Near field communication user positioning method and device based on beam offset

Abstract

The application provides a near field communication user positioning method and device based on beam offset, comprising: a target user feeds back a subcarrier frequency with maximum received signal power to a target base station subarray, the target base station subarray calculates a detection angle of the target user in a local coordinate system where the subarray is located according to the subcarrier frequency; based on the multiple detection angles and a pre-constructed positioning model, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by multiple subarrays. The application realizes the effect of positioning a near field user in a wideband communication system under the influence of beam offset with small time overhead.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, in particular to a near-field communication user positioning method and device based on beam offset. BACKGROUND

[0002] Integrated sensing and communication (ISAC) is considered as one of the key technologies of 6G communication, the idea of which is to use communication signals to sense the position of users. Once the position of the user is obtained, the base station can not only better serve the user's communication, but also support various intelligent services, such as path planning of Internet of Vehicles, intelligent security intrusion detection, etc. With the increasing size of massive MIMO (Multi Input Multi Output) arrays in 5G and future 6G communication, the position of the user can remain within the Rayleigh distance, resulting in the electromagnetic field of communication evolving from far-field effect to near-field effect. In the near-field ISAC system, when the user is close to the base station, the base station can simultaneously sense the angle and distance of the user, thereby realizing user positioning.

[0003] However, existing near-field user positioning schemes all assume that the communication signal is a narrowband signal, but 6G communication will use higher and wider frequency bands and advanced beamforming technology to achieve higher-rate communication transmission. At this time, for a wideband communication system using Orthogonal frequency-division multiplexing (OFDM) technology, beam offset phenomenon will occur in near-field communication, i.e. the beamforming of different subcarriers will focus on different positions, resulting in the energy of some subcarriers deviating from the expected user position. Therefore, beam offset is generally considered a negative effect, which can be compensated by true time delay lines, and when each antenna is equipped with a phase shifter and a true time delay line, the influence of beam offset on communication can be perfectly overcome. However, in actual systems, the deployment of true time delay lines is expensive, so it is usually considered to construct subarrays in the form of making some antennas in different subarrays share the same true time delay line, thereby reducing the economic cost. However, when considering the user positioning problem in a wideband system, the near-field beam offset phenomenon will be beneficial to quickly positioning the position of the near-field user. The current prior art does not consider the near-field user positioning problem under the influence of beam offset in a wideband communication system.

[0004] In the traditional near-field user positioning scheme based on beam scanning, time division multiplexing is usually used to scan different discrete positions in space, and after a period of continuous wave scanning, the coverage of part of the near-field space can be achieved, thereby sensing the position of the user. However, such a scheme requires a large time overhead, and therefore is difficult to apply in future integrated sensing and communication systems. SUMMARY

[0005] The present application provides a near field communication user positioning method based on beam offset, which solves the defects of the prior art that cannot solve the problem of near field user positioning under the influence of beam offset in a wideband communication system, and the defect that traditional beam scanning near field user positioning requires a large amount of time overhead, and achieves the purpose of near field user positioning under the influence of beam offset in a wideband communication system in a small time overhead.

[0006] The present application provides a near field communication user positioning method based on beam offset, which includes:

[0007] According to the antenna array division strategy of the target base station and the number of target base stations, the type of base station is determined;

[0008] When the target base station type is a single base station multi-subarray, each subarray performs time division multiplexing;

[0009] Each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near field beam offset point in different time division periods;

[0010] When each subarray time division multiplexing transmits multiple subcarrier beams, each subcarrier beam is gathered at different positions at different angles to achieve spatial full coverage in the target range;

[0011] The target user feeds back the subcarrier frequency with the maximum received signal power to the target base station subarray, and the target base station subarray calculates the detection angle of the target user in the local coordinate system of the subarray according to the subcarrier frequency;

[0012] Based on the multiple detection angles and the pre-constructed positioning model, the angle estimation result and the distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as the positioning result to complete the two-dimensional positioning of the target user; wherein the positioning model is trained by the angle samples and distance samples detected by multiple subarrays.

[0013] According to the near field communication user positioning method based on beam offset provided by the present application, each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near field beam offset point in different time division periods, and then includes:

[0014] The initial angle of beam scanning is determined as the maximum angle of the base station sensing range, the phase shift amount of the phase shifter is calculated and set, and the beamforming of the 0th subcarrier is directed to the first target position at the initial angle;

[0015] The termination angle of the beam scanning is determined as the minimum angle of the base station sensing range, the time delay value of the true time delay line is calculated and set, and the beamforming of the Mth subcarrier is directed to the second target position at the termination angle.

[0016] According to the application, a near field communication user positioning method based on beam offset is provided, and a first preset formula is used to calculate the detection angle of the target user in the local coordinate system of the subarray according to the subcarrier frequency.

[0017]

[0018] Wherein, W is the transmission bandwidth; is the baseband frequency of the subcarrier with the maximum received signal power of the kth user; f0 is the lowest passband frequency; f d,k is the subcarrier frequency with the maximum received signal power; θ max is the maximum angle of the base station sensing range; θ min is the minimum angle of the base station sensing range.

[0019] According to the application, a near field communication user positioning method based on beam offset is provided, and the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the method further includes:

[0020] In the case that the base station type is a single base station, if the antenna array in the single base station is a single array, the range and trajectory of the near field beam offset point are assisted and controlled by the true time delay line and the phase shifter;

[0021] When the target base station transmits multiple subcarriers, the beams of each subcarrier are gathered at different positions at different angles to realize spatial full coverage in the target range;

[0022] The target user feeds back the subcarrier frequency with the maximum received signal power to the target base station, and the target base station calculates the current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0023] The current angle of the target user is taken as the angle positioning result to complete the angle positioning of the target user.

[0024] According to the application, a near field communication user positioning method based on beam offset is provided, and the angle sample and the distance sample are obtained by the following method:

[0025] P angle data of the user sample detected by the P subarrays of the target base station are taken as input data;

[0026] The real angle and the real distance of the user sample are respectively taken as label data.

[0027] an angle training sample is formed by the angle data and the real angle, and a distance training sample is formed by the angle data and the real distance;

[0028] The angle training sample and the distance training sample are obtained by extending to a plurality of user samples randomly and uniformly distributed in the sensing range of the base station.

[0029] According to the application, a near field communication user positioning method based on beam offset is provided, the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the method further comprises:

[0030] In the case that the base station type is a double base station, the double base station comprises a main base station and an auxiliary base station;

[0031] The range and trajectory of the near field beam offset point are controlled by using the true time delay line and the phase shifter;

[0032] When the target base station emits a plurality of subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to realize spatial full coverage in the target range;

[0033] The target user feeds back the subcarrier frequency with the maximum received signal power to the target base station, and the target base station calculates the current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0034] The main base station and the auxiliary base station are time division multiplexed, the main base station detects the angle estimation value of the target user, and the auxiliary base station detects the auxiliary angle estimation value of the target user;

[0035] The two-dimensional position of the target user is calculated according to the angle estimation value and the auxiliary angle estimation value, and the two-dimensional position is taken as a two-dimensional positioning result.

[0036] The application further provides a near field communication user positioning device based on beam offset, comprising:

[0037] A base station type determination unit is configured to determine the base station type according to the antenna array division strategy of the target base station and the number of target base stations;

[0038] An offset control unit is configured to perform time division multiplexing on each subarray when the target base station type is a single base station with multiple subarrays, and the range and trajectory of the near field beam offset point are controlled by using the true time delay line and the phase shifter in different time division periods for each subarray, and when each subarray performs time division multiplexing to emit a plurality of subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to realize spatial full coverage in the target range.

[0039] a calculation unit configured to feed back, by a target user, a subcarrier frequency with a maximum received signal power to a target base station subarray, and the target base station subarray calculates a detection angle of the target user in a local coordinate system where the target base station subarray is located according to the subcarrier frequency;

[0040] a positioning unit configured to obtain an angle estimation result and a distance estimation result of the target user based on the plurality of detection angles and a pre-constructed positioning model, and take the angle estimation result and the distance estimation result of the target user as a positioning result to complete two-dimensional positioning of the target user, wherein the positioning model is trained by angle samples and distance samples detected by a plurality of subarrays.

[0041] The application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the above-mentioned any one of the beam offset-based near field communication user positioning method when executing the program.

[0042] The application further provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the above-mentioned any one of the beam offset-based near field communication user positioning method.

[0043] The application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the above-mentioned any one of the beam offset-based near field communication user positioning method.

[0044] The application provides a beam offset-based near field communication user positioning method and device, which comprises the following steps: determining a base station type according to an antenna array division strategy of a target base station and a target base station quantity; when the target base station type is a single base station multi-subarray, each subarray is subjected to time division multiplexing; each subarray respectively controls a range and a track of a near field beam offset point by using a true time delay line and a phase shifter in different time division periods; when each subarray time division multiplexing respectively emits a plurality of subcarrier beams, the subcarrier beams are gathered at different positions at different angles to realize spatial full coverage in a target range; a target user feeds back a subcarrier frequency with the largest received signal power to the target base station subarray, the target base station subarray calculates a detection angle of the target user in a local coordinate system of the subarray according to the subcarrier frequency; based on the plurality of detection angles and a positioning model constructed in advance, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by a plurality of subarrays. The application realizes the effect of positioning a near field user affected by beam offset in a wideband communication system under a small time overhead. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0046] Figure 1 is one of the flowcharts of the beam offset-based near field communication user positioning method provided by the application;

[0047] Figure 2 is another flowchart of the beam offset-based near field communication user positioning method provided by the application;

[0048] Figure 3 is a single base station link structure diagram assisted by a true time delay line provided by the application;

[0049] Figure 4 is a single base station multi-subarray link structure diagram assisted by a true time delay line provided by the embodiment of the application;

[0050] Figure 5 is a single base station multi-subarray time division multiplexing angle sensing detection diagram provided by the embodiment of the application;

[0051] Figure 6is a positioning model schematic diagram of a single base station and multiple sub-arrays pre-constructed according to an embodiment of the present application;

[0052] Figure 7 is a user positioning schematic diagram of a double base station according to an embodiment of the present application;

[0053] Figure 8 is a principle simulation result diagram of a near-field user angle perception scheme based on a single base station and beam offset according to the present application;

[0054] Figure 9 is a structural schematic diagram of a near-field communication user positioning device based on beam offset according to the present application;

[0055] Figure 10 is an entity structure schematic diagram of an electronic device according to the present application.

[0056] Reference signs:

[0057] 910: base station type determination unit; 920: offset control unit; 930: calculation unit; 940: positioning unit;

[0058] 1010: processor; 1020: communication interface; 1030: memory; 1040: communication bus. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0060] The present application will be described below in conjunction with Figures 1-8 A near-field communication user positioning method based on beam offset is described. Figure 1 And Figure 2 is a flow schematic diagram of a near-field communication user positioning method based on beam offset according to the present application, as shown in the figure, the method comprises the following steps: Figure 1

[0061] Step 110: determining the base station type according to the antenna array division strategy of the target base station and the number of target base stations.

[0062] Since the near-field user positioning mode based on a single base station and multiple sub-arrays and the beam offset is different from the high-precision near-field user positioning mode based on a double base station and the beam offset, before determining the angle positioning of the target user, the base station type needs to be determined first.

[0063] ​Step 120: when the target base station type is a single base station multi-subarray, each subarray performs time division multiplexing; each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam deflection point in different time division periods; when each subarray time division multiplexing transmits multiple subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage in the target range.

[0064] The application first considers a broadband massive MIMO system using OFDM modulation working in the millimeter wave frequency band, the base station is equipped with an N-element uniform linear array (ULA) with an antenna spacing d and a single radio frequency chain, where the spatial position of the nth antenna is (0, nd), Without loss of generality, it is assumed that the antenna spacing The carrier frequency and the transmission bandwidth are f c and W, it is assumed that a total of M+1 subcarriers are used for signal transmission, where the 0th subcarrier has the lowest passband frequency The passband frequency of the mth subcarrier is At the same time, the baseband frequency of the mth subcarrier is denoted as It is assumed that the base station serves K near-field users, and the rectangular coordinate position of the kth user is (x k ,y k ), and the corresponding polar coordinate position is (r k ,θ k ).

[0065] For this system model, due to the beam deflection phenomenon of the beamforming technology based on the traditional phase shifter structure in the broadband system, the beamforming of the different subcarriers transmitted by the base station end focuses on different positions.

[0066] Figure 3 is the single base station link structure schematic diagram based on true time delay line assistance provided by the application; as Figure 3 shown, a true time delay line is added between the radio frequency chain and each phase shifter. By setting the specific phase shift value of the phase shifter and the specific time delay value of the true time delay line, the range and trajectory of the near-field beam deflection point are autonomously controlled, so that all subcarriers cover different angles of the entire space.

[0067] Step 130: the target user feeds back the subcarrier frequency with the maximum received signal power to the target base station subarray, and the target base station subarray calculates the detection angle of the target user in the local coordinate system of the subarray according to the subcarrier frequency.

[0068] According to the above steps, the base station transmits multiple subcarriers, the user feeds back the subcarrier frequency with the maximum received signal power to the base station, and the base station can calculate the angle of the user using the first preset formula according to the frequency.

[0069] Step 140: obtaining an angle estimation result and a distance estimation result of the target user based on the plurality of detection angles and the pre-constructed positioning model, and taking the angle estimation result and the distance estimation result of the target user as the positioning result to complete the two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by a plurality of sub-array.

[0070] In the case of determining that the base station type is a single base station, if the antenna array in the single base station is divided into a plurality of sub-arrays, the plurality of current angles of the target user are taken as a plurality of detection angles in a plurality of local coordinate systems with the center of the sub-array as the coordinate origin. Then the plurality of detection angles are input into the angle network to calculate the angle estimation result of the user, and the plurality of detection angles are input into the distance network to calculate the distance estimation result of the user, thereby realizing the two-dimensional positioning of the near-field user.

[0071] That is, in the case of the base station type being a single base station, if the antenna array in the single base station is divided into a plurality of sub-arrays, the antenna array is divided into P sub-arrays, and the corresponding antennas in different sub-arrays share the same true time delay line, at this time, the base station link structure is as shown in Figure 4 .

[0072] Figure 5 is a single base station multi-sub-array time division multiplexing angle sensing schematic diagram provided by the embodiment of the application, as shown in Figure 5 , the P sub-arrays of the base station obtain the angle of the user in the local coordinate system with the center of the sub-array as the coordinate origin in the form of time division multiplexing according to the above method.

[0073] Figure 6 is a positioning model structure schematic diagram of a single base station multi-sub-array provided by the embodiment of the application, as shown in Figure 6 , the pre-constructed positioning model includes an angle network and a distance network based on a deep neural network, which are respectively used to predict the real angle and distance of the user.

[0074] A large number of angle training samples and distance training samples (i.e. data set) are respectively input into the angle network and the distance network, and the powerful feature extraction and learning ability of the deep neural network is used to obtain the output angle estimation result and distance estimation result after a plurality of hidden layers and activation function calculations. The loss value between the predicted output and the real label is calculated by using the preset loss function, and the best parameters of the network model are obtained by using the preset parameter optimizer through back training, and finally the training of the angle network and the distance network is completed. Wherein, the preset loss function can be a mean square error function; the preset parameter optimizer can be an Adam optimizer.

[0075] When the base station actually detects P angles of a user, the angles and distance networks are input into the trained angle network and distance network, and the angle estimation result and distance estimation result of the user are calculated through the network to realize two-dimensional positioning of the near-field user.

[0076] Based on the above embodiment, in the method, each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam deflection point in different time division periods, and then the method further includes:

[0077] The initial angle of beam scanning is determined as the maximum angle of the base station sensing range, the phase shift amount of the phase shifter is calculated and set, and the beamforming of the 0th subcarrier is directed to a first target position at the initial angle.

[0078] The termination angle of beam scanning is determined as the minimum angle of the base station sensing range, the time delay value of the true time delay line is calculated and set, and the beamforming of the Mth subcarrier is directed to a second target position at the termination angle.

[0079] Specifically, as shown in Figure 3 a true time delay line is added between the radio frequency chain and each phase shifter. By setting a specific phase shift value of the phase shifter and a specific time delay value of the true time delay line, the range and trajectory of the near-field beam deflection point are autonomously controlled, all subcarriers cover different angles of the entire space, and the angle of the near-field user is sensed. The specific steps are as follows:

[0080] The initial angle of beam scanning is determined as the maximum angle of the base station sensing range, the phase shift amount of the phase shifter is calculated and set, and the beamforming of the 0th subcarrier is directed to a first target position at the initial angle.

[0081] The termination angle of beam scanning is determined as the minimum angle of the base station sensing range, the time delay value of the true time delay line is calculated and set, and the beamforming of the Mth subcarrier is directed to a second target position at the termination angle.

[0082] According to the calculation results of the phase shifter and the true time delay line, the base station transmits M+1 subcarriers, and different subcarrier beams are focused on different positions at different angles to achieve full coverage of the space.

[0083] Based on the above embodiment, in the method, the target base station subarray calculates the detection angle of the target user in the local coordinate system of the subarray according to the subcarrier frequency using a first preset formula, and the first preset formula is:

[0084]

[0085] wherein W is the transmission bandwidth. The baseband frequency of the subcarrier with the maximum received signal power; f0 is the lowest passband frequency; f d,k The subcarrier frequency with the maximum received signal power; θ max The maximum angle of the base station sensing range; θ min The minimum angle of the base station sensing range.

[0086] Specifically, after the base station transmits M+1 subcarriers, different subcarrier beams focus at different positions at different angles to achieve spatial full coverage, the kth user will receive the subcarrier frequency f d,k Feedback to the base station, and the base station can calculate the angle of the user according to the frequency by using a first preset formula.

[0087] Based on the above embodiment, in the method, the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the method further comprises:

[0088] In the case where the base station type is a single base station, if the antenna array in the single base station is a single array, the range and trajectory of the near-field beam deflection point are controlled by using a true time delay line and a phase shifter;

[0089] When the target base station transmits a plurality of subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage in the target range;

[0090] The target user feeds back the subcarrier frequency with the maximum received signal power to the target base station, and the target base station calculates the current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0091] The current angle of the target user is taken as the angle positioning result to complete the angle positioning of the target user.

[0092] Specifically, in the case where the base station type is a single base station, if the antenna array in the single base station is a single array, according to the above steps, the base station transmits a plurality of subcarriers, the user feeds back the subcarrier frequency with the maximum received signal power to the base station, and the base station can calculate the angle of the user according to the frequency by using a first preset formula. The current angle of the target user is taken as the angle positioning result to complete the angle positioning of the target user.

[0093] Based on the above embodiment, in the method, the angle sample and the distance sample are obtained by the following method:

[0094] The P angle data of the user sample detected by the P subarrays of the target base station are taken as input data;

[0095] The real angle and real distance of the user sample are respectively taken as label data;

[0096] An angle training sample is constituted by the angle data and the real angle, and a distance training sample is constituted by the angle data and the real distance;

[0097] By extending to a plurality of user samples randomly and uniformly distributed in the sensing range of the base station, a large number of angle training samples and distance training samples are obtained.

[0098] Specifically, P angles detected by the base station for a certain user are taken as input data, and the real angle and the real distance of the user are taken as label data respectively, thereby constituting an angle training sample and a distance training sample respectively. The process is extended to a large number of users randomly and uniformly distributed in the sensing range of the base station, and finally a large number of angle training samples and distance training samples are obtained, thereby constituting a data set for training a pre-constructed positioning model.

[0099] Based on the above embodiment, in the method, the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the method further comprises:

[0100] In the case that the base station type is a double base station, the double base station comprises a main base station and an auxiliary base station;

[0101] The range and trajectory of the near-field beam deflection point are assisted to control by using the true time delay line and the phase shifter;

[0102] When the target base station transmits a plurality of subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to realize spatial full coverage in the target range;

[0103] The target user feeds back the subcarrier frequency with the largest received signal power to the target base station, and the target base station calculates the current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0104] The main base station and the auxiliary base station are time division multiplexed, the main base station detects the angle estimation value of the target user, and the auxiliary base station detects the auxiliary angle estimation value of the target user;

[0105] The two-dimensional position of the target user is calculated according to the angle estimation value and the auxiliary angle estimation value, and the two-dimensional position is taken as a two-dimensional positioning result.

[0106] Specifically, Figure 7 is a double base station user positioning schematic diagram provided by the embodiment of the application, as Figure 7, consider the single base station system as the main base station, on this basis, add a set of auxiliary base stations parallel to the main base station array, the center of the auxiliary base station is set to (L, 0), and the other configurations are exactly the same as the main base station. Two base stations respectively acquire the angle estimation of the user in the middle area of the two base stations according to the angle perception scheme in the first aspect in the form of time division multiplexing, and calculate the two-dimensional positioning of the user according to the two angles obtained. This scheme realizes the two-dimensional position of all users by 2 times of beam scanning, and the specific steps are as follows:

[0107] The main base station acquires the angle estimation of the user according to the method of perceiving the angle of the near field user, and takes the angle estimation as the final angle perception result of the user.

[0108] The auxiliary base station acquires the auxiliary angle estimation of the user according to the method of perceiving the angle of the near field user, and provides the result to the main base station.

[0109] The main base station calculates the distance of the user through the angle estimation and the auxiliary angle estimation, and takes the distance as the final distance perception result of the user.

[0110] The angle perception result and the distance perception result are taken as the positioning result of the target user.

[0111] Based on the above embodiment, the application provides an example of completing one positioning using the above-mentioned near field communication user positioning method based on beam offset. This embodiment also includes:

[0112] 1. Near field wideband channel model

[0113] For millimeter wave frequency band communication, this embodiment only considers one line of sight (LoS) channel between the user and the base station, but can be easily extended to a multipath scenario. The path delay of the antenna of the kth user to the nth antenna of the base station is

[0114] Where, r k,n k represents the distance from the kth user to the nth antenna of the base station, and c is the speed of light.

[0115]

[0116] Where, (x k ,y k ) is the rectangular coordinate position of the kth user, d represents the antenna spacing, Without loss of generality.

[0117] At this time, the downlink time domain channel of the nth antenna of the base station to the kth user is

[0118]

[0119] wherein, α represents channel gain, δ(·) represents Dirac function, τ k，n represents the path delay from the antenna of the kth user to the nth antenna of the base station, t represents time, j represents complex number unit, f0 represents that the 0th subcarrier has the lowest passband frequency.

[0120] Taking Fourier transform of the same, the frequency domain channel of the kth user and the nth antenna of the base station is

[0121]

[0122] wherein, α(f) represents specific channel fading, f represents baseband frequency, f0 represents that the 0th subcarrier has the lowest passband frequency, j represents complex number unit, τ k，n represents the path delay from the antenna of the kth user to the nth antenna of the base station.

[0123] Further, the specific channel fading is modeled as

[0124] wherein, r k，n represents the distance from the kth user to the nth antenna of the base station, c is the speed of light, and f represents baseband frequency.

[0125] Then, the frequency domain channel of the nth antenna of the base station and the kth user on the mth subcarrier can be represented as

[0126]

[0127] wherein, represents free space path loss, (x k , y k ) is the rectangular coordinate position of the kth user, f m is the passband frequency of the mth subcarrier, r k，n represents the distance from the kth user to the nth antenna of the base station, and c is the speed of light.

[0128] It should be noted that the channel model is an example of the present application, and the present application is still applicable under other channel models.

[0129] 2. Utilize true time delay line and phase shifter to assist in controlling the range and trajectory of near-field beam deflection point

[0130] Suppose the phase shift amount of the nth phase shifter is φ n , then its time domain response can be represented as Its frequency domain response and time domain response are the same. Suppose the time delay value of the nth true time delay line is t n , then its time domain response can be represented as δ(t-t n), the corresponding frequency domain response is At this time, with the aid of the true time delay line, the beamforming vector of the base station array is represented as:

[0131]

[0132] wherein φ n is the phase shift amount of the nth phase shifter, N represents the number of antennas of the base station, j represents a complex unit, f n represents the baseband frequency, t k represents the time delay value of the nth true time delay line.

[0133] Assuming that the frequency domain signal transmitted by the base station through all subcarriers is a full one vector, at this time, the power of the received signal received by the kth user on the mth subcarrier is

[0134]

[0135] wherein. h(x k , y k , f m ) represents the beamforming vector of the base station antenna array, h(x m , y k，n , f n ) represents the frequency domain channel of the kth user of the base station on the mth subcarrier, α'(f m ) represents the free space path loss, r n represents the distance from the kth user to the nth antenna of the base station, c is the speed of light, φ mean1 represents the phase shift amount of the nth phase shifter, N represents the number of antennas of the base station, j represents a complex unit, f mean2 represents the passband frequency of the mth subcarrier, f meanP represents the baseband frequency of the mth subcarrier, t max represents the time delay value of the nth true time delay line.

[0136] 3. Near-field user positioning based on single base station multi-subarray and beam offset

[0137] As shown in Figure 4 , all antennas of the base station are divided into P subarrays, and the corresponding antennas in different subarrays share the same true time delay line. The centers of the P subarrays can be represented as (0, y m ), (0, y m ),..., (0, y k，n ) respectively.

[0138] The present application is implemented by the technical solutions described in the following S1 to S6 steps:

[0139] S1: By adjusting the phase shift amount of the phase shifter, the beamforming of the 0th subcarrier is focused on the starting point (r0, θ n ), wherein θmax This is the maximum angle within the base station's sensing range; the phase of the phase shifter can then be calculated.

[0140] S2: By adjusting the delay value of the true delay line, the beamforming of the Mth subcarrier is focused at the termination point (r). c θ min ), where θ min It is the smallest angle within the base station's sensing range, from which the delay value of the true delay line can be calculated.

[0141] S3: Set up the phase shifter and true delay line according to the calculation results in S1 and S2. The base station transmits M+1 subcarriers. The beams of different subcarriers are focused at different positions at different angles to achieve full spatial coverage.

[0142] S4: The k-th user will receive the subcarrier frequency f with the highest signal power. d，k The feedback is sent to the base station, which can then calculate the user's angle based on this frequency.

[0143]

[0144] S5: Determine the base station type based on the antenna array partitioning strategy and the number of target base stations.

[0145] S61: If the base station type is a single base station and the antenna array in the single base station is a single array, then the current angle of the target user is used as the angle positioning result.

[0146] S62: If the base station type is a single base station, and the antenna array in the single base station is a multi-subarray. For example... Figure 5 As shown, the P subarrays of the base station acquire the user's angle in a local coordinate system with the subarray center as the origin, denoted as θ1, θ2, ..., θ3, using time-division multiplexing and the angle sensing scheme in the first aspect. P .

[0147] S621: As Figure 6 As shown, an angle network and a distance network based on deep neural networks are constructed to predict the user's true angle and distance, respectively. Both networks have P nodes in their input layer, taking the P angles detected by all subarrays as input. The angle network has one node in its output layer, representing the estimated angle of the user; the distance network has one node in its output layer, representing the estimated distance of the user. In this implementation example, the angle network has 5 hidden layers, and the distance network has 8 hidden layers. These hidden layers effectively extract deep features from the input data and map them to the desired output.

[0148] S622: In the data set preparation, the P angles detected by the base station for a certain user are taken as the input data, and the real angle and real distance of the user are taken as the label data respectively to form an angle training sample and a distance training sample respectively. The process is extended to a large number of users randomly and uniformly distributed in the sensing range of the base station, and finally a large number of angle training samples and distance training samples are obtained.

[0149] S623: The training samples constructed in S622 are taken as the training set, and the angle network and the distance network constructed in S621 are trained respectively, the mean square error function is taken as the loss function, the Adam optimizer is used to update and optimize the network parameters, and the network training is completed.

[0150] S624: In actual use, the base station inputs the P angles detected by all sub-arrays into the angle network to calculate the angle estimation result of the user, inputs the P angles into the distance network to calculate the distance estimation result of the user, and realizes the two-dimensional positioning of the near-field user.

[0151] S63: If the base station type is a double base station. The main base station obtains the angle estimation of the kth user according to the angle sensing scheme in S1-S4 and takes the angle estimation as the final angle sensing result of the user, that is

[0152] S631: The auxiliary base station obtains the auxiliary angle estimation of the user according to the angle sensing scheme in S1-S4 and provides the result to the main base station.

[0153] S632: The main base station calculates the distance estimation of the user as by using the angle estimation and the auxiliary angle estimation of the user, and takes it as the final distance sensing result of the user.

[0154] The embodiment also includes:

[0155] 4, Wave sweeping time overhead analysis

[0156] The near-field user angle sensing scheme based on a single base station and beam offset only needs to perform 1 beam sweeping, and can obtain the angles of all users.

[0157] The near-field user positioning scheme based on a single base station, multiple sub-arrays and beam offset only needs to perform P beam sweepings, and can obtain the two-dimensional positions of all users, and the typical value of P is usually small in actual application, such as P=4, and therefore the sensing time overhead of the scheme is also small.

[0158] The high-precision near-field user positioning scheme based on a double base station and beam offset only needs to perform 2 beam sweepings, and can obtain the two-dimensional positions of all users.

[0159] Therefore, the near-field user positioning scheme provided by the application can complete the positioning of the near-field user in a very short time overhead, and can adapt to the needs of fast sensing in the communication-sensing integrated system.

[0160] 5、MATLAB simulation results

[0161] The simulation parameters are as follows: the number of base station antennas N = 128, the carrier frequency f = 30 GHz, and the bandwidth is 3 GHz. In order to facilitate visual display, the number of OFDM subcarriers M is set to 8. c

[0162] Figure 8 It is shown that under the control of the true time delay line, the normalized power of the signal received by each discrete grid point in the near-field range of the wideband system on each subcarrier. The beamforming of the 0th subcarrier is focused on (60m, 30°), and the beamforming of the Mth subcarrier is focused on (60m, -30°). It can be clearly observed that the subcarrier beam emitted by the base station gradually shifts from 30° to -30° as the subcarrier frequency increases, and all subcarriers achieve full coverage of the base station sensing space.

[0163] Therefore, the angle of the user can be determined according to the subcarrier frequency of the maximum power fed back by the user, and when the number of OFDM subcarriers M is large enough, the scheme will be very effective.

[0164] ​In the foregoing detailed description, the application provides a near field communication user positioning method based on beam offset. The type of a base station is determined according to an antenna array division strategy of a target base station and a number of target base stations. When the type of the target base station is a single base station with multiple subarrays, each subarray is subjected to time division multiplexing. Each subarray uses a true time delay line and a phase shifter to assist in controlling a range and a trajectory of a near field beam offset point in different time division periods. When each subarray transmits multiple subcarrier beams in time division multiplexing, the beams of each subcarrier are gathered at different positions at different angles to achieve full coverage of a target range in space. A target user feeds back a subcarrier frequency with the largest received signal power to the target base station subarray. The target base station subarray calculates a detection angle of the target user in a local coordinate system in which the target base station subarray is located according to the subcarrier frequency. Based on the multiple detection angles and a positioning model constructed in advance, an angle estimation result and a distance estimation result of the target user are obtained. The angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user. The positioning model is trained by angle samples and distance samples detected by multiple subarrays. When the type of the base station is a single base station, if an antenna array in the single base station is a single array, a true time delay line and a phase shifter are used to assist in controlling a range and a trajectory of a near field beam offset point. When the target base station transmits multiple subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to achieve full coverage of a target range in space. A target user feeds back a subcarrier frequency with the largest received signal power to the target base station. The target base station calculates a current angle of the target user according to the subcarrier frequency. The current angle of the target user is taken as an angle positioning result to complete angle positioning of the target user. The application achieves the effect of positioning a near field user affected by beam offset in a wideband communication system with small time overhead.

[0165] The near field communication user positioning device based on beam offset provided by the application is described below. The near field communication user positioning device based on beam offset described below can be referred to in correspondence with the near field communication user positioning method based on beam offset described above.

[0166] Figure 9 The structure diagram of the near field communication user positioning device based on beam offset provided by the application is shown in FIG. 9. As shown in FIG. 9, the near field communication user positioning device based on beam offset comprises a base station type determination unit 910, an offset control unit 920, a calculation unit 930 and a positioning unit 940. Figure 9 The base station type determination unit 910 is configured to determine the type of the base station according to the antenna array division strategy of the target base station and the number of target base stations.

[0167] The base station type determination unit 910 is configured to determine the type of the base station according to the antenna array division strategy of the target base station and the number of target base stations.

[0168] The offset control unit 920 is configured to perform time division multiplexing on each subarray when the target base station type is a single base station and multiple subarrays; each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam offset point in different time division periods; and when each subarray time division multiplexes to respectively emit a plurality of subcarrier beams, the subcarrier beams are gathered at different positions at different angles to achieve spatial full coverage in the target range.

[0169] The calculation unit 930 is configured to feed back, by the target user, a subcarrier frequency with the largest received signal power to the target base station subarray, and the target base station subarray calculates a detection angle of the target user in a local coordinate system of the subarray according to the subcarrier frequency.

[0170] The positioning unit 940 is configured to obtain an angle estimation result and a distance estimation result of the target user based on the plurality of detection angles and a pre-constructed positioning model, and take the angle estimation result and the distance estimation result of the target user as a positioning result to complete two-dimensional positioning of the target user; and the positioning model is trained by angle samples and distance samples detected by a plurality of subarrays.

[0171] Based on the above embodiment, in the device, each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam offset point in different time division periods, and then the device further includes:

[0172] The initial angle of beam scanning is determined as the maximum angle of the base station sensing range, the phase shift amount of the phase shifter is calculated and set, and the beamforming of the 0th subcarrier is directed to a first target position at the initial angle;

[0173] The termination angle of beam scanning is determined as the minimum angle of the base station sensing range, the time delay value of the true time delay line is calculated and set, and the beamforming of the Mth subcarrier is directed to a second target position at the termination angle.

[0174] Based on the above embodiment, in the device, the target base station subarray calculates the detection angle of the target user in the local coordinate system of the subarray according to the subcarrier frequency by using a first preset formula, and the first preset formula is:

[0175]

[0176] Wherein, W is a transmission bandwidth; is a baseband frequency of a subcarrier with the largest received signal power for the kth user; f0 is the lowest passband frequency; f d，k is a subcarrier frequency with the largest received signal power; θ max is the maximum angle of the base station sensing range; θ minThe minimum angle of the base station sensing range.

[0177] Based on the above embodiment, in the device, the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the device further comprises:

[0178] In the case where the base station type is a single base station, if the antenna array in the single base station is a single array, the range and trajectory of the near-field beam deflection point are controlled by using a true time delay line and a phase shifter;

[0179] When the target base station transmits multiple subcarrier beams, the beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage within the target range;

[0180] The target user feeds back the subcarrier frequency with the largest received signal power to the target base station, and the target base station calculates the current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0181] The current angle of the target user is taken as the angle positioning result to complete the angle positioning of the target user.

[0182] Based on the above embodiment, in the device, the angle sample and the distance sample are obtained by the following method:

[0183] P angle data of the user sample detected by P subarrays of the target base station are taken as input data;

[0184] The real angle and the real distance of the user sample are respectively taken as label data;

[0185] An angle training sample is formed by the angle data and the real angle, and a distance training sample is formed by the angle data and the real distance;

[0186] By extending to a plurality of user samples randomly and uniformly distributed in the base station sensing range, a large number of angle training samples and distance training samples are obtained.

[0187] Based on the above embodiment, in the device, the base station type is determined according to the antenna array division strategy of the target base station and the number of target base stations, and then the device further comprises:

[0188] In the case where the base station type is a double base station, the double base station is defined to include a main base station and an auxiliary base station;

[0189] The range and trajectory of the near-field beam deflection point are controlled by using a true time delay line and a phase shifter;

[0190] The beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage within a target range when the target base station transmits beams of multiple subcarriers;

[0191] The target user feeds back a subcarrier frequency with the largest received signal power to the target base station, and the target base station calculates a current angle of the target user according to the subcarrier frequency by using a first preset formula;

[0192] The main base station and the auxiliary base station are time-division multiplexed, the main base station detects an angle estimation value of the target user, and the auxiliary base station detects an auxiliary angle estimation value of the target user;

[0193] A two-dimensional position of the target user is calculated according to the angle estimation value and the auxiliary angle estimation value, and the two-dimensional position is taken as a two-dimensional positioning result.

[0194] The application provides a near-field communication user positioning device based on beam offset. The type of a target base station is determined according to an antenna array division strategy of the target base station and the number of the target base station. When the target base station is a single base station with multiple subarrays, each subarray is time-division multiplexed. Each subarray uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of a near-field beam offset point in different time division periods. When each subarray time-division multiplexes and transmits beams of multiple subcarriers, the beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage within a target range. A target user feeds back a subcarrier frequency with the largest received signal power to the target base station subarray. The target base station subarray calculates a detection angle of the target user in a local coordinate system of the subarray according to the subcarrier frequency. Based on the multiple detection angles and a positioning model constructed in advance, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user. The positioning model is trained by angle samples and distance samples detected by multiple subarrays. When the type of the base station is a single base station, if an antenna array in the single base station is a single array, a true time delay line and a phase shifter are used to assist in controlling the range and trajectory of a near-field beam offset point. When the target base station transmits beams of multiple subcarriers, the beams of each subcarrier are gathered at different positions at different angles to achieve spatial full coverage within a target range. A target user feeds back a subcarrier frequency with the largest received signal power to the target base station. The target base station calculates a current angle of the target user according to the subcarrier frequency. The current angle of the target user is taken as an angle positioning result to complete angle positioning of the target user. The application realizes the effect of positioning a near-field user affected by beam offset in a wideband communication system with small time overhead.

[0195] Figure 10 An example of a schematic diagram of a physical structure of an electronic device is shown in Figure 10 The electronic device can include a processor 1010, a communications interface 1020, a memory 1030, and a communications bus 1040, wherein the processor 1010, the communications interface 1020, and the memory 1030 communicate with each other through the communications bus 1040. The processor 1010 can invoke a logical instruction in the memory 1030 to execute a beam offset-based near-field communication user positioning method, which includes determining a base station type according to an antenna array division strategy of a target base station and a target base station quantity; when the target base station type is a single-base-station multi-subarray, each subarray performs time division multiplexing; each subarray respectively controls a range and a trajectory of a near-field beam offset point using a true time delay line and a phase shifter in different time division periods; when each subarray time division multiplexing respectively emits a plurality of subcarrier beams, the subcarrier beams are gathered at different positions at different angles to achieve spatial full coverage in a target range; a target user feeds back a subcarrier frequency with the largest received signal power to the target base station subarray, and the target base station subarray calculates a detection angle of the target user in a local coordinate system in which the target base station subarray is located based on the subcarrier frequency; based on the plurality of detection angles and a pre-constructed positioning model, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by a plurality of subarrays.

[0196] In addition, the logical instruction in the memory 1030 described above can be implemented in the form of a software function unit and sold or used as an independent product, which can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0197] In another aspect, the present application also provides a computer program product, which comprises a computer program stored on a non-transitory computer readable storage medium, and the computer program can be executed by a processor to enable a computer to perform the beam offset based near field communication user positioning method provided by the above method, which comprises: determining a base station type according to an antenna array division strategy of a target base station and a target base station quantity; when the target base station type is a single base station with multiple sub-arrays, each sub-array is time division multiplexed; each sub-array respectively controls a range and a trajectory of a near field beam offset point by using a true time delay line and a phase shifter in different time division periods; when each sub-array time division multiplexes to respectively emit multiple sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage within a target range; a target user feeds back a sub-carrier frequency with the largest received signal power to the target base station sub-array, and the target base station sub-array calculates a detection angle of the target user in a local coordinate system in which the sub-array is located according to the sub-carrier frequency; based on the multiple detection angles and a pre-constructed positioning model, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by multiple sub-arrays.

[0198] In another aspect, the present application also provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the beam offset based near field communication user positioning method provided by the above method, which comprises: determining a base station type according to an antenna array division strategy of a target base station and a target base station quantity; when the target base station type is a single base station with multiple sub-arrays, each sub-array is time division multiplexed; each sub-array respectively controls a range and a trajectory of a near field beam offset point by using a true time delay line and a phase shifter in different time division periods; when each sub-array time division multiplexes to respectively emit multiple sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage within a target range; a target user feeds back a sub-carrier frequency with the largest received signal power to the target base station sub-array, and the target base station sub-array calculates a detection angle of the target user in a local coordinate system in which the sub-array is located according to the sub-carrier frequency; based on the multiple detection angles and a pre-constructed positioning model, an angle estimation result and a distance estimation result of the target user are obtained, and the angle estimation result and the distance estimation result of the target user are taken as a positioning result to complete two-dimensional positioning of the target user; wherein the positioning model is trained by angle samples and distance samples detected by multiple sub-arrays.

[0199] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0200] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and the necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0201] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for user positioning in near field communication based on beam offset, characterized in that, The method comprises the following steps: determining the base station type according to the antenna array division strategy of the target base station and the number of target base stations; when the target base station type is a single base station with multiple sub-arrays, each sub-array performs time division multiplexing; each sub-array uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam shift point in different time division periods; when each sub-array time division multiplexing respectively transmits multiple sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage within the target range; the target user feeds back the sub-carrier frequency with the maximum received signal power to the target base station sub-array, and the target base station sub-array calculates the detection angle of the target user in the local coordinate system of the sub-array according to the sub-carrier frequency using a first preset formula; the first preset formula is: wherein W is a transmission bandwidth; is a baseband frequency of the subcarrier with the largest received signal power for the kth user; f0is a lowest passband frequency; f d,k is a subcarrier frequency with the largest received signal power; θ max is a maximum angle of a base station sensing range; θ min is a minimum angle of a base station sensing range; based on the multiple detection angles and a pre-constructed positioning model, the angle estimation result and the distance estimation result of the target user are obtained, and in the case of a single base station, if the antenna array in the single base station is divided into multiple sub-arrays, it is divided into P sub-arrays, when the base station actually detects P angles of a certain user, the angles are input into the angle network and distance network which have been trained, and the angle estimation result and the distance estimation result of the target user are calculated through the network, and the angle estimation result and the distance estimation result of the target user are taken as the positioning result to complete the two-dimensional positioning of the target user; wherein the positioning model is trained by the angle samples and distance samples detected by multiple sub-arrays. 2.The beam offset based near field communication user positioning method according to claim 1, characterized in that, Each sub-array uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam shift point in different time division periods, and then comprises the following steps: determining the initial angle of beam scanning as the maximum angle of the base station sensing range, calculating and setting the phase shift amount of the phase shifter, so that the beam of the 0th sub-carrier is steered to point to the first target position at the initial angle; determining the termination angle of beam scanning as the minimum angle of the base station sensing range, calculating and setting the time delay value of the true time delay line, so that the beam of the Mth sub-carrier is steered to point to the second target position at the termination angle. 3.The beam offset based near field communication user positioning method according to claim 1, wherein, determining the base station type according to the antenna array division strategy of the target base station and the number of target base stations, and then comprising the following steps: in the case of a single base station, if the antenna array in the single base station is a single array, a true time delay line and a phase shifter are used to assist in controlling the range and trajectory of the near-field beam shift point; when the target base station transmits multiple sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage within the target range; the target user feeds back the sub-carrier frequency with the maximum received signal power to the target base station, and the target base station calculates the current angle of the target user according to the sub-carrier frequency using a first preset formula; the current angle of the target user is taken as the angle positioning result to complete the angle positioning of the target user. 4.The beam offset based near field communication user positioning method according to claim 1, wherein, The angle samples and the distance samples are obtained by the following method: P angle data of the user sample detected by P sub-arrays of the target base station are taken as input data; The real angle and real distance of the user sample are taken as label data respectively; An angle training sample is formed by the angle data and the real angle, and a distance training sample is formed by the angle data and the real distance; A large number of angle training samples and distance training samples are obtained by extending to a large number of user samples randomly and uniformly distributed in the sensing range of the base station.

5. The beam offset based near field communication user positioning method of claim 1, wherein, According to the antenna array division strategy of the target base station and the number of target base stations, the base station type is determined, and then the method further includes: In the case that the base station type is a double base station, the double base station includes a main base station and an auxiliary base station, and the main base station and the auxiliary base station are parallel to each other; The range and trajectory of the near-field beam deflection point are assisted to control by using the true time delay line and the phase shifter; When the target base station transmits a plurality of sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage in the target range; The target user feeds back the sub-carrier frequency with the maximum received signal power to the target base station, and the target base station calculates the current angle of the target user according to the sub-carrier frequency by using a first preset formula; The main base station and the auxiliary base station are time division multiplexed, the main base station detects the angle estimation value of the target user, and the auxiliary base station detects the auxiliary angle estimation value of the target user; The two-dimensional position of the target user is calculated according to the angle estimation value and the auxiliary angle estimation value, and the two-dimensional position is taken as a two-dimensional positioning result, wherein the calculation formula of the two-dimensional position is: where L is the distance between the primary base station and the center of the secondary base station, an angle estimate for the kth user obtained by the primary base station, a secondary angle estimate for the kth user obtained by the secondary base station.

6. A near field communication user positioning device based on beam offset, characterized in that, It includes: A base station type determination unit is configured to determine the base station type according to the antenna array division strategy of the target base station and the number of target base stations; When the target base station type is a single base station with multiple sub-arrays, each sub-array is time division multiplexed; Each sub-array uses a true time delay line and a phase shifter to assist in controlling the range and trajectory of the near-field beam deflection point in different time division periods; when each sub-array time division multiplexes to transmit a plurality of sub-carrier beams, the beams of each sub-carrier are gathered at different positions at different angles to achieve spatial full coverage in the target range; A calculation unit is configured to feed back the sub-carrier frequency with the maximum received signal power to the target base station sub-array, and the target base station sub-array calculates the detection angle of the target user in the local coordinate system of the sub-array according to the sub-carrier frequency by using a first preset formula; the first preset formula is: wherein W is a transmission bandwidth; is a baseband frequency of the subcarrier with the largest received signal power for the kth user; f0is a lowest passband frequency; f d,k is a subcarrier frequency with the largest received signal power; θ max is a maximum angle of a base station sensing range; θ min is a minimum angle of a base station sensing range; A positioning unit is configured to obtain an angle estimation result and a distance estimation result of the target user based on the multiple detection angles and a pre-constructed positioning model, in a case where the base station type is a single base station, if an antenna array in the single base station is divided into multiple sub-arrays, the antenna array is divided into P sub-arrays, when the base station actually detects P angles of a user, the P angles are input into an angle network and a distance network which have been trained, the angle estimation result and the distance estimation result of the target user are obtained through network calculation, the angle estimation result and the distance estimation result of the target user are taken as a positioning result, and two-dimensional positioning of the target user is completed; wherein the positioning model is trained by angle samples and distance samples obtained through multiple sub-array detections.

7. 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 program to implement the near field communication user positioning method based on beam offset according to any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the near field communication user positioning method based on beam offset according to any one of claims 1 to 5.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the near field communication user positioning method based on beam offset according to any one of claims 1 to 5. The computer program is executed by the processor to implement the near field communication user positioning method based on beam offset according to any one of claims 1 to 5.

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