Method and system for wireless communication channel estimation based on holographic multiple-input multiple-output

Abstract

The application provides a wireless communication channel estimation method and system based on holographic multiple-input and multiple-output, comprising: equipping a uniform planar array for a holographic multiple-input and multiple-output channel, and sending a pilot signal by a user equipment for uplink channel estimation; predefining an antenna element index of the uniform planar array, and establishing a coordinate system with the center of the uniform planar array as the origin; constructing an angle covariance matrix, so that the original channel including three-dimensional angle and distance information is converted into the current covariance matrix only having angle information; constructing a distance covariance matrix based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is converted into the covariance matrix containing distance information; and based on the constructed angle covariance matrix and distance covariance matrix, informing the user equipment by a transmission and reception point that the two matrix estimation tasks are completed, so that the construction of the wireless communication channel is realized. The application solves the problem of high cost of antenna control technology in the next generation of wireless communication.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a wireless communication channel estimation method and system based on holographic multiple input / output. Background Technology

[0002] To realize ubiquitous intelligent information networks, the upcoming sixth-generation (6G) wireless communication systems place stringent demands on antenna technology, such as precise beam control and enhanced capacity. While these goals can be achieved through large-scale phased arrays, i.e., massively multi-input multi-output (MIMO), the inherent limitations of phased arrays will more or less hinder the evolution of antenna technology in new directions. Specifically, phased arrays rely heavily on power amplifiers and phase shifters, especially at high frequencies, where these phase shifters are extremely expensive. Therefore, more cost-effective antenna technologies are needed to meet the exponentially growing data demands of future wireless communications.

[0003] To overcome the shortcomings of existing antenna technologies, holographic antennas, as small-sized, low-cost planar antennas, have attracted increasing attention due to their low-power, multi-beam steering capabilities. Holographic antennas utilize numerous patches attached to the surface of a panel to construct holographic patterns, thereby recording the interference information between the incident electromagnetic wave (also known as the reference wave) generated by the holographic antenna and the target wave. As the reference wave propagates across the antenna surface, its radiation characteristics can be altered through the holographic pattern, thus generating the desired radiation pattern. Thanks to the programmability of metamaterials, printed circuit board (PCB) technology can be integrated into the construction of holographic antennas, making holographic MIMO an ultra-thin and lightweight surface antenna. How to control the radiation amplitude of the reference wave to generate the desired beam according to the holographic pattern is a problem that needs to be solved. Summary of the Invention

[0004] This invention provides a wireless communication channel estimation method and system based on holographic multi-input output, which aims to solve the problem of high cost of antenna control technology in next-generation wireless communication.

[0005] This invention provides a wireless communication channel estimation method based on holographic multiple input / output, comprising:

[0006] A uniform planar array is provided for the holographic multiple-input multiple-output channel, and the user equipment transmits pilot signals to perform uplink channel estimation.

[0007] Predefine the antenna element indexes for the uniform planar array, and establish a coordinate system with the center of the uniform planar array as the origin;

[0008] Construct an angle covariance matrix to transform the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0009] Based on the estimated angle information, a distance covariance matrix is ​​constructed, which transforms the original channel containing three-dimensional angle and distance information into a covariance matrix containing distance information.

[0010] Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving points inform the user equipment that the two matrix estimation tasks have been completed, thus realizing the construction of the wireless communication channel.

[0011] According to the present invention, a wireless communication channel estimation method based on holographic multiple input / output is provided, wherein the predefined antenna element index of the uniform planar array is used to establish a coordinate system with the center of the uniform planar array as the origin, specifically including:

[0012] Using the center of the uniform planar array as the origin, determine the elements along the y-axis and along the z-axis;

[0013] Define the pilot sequence length, determine the uplink signal received at the base station, merge the received pilot sequences, and determine the spherical wave-based channel.

[0014] According to the present invention, a wireless communication channel estimation method based on holographic multi-input multi-output is provided, wherein the construction of an angle covariance matrix, which transforms the original channel including three-dimensional angle and distance information into a current covariance matrix containing only angle information, specifically includes:

[0015] Angle estimation is performed, and the covariance matrices of azimuth and elevation angles are constructed respectively;

[0016] When constructing the angular covariance matrix, the element indices corresponding to the original channel and the element indices corresponding to the conjugate channel are symmetrical about the center of the uniform planar array;

[0017] The angle parameters are obtained by channel estimation using the least squares method, and the angle covariance matrix is ​​constructed.

[0018] According to the present invention, a wireless communication channel estimation method based on holographic multi-input multi-output is provided. A range covariance matrix is ​​constructed based on the estimated angle information, transforming the original channel, which includes three-dimensional angle and range information, into a covariance matrix containing range information. Specifically, the method includes:

[0019] The distance covariance matrix can be constructed by obtaining two angle estimates of the angle covariance matrix.

[0020] According to the present invention, a wireless communication channel estimation method based on holographic multi-input multi-output is provided. When constructing the distance-related covariance matrix, the antenna element indices of the original channel and the conjugate channel are symmetrical about the z-axis. The user equipment sends a pilot signal to the transmission and reception point. The pilot signal undergoes spatial filtering to calculate the distance, thus completing the construction of the distance covariance matrix.

[0021] According to the present invention, a wireless communication channel estimation method based on holographic multi-input multi-output is provided. The method involves the transmitting and receiving points informing the user equipment that the two-matrix estimation task has been completed based on the obtained constructed angle covariance matrix and distance covariance matrix, thereby realizing the construction of the wireless communication channel. Specifically, this includes:

[0022] Obtain the angle covariance matrix and the distance covariance matrix;

[0023] The transmitting and receiving point sends a message to the user equipment indicating that the two-matrix estimation task is complete, thus completing the construction of the wireless communication channel;

[0024] The wireless communication channel is applicable to both near-field communication based on spherical wave representation and far-field communication based on plane wave representation.

[0025] The present invention also provides a wireless communication channel estimation system based on holographic multiple input / output, comprising:

[0026] The initialization module is used to equip the holographic multiple-input multiple-output channel with a uniform planar array, and the user equipment sends pilot signals to perform uplink channel estimation.

[0027] The holographic antenna element index predefined module is used to predefine the antenna element index of a uniform planar array, and establish a coordinate system with the center of the uniform planar array as the origin.

[0028] The angle parameter calculation module is used to construct the angle covariance matrix, transforming the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0029] The distance parameter calculation module is used to construct a distance covariance matrix based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is transformed into a covariance matrix containing distance information.

[0030] The estimation result feedback module is used to inform the user equipment that the estimation task of the two matrices has been completed based on the obtained angle covariance matrix and distance covariance matrix, thereby realizing the construction of the wireless communication channel.

[0031] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the wireless communication channel estimation method based on holographic multiple input / output as described above.

[0032] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the wireless communication channel estimation method based on holographic multiple input / output as described above.

[0033] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the wireless communication channel estimation method based on holographic multiple input / output as described above.

[0034] This invention provides a wireless communication channel estimation method and system based on holographic multi-input output. By predefining the antenna element index of the uniform planar array at the holographic multi-input output, and constructing the covariance matrix of each type of parameter based on the predefined antenna element index, the angle and distance parameters are decoupled, demonstrating a two-stage channel estimation process for angle and distance estimation. Based on the predefined antenna element index, the angle and distance parameters are obtained respectively. It is perfectly adapted to the traditional far-field communication scenario based on plane wave representation, reducing costs. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is one of the flowcharts of the wireless communication channel estimation method based on holographic multiple input / output provided by the present invention;

[0037] Figure 2 This is the second flowchart of the wireless communication channel estimation method based on holographic multiple input / output provided by the present invention;

[0038] Figure 3 This is the third flowchart of the wireless communication channel estimation method based on holographic multiple input / output provided by the present invention;

[0039] Figure 4 This is the fourth flowchart of the wireless communication channel estimation method based on holographic multiple input / output provided by the present invention;

[0040] Figure 5This is a schematic diagram of the module connections of the wireless communication channel estimation system based on holographic multiple input / output provided by the present invention;

[0041] Figure 6 This is a schematic diagram of a holographic uniform planar array provided by the present invention;

[0042] Figure 7 This is a schematic diagram of the physical implementation of constructing the angular covariance matrix provided by the present invention.

[0043] Figure 8 This is a schematic diagram of the channel process traversed by the pilot signal transmitted from the user equipment in constructing the angular covariance matrix, as provided by the present invention.

[0044] Figure 9 This is a schematic diagram of the physical implementation of constructing the distance covariance matrix provided by the present invention;

[0045] Figure 10 This is a schematic diagram of the channel process traversed by the pilot signal transmitted from the user equipment in constructing the distance covariance matrix, as provided by the present invention.

[0046] Figure 11 This invention provides the signaling exchange process between the UE and TRP during the two-stage channel estimation process.

[0047] Figure 12 This is a schematic diagram of a spherical wave channel in holographic MIMO communication provided by the present invention, in which two scatterers correspond to two salient paths;

[0048] Figure 13 This is a schematic diagram illustrating the variation of the normalized minimum mean square error (NMSE) curve with signal-to-noise ratio (SNR) provided by the present invention.

[0049] Figure 14 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0050] Figure label:

[0051] 110: Initialization module; 120: Holographic antenna element index predefined module; 130: Angle parameter calculation module; 140: Distance parameter calculation module; 150: Estimation result feedback module;

[0052] 1410: Processor; 1420: Communication interface; 1430: Memory; 1440: Communication bus. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0054] The following is combined Figures 1-4 The present invention describes a wireless communication channel estimation method based on holographic multiple input / output, comprising:

[0055] S100: Equipped with a uniform planar array for the holographic multiple-input multiple-output channel, the user equipment sends pilot signals to perform uplink channel estimation;

[0056] S200, Predefined antenna element indexes for a uniform planar array, establishing a coordinate system with the center of the uniform planar array as the origin;

[0057] S300. Construct an angle covariance matrix to transform the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0058] S400. Construct a distance covariance matrix based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is transformed into a covariance matrix containing distance information.

[0059] S500: Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving point informs the user equipment that the two matrix estimation task has been completed, thus realizing the construction of the wireless communication channel.

[0060] In this invention, by controlling the electromagnetic response of metamaterials, holographic patterns and corresponding desired beam directions can be easily reconfigured. Specifically, the radiation amplitude of a reference wave can be controlled by controlling the propagation of electromagnetic waves on a surface composed of numerous patch elements to generate the desired beam according to the holographic pattern. Therefore, holographic beamforming can be achieved through multiple inputs and outputs of holography without the need for complex phase-shifting circuits.

[0061] The antenna element indices of the predefined uniform planar array are used to establish a coordinate system with the center of the uniform planar array as the origin. Specifically, this includes:

[0062] S201. Using the center of the uniform planar array as the origin, determine the elements along the y-axis and along the z-axis;

[0063] S202. Define the pilot sequence length, determine the uplink signal received at the base station, merge the received pilot sequences, and determine the channel based on spherical waves.

[0064] In this invention, we consider an uplink TDD holographic MIMO communication system, where the holographic metasurface has N = N y ×N z Each element is essentially a uniform planar array (UPA). The number of elements along the y-axis and z-axis is N, with the center of the UPA as the origin. y and N z As shown in the attached image Figure 6 As shown. For simplicity, consider N separately. y and N z Since it is an odd number, therefore, the (n)th y ,n z The center position of each element can be written as in as well as The physical dimensions of UPA along the y and z axes are approximately N. y v and N z δ, where δ is the antenna spacing.

[0065] Define P as the length of the pilot sequence, x p For the transmission pilot sequence, and assuming x p If x = 1, p = 1, ..., P, then the pilot frequency is x = [x1, ..., x2]. P Therefore, the uplink signal received at the base station (BS) For y p =F p D p hx p +F p n p p = 1, ..., P

[0066] in: Here is the receiving beam matrix at BS. The beam pattern of holographic MIMO. For the channel to be estimated, It is complex Gaussian noise and follows a distribution. Combined received pilot sequences That is, the above formula can be expressed as

[0067] y = FDh + n

[0068] For the noise matrix, F represents the merged receive beam matrix, and all elements in F are independent of each other. Next, the spherical wave-based channel can be represented as...

[0069]

[0070] Where βl r is the complex gain corresponding to the l-th path. l This indicates the distance between the center of the antenna array at the BS and the user equipment (UE) or the scattering surface. This indicates the path on the (n)th path. y ,n z The distance between each element and the user equipment (UE) or the l-th scatterer is obtained by expanding the array response function.

[0071]

[0072] in Let represent the distance from the UE or scatterer to the center of the antenna array along the l-th path, and k represent the beamwidth. take out The nth element in: definition This indicates that, relative to the reference antenna (center point), the waveform reaches the (n)th... y ,n z The additional distance traveled by each element. Since N = N y N z Give the values ​​from n to (n y ,n z Mapping of ) And there are

[0073]

[0074] in in Indicates the (n)th y ,n z The direction vectors of each element to the reference antenna (center point). Based on the Fresnel approximation, It can be approximated as

[0075]

[0076] Due to the characteristics of spherical waves, compressed sensing (CS) cannot be directly applied to the received signal y. Specifically, the sparse basis used to represent the sparse signal requires a basis for the distance vector r and the angle vector r. Meshization can be performed, but this is computationally more complex than meshing only the angles. To address this, we can leverage the spatial correlation in the channel matrix h, decomposing the 3D compressed sensing problem into a smaller, more easily solved 1D compressed sensing problem, thus decoupling the distance and angle vectors.

[0077] Constructing an angle covariance matrix transforms the original channel, which included three-dimensional angle and distance information, into a covariance matrix containing only angle information. Specifically, this includes:

[0078] S301. Perform angle estimation and construct the covariance matrices of azimuth and elevation angles respectively.

[0079] S302. When constructing the angular covariance matrix, the element indices corresponding to the original channel and the element indices corresponding to the conjugate channel are symmetrical about the center of the uniform planar array.

[0080] S303. Obtain the angle parameters by estimating the channel using the least squares method, and complete the construction of the angle covariance matrix.

[0081] In this invention, the core idea of ​​decomposition during the construction of the angle covariance matrix is ​​to construct the covariance matrix of each dimension of the parameter, such that the covariance matrix is ​​only related to the parameter to be estimated. Considering the Fresnel approximation, It can be written as the difference of two terms: one term depends on both angle and distance, and the other term depends only on angle, that is:

[0082]

[0083] It can be decomposed using necessary mathematical techniques, and only the angle-related phases can be retained when estimating the angle. Since the holographic MIMO metasurface under consideration is a two-dimensional UPA, both azimuth angle θ and pitch angle exist simultaneously. First, construct the covariance matrices related to these two angles. By assuming that the loudness is independent between any two paths, the first [path] in this matrix... element for

[0084]

[0085] in and It can be seen that the above formula only includes angle information, therefore, the original channel including three-dimensional angle-distance information can be obtained. Transformed into the current covariance matrix containing only angle information

[0086]

[0087] For detailed implementation process, please refer to the attached diagram. Figure 7 Its physical meaning is the original channel. Corresponding component index and conjugate channel The corresponding component indexes are symmetrical about the center of the UPA. The transmitted signal x at the UE. p The channel process is shown in the attached diagram. Figure 8 As shown. Based on this, the azimuth angle θ and the elevation angle This can be achieved using traditional channel estimation techniques, such as the least squares (LS) method.

[0088] Based on the estimated angle information, a distance covariance matrix is ​​constructed, transforming the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing distance information. Specifically, this includes:

[0089] The distance covariance matrix can be constructed by obtaining two angle estimates of the angle covariance matrix.

[0090] When constructing the distance-related covariance matrix, the antenna element indices of the original channel and the conjugate channel are symmetric about the z-axis. The user equipment sends pilot signals to the transmission and reception points. The pilot signals undergo spatial filtering to calculate the distance, thus completing the construction of the distance covariance matrix.

[0091] In this invention, the operation of constructing the angle covariance matrix retains terms that are only related to the angle. This stage requires retaining distance-related items. Therefore, when constructing the distance covariance matrix, different element indices need to be selected for the conjugate channels. The indices of the conjugate channels required to construct the covariance matrix can be denoted as (n′). y ,n′ z )=(n y ,n z For each transmission pilot x p The following equation holds true:

[0092]

[0093] When the antenna element spacing is λ / 4, the above equation can be further simplified to:

[0094]

[0095] As can be seen from the above formula, estimates of two angles are needed in stage one. and This allows us to construct the distance covariance matrix V(r).

[0096] For detailed implementation process, please refer to the attached diagram. Figure 9 From a physical perspective, when constructing the distance-related covariance matrix, the antenna element indices of the original channel and the conjugate channel are symmetric about the z-axis. The transmitted signal x at the UE... p The channel process is shown in the attached diagram. Figure 10 As shown.

[0097] Figure 10The channel estimation process is a two-stage process. First, the antenna index is predefined at the TRP. In the first stage, the UE sends a pilot signal x to the TRP. p p = 1, ..., P, the pilot signal undergoes spatial filtering to make Next, calculate the angle. In obtaining Afterwards, the TRP notifies the UE that the first phase estimation is complete. In the second phase, the UE sends a pilot signal to the TRP, which undergoes spatial filtering to... Next, the distance r is calculated, and then... Afterwards, TRP notified that the entire estimation phase was complete.

[0098] Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving points inform the user equipment that the two-matrix estimation task has been completed, thus realizing the construction of the wireless communication channel, specifically including:

[0099] S401. Obtain the angle covariance matrix and the distance covariance matrix;

[0100] S402, The transmitting and receiving point sends information about the completion of the two-matrix estimation task to the user equipment, thus completing the construction of the wireless communication channel;

[0101] S403. The wireless communication channel is applicable to the near-field communication range based on spherical wave representation, and also to the far-field communication range based on plane wave representation.

[0102] refer to Figure 11 and Figure 12 In one specific embodiment, corresponding simulation results are provided to illustrate the effectiveness of the channel estimation framework. This patent considers a near-field channel model for spherical waves, where the transmit-receive point (TRP) is equipped with a uniform planar array (UPA) with N = 16 × 16 antenna elements and N feed sources. RF =4×4, the number of pilots is P=N / N RF =16. The distance between TRP and UE follows a uniform distribution, i.e. Assume there are two scatterers in the physical propagation environment, corresponding to two significant propagation paths, with preset elevation angles θ1 = 0.15π and θ2 = 0.25π for each path. The purpose of this simulation is to distinguish the truly significant angles in the propagation environment by mitigating energy diffusion effects.

[0103] In the appendix Figure 13 In this invention, the least squares (LS) method is used to consider the performance of normalized minimum square error (NMSE) under different settings, i.e.

[0104]

[0105] In the figure, "Angle and distance coupling scheme - configuration I" represents the number N of radio frequency (RF) chains without using the channel estimation framework proposed in this patent. RF = N / 2; "Angle and distance coupling scheme - configuration I" refers to the number N of radio frequency (RF) chains without using the channel estimation framework proposed in this patent. RF = N / 4. As can be clearly seen in the attached figure, under the near-field radiation conditions of holographic MIMO, the channel scheme proposed in this invention can achieve superior NMSE performance. With the increase of SNR, the NMSE performance improves significantly. For the angle-range coupling scheme, the increase of SNR does not lead to an improvement in NMSE performance, mainly due to the energy scattering effect caused by the non-ideal angle-range coupling effect.

[0106] refer to Figure 5 The present invention also discloses a wireless communication channel estimation system based on holographic multiple input / output, comprising:

[0107] Initialization module 110 is used to equip a uniform planar array for the holographic multiple input multiple output channel, and the user equipment sends pilot signals to perform uplink channel estimation.

[0108] The holographic antenna element index predefined module 120 is used to predefine the antenna element index of the uniform planar array and establish a coordinate system with the center of the uniform planar array as the origin.

[0109] Angle parameter calculation module 130 is used to construct the angle covariance matrix, transforming the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0110] The distance parameter calculation module 140 is used to construct a distance covariance matrix from the estimated angle information, so that the original channel including three-dimensional angle and distance information is transformed into a covariance matrix containing distance information.

[0111] The estimation result feedback module 150 is used to inform the user equipment that the two matrix estimation tasks have been completed based on the obtained angle covariance matrix and distance covariance matrix, thereby realizing the construction of the wireless communication channel.

[0112] Among them, the holographic antenna element index predefined module 120 determines the elements along the y-axis and along the z-axis with the center of the uniform planar array as the origin;

[0113] Define the pilot sequence length, determine the uplink signal received at the base station, merge the received pilot sequences, and determine the spherical wave-based channel.

[0114] The angle parameter calculation module 130 performs angle estimation and constructs the covariance matrices of the azimuth and elevation angles respectively.

[0115] When constructing the angular covariance matrix, the element indices corresponding to the original channel and the element indices corresponding to the conjugate channel are symmetrical about the center of the uniform planar array;

[0116] The angle parameters are obtained by channel estimation using the least squares method, and the angle covariance matrix is ​​constructed.

[0117] The distance parameter calculation module 140 can complete the construction of the distance covariance matrix by obtaining two angle estimates of the angle covariance matrix. When constructing the distance-related covariance matrix, the antenna element indices of the original channel and the conjugate channel are symmetrical about the z-axis. The user equipment sends pilot signals to the transmission and reception points. The pilot signals undergo spatial filtering to calculate the distance and complete the construction of the distance covariance matrix.

[0118] The estimation result feedback module 150 obtains the angle covariance matrix and the distance covariance matrix;

[0119] The transmitting and receiving point sends a message to the user equipment indicating that the two-matrix estimation task is complete, thus completing the construction of the wireless communication channel;

[0120] The wireless communication channel is applicable to both near-field communication based on spherical wave representation and far-field communication based on plane wave representation.

[0121] The present invention provides a wireless communication channel estimation system based on holographic multi-input output. By predefining the antenna element index of the uniform planar array at the holographic multi-input output, the system decouples the angle and range parameters by constructing the covariance matrix of each type of parameter based on the predefined antenna element index, demonstrating a two-stage channel estimation process for angle and range estimation. Based on the predefined antenna element index, the angle and range parameters are obtained respectively. This system is perfectly adapted to traditional far-field communication scenarios based on plane wave representation, reducing costs.

[0122] Figure 14 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 14As shown, the electronic device may include a processor 1410, a communications interface 1420, a memory 1430, and a communication bus 1440. The processor 1410, communications interface 1420, and memory 1430 communicate with each other via the communication bus 1440. The processor 1410 can call logic instructions in the memory 1430 to execute a holographic multiple-input multiple-output (HMI) wireless communication channel estimation method. This method includes: equipping the holographic HMI channel with a uniform planar array, and the user equipment transmitting pilot signals to perform uplink channel estimation.

[0123] Predefine the antenna element indexes for the uniform planar array, and establish a coordinate system with the center of the uniform planar array as the origin;

[0124] Construct an angle covariance matrix to transform the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0125] Based on the estimated angle information, a distance covariance matrix is ​​constructed, which transforms the original channel containing three-dimensional angle and distance information into a covariance matrix containing distance information.

[0126] Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving points inform the user equipment that the two matrix estimation tasks have been completed, thus realizing the construction of the wireless communication channel.

[0127] Furthermore, the logical instructions in the aforementioned memory 1430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0128] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program, the computer program being able to be stored on a non-transitory computer-readable storage medium, the computer program being executed by a processor, the computer being able to execute the wireless communication channel estimation method based on holographic multiple input multiple output provided by the above methods, the method including: equipping a holographic multiple input multiple output channel with a uniform planar array, and the user equipment transmitting pilot signals to perform uplink channel estimation;

[0129] Predefine the antenna element indexes for the uniform planar array, and establish a coordinate system with the center of the uniform planar array as the origin;

[0130] Construct an angle covariance matrix to transform the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0131] Based on the estimated angle information, a distance covariance matrix is ​​constructed, which transforms the original channel containing three-dimensional angle and distance information into a covariance matrix containing distance information.

[0132] Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving points inform the user equipment that the two matrix estimation tasks have been completed, thus realizing the construction of the wireless communication channel.

[0133] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the wireless communication channel estimation method based on holographic multiple input multiple output provided by the above methods, the method comprising: equipping a holographic multiple input multiple output channel with a uniform planar array, and a user equipment transmitting pilot signals to perform uplink channel estimation;

[0134] Predefine the antenna element indexes for the uniform planar array, and establish a coordinate system with the center of the uniform planar array as the origin;

[0135] Construct an angle covariance matrix to transform the original channel, which includes three-dimensional angle and distance information, into a covariance matrix containing only angle information.

[0136] Based on the estimated angle information, a distance covariance matrix is ​​constructed, which transforms the original channel containing three-dimensional angle and distance information into a covariance matrix containing distance information.

[0137] Based on the obtained angle covariance matrix and distance covariance matrix, the transmitting and receiving points inform the user equipment that the two matrix estimation tasks have been completed, thus realizing the construction of the wireless communication channel.

[0138] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0139] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for wireless communication channel estimation based on holographic multiple-input-multiple-output, characterized in that, The application relates to a method for constructing a wireless communication channel. The method comprises the following steps: A user equipment is equipped with a uniform planar array for a holographic multiple-input multiple-output channel, and the user equipment sends a pilot signal for uplink channel estimation; Antenna element indexes of the uniform planar array are predefined, and a coordinate system is established with the center of the uniform planar array as an origin; An angle covariance matrix is constructed, so that an original channel including three-dimensional angle and distance information is converted into a current covariance matrix only having angle information; A distance covariance matrix is constructed based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is converted into a covariance matrix containing distance information; 2. The holographic multiple-input multiple-output based wireless communication channel estimation method of claim 1, wherein, Based on the constructed angle covariance matrix and distance covariance matrix, a transmission receiving point informs the user equipment that the two matrix estimation tasks have been completed, and the construction of the wireless communication channel is realized. The antenna element indexes of the uniform planar array are predefined, and the coordinate system is established with the center of the uniform planar array as an origin, and the method comprises the following steps: The center of the uniform planar array is taken as an origin to determine the elements along the y-axis and the z-axis; 3. The holographic multiple-input multiple-output based wireless communication channel estimation method of claim 1, wherein, A pilot sequence length is defined, uplink signals received at a base station are determined, received pilot sequences are combined, and a channel based on a spherical wave is determined. The angle covariance matrix is constructed, so that the original channel including three-dimensional angle and distance information is converted into the current covariance matrix only having angle information, and the method comprises the following steps: Angle estimation is performed, and covariance matrices of an azimuth angle and a pitch angle are respectively constructed; When the angle covariance matrix is constructed, element indexes of an original channel and element indexes of a conjugate channel are symmetrical along the center of the uniform planar array; 4. The holographic multiple-input multiple-output based wireless communication channel estimation method of claim 1, wherein, Angle parameters are obtained through channel estimation by using a least square method, and the construction of the angle covariance matrix is completed. The distance covariance matrix is constructed based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is converted into the covariance matrix containing distance information, and the method comprises the following steps:

5. The holographic multiple-input multiple-output based wireless communication channel estimation method of claim 4, wherein, The construction of the distance covariance matrix can be completed through two angle estimation values of the angle covariance matrix.

6. The holographic multiple-input multiple-output based wireless communication channel estimation method of claim 1, wherein, When the distance covariance matrix is constructed, the antenna element indexes of the original channel and the conjugate channel are symmetrical along the z-axis, the user equipment sends the pilot signal to the transmission receiving point, the pilot signal is subjected to space domain filtering to calculate the distance, and the construction of the distance covariance matrix is completed. Based on the constructed angle covariance matrix and distance covariance matrix, the transmission receiving point informs the user equipment that the two matrix estimation tasks have been completed, and the construction of the wireless communication channel is realized, and the method comprises the following steps: The angle covariance matrix and the distance covariance matrix are obtained; The transmission receiving point sends information that the two matrix estimation tasks are completed to the user equipment, and the construction of the wireless communication channel is completed.

7. A holographic multiple-input-multiple-output based wireless communication channel estimation system, comprising: The wireless communication channel is suitable for a near-field communication range based on spherical wave representation and is also suitable for a far-field communication range based on plane wave representation. The application relates to a method for constructing a wireless communication channel. The method comprises the following steps: A user equipment is equipped with a uniform planar array for a holographic multiple-input multiple-output channel, and the user equipment sends a pilot signal for uplink channel estimation; Antenna element indexes of the uniform planar array are predefined, and a coordinate system is established with the center of the uniform planar array as an origin; An angle parameter calculation module is configured to construct an angle covariance matrix, so that the original channel including three-dimensional angle and distance information is converted into a current covariance matrix only having angle information. A distance parameter calculation module is configured to construct a distance covariance matrix based on the estimated angle information, so that the original channel including three-dimensional angle and distance information is converted into a covariance matrix containing distance information. An estimation result feedback module is configured to inform the user equipment that the two matrix estimation tasks are completed by the transmission and reception point based on the obtained constructed angle covariance matrix and distance covariance matrix, so as to realize the construction of the wireless communication channel.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the holographic multiple-input-output-based wireless communication channel estimation method according to any one of claims 1 to 6 when executing the program. 9.A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program implements the holographic multiple-input-output-based wireless communication channel estimation method according to any one of claims 1 to 6 when executed by the processor.

10. A computer program product comprising a computer program, characterized in that, The computer program implements the holographic multiple-input-output-based wireless communication channel estimation method according to any one of claims 1 to 6 when executed by the processor.

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