Near-field csi distributed estimation method for broadband xl-mimo

Abstract

The application discloses a near-field CSI distributed estimation method for wideband XL-MIMO. Firstly, a center LPU estimates path delay parameters of a center subarray channel, other LPUs quickly extrapolate path delay parameters of other subarray channels, and the estimation results are transmitted to a CPU. Then, based on near-field beam oblique vision and parameter symmetry characteristics caused by a large array and a large bandwidth, the CPU fuses the delay parameters estimated by different subarrays, decouples and independently estimates near-field channel parameters, including angle, distance and range parameters. Then, the CPU transmits the estimated near-field channel parameters back to the LPUs, each LPU independently estimates path gain of the subarray channel, and finally, the LPUs transmit the estimated path gain to the CPU, and then reconstruct the full-dimensional wideband near-field channel. The method overcomes the problems of too large CSI acquisition and calculation complexity and low reconstruction accuracy in the large array and large bandwidth scene.

Description

Technical Field

[0001] This invention relates to a distributed near-field CSI estimation method for wideband XL-MIMO, belonging to the field of near-field channel state information estimation technology. Background Technology

[0002] Ultra-large-scale multiple-input multiple-output (XL-MIMO) is considered a promising technology for sixth-generation (6G) wireless communication systems, capable of meeting the rapidly growing demands for spectral efficiency and capacity. By deploying a large number of additional antenna elements (thousands or more) at base stations (BSs), enhanced coverage, higher data transmission rates, and better user equipment (UE) quality of service can be provided for future wireless communications. Furthermore, higher frequency spectrum bands, such as the upper half of 6 GHz (U6G), i.e., 6.425 GHz–7.125 GHz, are becoming a strategic choice for 6G international mobile communication services. These bands offer abundant spectrum resources, while the higher frequencies mean that antenna size can be further reduced, enabling the deployment of XL-MIMO within limited areas. Therefore, wideband XL-MIMO systems demonstrate enormous potential for future wireless communications.

[0003] To fully utilize the beamforming gain of wideband XL-MIMO, accurate Channel State Information (CSI) is required. However, the deployment of large arrays and wide bandwidths in wideband XL-MIMO leads to near-field beam squint, causing the channel to lose its spatial sparsity, rendering traditional compressed sensing-based algorithms unsuitable. Furthermore, the need to estimate more parameters in the near-field channel, coupled with the high-dimensional received signal resulting from the large arrays and wide bandwidths, leads to unacceptable computational complexity in CSI acquisition. In addition, to reduce hardware costs, XL-MIMO typically deploys a hybrid precoding architecture, connecting all antenna elements through a small number of RF chains. This hybrid precoding architecture results in a more complex received signal format, and the UE needs to transmit multiple uplink pilots to compensate for the received signal dimensions, making the pilot overhead for high-dimensional near-field CSI acquisition excessive and reducing accuracy. Therefore, low-complexity estimation of wideband near-field CSI under a hybrid architecture has become a critical challenge that urgently needs to be addressed in XL-MIMO systems.

[0004] Preliminary research has been conducted on full-dimensional near-field CSI acquisition for hybrid architecture broadband XL-MIMO systems. Currently, the widely adopted strategy involves analyzing the beam-squinting characteristics of broadband near-field signals, constructing frequency-dependent near-field parameter codebooks, and then detecting near-field channel parameters along multiple paths. However, in practical broadband XL-MIMO systems, the large number of antenna elements and subcarriers makes parameter estimation using codebooks computationally expensive. Furthermore, users need to transmit multiple uplink pilots to compensate for the received signal dimensions, resulting in significant pilot overhead. Moreover, the new parameter characteristics brought by large arrays and bandwidths are not fully utilized. Therefore, the estimation accuracy of full-dimensional broadband near-field CSI is limited and the overhead is too high, failing to meet the requirements of low computational complexity and high accuracy for full-dimensional near-field CSI estimation in practical hybrid architecture broadband XL-MIMO systems.

[0005] In summary, how to obtain high-precision hybrid architecture broadband XL-MIMO full-dimensional near-field CSI with relatively low computational complexity has become a pressing challenge for sixth-generation mobile communication. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a distributed near-field CSI estimation method for broadband XL-MIMO, which breaks through the bottleneck of full-dimensional near-field CSI acquisition for hybrid architecture broadband XL-MIMO systems. It achieves full-dimensional near-field CSI reconstruction of hybrid architecture broadband XL-MIMO systems with low hardware cost, extremely low computational complexity and single pilot overhead, while ensuring the high accuracy of the reconstructed channel.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A distributed near-field CSI estimation method for wideband XL-MIMO is proposed. In wideband XL-MIMO wireless transmission systems, the base station is equipped with a uniformly distributed antenna element array, and the entire antenna element array is divided into... Subarrays, If the number is even, all antenna elements in each subarray are connected via analog phase shifters. A separate radio frequency chain, , This refers to the number of antenna elements in each subarray. Each radio frequency chain processes the received signal through a local processing unit. Each local processing unit is connected to the same central processing unit, and Information exchange between local processing units; the method includes the following steps:

[0009] Step 1: The user sends an uplink broadband pilot signal. The broadband pilot signal frequency band is U6G and above. The local processing unit corresponding to the central subarray in each subarray uses the received uplink broadband pilot signal to estimate the time delay parameters of the central subarray channel, and then extrapolates the time delay parameters of their respective subarray channels through other local processing units.

[0010] Step 2: Each local processing unit transmits the estimated corresponding subarray delay parameters to the central processing unit. The central processing unit uses the symmetry characteristics of the broadband near-field channel parameters to linearly fuse the delay parameters, decouple and independently estimate the angle parameter information of the near-field channel.

[0011] Step 3: Based on the estimated angle and the time delay parameter information of each subarray, the central processing unit uses the symmetry characteristics of the broadband near-field channel parameters to linearly fuse the time delay parameters, decouple and independently estimate the distance parameter information of the near-field channel;

[0012] Step 4: Based on the estimated angle, distance, and delay parameter information of each subarray, the central processing unit estimates the range parameter information of the near-field channel and transmits all estimated near-field channel parameters, including angle, distance, and range parameter information, back to each local processing unit; each local processing unit separately estimates the path gain of its corresponding subarray, transmits the estimated path gain back to the central processing unit, and removes the detected path information from the received signal.

[0013] Step 5, repeat steps 1-4. Next, detect sequentially from the received signal of the local processing unit. The near-field channel parameters of each path and the path gain of each subarray are used by the central processing unit to reconstruct the full-dimensional broadband near-field channel.

[0014] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0015] 1. This invention explores the new degrees of freedom provided by the near-field beam squint effect in large array and large bandwidth systems. By utilizing the parametric symmetry between the differences in path delay parameters observed by different antenna elements, the invention linearly fuses the delay parameters observed by different antenna elements, decouples and independently estimates the near-field channel parameters, and overcomes the challenge to CSI acquisition brought about by the near-field beam squint effect.

[0016] 2. This invention utilizes a distributed estimation strategy to separate the full-dimensional signal processing process into multiple independent processing processes for sub-array signals. Furthermore, the central processing unit (CPU) only needs to perform a simple linear combination of the time delay parameters estimated by different local processing units (LPUs), which greatly reduces the computational complexity of broadband near-field channel CSI acquisition.

[0017] 3. Although each subarray deploys only a single RF chain, the method proposed in this invention obtains the time delay parameters by observing the multi-subcarrier signals and estimates the near-field channel parameters by linearly combining the time delay parameters of different subarrays. It does not require obtaining the antenna domain received signals inside the subarray. Therefore, the user only needs to send an uplink pilot signal, which effectively reduces the pilot overhead of full-dimensional near-field CSI acquisition in the hybrid architecture broadband XL-MIMO system.

[0018] 4. This invention estimates the angle, distance, and range parameters based on the parametric symmetry characteristics of broadband near-field channels, avoiding the challenges of high computational complexity and low estimation accuracy faced by codebook-based estimation algorithms. Moreover, the estimation results are continuous values ​​off-network, which can achieve improved broadband near-field channel reconstruction accuracy. Attached Figure Description

[0019] Figure 1 This is a flowchart of the near-field CSI distributed estimation method for broadband XL-MIMO according to the present invention;

[0020] Figure 2 This is a model diagram of a distributed hybrid architecture broadband XL-MIMO system according to an embodiment of the present invention;

[0021] Figure 3 This is a flowchart illustrating the collaboration between the CPU and LPUs in an embodiment of the present invention. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] like Figure 1 As shown, this invention proposes a low-complexity distributed near-field CSI estimation method for wideband XL-MIMO. In a wideband XL-MIMO wireless transmission system, the BS divides the large array into multiple subarrays. Each subarray deploys an independent RF chain and processes the received signal through an independent LPU. After the central LPU estimates the channel delay parameters of the central subarray, other LPUs quickly extrapolate the channel delay parameters of other subarrays. The CPU utilizes the symmetry characteristics of wideband near-field channel parameters to perform linear data fusion on the delay parameters of different subarrays, decouples the near-field channel parameters, and estimates them independently. The LPUs calculate the path gain of each subarray, and then the CPU reconstructs the full-dimensional wideband near-field channel.

[0024] The array element distribution of a base station includes, but is not limited to, the following forms: uniform linear array, uniform planar array, and uniform circular array.

[0025] The subarray partitioning strategy for base stations includes, but is not limited to, the following forms: the entire array is uniformly divided into several subarrays of the same dimension, the entire array is divided into several subarrays of different dimensions, and each antenna element is regarded as an independent subarray.

[0026] The hardware architecture of a single subarray of a base station includes, but is not limited to, the following forms: different antenna elements are deployed with independent RF chains, all antenna elements are connected to a small number of RF chains, and all antenna elements are connected to the same RF chain.

[0027] A near-field channel consists of one or more propagation paths, with the number of near-field propagation paths being L, where L is greater than or equal to 1.

[0028] A base station simultaneously serves one or more users, the number of which is T, and T is greater than or equal to 1. Different users send orthogonal broadband pilot signals.

[0029] Specifically, the steps include the following:

[0030] (1) The user equipment (UE) sends an uplink wideband pilot signal. The array center LPU first estimates the path delay parameters of the central subarray channel, and then extrapolates the path delay parameters of other subarray channels through other LPUs.

[0031] Broadband signal frequency bands include, but are not limited to, the following: the upper half of 6 GHz (U6G), millimeter wave bands, Asia-Pacific Hertz bands, terahertz bands, and higher frequency bands.

[0032] (2) The LPUs transmit the estimated path delay parameters of different subarrays to the CPU. The CPU uses the symmetric characteristics of the broadband near-field channel parameters to perform linear data fusion, decouple and independently estimate the angle parameter information of the near-field channel.

[0033] (3) Based on the estimated angle and multi-subarray delay parameter information, the CPU uses the symmetric characteristics of broadband near-field channel parameters to perform deep linear fusion of data, decouple and independently estimate the distance parameter information of the near-field channel;

[0034] (4) Based on the estimated angle, distance and multi-subarray delay parameter information, the CPU estimates the range parameter information of the near-field channel and transmits all the estimated near-field channel parameters back to the LPUs; each LPU uses the near-field channel parameters fed back by the CPU to independently estimate the subarray path gain, removes the detected path information from the received signal, and transmits the path gain information to the CPU.

[0035] (5) Repeat (1)-(4) above L times, each time detecting the near-field channel parameters of one path, and then detect the near-field channel parameters of all L paths L times. Finally, the CPU reconstructs the full-dimensional broadband near-field channel.

[0036] Example

[0037] like Figure 2 As shown, in a hybrid architecture broadband XL-MIMO system, assuming the BS is equipped with a uniform linear array (ULA) with an antenna element spacing of half a wavelength, the number of antenna elements is... The entire array is divided into equal parts. Subarrays, The number is even, and the number of antenna elements in each subarray is... All antenna elements in each subarray are combined into an independent RF chain via analog phase shifters, and the received signals are processed by an independent LPU. Each LPU is connected to the same CPU, and The LPUs can exchange information. The system carrier frequency is... The number of subcarriers is The frequency interval between different subcarriers is Consider the U6G band. Assume a single user equipment (UE) uses a single antenna configuration. To perform data detection and transmission, the base station needs to acquire full-dimensional broadband near-field CSI and reconstruct the full-dimensional broadband near-field channel. This embodiment will... The reconstruction process includes the following steps:

[0038] Step 1: The user equipment sends an uplink wideband all-one pilot signal. Each subarray of the XL-MIMO receives the uplink pilot signal through a hybrid precoding architecture, and the LPU processes the received signal. The phase of each analog phase shifter is within the interval... Randomly generated within. (Number) The signal model received by each subarray is:

[0039]

[0040] in, For the first The broadband signal received by each subarray For UE and the Uplink channels between subarrays To simulate the phase shift matrix, each element satisfies the constant modulus and random phase characteristics, i.e. , , For signal transmission power, The mean is 0 and the variance is Additive white Gaussian noise. The uplink full-dimensional wideband near-field channel has the following expression:

[0041]

[0042] in, For the number of propagation paths, For the first in the channel Gain of each path For the first The azimuth angle of the incident signal in the path, Indicates the first The range parameters from the user to the scatterer in the path, Indicates the first The distance parameter from the scatterer to the center of the BS in the path, where the user is considered the scatterer in the line-of-sight (LoS) path. For the first Near-field steering vector of the antenna domain along the path. For the first Multi-subcarrier steering vector along a single path For the first Near-field beam slant vector along the path, .

[0043] Due to the near-field beam squint effect, the full-dimensional broadband near-field channel does not exhibit spatial domain sparsity. However, because the overall array is divided into... There are several subarrays, each with a small aperture. The beam squinting effect within each subarray is negligible, but the beam squinting effect between different subarrays still needs to be considered. Each subarray channel has the following expression:

[0044]

[0045] in, For the first The path in the first Antenna domain near-field steering vector on each subarray For the first The near-field beam squint effect affects each subarray. It is a vector of all one. and The first Subarray observations The azimuth and distance of the path. Furthermore, the... The received signal of each subarray can be represented as:

[0046]

[0047] in, , For the first Subarray observations Multi-subcarrier steering vector for each path, Indicates the first Subarray observations The equivalent delay parameters of the path.

[0048] For ease of understanding, let's assume... ,when An iterative estimation strategy can be used to detect sequentially. Near-field channel parameters for each path. Taking the estimation process of a single broadband near-field path as an example, path index subscripts are omitted. Set the central subarray index as The central LPU performs an inverse Fourier transform on the received uplink pilot signal and detects the delay parameters based on the delay domain codebook. Because the difference in delay parameters between adjacent subarrays is less than the delay resolution. , No. The delay parameters of each subarray can be extrapolated as follows: ,in Its value selection rule is to make the first The correlation between the received signal of the first subarray and the multi-subcarrier steering vector is the strongest, and similarly for the second... The delay parameters of each subarray can be extrapolated as follows: Based on this, the delay parameters of all subarrays are extrapolated sequentially and saved as follows. ,in .

[0049] Step Two: As Figure 3 As shown, Each LPU transmits the estimated time delay parameters of different subarrays to the CPU, which performs linear data fusion to decouple and estimate near-field channel parameters, including angle, distance, and range parameters. Specifically, the first... The time delay parameters of each subarray can be equivalently expressed as:

[0050]

[0051] in, , , At the speed of light, This represents the spacing between adjacent antennas. Note. With antenna index The relevant odd and even symmetry properties, namely ,as well as Therefore, we have:

[0052]

[0053] Among them, by combining the first The and the first The time delay and angle parameters of each subarray can be decoupled and estimated independently. Therefore, through combination The time delay and angle parameters for detection by different subarrays can be estimated as follows:

[0054]

[0055] Among them, it means Pseudo-inverse operation.

[0056] Step 3: The CPU performs further deep linear fusion of the latency parameters of different subarrays, where the first... The and the first The delay parameters of the subarrays satisfy:

[0057]

[0058] Therefore, by combining the first The and the first The time delay and distance parameters of each subarray can be decoupled and estimated independently. Furthermore, the above formula can be expressed as:

[0059]

[0060] By combination The time delay parameters detected by different subarrays, as well as the angle and distance parameters estimated in step two, can be estimated as follows:

[0061]

[0062] Step 4: Once the angle and distance parameters are accurately estimated, the... The and the first The delay parameters of each subarray can be recombine as follows:

[0063]

[0064] By combining the first The and the first The delay parameters of each subarray The range parameter can be linearly estimated as:

[0065]

[0066] The CPU will detect the near-field channel parameters Feedback is sent to the LPUs, and each LPU individually estimates the path gain of the subarray, where the first... The path gain of each subarray can be calculated as follows:

[0067]

[0068] Wherein, the coefficient matrix It can be represented as:

[0069]

[0070] in, , For the first The distance parameter of the incident signal observed by each subarray can be obtained through... Calculations, based on this, Each LPU removes the detected path information from the received signal and passes the estimated path gain back to the CPU. The received signal of each LPU is updated as follows:

[0071]

[0072] Step 5: The above steps are performed iteratively. Next, detect sequentially from the received signal. The near-field channel parameters of each path and the path gain of different subarrays are obtained and saved as follows. ,in , The CPU utilizes the estimated The angle, distance, range, and gain of each path are used to reconstruct the full-dimensional broadband near-field channel between the user and the BS:

[0073]

[0074] in, For the reconstruction of the full-dimensional broadband near-field channel between the user and the BS.

[0075] Based on the same inventive concept, embodiments of this application provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the aforementioned distributed near-field CSI estimation method for broadband XL-MIMO.

[0076] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the aforementioned distributed near-field CSI estimation method for broadband XL-MIMO.

[0077] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0078] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0079] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0080] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0081] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A distributed near-field CSI estimation method for wideband XL-MIMO: In wideband XL-MIMO wireless transmission systems, the base station is equipped with a uniformly distributed antenna element array, and the entire antenna element array is divided into... Subarrays, If the number is even, all antenna elements in each subarray are connected via analog phase shifters. A separate radio frequency chain, , This refers to the number of antenna elements in each subarray. Each radio frequency chain processes the received signal through a local processing unit. Each local processing unit is connected to the same central processing unit, and Information exchange between local processing units; characterized in that... The method includes the following steps: Step 1: The user sends an uplink broadband pilot signal. The broadband pilot signal frequency band is U6G and above. The local processing unit corresponding to the central subarray in each subarray uses the received uplink broadband pilot signal to estimate the time delay parameters of the central subarray channel, and then extrapolates the time delay parameters of their respective subarray channels through other local processing units. No. The expression for each subarray channel is as follows: ， in, For users to the first Broadband near-field steering vectors of individual subarrays For the number of propagation paths, For the first in the channel Gain of each path For the first The azimuth angle of the incident signal in the path, For the first The range parameter from the user to the scatterer in the path, For the first The distance parameter from the scatterer to the center of the base station in the path, For the first The path in the first Antenna domain near-field steering vector on each subarray For the first Multi-subcarrier steering vector along a single path For the first The near-field beam squint effect affects each subarray. and The first Subarray observations The azimuth and distance of the path, ; No. The received signals of each subarray are represented as follows: ， in, For the first The broadband signal received by each subarray For signal transmission power, , To simulate the phase shift matrix, For the first Subarray observations Multi-subcarrier steering vector for each path, Indicates the first Subarray observations The equivalent delay parameters of the path, The frequency spacing between adjacent subcarriers, At the speed of light, The mean is 0 and the variance is Additive white Gaussian noise; Let the index of the central subarray be The local processing unit corresponding to the central subarray performs an inverse Fourier transform on the received uplink broadband pilot signal based on the time delay domain codebook to calculate the time delay parameters. ;No. The extrapolation of the delay parameters of each subarray is as follows: ,in, For time-delay resolution, , The rule for taking the value of is to make the first The subarray receives signals and the first Subarray observations Multi-subcarrier steering vector of the path The correlation between them is the strongest, and the delay parameters of all subarrays are extrapolated in turn. Step 2: Each local processing unit transmits the estimated corresponding subarray delay parameters to the central processing unit. The central processing unit uses the symmetry characteristics of the broadband near-field channel parameters to linearly fuse the delay parameters, decouple and independently estimate the angle parameter information of the near-field channel. The first Delay parameters of each subarray The equivalent representation is: ， in, The range parameter from the user to the scatterer. The distance parameter is from the scatterer to the center of the base station. The distance between adjacent antennas. The azimuth angle of the incident signal observed by the entire XL-MIMO array; , With subarray index The relevant odd and even symmetry properties, namely ,as well as Therefore: ， By combining the first and the The delay parameters of each subarray The angle parameters are decoupled and independently estimated as follows: ， in, For the estimated azimuth angle of the incident signal observed by the overall XL-MIMO array, They are the 1st and 2nd respectively. The delay parameters of each subarray The first The delay parameters of each subarray Indicates a pseudo-inverse operation; Step 3: Based on the estimated angle and the time delay parameter information of each subarray, the central processing unit uses the symmetry characteristics of the broadband near-field channel parameters to linearly fuse the time delay parameters, decouple and independently estimate the distance parameter information of the near-field channel; No. Passing the exam The delay parameters of the subarrays satisfy: ， Then the combination of the first and the The delay parameters of each subarray The distance parameters are decoupled and estimated independently as follows: ， in, The range parameters for the estimated overall XL-MIMO array observation incident signal are given. The first The delay parameters of each subarray; Step 4: Based on the estimated angle, distance, and delay parameter information of each subarray, the central processing unit estimates the range parameter information of the near-field channel and transmits all estimated near-field channel parameters, including angle, distance, and range parameter information, back to each local processing unit; each local processing unit separately estimates the path gain of its corresponding subarray, transmits the estimated path gain back to the central processing unit, and removes the detected path information from the received signal. No. and the The delay parameters of the subarrays are recombined as follows: ， By combining the first and the The delay parameters of each subarray The range parameter is linearly estimated as: ， in, The range parameter for the estimated overall XL-MIMO array observation incident signal; The central processing unit transmits the estimated angle, distance, and range parameters back to each local processing unit. Each local processing unit independently estimates the path gain of its corresponding subarray. Path gain of subarrays as follows: ， coefficient matrix Represented as: ， in, For the first Near-field steering vector of the antenna domain of each subarray For the first The time-delay domain steering vector of each subarray, For the first The distance parameters of the incident signal are observed by each subarray; No. The received signals of each local processing unit are updated as follows: ， in, For the first The received signal updated by each local processing unit; Step 5, repeat steps 1-4. Next, detect sequentially from the received signal of the local processing unit. The near-field channel parameters of each path and the path gain of each subarray are used by the central processing unit to reconstruct the full-dimensional broadband near-field channel. when After all paths have been detected, the full-dimensional broadband near-field channel between the user and the base station is reconstructed as follows: ， in, To reconstruct the full-dimensional broadband near-field channel between the user and the base station, The 1st and the 2nd respectively The estimated subarray of the first subarray Gain of each path For the estimated first Full-dimensional antenna domain steering vector along the path For the estimated first Path delay domain steering vector, For the estimated first Near-field beam slant effect matrix for each path.

2. A computer device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the near-field CSI distributed estimation method for broadband XL-MIMO as described in claim 1.

3. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the near-field CSI distributed estimation method for broadband XL-MIMO as described in claim 1.

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