determining the spatial angular range. Assuming that the position of the network device (such as a base station) remains unchanged and the user's handheld terminal device is moving slowly while walking, the relative position and relative angle between the network device and the terminal device are also slowly changing. Therefore, the prediction method can predict in advance the optimal area of ​​interest (i.e., the spatial angular range) of the Huygens equivalent surface for the next period of time, thereby reducing the degradation of the received signal quality caused by terminal movement.

[0193] Further optionally, the N received signals are received within N transmission periods within the coherence time, respectively. The coherence time may include N transmission periods, wherein the lengths of the N transmission periods are equal. Exemplarily, the coherence time is composed of N transmission periods, or the duration of the coherence time is greater than the duration of the N transmission periods. For example, the time domain positions of the N received signals received by the receiving end are located at the starting moments of the N transmission periods, for example, the first received signal is located at the starting moment of the first transmission period within the coherence time, the second received signal is located at the starting moment of the second received signal within the coherence time, and so on. Alternatively, the time domain position of the received signal may also be separated from the starting moment of the transmission period by a certain time offset value, which is not specifically required.

[0194] As an example, the N received signals may be received at equal time intervals. Therefore, it can also be understood that the receiving end receives the N received signals at N sampling moments within the coherence time. The N sampling moments may be distributed at equal time intervals, which may be denoted as Δt.

[0195] The following example describes how to determine the coherence time.

[0196] Taking the terminal device as the receiving end as an example, the receiving end can measure the moving speed v of the local terminal, and then convert the speed v or the coherence time T determined according to the speed v into c The speed is reported (or indicated or notified) to the sending network device via air interface signaling. Methods for the receiving end to determine the moving speed include but are not limited to measuring the moving speed through speed sensors, GPS navigation, lidar, millimeter wave radar, etc. Similarly, if the terminal device acts as the sending end, the sending end can measure and report (or indicate or notify) the speed v or coherence time T to the receiving end. c In addition, the speed of the terminal device may also be measured by the network device, and this application does not make any specific requirements on the subject of speed measurement.

[0197] Optionally, velocity v and coherence time T c The relationship between is shown in the following formula:

[0198]

[0199]

[0200] Where v represents the speed of the receiving end, λ represents the carrier wavelength of the receiving end, θ represents the angle between the speed direction of the receiving end and the line connecting the two ends of the transmitter and receiver, θ is an acute angle, and f d Represents the Doppler shift. T c Represents the coherence time in the motion Doppler frequency domain. The number 0.423 is an empirical formula value, which can be updated based on actual scenarios. It can be understood that the carrier wavelength at the receiving end can be determined based on the receiving end's center frequency.

[0201] Furthermore, the receiving end and the transmitting end may also agree on the length of N, N time periods or the time interval Δt between N sampling moments. Specifically, the negotiation method may be, for example, that the receiving end sends second information to the transmitting end, where the second information is used to indicate the length of N, N time periods or the time interval Δt between N sampling moments. Alternatively, the receiving end may receive third information from the transmitting end, where the third information is used to indicate the length of N, N time periods or the time interval Δt between N sampling moments.

[0202] It is understood that the receiving end can calculate N second Huygens equivalent surfaces and determine the corresponding indication information of the Huygens equivalent surface blueprint. In one feedback method, the receiving end can carry the indication information of the N second Huygens equivalent surfaces and determine the corresponding Huygens equivalent surface blueprint in N feedback information, that is, the receiving end performs N feedback. In another feedback method, the receiving end can carry the indication information of the complete Huygens equivalent surface blueprint in the feedback information sent for the first time, and carry the parameter change compared with the previous feedback information in the subsequent feedback information. It is understood that the indication information of the complete Huygens equivalent surface blueprint refers to the index of the Huygens equivalent surface and at least one of the mutual correlation coefficient, compression ratio and spatial angular range corresponding to the index. For example, in subsequent feedback, the receiving end can employ a graphical compression method. This method leverages the similarity of multiple Huygens equivalent surfaces within the coherence time, and includes in the feedback information the changes in the Huygens equivalent surface template corresponding to the subsequent received signal compared to the Huygens equivalent surface template corresponding to the previous received signal. The unchanged portions are omitted from the feedback, thereby conserving air interface bandwidth. For example, if the first indication information is not the first feedback information sent by the receiving end within the coherence time, the first indication information may include the parameter changes in the indication information of at least one Huygens equivalent surface determined based on the first Huygens equivalent surface, compared to the feedback information previously sent by the receiving end.

[0203] After receiving multiple pieces of feedback information corresponding to the coherence time, the transmitting end may determine the precoding scheme G according to the multiple pieces of feedback information.

[0204] Here, several feasible methods for determining the precoding scheme G according to multiple pieces of feedback information are introduced by way of examples.

[0205] Method 1: The transmitter averages the matrix W of N feedback information to obtain based on G is determined using the method shown in Formula 1. It can be understood that Formula 1 can refer to the above description of determining the precoding scheme G, which will not be expanded here.

[0206] Method 2: The transmitter receives the feedback information W corresponding to the last received signal among the N received signals. N , use the method shown in formula 1 to determine G.

[0207] Method 3: The transmitter predicts the feedback information W corresponding to the next transmission cycle (or sampling moment) of the Nth transmission cycle (or sampling moment) based on the changing trend of N feedback information. N+1 , based on W N+1 , use the method shown in formula 1 to determine G. This application predicts feedback information W N+1 There is no specific requirement for the method.

[0208] Method 4: The sender is based on W1, W2, ..., W N , use the method shown in formula 1 to determine G1, G2, ..., G N , and periodically adopt G1, G2, ..., G according to the time interval Δt N Send.

[0209] It is understood that the above methods 1 to 4 are merely examples and are not intended to be a specific limitation on determining the precoding scheme G based on multiple pieces of feedback information. Any of the above methods 1 to 4 may also be implemented in combination.

[0210] Optionally, in a scenario where the communication system of the present application includes RIS, if RIS is turned on, RIS can convert the Huygens equivalent surface of the transmitting antenna of the transmitter into the Huygens equivalent surface of the receiving antenna of the receiver. The Huygens equivalent surface of the transmitting antenna can be regarded as the electromagnetic field distribution on the three-dimensional closed surface near the transmitting antenna when the transmitting antenna of the transmitter is transmitting. As shown in Figure 12, when there are one or more RIS between the transmitting antenna and the receiving antenna, the configuration parameters of the RIS can be artificially controlled so that when the Huygens surface of the transmitting antenna reaches the Huygens equivalent surface of the receiving antenna, a structured mapping relationship that is conducive to wireless communication is constructed and maintained in spatial geometry. Specifically, this relationship can be mapped as a graphic transformation of the pixel points of the Huygens equivalent surface Hyg2D of the transmitting end to the Huygens equivalent surface Hyg2D of the receiving end shown in Figure 12. The transformation here can be a translation, rotation, scaling, superposition, and other relationships.

[0211] In this application, the transmitting end and the receiving end can communicate through M RISs. However, this application does not require the RIS to have the CSI feedback capability.

[0212] It is understood that in the RIS scenario, the first received signal may be a default reference signal when the RIS is enabled, or the first received signal may be a default reference signal when the RIS is disabled. The RIS here may refer to part or all of the RIS between the transmitter and receiver.

[0213] The following describes the method flow of the present application in the RIS scenario with reference to FIG13 . As shown in FIG13 , the process may include the following steps:

[0214] S201: The network device indicates that the operation state of the RIS is closed, and the network device sends a detection signal in a broadcast manner, so that at least one terminal device can receive the detection signal.

[0215] It can be understood that the detection signal received by the terminal device may correspond to the first received signal in S101.

[0216] S202: At least one terminal device sends feedback information to the network device, and the feedback information is recorded as W1.

[0217] The method for determining the feedback information may refer to the description of the method for determining the first indication information in S102. That is, any terminal device may refer to the description in S102 to determine the first received signal.

[0218] Exemplarily, the feedback information in S202 may include first indication information. For example, any terminal device may provide feedback information, which is the first indication information shown in S102. For another example, any terminal device may provide feedback information determined based on multiple received signals received within the coherence time, which may include the first indication information shown in S102.

[0219] S203: The network device indicates that the running status of the selected one or more RIS is turned on, and broadcasts the detection signal again.

[0220] Optionally, the detection signal in S201 and the detection signal in S203 may be the same.

[0221] Optionally, the RIS in this application supports 1-bit quantization accuracy.

[0222] If the RIS has only two states, 0 and 1 (for example, corresponding to the on and off states, respectively), it is said to support only 1-bit quantization precision. If the RIS supports four states, 00, 01, 10, and 11 (for example, corresponding to off, on with a 60° phase shift, on with a 120° phase shift, and on with a 180° phase shift, respectively), it is said to support 2-bit quantization precision. Similarly, 3-bit quantization precision corresponds to 8 RIS state spaces, and 4-bit quantization precision corresponds to 16 RIS state spaces. As you can see, the larger the number of bits of quantization precision, the higher the hardware cost and overhead.

[0223] S204: At least one terminal device sends feedback information to the network device, and the feedback information is recorded as W2.

[0224] In S204, the at least one terminal device may be the same as or different from the at least one terminal device in S202, without specific limitation. Optionally, if the at least one terminal device involved in S202 and S204 is not identical, the distance between these terminal devices must be significantly smaller than the distance between any terminal device and the network device. For example, "significantly smaller" means that the difference between the two distances is at least 10 times.

[0225] Similar to S202 , the method for determining the feedback information in S204 can refer to the description of the method for determining the first indication information in S102 .

[0226] It is understood that when the RIS operating state changes from off to on, the feedback information W1 and W2 provided by the same terminal device at the same location may differ. It is also understood that if the RIS supports 2-bit or higher quantization accuracy, the on state is replaced by a state in which a certain phase shift angle is enabled, and the corresponding channel measurement results correspond to that state. In practical applications, the channel measurement results can be measured under different phase shift angles by changing the on state. The implementation method is not further described.

[0227] With reference to the description of the first indication information, the feedback information W1 and / or W2 of any terminal device may include the contents of Table 3 or Table 4, or only include the blueprint serial number, or only include the blueprint serial number and the normalized correlation coefficient.

[0228] S205: The network device generates a precoding scheme for the terminal device based on the feedback information W1, feedback information W2, the location and configuration parameters of the RIS. The precoding scheme of the network device for the kth terminal device can be recorded as G k .

[0229] For the mth and nth terminal devices, their precoding schemes ideally satisfy the Kronecker (δ) function, that is, satisfy the following formula:

[0230]

[0231] Among them, G m is the precoding scheme of the mth terminal device, G n is the precoding scheme for the nth terminal device.

[0232] S206: The network device uses the precoding scheme (G k ) sends data to the kth UE. When there are K UEs sending data simultaneously at a certain instant, the total transmitted signal X of the base station is the weighted sum of multiple signals, as shown in the following formula:

[0233]

[0234] Among them, X k Represents the data sent by the k-th terminal device, 1≤k≤K.

[0235] Based on the process shown in Figure 13, the method provided in the embodiment of the present application can be applied to the scenario where the transmitter and receiver communicate through RIS, thereby improving the utilization of useful signal energy and the spatial channel freedom in this scenario, thereby improving communication performance.

[0236] The above is an introduction to the method provided in the embodiment of the present application. In order to realize the various functions in the method provided in the embodiment of the present application, the communication device (which may be referred to as a communication device) using the Huygens equivalent surface provided in the embodiment of the present application may include a hardware structure and / or a software module, and realize the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution. For example, the communication device provided in the present application may include a transmitting end and a receiving end shown in Figure 5.

[0237] As shown in Figure 14, based on the same technical concept, an embodiment of the present application also provides a communication device 1400. The communication device 1400 can be a communication device that uses the Huygens equivalent surface, or a component in a communication device that uses the Huygens equivalent surface, or a device that can be used in conjunction with a communication device that uses the Huygens equivalent surface. The communication device that uses the Huygens equivalent surface can be a terminal device or a network device. In one design, the communication device 1400 can include a module that corresponds to the method / operation / step / action involved in the above-mentioned method embodiment. The module can be a hardware circuit, software, or a combination of hardware circuit and software. In one design, the communication device 1400 can include a sending unit 1401 and a receiving unit 1402. The sending unit 1401 and the receiving unit 1402 can serve as transceiver units. Optionally, the communication device 1400 can also include a processing unit for performing the processing actions involved in the above-mentioned method embodiment. Optionally, the processing unit can be connected to at least one of the sending unit 1401 and the receiving unit 1402. For example, the processing unit can be used to perform at least one of the following actions: determining the second Huygens equivalent surface, or performing antenna configuration actions related to the above-mentioned method embodiments, or generating information, data, messages or signals sent by the sending unit 1401, or processing the information, data, messages or signals received by the receiving unit 1402.

[0238] Exemplarily, when the apparatus is used to execute the method performed by the receiving end described in each of the above embodiments, the apparatus may include a sending unit 1401 and a receiving unit 1402. The receiving unit 1402 may be configured to receive a first received signal based on the first Huygens equivalent surface, or the receiving unit 1402 may be configured to execute S101. The sending unit 1401 may be configured to send first indication information, or the sending unit 1401 may be configured to execute S102. For the first received signal and the first indication information, please refer to the description of the method embodiment section of this application.

[0239] In addition, optionally, the receiving unit 1402 may be configured to receive second indication information.

[0240] Optionally, the apparatus may further include a processing unit configured to obtain a second Huygens equivalent surface. For example, the processing unit may be configured to obtain the second Huygens equivalent surface based on a first compressibility corresponding to the first Huygens equivalent surface. The first compressibility can be found in the description of the embodiment of the method of this application.

[0241] Optionally, the receiving unit 1402 may also be used to receive the second information, or the sending unit 1401 may also be used to send the third information. The second information and the third information may be described in the method embodiment of the present application.

[0242] Exemplarily, when the apparatus is used to perform the method described in the second aspect, the apparatus may include a receiving unit 1402 and a sending unit 1401. The sending unit 1401 may be configured to send a first received signal. The receiving unit 1402 may be configured to receive first indication information. For details about the first received signal and the first indication information, see the description in the method embodiment section of this application.

[0243] In addition, optionally, the sending unit 1401 can be used to send second indication information.

[0244] Optionally, the sending unit 1401 may also be used to send the second information, or the receiving unit 1402 may also be used to receive the third information. The second information and the third information may be described in the method embodiment of this application.

[0245] It is understood that when implementing the process shown in Figure 13, if the communication device 1400 serves as a transmitting end, the transmitting unit 1401 may be used to perform the transmitting actions shown in S201 and S203, the receiving unit 1402 may be used to receive the feedback information W1 in S202 and the feedback information W2 in S204, and the processing unit may be used to perform S205. When implementing the process shown in Figure 13, if the communication device 1400 serves as a receiving end, the transmitting unit 1401 may be used to perform the transmitting actions shown in S202 and S204, and the receiving unit 1402 may be used to receive the detection signals in S201 and S203.

[0246] The division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0247] As shown in Figure 15, a communication device 1500 provided in an embodiment of the present application is used to implement the communication method using the Huygens equivalent surface provided in the present application. The communication device 1500 can be a communication device using the Huygens equivalent surface, or a component in a communication device using the Huygens equivalent surface, or a device that can be used in conjunction with a communication device using the Huygens equivalent surface. The communication device using the Huygens equivalent surface can be a terminal device or a network device. The communication device 1500 can be a chip system or a chip. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. The communication device 1500 includes at least one processor 1520 for implementing the communication using the Huygens equivalent surface provided in the embodiment of the present application. The communication device 1500 can also include an output interface 1510, which can also be referred to as an input / output interface. In the embodiment of the present application, the output interface 1510 can be used to communicate with other devices via a transmission medium, and its functions may include sending and / or receiving. For example, when the communication device 1500 is a chip, transmission with other chips or devices is performed via the output interface 1510. The processor 1520 may be configured to implement the method described in the above method embodiment.

[0248] Exemplarily, when the device is used to execute the method performed by the receiving end described in each of the above embodiments, the device may include an output interface 1510 and a processor 1520. The output interface 1510 may be used to receive a first received signal according to the first Huygens equivalent surface, or the receiving unit 1402 may be used to execute S101. The output interface 1510 may also be used to send first indication information, or the output interface 1510 may also be used to execute S102. The first received signal and the first indication information may be referred to in the description of the method embodiment of this application.

[0249] In addition, optionally, the output interface 1510 can be used to receive second indication information.

[0250] Optionally, the processor 1520 may be configured to obtain a second Huygens equivalent surface according to a first compression ratio corresponding to the first Huygens equivalent surface. The first compression ratio may be described in the method embodiment of this application.

[0251] Optionally, the output interface 1510 may also be used to receive second information, or the output interface 1510 may also be used to send third information. The second information and the third information may be described in the method embodiment of the present application.

[0252] Exemplarily, when the apparatus is used to perform the method described in the second aspect, the apparatus may include an output interface 1510 and a processor 1520. The output interface 1510 may be used to send a first received signal and to receive first indication information. For details about the first received signal and the first indication information, see the description in the method embodiment section of this application.

[0253] In addition, optionally, the output interface 1510 can also be used to send second indication information.

[0254] Optionally, the output interface 1510 may also be used to send the second information, or the output interface 1510 may also be used to receive the third information. The second information and the third information may be described in the method embodiment of the present application.

[0255] Optionally, the communication device 1500 may further include at least one memory 1530 for storing program instructions and / or data. The memory 1530 is coupled to the processor 1520. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 1520 may operate in conjunction with the memory 1530. The processor 1520 may execute program instructions stored in the memory 1530. At least one of the at least one memory may be integrated with the processor.

[0256] In an embodiment of the present application, the memory 1530 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or a volatile memory (volatile memory), such as a random-access memory (RAM). A memory is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application may also be a circuit or any other device that can implement a storage function, for storing program instructions and / or data.

[0257] In the embodiments of the present application, the processor 1520 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present application may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0258] As shown in Figure 16, a communication device 1600 provided in an embodiment of the present application is used to implement the communication method using the Huygens equivalent surface provided in the present application. The communication device 1600 can be a communication device using the Huygens equivalent surface, or a component in a communication device using the Huygens equivalent surface, or a device that can be used in combination with a communication device using the Huygens equivalent surface. The communication device using the Huygens equivalent surface can be a terminal device or a network device. Among them, the data transmission device 1600 can be a chip system or a chip. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. Part or all of the communication method using the Huygens equivalent surface provided in the above embodiment can be implemented by hardware or by software. When implemented by hardware, the data transmission device 1600 may include: an input interface circuit 1601, a logic circuit 1602 and an output interface circuit 1603. Optionally, taking the example of the device being used to implement the function of a receiver, the input interface circuit 1601 may be used to receive a first received signal based on the first Huygens equivalent surface, the logic circuit 1602 may be used to execute the processing action of the receiver, and the output interface circuit 1603 may be used to send the first indication information. For another example, taking the example of the device being used to implement the function of a transmitter, the logic circuit 1602 may be used to execute the processing action of the transmitter, the output interface circuit 1603 may be used to send the first received signal, and the input interface circuit 1601 may be used to receive the first indication information.

[0259] Optionally, the data transmission device 1600 may be a chip or an integrated circuit in a specific implementation.

[0260] Part or all of the operations and functions performed by the data transmission device described in the above method embodiments of the present application can be completed using a chip or an integrated circuit.

[0261] An embodiment of the present application provides a computer-readable storage medium storing a computer program, wherein the computer program includes instructions for executing the above method embodiment.

[0262] An embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the above method embodiment.

[0263] The present application provides a communication system. Specifically, the communication system may include a receiving end and a transmitting end for implementing the method shown in FIG11. For details, please refer to the relevant descriptions in the above method embodiments, which will not be repeated here. The communication system may include the structure shown in FIG1 or FIG5.

[0264] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0265] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one flow chart flow or multiple flows and / or one box or multiple boxes of the block diagram.

[0266] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0267] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0268] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0269] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the embodiments and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

Claims

1. A communication method using a Huygens equivalent surface, characterized in that: include: receiving a first received signal according to a first Huygens equivalent surface; First indication information is sent, where the first indication information includes indication information of at least one Huygens equivalent surface, where the indication information of the at least one Huygens equivalent surface is determined according to a second Huygens equivalent surface, where the second Huygens equivalent surface corresponds to the first received signal.

2. The method according to claim 1, wherein The second Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a closed surface in three-dimensional space where the receiving antenna is located. The method further includes: Second indication information is received, where the second indication information is used to indicate that the first Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a closed surface in a three-dimensional space where a receiving antenna is located.

3. The method according to claim 1 or 2, wherein: The indication information of any of the Huygens equivalent surfaces includes the index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: the normalized correlation coefficient, the compression rate and the spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface.

4. The method according to claim 3, wherein The larger the absolute value of the normalized cross-correlation coefficient is, the higher the transmission priority of the indication information of the Huygens equivalent surface is.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: The second Huygens equivalent surface is obtained according to a first compression ratio corresponding to the first Huygens equivalent surface, the first compression ratio is related to the size of the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1.

6. The method according to any one of claims 1 to 5, wherein: The first received signal is a received signal received in an n-th transmission period in a coherence time, the coherence time includes N transmission periods, 1≤n≤N, and n is an integer.

7. The method according to claim 6, wherein The method further comprises: receiving second information, where the second information is used to indicate N and / or the time interval between the N transmission cycles; or, Sending third information, where the second information is used to indicate N and / or the time interval between the N transmission cycles.

8. The method according to claim 6 or 7, wherein: The first indication information includes a parameter change amount of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time.

9. The method according to any one of claims 1 to 8, wherein: The first received signal includes a first reference signal, which is a default reference signal when the reconfigurable smart surface RIS is turned on; or The first received signal includes a second reference signal, where the second reference signal is a default reference signal in a RIS off state.

10. A communication method using a Huygens equivalent surface, characterized in that: include: sending a first received signal; First indication information is received, where the first indication information includes indication information of at least one Huygens equivalent surface, where the indication information of the at least one Huygens equivalent surface is determined according to a second Huygens equivalent surface, where the second Huygens equivalent surface corresponds to the first received signal.

11. The method according to claim 10, wherein The second Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a closed surface in three-dimensional space where the receiving antenna is located. The method further includes: Second indication information is sent, where the second indication information is used to indicate that the first Huygens equivalent surface is the electric field vector and / or the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located.

12. The method according to claim 10 or 11, wherein: The indication information of any of the Huygens equivalent surfaces includes the index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: the normalized correlation coefficient, the compression rate and the spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface.

13. The method according to claim 12, wherein: The larger the absolute value of the normalized cross-correlation coefficient is, the higher the transmission priority of the indication information of the Huygens equivalent surface is.

14. The method according to any one of claims 10 to 13, wherein: The second Huygens equivalent surface is obtained according to a first compression ratio, the first compression ratio is related to the size of the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1.

15. The method according to any one of claims 10 to 14, wherein: The first received signal is a received signal received in an n-th transmission period in a coherence time, the coherence time includes N transmission periods, 1≤n≤N, and n is an integer.

16. The method according to claim 15, wherein The method further comprises: sending second information, where the second information is used to indicate N and / or the time interval between the N transmission cycles; or, Third information is received, where the second information is used to indicate N and / or a time interval between the N transmission cycles.

17. The method according to claim 15 or 16, wherein: The first indication information includes a parameter change amount of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time.

18. The method according to any one of claims 10 to 17, wherein: The first received signal includes a first reference signal, which is a default reference signal when the reconfigurable smart surface RIS is turned on; or The first received signal includes a second reference signal, where the second reference signal is a default reference signal in a RIS off state.

19. A communication device using a Huygens equivalent surface, characterized in that: include: a receiving unit, configured to receive a first received signal according to a first Huygens equivalent surface; A sending unit is used to send first indication information, where the first indication information includes indication information of at least one Huygens equivalent surface, where the indication information of the at least one Huygens equivalent surface is determined according to a second Huygens equivalent surface, where the second Huygens equivalent surface corresponds to the first received signal.

20. The device according to claim 19, wherein The second Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a three-dimensional closed surface where the receiving antenna is located, and the receiving unit is further configured to: Second indication information is received, where the second indication information is used to indicate that the first Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a closed surface in a three-dimensional space where a receiving antenna is located.

21. The device according to claim 19 or 20, characterized in that The indication information of any of the Huygens equivalent surfaces includes the index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: the normalized correlation coefficient, the compression rate and the spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface.

22. The device according to claim 21, wherein The larger the absolute value of the normalized cross-correlation coefficient is, the higher the transmission priority of the indication information of the Huygens equivalent surface is.

23. The device according to any one of claims 19 to 22, characterized in that The device further comprises: A processing unit is configured to obtain the second Huygens equivalent surface based on a first compression ratio corresponding to the first Huygens equivalent surface, wherein the first compression ratio is related to the size of the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1.

24. The device according to any one of claims 19 to 23, characterized in that The first received signal is a received signal received in an n-th transmission period in a coherence time, the coherence time includes N transmission periods, 1≤n≤N, and n is an integer.

25. The device according to claim 24, wherein The receiving unit is further configured to: receiving second information, where the second information is used to indicate N and / or a time interval between the N transmission cycles; Alternatively, the sending unit is further configured to: Sending third information, where the second information is used to indicate N and / or the time interval between the N transmission cycles.

26. The device according to claim 24 or 25, characterized in that The first indication information includes a parameter change amount of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time.

27. The device according to any one of claims 19 to 26, characterized in that The first received signal includes a first reference signal, which is a default reference signal when the reconfigurable smart surface RIS is turned on; or The first received signal includes a second reference signal, where the second reference signal is a default reference signal in a RIS off state.

28. A communication device using a Huygens equivalent surface, characterized in that: include: a sending unit, configured to send a first received signal; A receiving unit is configured to receive first indication information, where the first indication information includes indication information of at least one Huygens equivalent surface, where the indication information of the at least one Huygens equivalent surface is determined based on a second Huygens equivalent surface, where the second Huygens equivalent surface corresponds to the first received signal.

29. The device according to claim 28, wherein The second Huygens equivalent surface is an electric field vector and / or a magnetic field vector of a closed surface in a three-dimensional space where the receiving antenna is located, and the sending unit is further configured to: Second indication information is sent, where the second indication information is used to indicate that the first Huygens equivalent surface is the electric field vector and / or the magnetic field vector of the three-dimensional closed surface where the receiving antenna is located.

30. The device according to claim 28 or 29, characterized in that The indication information of any of the Huygens equivalent surfaces includes the index of the Huygens equivalent surface and at least one of the following parameters corresponding to the index: the normalized correlation coefficient, the compression rate and the spatial angular range between the Huygens equivalent surface and the second Huygens equivalent surface.

31. The device according to claim 30, wherein The larger the absolute value of the normalized cross-correlation coefficient is, the higher the transmission priority of the indication information of the Huygens equivalent surface is.

32. The device according to any one of claims 28 to 31, characterized in that The second Huygens equivalent surface is obtained according to a first compression ratio, the first compression ratio is related to the size of the spatial angular granularity of the second Huygens equivalent surface, and the first compression ratio is greater than 0 and less than or equal to 1.

33. The device according to any one of claims 28 to 32, characterized in that The first received signal is a received signal received in an n-th transmission period in a coherence time, the coherence time includes N transmission periods, 1≤n≤N, and n is an integer.

34. The device according to claim 33, wherein The sending unit is further configured to: Sending second information, where the second information is used to indicate N and / or the time interval between the N transmission cycles; Alternatively, the receiving unit is further configured to: Third information is received, where the second information is used to indicate N and / or a time interval between the N transmission cycles.

35. The device according to claim 33 or 34, characterized in that The first indication information includes a parameter change amount of the indication information of the at least one Huygens equivalent surface relative to the feedback information sent last time.

36. The device according to any one of claims 28 to 35, characterized in that The first received signal includes a first reference signal, which is a default reference signal when the reconfigurable smart surface RIS is turned on; or The first received signal includes a second reference signal, where the second reference signal is a default reference signal in a RIS off state.

37. A communication device, characterized in that: include: processor and memory; The memory is used to store one or more computer programs, and the one or more computer programs include computer-executable instructions. When the communication device is running, the processor executes the one or more computer programs stored in the memory to cause the communication device to perform the method according to any one of claims 1 to 9, or causes the communication device to perform the method according to any one of claims 10 to 18.

38. A chip system, characterized in that: The chip system includes a logic circuit and an input / output interface, wherein: The input and output interface is used to communicate with other communication devices outside the chip system, and the logic circuit is used to execute the method according to any one of claims 1 to 9; Alternatively, the input and output interface is used to communicate with other communication devices outside the chip system, and the logic circuit is used to execute the method as described in any one of claims 10-18.

39. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store a computer program, which, when executed on a computer, enables the computer to execute the method according to any one of claims 1 to 9, or enables the computer to execute the method according to any one of claims 10 to 18.

40. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is run on a computer, causes the computer to perform the method according to any one of claims 1 to 9, or causes the computer to perform the method according to any one of claims 10 to 18.

41. A communication system, characterized in that The method comprises a receiving end and a transmitting end, wherein the receiving end is used to execute the method according to any one of claims 1 to 9, and the transmitting end is used to execute the method according to any one of claims 10 to 18.

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