Mobile terminal positioning method and device

Abstract

The invention relates to the technical field of mobile positioning, and discloses a mobile terminal positioning method and device, and the method comprises the steps: a mobile terminal is accessed to a wireless communication base station to complete identity recognition, the mobile terminal is triggered to transmit an uplink signal at the maximum power, and a phased array radar receives and measures the uplink signal; fusing the measurement data and calculating the position of the terminal based on a signal screening and fusion mechanism of time-frequency-identity triple matching; the invention further discloses a positioning device suitable for the method. The positioning device is composed of a wireless communication base station, a phased array radar system and a positioning processing unit. According to the invention, interference signal elimination and effective acquisition end optimization are completed in the positioning process, the distance, orientation and latitude and longitude coordinates of the terminal can be accurately calculated in combination with time difference and angle information, and the effect of accurate positioning of the mobile terminal is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mobile positioning technology, in particular to a mobile terminal positioning method and device. BACKGROUND

[0002] With the rapid development of mobile communication technology, terminal positioning technology is increasingly widely used in various industries. Traditional positioning methods mainly rely on GPS (Global Positioning System) or Beidou satellite navigation systems, however, in some complex terrain environments or special application scenarios, such as large mining areas, desert areas, emergency rescue sites, offshore platforms, and underground engineering, etc., due to weak satellite signals, serious shielding or inability to receive satellite signals, etc., the traditional positioning means are difficult to meet the demand of high precision and real-time.

[0003] It is urgent to solve the problem of high-precision positioning of mobile terminals (such as mobile phones, wearable devices, etc.) under the condition of limited or missing satellite signals, including the following typical application scenarios: 1. Satellite signal limitation: In large mining areas, deserts, oceans or underground environments, the signals of GPS or other satellite navigation systems may be blocked by terrain, buildings or natural obstacles, making it impossible to accurately position.

[0004] 2. Insufficient accuracy: Cell-based positioning methods (such as Cell-ID, OTDOA) can usually only provide low positioning accuracy, making it difficult to meet the needs of high-precision application scenarios.

[0005] 3. Cost and deployment complexity: Wi-Fi / Bluetooth positioning can provide high accuracy within a short distance, but requires the pre-installation of a large number of Wi-Fi access points or Bluetooth beacons, increasing the cost and deployment difficulty.

[0006] 4. Hardware dependency: UWB ultra-wideband positioning technology can provide centimeter-level positioning accuracy, but its application range is limited to specific hardware support, and the device price is expensive, making it unsuitable for large-scale popularization.

[0007] 5. Poor environmental adaptability: Existing positioning systems perform poorly in harsh weather conditions or environments with severe electromagnetic interference, which may lead to positioning failure or increased error.

[0008] 6. Lack of comprehensive solutions: There is currently no unified technical solution that can provide efficient and accurate positioning services in all scenarios. Different positioning technologies have their own advantages and disadvantages, making it difficult to individually address complex actual needs.

[0009] 7. Real-time and response speed: Some positioning technologies may experience delays when processing large amounts of data, affecting the real-time requirements, especially in emergency rescue and other emergency situations, where fast response is crucial. SUMMARY

[0010] The present application mainly solves the original technical problems, and provides a mobile terminal positioning method and device, which combines the access control of the wireless communication base station to the terminal and the signal feature recognition capability, so that efficient and accurate positioning of the mobile terminal can be realized without satellite signal support.

[0011] The above technical problems of the present application are mainly solved by the following technical scheme: the present application comprises the following steps: S1. The mobile terminal accesses the wireless communication base station and completes identity recognition; S2. The mobile terminal is triggered to send uplink signals at maximum power; S3. The phased array radar receives and measures the uplink signals; S4. The measurement data is fused and the terminal position is calculated.

[0012] By adopting the above technical scheme, the identity information of the terminal can be confirmed by the mobile terminal accessing the base station and completing identity recognition, the signal strength can be enhanced by triggering the terminal to send uplink signals at maximum power, which is beneficial to subsequent reception and measurement, the signal related data can be obtained by the phased array radar receiving and measuring the uplink signals, and the specific position of the mobile terminal can be obtained by fusing the measurement data and calculating the terminal position.

[0013] Preferably, the step S1 specifically comprises that the mobile terminal enters the coverage area of the wireless communication base station, initiates an access request to the base station due to signal strength change or cell reselection mechanism; after the base station receives the access request, an authentication process is started, the international mobile subscriber identity (IMSI) and the radio network temporary identifier (RNTI) of the mobile terminal are obtained; the base station records the access time of the mobile terminal, and prepares to issue a power control instruction.

[0014] By initiating the access request, the base station can obtain the IMSI and RNTI of the mobile terminal, realize identity recognition of the mobile terminal, record the access time for subsequent time-related processing, and prepare to issue a power control instruction for subsequent control of the mobile terminal sending uplink signals.

[0015] Preferably, the step S2 specifically comprises that the wireless communication base station notifies the mobile terminal to increase its uplink transmission power to the maximum value through TPC (transmit power control) transmission power control signaling, the mobile terminal responds to the instruction and sends uplink wireless signals at maximum power; the base station marks the accurate time stamp T0 of the mobile terminal sending the uplink signals.

[0016] By adopting the technical scheme, after the mobile terminal accesses the wireless communication base station and completes identity recognition, the wireless communication base station can make the mobile terminal send uplink wireless signals at maximum power through TPC transmission power control signaling, and the base station marks the accurate time stamp T0, so that the accuracy of subsequent phased array radar receiving and measuring uplink signals can be improved, and then the fusion of measurement data and the calculation of the terminal position are more accurate.

[0017] Preferably, the step S3 specifically comprises that the phased array radar module monitors the air signal frequency band in real time, and when detecting the uplink signal sent by the terminal, the phased array radar module records data.

[0018] By adopting the technical scheme, the phased array radar module monitors the air signal frequency band in real time, can detect the uplink signal sent by the terminal in time and record data, and provides basic data for subsequent fusion of measurement data and calculation of the terminal position.

[0019] Preferably, the data recording of the phased array radar module specifically comprises that the direction of arrival DOA of the signal is estimated by using a multi-antenna array; the time of arrival TOA of the signal to the radar is accurately measured; if multiple radars are deployed, each radar records the DOA and TOA measured by itself respectively, and the exact position of the mobile terminal is determined through cross positioning by combining the coordinate position of each antenna device and the measurement result of the DOA of the signal.

[0020] By adopting the technical scheme, the direction information of the signal can be determined by estimating the direction of arrival DOA of the signal by using a multi-antenna array, and the distance between the terminal and the radar can be calculated by accurately measuring the time of arrival TOA of the signal to the radar, and if multiple radars are deployed, the exact position of the mobile terminal can be determined through cross positioning by combining the coordinate position of the antenna device and the measurement result of the DOA.

[0021] Preferably, the step S4 is based on a signal screening and fusion mechanism of time-frequency-identity triple matching, and interference signal elimination and effective acquisition terminal optimization are completed before data fusion, specifically comprising: The positioning unit, the base station module and the phased array radar module are in the same local area network, the base station module and the phased array radar module synchronize data and information through the network; the positioning processing unit obtains the IMSI of each terminal and the uplink sending time T0 from the base station; the positioning processing unit obtains the base station scheduling context information through the network interface; and the positioning processing unit further obtains key scheduling information from the base station on the basis of obtaining the IMSI of the terminal and the uplink sending time T0.

[0022] By adopting the technical scheme, the interference signal elimination and effective acquisition terminal optimization are completed before data fusion by using the signal screening and fusion mechanism of time-frequency-identity triple matching, so that the positioning data accuracy can be improved; the positioning unit, the base station module and the phased array radar module are in the same local area network and synchronize data and information, so that the consistency and timeliness of the data can be ensured; the positioning processing unit obtains the IMSI of each terminal, the uplink sending time T0, the base station scheduling context information and the key scheduling information, so as to provide a comprehensive and key data basis for subsequent accurate calculation of the terminal position.

[0023] Preferably, the key scheduling information includes time domain identified synchronization subframe information, frequency domain identified resource block allocation information and cell radio network temporary identifier C-RNTI, and specifically includes: obtaining the unique C-RNTI of the current scheduled terminal as the logical identity tag of the terminal in air communication, for subsequent identity authentication after signal demodulation; after time domain and frequency domain confirmation, retaining the signal measurement results DOA and TOA of the target terminal consistent with the CRNTI, and eliminating the interference signals of other terminals; meanwhile, obtaining the TOA and DOA corresponding to each terminal from each phased radar; calculating the signal propagation time Δt according to the difference between TOA and T0, and then calculating the distance between the terminal and the radar; combining the DOA information, the plane position of the terminal is determined by using the intersection method; finally, outputting the position coordinates of each terminal.

[0024] By adopting the technical scheme, the unique C-RNTI of the terminal is obtained for identity authentication, so that the accuracy of identity authentication after signal demodulation can be ensured; after time domain and frequency domain confirmation, the interference signals of other terminals are eliminated, so that the purity and accuracy of the measurement results can be improved; the TOA and DOA of each terminal are obtained, the distance between the terminal and the radar is calculated by calculating the signal propagation time Δt, the plane position of the terminal is determined by using the intersection method in combination with the DOA information, and the position coordinates are outputted, so that the terminal position can be accurately positioned.

[0025] Preferably, the direction of arrival DOA estimation specifically includes: a plurality of antenna units of the phased array radar synchronously receive the uplink wireless signals from the terminal and digitize; a received signal covariance matrix is constructed; the eigenvalue decomposition is performed on the covariance matrix, and the corresponding eigenvalue and eigenvector are extracted; the signal subspace and noise subspace are divided according to the eigenvalue size; the MUSIC spatial spectrum function is constructed to realize spatial spectrum search; the angle corresponding to the spatial spectrum peak is the direction of arrival DOA of the signal.

[0026] By adopting the technical scheme, the mobile terminal accesses the wireless communication base station to complete identity recognition, and then transmits an uplink signal at maximum power, and the phased array radar receives the signal, synchronously receives and digitizes the uplink wireless signal through a plurality of antenna units of the phased array radar, constructs a covariance matrix, performs eigenvalue decomposition, divides a signal subspace and a noise subspace, constructs a MUSIC spatial spectrum function search, and can accurately estimate a direction of arrival (DOA) of the signal, thereby providing a basis for subsequent calculation of a terminal position in combination with other information.

[0027] Preferably, the distance is calculated according to a time of arrival (TOA) measurement of the measurement signal, and specifically includes: the mobile terminal accesses the wireless communication base station and completes identity recognition, the base station controls the mobile terminal to transmit an uplink signal at maximum power, and records a time T0 at which the terminal starts to transmit the signal; the phased array antenna system receives the signal as a synthetic beam, denoted as s(t); the received signal is preprocessed to obtain a baseband digital signal, and a RACH preamble of the signal is extracted; an uplink synchronization sequence possibly used by the terminal is stored locally as a reference signal r(t), and a normalized cross-correlation operation is performed on the received signal s(t) and the reference signal r(t); a main peak position in the cross-correlation function is detected, and a time corresponding to the peak value is marked as a signal arrival time; a signal propagation time difference is calculated according to the transmission time T0 recorded by the base station, and a straight-line distance between the terminal and the phased array antenna is obtained by conversion using the speed of light.

[0028] By adopting the technical scheme, the mobile terminal accesses the base station to complete identity recognition, and then transmits an uplink signal at maximum power, the base station records the transmission time, the phased array antenna system receives the signal, the received signal is preprocessed and a preamble is extracted, a normalized cross-correlation operation is performed on the received signal and a reference signal stored locally, a main peak position is detected to determine a signal arrival time, a propagation time difference is calculated in combination with the transmission time recorded by the base station, and then a straight-line distance between the terminal and the phased array antenna is obtained by conversion using the speed of light, thereby realizing accurate measurement of the distance between the mobile terminal and the phased array antenna.

[0029] A mobile terminal positioning device includes a wireless communication base station responsible for constructing a wireless coverage cell and receiving an access request initiated by a mobile terminal, a phased array radar system in which one or more phased array antennas are deployed, and a positioning processing unit receiving data from the wireless communication base station and the phased array radar system, the wireless communication base station acquires terminal identity information IMSI and confirms a target terminal RNTI, triggers the terminal to transmit an uplink signal at maximum power through a TPC transmission power control instruction, and marks a time stamp at which the mobile terminal transmits the uplink signal; the phased array radar system performs real-time detection on the uplink signal transmitted by the terminal, measures a time of arrival (TOA) and a direction of arrival (DOA) of the signal, and calculates a distance and a position of the terminal in combination with the time difference and the angle information; and the positioning processing unit comprehensively analyzes a signal time difference and a direction of arrival, and calculates a longitude and latitude coordinate of the terminal.

[0030] By adopting the technical scheme, the wireless communication base station constructs a wireless coverage cell, receives an access request, acquires terminal identity information, confirms a target terminal, triggers the terminal to send an uplink signal at maximum power and marks a time stamp, the phased array radar system detects the uplink signal in real time, measures the time of arrival and the direction of arrival and calculates the distance and the direction of the terminal in combination with the information, and the positioning processing unit comprehensively analyzes the signal time difference and the direction of arrival, so that the positioning of the mobile terminal can be completed, and the longitude and latitude coordinates of the terminal are calculated.

[0031] The present application has the following advantages: 1. After the mobile terminal accesses the wireless communication base station and completes identity recognition, the mobile terminal sends an uplink signal at maximum power, the phased array radar receives and measures the signal, and the problem of decreased positioning accuracy caused by signal shielding can be effectively avoided, and the defect that the positioning accuracy of the global positioning system greatly decreases or even cannot be positioned in indoor, underground parking lot and other areas is solved.

[0032] 2. The direction of arrival of the signal and the time of arrival of the signal at the radar are estimated by the phased array radar module using a multi-antenna array, the measurement results of multiple radars are combined to cross-position the mobile terminal, the positioning accuracy is improved, and the problem of relatively low accuracy of the positioning method based on the cellular network is solved.

[0033] 3. The signal screening and fusion mechanism based on time-frequency-identity triple matching completes interference signal elimination and effective acquisition terminal optimization before data fusion, the accuracy of the positioning result can be ensured, and the problems of the wireless local area network positioning being limited by the coverage range of the access point and the signal stability and the effective distance of the Bluetooth positioning being short are solved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a flowchart of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the technical scheme of the present application is further specifically described below through examples and in combination with the drawings. It should be understood that the specific embodiments described herein are only one of the best embodiments of the present application, which are used to explain the present application and do not limit the protection scope of the present application, and all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0036] The technical scheme of the present application is further specifically described below through examples and in combination with the drawings. Embodiments

[0037] A mobile terminal positioning method of the present embodiment, as shown in Figure 1 includes the following steps: S1. The mobile terminal accesses the wireless communication base station and completes identity recognition. Specifically, the mobile terminal enters the coverage area of the wireless communication base station, initiates an access request to the base station due to signal strength changes or cell reselection mechanism, the base station receives the access request, starts the authentication process, obtains the international mobile subscriber identity (IMSI) and the radio network temporary identifier (RNTI) of the mobile terminal, records the access time of the mobile terminal, and prepares to issue a power control instruction. The mobile terminal can initiate an access request to the base station in time when the signal strength changes or the cell reselection, the base station can obtain the IMSI and RNTI of the mobile terminal, realize the identity recognition of the mobile terminal, record the access time for subsequent time-related processing, and prepare to issue a power control instruction for subsequent control of the mobile terminal to send uplink signals.

[0038] S2. Trigger the mobile terminal to send uplink signals at maximum power. Specifically, the wireless communication base station notifies the mobile terminal to increase its uplink transmission power to the maximum value through TPC transmit power control signaling, and the mobile terminal responds to the instruction to send uplink wireless signals at maximum power; the base station marks the accurate timestamp T0 of the mobile terminal sending uplink signals. After the mobile terminal accesses the wireless communication base station and completes identity recognition, the wireless communication base station can make the mobile terminal send uplink wireless signals at maximum power through TPC transmit power control signaling, and the base station marks the accurate timestamp T0, which can improve the accuracy of subsequent phased array radar reception and measurement of uplink signals, and further make the fusion of measurement data and calculation of terminal position more accurate.

[0039] S3. The phased array radar receives and measures the uplink signals. Specifically, the phased array radar module monitors the air signal frequency band in real time, and records data when detecting the uplink signals sent by the terminal.

[0040] The phased array radar module records data specifically including estimating the direction of arrival (DOA) of the signal using a multi-antenna array; The direction of arrival (DOA) estimation specifically includes: The phased array radar synchronously receives and digitizes the uplink wireless signals from the terminal through a plurality of antenna units; Construct a received signal covariance matrix; Perform eigenvalue decomposition on the covariance matrix to extract corresponding eigenvalues and eigenvectors; Divide the signal subspace and noise subspace according to the eigenvalue size; Construct a MUSIC spatial spectrum function to realize spatial spectrum search; The angle corresponding to the spatial spectrum peak is the direction of arrival (DOA) of the signal.

[0041] Accurately measure the time of arrival (TOA) of the signal to the radar; calculate the distance according to the measured time of arrival (TOA) of the signal to the radar, specifically including: The mobile terminal accesses a wireless communication base station and completes identity recognition, the base station controls the mobile terminal to send uplink signal with maximum power, and records the time T0 when the terminal starts to send signal; The phased array antenna system receives the signal as a synthetic beam, denoted as s(t); The received signal is preprocessed to obtain a baseband digital signal, and the RACH preamble of the signal is extracted; The uplink synchronization sequence possibly used by the terminal is stored locally as a reference signal r(t), and the received signal s(t) and the reference signal r(t) are normalized and correlated; The main peak position in the cross-correlation function is detected, and the time corresponding to the peak value is marked as the signal arrival time; According to the sending time T0 recorded by the base station, the signal propagation time difference is calculated, and the linear distance between the terminal and the phased array antenna is obtained by converting the speed of light.

[0042] If multiple radars are deployed, each radar records the DOA and TOA measured by itself, and the exact position of the mobile terminal is determined by cross positioning combined with the coordinate position of each antenna device and the measurement result of the signal direction of arrival DOA. The direction information of the signal can be determined by using the multiple antenna array to estimate the direction of arrival DOA of the signal, and the signal arrival time TOA can be used to calculate the signal propagation time and then calculate the distance between the terminal and the radar. If multiple radars are deployed, each radar records DOA and TOA, and the exact position of the mobile terminal is determined by cross positioning combined with the coordinate position of the antenna device and the measurement result of DOA.

[0043] Cross positioning algorithm In order to accurately calculate the position of the mobile terminal, the present application adopts a cross positioning algorithm based on two or more phased array antenna devices. The algorithm determines the exact position of the signal source (i.e. the mobile terminal) by combining the coordinate position of each antenna device itself and the measurement result of the signal direction of arrival (DOA).

[0044] The implementation steps are specifically: Obtain the antenna device position and DOA data Obtain the position coordinates P1 and P2 of the two phased array antenna devices; Respectively execute DOA estimation algorithm on the two antenna devices to obtain the signal direction of arrival angles θ1 and θ2.

[0045] Construct a geometric model Assume that the target terminal is located at point T, then there are two rays respectively pointing to T from P1 and P2, and the included angles formed by the two rays and the respective antenna device positions are θ1 and θ2.

[0046] According to the principles of geometry, the following equation set can be established to represent the two conditions: Solving target terminal coordinates Solving the above two equations together can obtain the coordinates (X, Y) of the target terminal: First, convert the equation into a linear form about X and Y.

[0047] Then, let the two equations be equal, solve X, and solve the equation to get the value of X.

[0048] Finally, substitute the value of X into any equation to solve Y.

[0049] S4. Fuse measurement data and calculate terminal position.

[0050] Based on the signal screening and fusion mechanism of time-frequency-identity triple matching, interference signal elimination and effective acquisition terminal optimization are completed before data fusion, which specifically includes: The positioning unit, base station module and phased array radar module are in the same local area network, and the base station module and phased array radar module synchronize data and information through the network; The positioning processing unit obtains the IMSI of each terminal and the uplink sending time T0 from the base station; The positioning processing unit obtains the base station scheduling context information through the network interface; The positioning processing unit further obtains key scheduling information from the base station based on the obtained terminal IMSI and uplink sending time T0.

[0051] Using the signal screening and fusion mechanism of time-frequency-identity triple matching, interference signal elimination and effective acquisition terminal optimization are completed before data fusion, which can improve the accuracy of positioning data; The positioning unit, base station module and phased array radar module are in the same local area network and synchronize data and information, which can ensure the consistency and timeliness of the data; The positioning processing unit obtains the IMSI of each terminal, the uplink sending time T0, the base station scheduling context information and the key scheduling information, which provides a comprehensive and key data basis for subsequent accurate calculation of terminal position.

[0052] Obtaining key scheduling information includes time domain identification synchronization subframe information, frequency domain identification resource block allocation information and cell radio network temporary identifier C-RNTI, which specifically includes: Obtain the unique C-RNTI of the current scheduled terminal as the logical identity tag of the terminal in air communication, which is used for identity verification after subsequent signal demodulation; After confirming in time domain and frequency domain, keep the signal measurement results DOA and TOA of the target terminal consistent with CRNTI, and eliminate the interference signals of other terminals; Meanwhile, obtain the TOA and DOA corresponding to each terminal from each phased radar; The signal propagation time Δt is calculated according to the difference between TOA and T0, and the distance between the terminal and the radar is calculated; The planar position of the terminal is determined by using the intersection method in combination with the DOA information; The unique C-RNTI of the terminal is obtained for identity verification, which can ensure the accuracy of identity verification after signal demodulation; after confirmation in the time domain and the frequency domain, the interference signals of other terminals are removed, which can improve the purity and accuracy of the measurement results; the TOA and the DOA of each terminal are obtained, the distance between the terminal and the radar is calculated by calculating the signal propagation time Δt, the planar position of the terminal is determined by using the intersection method in combination with the DOA information, and the position coordinates are output, which can accurately locate the position of the terminal.

[0053] The position coordinates of each terminal are finally output.

[0054] A mobile terminal positioning device includes a wireless communication base station responsible for building a wireless coverage cell and receiving an access request initiated by a mobile terminal, a phased array radar system deploying one or more phased array antennas, and a positioning processing unit receiving data from the wireless communication base station and the phased array radar system, the wireless communication base station obtains terminal identity information IMSI and confirms target terminal RNTI, triggers the terminal to send uplink signals at maximum power through TPC transmission power control instructions, and marks the time stamp of the mobile terminal sending uplink signals; the phased array radar system detects the uplink signals sent by the terminal in real time, measures the time of arrival TOA and the direction of arrival DOA of the signals, calculates the distance and direction of the terminal in combination with the time difference and angle information; the positioning processing unit comprehensively analyzes the signal time difference and the direction of arrival, and calculates the longitude and latitude coordinates of the terminal.

[0055] The wireless communication base station builds a wireless coverage cell, receives an access request, obtains terminal identity information, confirms a target terminal, triggers the terminal to send uplink signals at maximum power and marks the time stamp, the phased array radar system detects uplink signals in real time, measures the time of arrival and the direction of arrival and calculates the distance and direction of the terminal in combination with the information, and the positioning processing unit comprehensively analyzes the signal time difference and the direction of arrival, which can complete the positioning of the mobile terminal and calculate the longitude and latitude coordinates of the terminal.

[0056] Embodiment

[0057] 1. The wireless communication base station: is responsible for building a wireless coverage cell; receives an access request initiated by a terminal; obtains terminal identity information (IMSI) and confirms a target terminal RNTI; triggers the terminal to send uplink signals at maximum power through TPC (transmission power control) instructions; marks the time stamp of the terminal sending uplink signals.

[0058] 2. Phased array radar system: Deploy one or more phased array antennas; Real-time detection of uplink signals sent by the terminal; Measure the time of arrival (TOA) and direction of arrival (DOA) of the signal. By combining time difference and angle information, the distance and orientation of the terminal are calculated.

[0059] 3. Positioning Processing Unit: Receive data from base stations and radar; Comprehensive analysis of parameters such as signal time difference and direction of arrival; Calculate the latitude and longitude coordinates of the terminal; Implementation

[0060] Step S1: The terminal accesses the base station and completes identity verification. When a mobile terminal enters the coverage area of ​​a base station, it may initiate an access request to the base station due to changes in signal strength or cell reselection mechanisms. After receiving the access request, the base station initiates the authentication process to obtain the terminal's International Mobile Subscriber Identity (IMSI) and Radio Network Temporary Identifier (RNTI). The base station records the terminal access time and prepares to issue power control commands.

[0061] Step S2: Trigger the terminal to send uplink signals at maximum power. The base station notifies the terminal to increase its uplink transmit power to the maximum value via TPC (Transmit Power Control) signaling; The terminal responds to the command and transmits uplink wireless signals at maximum power; The base station marks the precise timestamp (T0) of the uplink signal sent by the terminal.

[0062] Step S3: The phased array radar receives and measures the uplink signal. The equipment's phased array radar module monitors airborne signal frequency bands in real time; Upon detecting an uplink signal from the terminal, the radar processes it as follows: The direction of arrival (DOA) of a signal is estimated using a multi-antenna array. Accurately measure the time of arrival (TOA) of the signal at the radar; If multiple radars are deployed, each radar will record its own measured DOA and TOA.

[0063] Step S4: Merge measurement data and calculate terminal location In a complex electromagnetic environment where multiple mobile terminals are simultaneously within the coverage of a base station, a phased array radar can receive mixed DOA and TOA measurements from multiple signal sources. To achieve high-precision positioning of a specific target terminal (distinguishing, for example, a user equipment that is talking or transmitting critical data), the present invention proposes a signal screening and fusion mechanism based on time-frequency-identity triple matching, which completes interference signal rejection and effective acquisition terminal optimization before data fusion.

[0064] The positioning unit, base station module, and phased array radar module are in the same local area network, and the base station module and phased array radar module synchronize data and information through the network The positioning processing unit obtains the IMSI of each terminal and the uplink transmission time T0 from the base station; The positioning processing unit obtains the base station scheduling context information through the network interface Based on the obtained terminal IMSI and uplink transmission time T0, the positioning processing unit further obtains the following key scheduling information from the base station: Synchronization subframe information (time domain identifier): Obtain the TDD uplink configuration subframe number in the current wireless frame structure or the uplink subframe number in FDD; determine the specific subframe position to which the T0 belongs (for example: wireless frame #12345, subframe #2); used to limit the signals collected by the radar in this subframe time period as valid candidate signals, excluding interference in other time periods.

[0065] Resource block (RB) allocation information (frequency domain identifier): Obtain the starting position and bandwidth of the uplink physical resource block (PRB) allocated by the base station for the terminal (for example: starting RB = 12, bandwidth = 6 RB); corresponding center frequency fc = f0 + Δf * RBcenter, where Δf = 180 kHz; used to guide the radar receiver to tune to the correct frequency band for signal acquisition, avoiding mis-sampling adjacent channel signals.

[0066] C-RNTI (Cell Radio Network Temporary Identifier, Cell Radio Network Temporary Identifier) Obtain the unique C-RNTI of the currently scheduled terminal (for example: 0x4A2F); as the logical identity tag of the terminal in air interface communication, used for identity verification after signal demodulation.

[0067] After time and frequency domain confirmation, retain the signal measurement results (DOA, TOA) consistent with the target terminal's CRNTI and eliminate interference signals from other terminals Meanwhile, obtain the TOA and DOA corresponding to each terminal from each phased radar; The signal propagation time Δt is calculated according to the difference between TOA and T0, and the distance between the terminal and the radar is calculated (d = c × Δt); Combined with the DOA information, the plane position of the terminal is determined by the intersection method; Finally, the position coordinates (longitude, latitude) of each terminal are output for the application system to call.

[0068] Key algorithms and technical implementation DOA estimation MUSIC algorithm is a high-resolution DOA estimation algorithm based on the orthogonality of signal subspace and noise subspace. It divides the signal space into signal subspace and noise subspace by eigenvalue decomposition of the received signal covariance matrix, and uses the orthogonality between them to search for the signal incident direction.

[0069] Step 1: Signal reception and digitization The multiple antenna elements of the phased array radar synchronously receive the uplink wireless signals from the terminal; After down-conversion and analog-to-digital conversion, the channel signals form digital baseband signals.

[0070] Step 2: Constructing the received signal covariance matrix Statistical analysis is performed on the multi-channel received data to construct the covariance matrix of the received signal; The covariance matrix reflects the correlation between the antenna elements.

[0071] Step 3: Eigenvalue decomposition Eigenvalue decomposition is performed on the covariance matrix to extract the corresponding eigenvalues and eigenvectors; The signal subspace and noise subspace are divided according to the eigenvalue size.

[0072] Step 4: Spatial spectrum search Construct the MUSIC spatial spectrum function:

[0073] Where a(θ) is the array manifold vector, and En is the noise subspace. Within the preset angle range (such as 0°~360°), the spatial spectrum is scanned to find the spectral peak position.

[0074] Table 1 MUSIC spatial spectrum function parameter meaning table

[0075] Step 5: Determine DOA The angle corresponding to the spectral peak is the direction of arrival (DOA) of the signal; TOA measurement calculates the distance In order to realize high-precision time measurement of the mobile terminal transmitting signal, a complete phased array antenna system is adopted to estimate the TOA (Time of Arrival) of the received uplink signal. Through multi-channel reception, clock synchronization and reference signal cross-correlation analysis, the system realizes accurate detection of the signal arrival time.

[0076] 1) Variable definition: T0: the timestamp recorded by the base station of the terminal sending uplink signal; s(t): the phased array antenna system receives the terminal transmitting signal as a whole; r(t): known reference signal (such as RACH preamble, etc.); y(t)=s(t) h(t)+n(t): received signal model, where h(t) is the channel response and n(t) is the additive noise; Pcorr(t): cross-correlation function between received signal and reference signal; tpeak: the maximum point of the cross-correlation function, used to estimate the signal arrival time; Δt=tpeak T0: signal propagation time difference; d=c*Δt: the straight-line distance from the terminal to the phased array antenna system, where c is the speed of light.

[0077] 2) Implementation steps Step one: the terminal sends uplink signal The mobile terminal initiates access request after entering the coverage area of the base station; The base station obtains the terminal identity information (IMSI) and controls it to send uplink signal at maximum power through TPC instruction; The base station records the time T0 when the terminal starts sending signal.

[0078] Step two: phased array antenna receives signal The entire phased array antenna system receives the uplink wireless signal from the terminal as a whole; The antenna system is composed of multiple antenna units, but in this mode it receives as a synthetic beam; The received signal is denoted as s(t), which contains multipath effect, channel fading and other influences.

[0079] Step three: signal preprocessing Downconvert, filter, analog-to-digital conversion and other processing are performed on the received signal to obtain the baseband digital signal; The effective part of the signal (RACH preamble) is extracted for subsequent correlation operation.

[0080] Step four: cross-correlation calculation with reference signal The uplink synchronization sequence that the local storage terminal can use as the reference signal r(t); The normalized cross-correlation operation is performed on the received signal s(t) and the reference signal r(t):

[0081] Wherein, represents the complex conjugate, t is the time offset.

[0082] Table 2: Normalized cross-correlation function parameter meaning table

[0083] Step five: detect the cross-correlation peak and estimate the arrival time.

[0084] Detect the main peak position in the cross-correlation function Pcorr(t); Mark the time corresponding to the peak as the signal arrival time:

[0085] Step six: calculate the signal propagation time difference and distance According to the sending time T0 recorded by the base station, the signal propagation time difference is calculated:

[0086] Convert the terminal and phased array antenna linear distance using the speed of light:

[0087] Cross positioning algorithm In order to accurately calculate the position of the mobile terminal, the present application adopts a cross positioning algorithm based on two or more phased array antenna devices. This algorithm determines the exact position of the signal source (i.e. the mobile terminal) by combining the coordinate position of each antenna device itself and the measurement result of the signal direction of arrival (DOA).

[0088] 1) Variable definition P1(x1,y1): Two-dimensional coordinates of the first phased array antenna device; P2(x2,y2): Two-dimensional coordinates of the second phased array antenna device; θ1: The signal direction of arrival angle (measured clockwise relative to the north direction) measured by the first phased array antenna device; θ2: The signal direction of arrival angle (as above) measured by the second phased array antenna device; T(X,Y): Two-dimensional coordinates of the target terminal to be solved; d1, d2: distance from target terminal to two antenna devices (optional, used to assist calculation); a, b: angle formed by antenna device and target terminal (used for geometric relationship analysis).

[0089] 2) Implementation steps Step 1: Obtain antenna device position and DOA data Obtain the position coordinates P1 and P2 of the two phased array antenna devices; Perform DOA estimation algorithm on the two antenna devices respectively to obtain the signal direction of arrival angles θ1 and θ2.

[0090] Step 2: Build geometric model Assume that the target terminal is located at point T, then there are two rays pointing to T from P1 and P2 respectively, and the angles formed by the two rays and the respective antenna device positions are θ1 and θ2.

[0091] According to the principles of geometry, the following system of equations can be established to represent the two conditions:

[0092] Step 3: Solve the target terminal coordinates Solving the above two equations simultaneously can obtain the coordinates (X, Y) of the target terminal: First, convert the equations to linear form with respect to X and Y:

[0093] Then, set the two equations equal to each other and solve for X

[0094] Solving this equation gives the value of X.

[0095] Finally, substitute the value of X into any equation to solve for Y

[0096] The mobile terminal positioning method provided by the embodiments of the present application comprises the following steps: a mobile terminal accesses a base station and identifies an identity, a terminal maximum power signal is triggered, a phased array radar receives a measurement signal, and data fusion is performed to calculate a terminal position, wherein the phased array radar measures the signal emitted by the mobile terminal, and data fusion is performed in combination with the information provided by the base station, so that the positioning accuracy and applicability of the mobile terminal are improved. The reason is that the phased array radar has high signal measurement capability, can obtain accurate signal information in different environments, and can overcome the limitations of a single method by comprehensively utilizing various information in multiple steps. Specifically, in the step of the mobile terminal accessing the base station and identifying the identity, the mobile terminal enters the coverage area of the wireless communication base station, initiates an access request to the base station due to signal strength changes or a cell reselection mechanism. The mobile terminal can be a common device such as a smart phone or a tablet computer, as long as it has a wireless communication function. After the base station receives the access request, an authentication process is started, and the international mobile subscriber identity (IMSI) and the radio network temporary identifier (RNTI) of the mobile terminal are obtained. The authentication process can use an encryption algorithm to verify the identity of the terminal to ensure communication security. The base station records the access time of the mobile terminal and prepares to issue a power control instruction.

[0097] In the step of triggering the terminal maximum power signal, the wireless communication base station notifies the mobile terminal to increase the uplink transmission power to the maximum value through TPC transmission power control signaling, and the mobile terminal responds to the instruction to transmit the uplink wireless signal at the maximum power. The TPC transmission power control signaling can be a specific coded signal, and the mobile terminal will adjust the transmission power according to the preset program after receiving it. The base station marks the accurate timestamp T0 of the uplink signal sent by the mobile terminal, which can be accurate to the millisecond level, providing an accurate time basis for subsequent calculation.

[0098] In the step of receiving and measuring the signal by the phased array radar, the phased array radar module monitors the air signal frequency band in real time, and records data when detecting the uplink signal emitted by the terminal. The phased array radar module can be composed of multiple antennas to form an antenna array, which can more accurately receive and measure the signal. The specific recording content includes estimating the direction of arrival (DOA) of the signal using a multi-antenna array and accurately measuring the time of arrival (TOA) of the signal to the radar. If multiple radars are deployed, each radar records the DOA and TOA measured by itself, combines the coordinate position of each antenna device and the measurement result of the direction of arrival (DOA) of the signal, and determines the exact position of the mobile terminal through cross positioning.

[0099] The step of fusing data computing terminal position is based on signal screening and fusing mechanism of time-frequency-identity triple matching, and interference signal elimination and effective acquisition terminal optimization are completed before data fusion. The positioning unit, base station module and phased array radar module are in the same local area network, and the base station module and the phased array radar module synchronize data and information through the network. The positioning processing unit obtains the IMSI of each terminal and the uplink sending time T0 from the base station, and also obtains the base station scheduling context information through the network interface. On the basis of obtaining the terminal IMSI and the uplink sending time T0, the key scheduling information is further obtained from the base station, including the synchronization subframe information identified by the time domain, the resource block allocation information identified by the frequency domain and the cell radio network temporary identifier C-RNTI. The unique C-RNTI of the current scheduled terminal is obtained as the logical identity tag of the terminal in air interface communication, which is used for identity verification after subsequent signal demodulation. After the time domain and frequency domain are confirmed, the signal measurement results DOA and TOA of the CRNTI consistent with the target terminal are reserved, and the interference signals of other terminals are eliminated. At the same time, the TOA and DOA corresponding to each terminal are obtained from each phased radar, the signal propagation time Δt is calculated according to the difference between TOA and T0, and then the distance between the terminal and the radar is calculated, combined with the DOA information, the plane position of the terminal is determined by using the intersection method, and finally the position coordinates of each terminal are output.

[0100] The DOA estimation specifically includes that the phased array radar synchronously receives the uplink wireless signals from the terminal by a plurality of antenna units and digitizes the signals, constructs a received signal covariance matrix, performs eigenvalue decomposition on the covariance matrix, extracts corresponding eigenvalues and eigenvectors, divides the signal subspace and noise subspace according to the eigenvalue size, constructs a MUSIC spatial spectrum function to realize spatial spectrum search, and the angle corresponding to the spatial spectrum peak is the DOA of the signal.

[0101] The distance is calculated based on the Time of Arrival (TOA) of the measured signal at the radar. Specifically, this involves the mobile terminal accessing the wireless communication base station and completing identity verification. The base station controls the mobile terminal to transmit uplink signals at maximum power, and the time T0 when the terminal begins transmitting the signal is recorded. The phased array antenna system receives the signal as a synthetic beam, denoted as s(t). The received signal is preprocessed to obtain the baseband digital signal, and the RACH preamble is extracted. The uplink synchronization sequence that the terminal may use is stored locally as a reference signal r(t). A normalized cross-correlation operation is performed between the received signal s(t) and the reference signal r(t). The position of the main peak in the cross-correlation function is detected, and the time corresponding to this peak is marked as the signal arrival time. Based on the transmission time T0 recorded by the base station, the signal propagation time difference is calculated, and the straight-line distance between the terminal and the phased array antenna is obtained using the speed of light. The implementation principle of this embodiment is as follows: This embodiment, through multi-step collaboration, comprehensively utilizes the signal measurement capabilities of phased array radar and the identity and time information provided by the base station, and adopts a time-frequency-identity triple matching signal filtering and fusion mechanism to overcome the defects of existing mobile terminal positioning methods in different environments, improves positioning accuracy and applicability, and can achieve more accurate positioning in complex environments such as indoors and remote areas, providing more reliable technical support for various industries that rely on mobile terminal positioning.

[0102] In the step of receiving measurement signals with a phased array radar, different antenna layouts can be employed. For example, a circular antenna array layout can provide good signal reception in all directions, offering more comprehensive coverage of the surrounding space and reducing blind spots compared to traditional linear antenna arrays. A circular antenna array can consist of multiple antennas of the same specifications evenly distributed around a circle, each capable of independently receiving signals, which are then processed by a signal processing unit. The implementation principle of this embodiment is as follows: different antenna layouts can be optimized according to specific application scenarios and requirements. A circular antenna array layout enhances the signal reception capability of the phased array radar in complex environments, further improving the accuracy and reliability of positioning, especially suitable for scenarios requiring omnidirectional monitoring, thus expanding the applicability of mobile terminal positioning methods.

[0103] Example

[0104] Real-time personnel positioning system in mining areas 1. Work Background and Deployment Environment A large open-pit mine is located in a mountainous area with complex terrain and severe obstruction, making it difficult for traditional GPS positioning signals to provide stable coverage. To improve safety management efficiency, the terminal positioning system based on the fusion of wireless communication base stations and phased array radar, as described in this invention, is deployed for real-time, high-precision positioning of workers wearing mobile terminals (smart safety helmets).

[0105] 2. System components and key devices Base station module: Support 4G / 5G communication protocol; With TPC transmit power control function; Can record the timestamp T0 of terminal initiated uplink signal Installed in the central area of the mine, covering a radius of about 3 kilometers.

[0106] Two phased array radar antenna units: Deployed in the commanding heights of the mine, respectively in different directions, forming an intersection angle; The antenna adopts a 16-element linear array structure; Support DOA estimation and TOA measurement; Built-in high-speed ADC / DAC module, realizing real-time processing of terminal uplink signals.

[0107] Positioning processing unit: Run the MUSIC algorithm, cross-correlation TOA extraction algorithm and cross-positioning algorithm described in the application; Real-time output of terminal position coordinates and upload to the mine dispatching platform.

[0108] 3. Actual application process Terminal access and signal triggering After the intelligent safety helmet enters the base station coverage area, it sends an access request to the base station; The base station completes authentication and obtains the terminal IMSI, records the time T0=14:23:05 of sending uplink signal; The base station issues a TPC instruction, requiring the terminal to send the RACH preamble at the maximum power.

[0109] Radar reception and DOA estimation: Two phased array radars synchronously receive the uplink signal transmitted by the terminal; Use the MUSIC algorithm to perform spatial spectrum analysis on the signal, and get the incoming wave direction as: Radar A: θ1=45∘ Radar B: θ2=130∘ TOA measurement and distance calculation: Perform normalized cross-correlation operation on each radar received signal and reference sequence to find the peak time Radar A: tpeak,A=14:23:05.003 Radar B: tpeak,B=14:23:05.0032 Calculate the propagation time difference ΔtA=3ms, ΔtB=3.2ms Get the distance information: dA=c ΔtA=900m dB=c ΔtB=960m Cross location solution: According to the location coordinates of Radar A and Radar B, combined with the measured angle and distance, the terminal position is solved using the intersection method as: North Latitude 39.71°, East Longitude 106.88°.

[0110] Result output and monitoring The data is uploaded to the mine monitoring large screen to display the positions of all operating personnel in real time; In the simulation exercise, the positioning accuracy within ±1 meter is successfully achieved, meeting the emergency response requirements.

[0111] Embodiment

[0112] 1. Work background and deployment environment In a remote mountainous area, due to complex terrain and poor signal coverage, traditional GPS and mobile communication networks are difficult to provide reliable positioning services. In emergency situations, such as lost hikers or natural disasters, quickly and accurately locating the position of the trapped personnel is crucial for rescue operations. Therefore, the terminal positioning system based on the fusion of wireless communication base stations and phased array radars described in the present invention is applied to such mountain rescue scenarios.

[0113] 2. System composition and key devices Base station module: Supports 4G / 5G communication protocol; Equipped with high-precision time synchronization function to ensure that the timestamp T0 of the terminal initiating uplink signal can be recorded; Installed near the temporarily established rescue command center, covering a radius of about 2 kilometers.

[0114] Two phased array radar antenna units: Deployed at different positions on the mountain slope to form an effective intersection angle to improve positioning accuracy; The antenna adopts an 8-element circumferential array structure, supporting omnidirectional scanning; Built-in high-speed ADC / DAC module to realize real-time processing of terminal uplink signals.

[0115] Positioning processing unit: Run the MUSIC algorithm, cross-correlation TOA extraction algorithm, and cross-location algorithm described in the present invention; Real-time output of terminal position coordinates and upload to the rescue command platform to assist in developing rescue strategies.

[0116] 3. Actual application process Signal triggering and reception During an outdoor adventure, 13 hikers lost their way due to sudden weather changes and lost contact with the outside world. Upon arrival, the rescue team set up a base station at the command center and used a drone to search for areas with weak cell phone signals. The base station issued instructions to all detectable phones to send RACH preambles at maximum power, recording the time as T0=16:30:00.

[0117] DOA estimation Both phased array radar antennas simultaneously received the uplink signal from one of the missing hikers' phones. Using the MUSIC algorithm for spatial spectrum analysis, the directions of arrival were determined as: Radar A: θ1=270∘ Radar B: θ2=180∘ TOA measurement and distance calculation Perform normalized cross-correlation operation on each radar received signal and reference sequence to find the peak time: Radar A: tpeak,A=16:30:00.0025 Radar B: tpeak,B=16:30:00.0030 Calculate the propagation time difference ΔtA=2.5ms,ΔtB=3ms Get distance information: dA=c ΔtA=750mdA=c ΔtA=750m dB=c ΔtB=900mdB=c ΔtB=900m Cross-location solution According to the location coordinates of Radar A and Radar B (known), combined with the measured angle and distance information, use the intersection method to solve the terminal location as: North Latitude 39.71°, East Longitude 106.88° Result output and rescue operation Upload data to the rescue command platform to display the location of the missing person in real time. The rescue team quickly organized the search and rescue based on the accurate coordinates provided, and successfully rescued all the trapped hikers. Tests show that in complex mountainous environments, the system can provide stable positioning services, with an average positioning error of less than ±3 meters.

[0118] The specific embodiments described herein are merely illustrative of the principles of this application. These embodiments are presented by way of example only, and are not intended to limit the scope of the application. Numerous alternatives to the embodiments described herein will be readily apparent to those skilled in the art. The principles of the application described herein can be employed in any of various embodiments or examples not specifically described herein. Thus, the scope of the application should be determined by the following claims, and not by the ability of the claims to express one of the specific embodiments described herein.

Claims

1. A mobile terminal positioning method, characterized in that, Includes the following steps: S1. The mobile terminal accesses the wireless communication base station and completes identity verification; S2. Trigger the mobile terminal to send uplink signals at maximum power; S3. The phased array radar receives and measures the uplink signal; S4. Merge measurement data and calculate terminal location.

2. The mobile terminal positioning method according to claim 1, characterized in that, Step S1 specifically includes the following steps: when a mobile terminal enters the coverage area of ​​a wireless communication base station, it initiates an access request to the base station due to changes in signal strength or cell reselection mechanism; after receiving the access request, the base station initiates an authentication process to obtain the International Mobile Subscriber Identity (IMSI) and the Radio Network Temporary Identifier (RNTI) of the mobile terminal. The base station records the access time of the mobile terminal and prepares to issue power control commands.

3. The mobile terminal positioning method according to claim 1, characterized in that, Step S2 specifically includes the following steps: the wireless communication base station notifies the mobile terminal to increase its uplink transmission power to the maximum value through TPC transmit power control signaling; the mobile terminal responds to the instruction and transmits uplink wireless signals at the maximum power. The base station marks the precise timestamp T0 of the uplink signal sent by the mobile terminal.

4. The mobile terminal positioning method according to claim 1, characterized in that, Step S3 specifically includes the phased array radar module monitoring the air signal frequency band in real time, and recording the data after detecting the uplink signal sent by the terminal.

5. A mobile terminal positioning method according to claim 4, characterized in that, The phased array radar module performs data recording specifically by using a multi-antenna array to estimate the direction of arrival (DOA) of the signal; accurately measuring the time of arrival (TOA) of the signal at the radar; and if multiple radars are deployed, each radar records its own measured DOA and TOA, and by combining the coordinate position of each antenna device and the measurement result of the DOA of the signal arrival, cross-location is used to determine the exact location of the mobile terminal.

6. A mobile terminal positioning method according to claim 1, characterized in that, Step S4, based on a time-frequency-identity triple matching signal filtering and fusion mechanism, completes interference signal removal and effective acquisition end selection before data fusion, specifically including: The positioning unit, base station module, and phased array radar module are located on the same local area network, and the base station module and phased array radar module synchronize data and information through the network; The positioning processing unit obtains the IMSI and uplink transmission time T0 of each terminal from the base station; The positioning processing unit obtains base station scheduling context information through the network interface; Based on the terminal IMSI and uplink transmission time T0, the positioning processing unit further obtains key scheduling information from the base station.

7. A mobile terminal positioning method according to claim 6, characterized in that, The acquisition of key scheduling information includes synchronization subframe information with time-domain identifiers, resource block allocation information with frequency-domain identifiers, and cell radio network temporary identifier (C-RNTI), specifically including: Obtain the unique C-RNTI of the currently scheduled terminal as the logical identity tag of the terminal in air interface communication, which will be used for authentication after subsequent signal demodulation. After confirming in the time and frequency domains, retain the signal measurement results DOA and TOA consistent with the target terminal of CRNTI, and eliminate interference signals from other terminals; Simultaneously, the TOA and DOA corresponding to each terminal are obtained from each phased radar; The propagation time Δt of each signal is calculated based on the difference between TOA and T0, and then the distance between the terminal and the radar is deduced. By combining DOA information, the intersection method is used to determine the planar position of the terminal; Finally, the position coordinates of each terminal are output.

8. A mobile terminal positioning method according to claim 5, characterized in that, The DOA estimation of the incoming wave direction specifically includes: Several antenna elements of the phased array radar synchronously receive uplink wireless signals from the terminal and digitize them; Construct the covariance matrix of the received signal; Eigenvalue decomposition is performed on the covariance matrix to extract the corresponding eigenvalues ​​and eigenvectors; Divide the signal subspace and noise subspace according to the magnitude of the eigenvalues; Construct a MUSIC spatial spectrum function to achieve spatial spectrum search; The angle corresponding to the spatial spectral peak is the direction of arrival (DOA) of the signal.

9. A mobile terminal positioning method according to claim 5, characterized in that, The distance is calculated based on the Time of Arrival (TOA) of the measured signal at the radar, specifically including: The mobile terminal accesses the wireless communication base station and completes identity verification. The base station controls the mobile terminal to send uplink signals at maximum power and records the time T0 when the terminal starts sending signals. The phased array antenna system receives signals as a synthetic beam, denoted as s(t); The received signal is preprocessed to obtain the baseband digital signal, and the RACH preamble of the signal is extracted. The uplink synchronization sequence that the local storage terminal may use as a reference signal r(t) is used to perform normalized cross-correlation operation on the received signal s(t) and the reference signal r(t); Detect the position of the main peak in the cross-correlation function and mark the time corresponding to the peak as the signal arrival time; Based on the transmission time T0 recorded by the base station, the signal propagation time difference is calculated, and the straight-line distance between the terminal and the phased array antenna is obtained by converting the speed of light.

10. A mobile terminal positioning device, applicable to the method described in any one of claims 1-9, characterized in that, The system includes a wireless communication base station responsible for building wireless coverage cells and receiving access requests initiated by mobile terminals; a phased array radar system deploying one or more phased array antennas; and a positioning processing unit that receives data from the wireless communication base station and the phased array radar system. The wireless communication base station obtains the terminal identity information IMSI and confirms the target terminal RNTI. It triggers the terminal to transmit uplink signals at maximum power through a TPC transmit power control command and marks the timestamp of the uplink signal transmission. The phased array radar system detects the uplink signals transmitted by the terminal in real time, measures the time of arrival (TOA) and direction of arrival (DOA) of the signal, and calculates the distance and azimuth of the terminal by combining the time difference and angle information. The positioning processing unit comprehensively analyzes the signal time difference and direction of arrival to calculate the latitude and longitude coordinates of the terminal.

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