Terminal positioning method and apparatus, electronic device, storage medium, and program product

Abstract

The application provides a terminal positioning method and device, electronic equipment, storage medium and program product, and relates to the technical field of wireless communication. The method comprises the following steps: identifying and locking a target terminal, and listening to the uplink time domain signal of the target terminal; performing timing processing on the uplink time domain signal according to a downlink frame synchronization point and uplink parameters, calculating a time domain timing advance (TA) value and a frequency domain TA value based on the processing result; when it is determined that TA verification is passed according to the time domain TA value and the frequency domain TA value, calculating target distance information according to the time domain TA value; calculating target direction information based on the uplink time domain signal through a phase comparison method; and determining the position of the target terminal according to the target distance information and the target direction information. The application can realize accurate positioning of the target terminal.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a terminal positioning method, apparatus, electronic device, storage medium, and program product. Background Technology

[0002] In recent years, with the rapid evolution of mobile communication technology, especially the large-scale commercial deployment of fifth-generation (5G) communication technology, mobile data traffic has exploded. This has greatly promoted the development and popularization of location-based services (LBS). LBS not only demonstrates enormous commercial value in civilian and commercial fields such as navigation, social networking, targeted advertising, and IoT device management, but also plays a crucial role in many professional industry applications where high-precision real-time positioning capabilities are essential.

[0003] Currently, existing terminal positioning technologies generally perform coarse positioning by obtaining the ID (identity) of the serving cell where the target terminal is located. Its accuracy depends on the cell coverage radius, which is usually in the range of several hundred meters to several kilometers. The positioning accuracy is insufficient and cannot meet the requirements of precise tracking.

[0004] Therefore, how to achieve high-precision positioning of target terminals to overcome the shortcomings of existing technologies has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention provides a terminal positioning method, device, electronic device, storage medium, and program product to address the shortcomings of existing terminal positioning methods in terms of insufficient positioning accuracy.

[0006] This invention provides a terminal positioning method, comprising:

[0007] The target terminal is identified and locked, and the uplink time domain signal of the target terminal is monitored;

[0008] Based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is subjected to timing processing, and the time-domain timing advance (TA) value and frequency-domain TA value are calculated based on the processing results.

[0009] When the TA verification is deemed successful based on the time-domain TA value and the frequency-domain TA value, the target distance information is calculated based on the time-domain TA value.

[0010] The target direction information is calculated based on the uplink time-domain signal using the phase comparison method.

[0011] The location of the target terminal is determined based on the target distance information and the target direction information.

[0012] According to a terminal positioning method provided by the present invention, the step of performing timing processing on the uplink time-domain signal based on the downlink frame synchronization point and uplink parameters, and calculating the time-domain timing advance (TA) value and the frequency-domain TA value based on the processing result includes:

[0013] Based on the downlink frame synchronization point and the uplink parameters, the uplink time domain signal is processed in a timing manner to locate and extract the uplink time domain data;

[0014] Based on the uplink time domain data, extract the frequency domain data of the first received demodulation reference signal (DMRS);

[0015] Calculate the local DMRS frequency domain data based on the downlink control information (DCI) parameters;

[0016] The frequency domain channel response is calculated based on the first received DMRS frequency domain data and the local DMRS frequency domain data;

[0017] The frequency domain channel response is converted into the time domain channel impulse response by using the inverse fast Fourier transform (IFFT).

[0018] The time-domain channel impulse response is subjected to modulus square operation, and the peak position is determined based on the operation result;

[0019] Calculate the time-domain TA value based on the peak position;

[0020] Perform a transpose-misaligned multiplication operation on the frequency domain channel response to obtain a complex scalar;

[0021] The frequency domain TA value is calculated based on the angle value of the complex scalar and the IFFT transform length.

[0022] According to a terminal positioning method provided by the present invention, before calculating target distance information based on the time-domain TA value when determining that the TA verification has passed based on the time-domain TA value and the frequency-domain TA value, the method further includes:

[0023] Based on the time-domain TA value, time-domain compensation is performed on the first received DMRS frequency-domain data to obtain the second received DMRS frequency-domain data.

[0024] Normalized energy calculations are performed on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy;

[0025] Based on the frequency domain TA value, the first received DMRS frequency domain data is frequency domain compensated to obtain the third received DMRS frequency domain data.

[0026] The normalized energy is calculated by performing normalized energy calculation on the third received DMRS frequency domain data and the local DMRS frequency domain data to obtain the second energy;

[0027] Calculate the average value of the first energy and the second energy to obtain the average energy;

[0028] The average energy is checked to see if it is greater than a preset threshold in order to determine whether the TA verification is successful.

[0029] According to a terminal positioning method provided by the present invention, the step of performing time-domain compensation on the first received DMRS frequency-domain data based on the time-domain TA value to obtain the second received DMRS frequency-domain data includes:

[0030] Calculate the starting address of the DMRS symbol data based on the time-domain TA value;

[0031] Extract DMRS symbol data based on the starting address;

[0032] The DMRS symbol data is sequentially processed by decyclic prefix removal and Fast Fourier Transform to extract the second received DMRS frequency domain data; and / or,

[0033] The step of performing normalized energy calculation on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy includes:

[0034] After transposing the local DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the first calculation result;

[0035] Perform a modular square operation on the first calculation result to obtain the total energy of the first signal alignment;

[0036] After transposing the second received DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the total energy of the first received signal;

[0037] The first energy is calculated based on the first signal alignment total energy, the first received signal total energy, and the total number of DMRS subcarriers.

[0038] According to a terminal positioning method provided by the present invention, the step of calculating target direction information based on the uplink time-domain signal using a phase comparison method includes:

[0039] Obtain the frequency point to be measured, and construct a theoretical phase difference sample based on the frequency point to be measured, the antenna spacing, and the rotational incident angle;

[0040] Obtain the complex signal corresponding to the uplink time-domain signal in each antenna of the antenna array, and calculate the true phase difference based on the complex signal;

[0041] Calculate the mean cosine similarity between the actual phase difference and the theoretical phase difference sample;

[0042] The rotational incident angle corresponding to the maximum value in the average cosine similarity is determined as the azimuth angle of the incoming wave from the target.

[0043] According to a terminal positioning method provided by the present invention, the identification of the target terminal includes:

[0044] Establish downlink synchronization with the target base station, and monitor and decode the physical downlink control channel of the target base station to obtain the transport block size (TBS) in the downlink control information;

[0045] When no inducement message is sent to the target terminal, the average value of all TBSs obtained within a preset time window is calculated and used as the background TBS baseline.

[0046] Send an inducement message to the target terminal and start a listening timer. During the duration of the listening timer, monitor the maximum value of TBS as a candidate TBS peak value.

[0047] When the peak value of the candidate TBS is detected to be greater than the background TBS baseline and the preset TBS threshold, it is determined to be a valid identification event;

[0048] The steps of sending the inducement message, starting the listening timer, and detecting the candidate TBS peak are repeated N times. If the number of times the effective event is identified reaches M, the target terminal is determined to be identified. Where N and M are both positive integers, and M≤N.

[0049] The present invention also provides a terminal positioning device, comprising:

[0050] The terminal identification module is used to identify and lock the target terminal, and to listen to the uplink time domain signal of the target terminal;

[0051] The TA value calculation module is used to perform timing processing on the uplink time domain signal based on the downlink frame synchronization point and uplink parameters, and calculate the time domain timing advance TA value and the frequency domain TA value based on the processing results;

[0052] The distance calculation module is used to calculate the target distance information based on the time-domain TA value when the TA verification is determined to be passed based on the time-domain TA value and the frequency-domain TA value.

[0053] The direction calculation module is used to calculate the target direction information based on the uplink time-domain signal using the phase comparison method;

[0054] The location determination module is used to determine the location of the target terminal based on the target distance information and the target direction information.

[0055] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the terminal positioning methods described above.

[0056] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the terminal positioning method as described in any of the preceding claims.

[0057] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the terminal positioning method as described in any of the preceding claims.

[0058] The terminal positioning method, apparatus, electronic device, storage medium, and program product provided by this invention identify and lock onto the target terminal, and monitor the uplink time-domain signal of the target terminal. Then, based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is processed at regular intervals. The time-domain TA value and frequency-domain TA value are calculated based on the processing results, and then TA verification is performed. When the TA verification passes, the target distance information is calculated based on the time-domain TA value. This joint verification method effectively eliminates erroneous measurements caused by multipath interference and other factors, ensuring the reliability of TA value measurement and thus improving the accuracy of target distance estimation. Simultaneously, by using the phase comparison method to calculate the target direction information based on the uplink time-domain signal, high-precision direction positioning can be achieved. Finally, based on the aforementioned highly reliable target distance information and high-precision target direction information, the location of the target terminal is determined. Compared to the existing technology that uses the ID of the serving cell where the target terminal is located for coarse positioning, this invention can greatly improve the positioning accuracy of the target terminal. Furthermore, this invention only requires a single positioning device to complete distance and direction measurements and achieve target terminal positioning, greatly reducing the complexity and cost of system deployment. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0060] Figure 1 This is one of the flowcharts illustrating the terminal positioning method provided by the present invention;

[0061] Figure 2 This is the second flowchart illustrating the terminal positioning method provided by the present invention;

[0062] Figure 3This is the third flowchart illustrating the terminal positioning method provided by the present invention;

[0063] Figure 4 This is the fourth flowchart of the terminal positioning method provided by the present invention;

[0064] Figure 5 This is a schematic diagram of the terminal positioning system provided by the present invention;

[0065] Figure 6 This is a schematic diagram of the terminal positioning device provided by the present invention;

[0066] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0068] Before introducing the embodiments of the present invention, the basic process of scheduling and data service interaction between the base station (BS) and the user equipment (UE) is described as follows:

[0069] ①The BS continuously broadcasts the PSS (Primary Synchronization Signal), SSS (Secondary Synchronization Signal), and PBCH (Physical Broadcast Channel). The UE performs cell search to obtain the base station's time frame location, cell PCI (Physical Cell ID), system frame number, subcarrier spacing, SSB (Synchronization Signal / PBCH Block) subcarrier offset, and other MIB (Master Information Block) information to achieve downlink synchronization.

[0070] ② After achieving downlink synchronization, the UE needs to achieve uplink synchronization with the base station and request a unique identifier within the network. Specifically, the UE selects an available C-RNTI (Cell-Radio Network Temporary Identifier) ​​from the current SIB (System Information Block) message broadcast by the base station, sends a PRACH (Physical Random Access Channel) to request the BS to allocate it for its use. The BS receives the PRACH, obtains the TA (Timing Advance) for each UE, and sends a RAR (Random Access Response) to the UE. Correspondingly, the UE uses the RA-RNTI (Random Access-RadioNetwork Temporary Identifier) ​​to decrypt the RAR DCI (Downlink Control Information) and complete the uplink synchronization.

[0071] ③ The BS sends PDCCH (Physical Downlink Control Channel) and PDSCH (Physical Downlink Shared Channel). PDCCH carries DCI, and PDSCH carries SIB information, scrambled with SI-RNTI (System Information-RNTI). The UE performs blind detection in CSS (Common Search Space) to obtain Paging (Paging, i.e., Paging-RNTI), SIB, or RAR, etc., to understand all cell rules and configurations. Key information carried in the SIB includes: SIB cell access and cell selection information, 5G-TDD (Time Division Duplex) time slot configuration, PRACH configuration, uplink frequency information (e.g., FDD (Frequency Division Duplex) mode), MBSFN (Multicast-Broadcast Single Frequency Network) related configuration, and scheduling information from other SIBs.

[0072] ④ After receiving information such as RAR, SIB, and TA, the UE sends PUCCH (Physical Uplink Control Channel) and SRS (Sounding Reference Signal) to the BS. PUCCH transmits UCI (Uplink Control Information), which carries SR (Scheduling Request) and BSR (Buffer Status Report). SRS represents the uplink channel sounding signal, providing decision-making support for base station scheduling.

[0073] ⑤ The BS sends PDCCH and PDSCH, and assigns DL-grant (Downlink Grant) and C-RNTI (Cell-Radio Network Temporary Identifier) ​​to the UE. The UE captures the DL-grant according to the C-RNTI, and then decrypts the PDSCH according to the DL-grant to obtain its own service data.

[0074] ⑥ In UL-grant (also carried in downlink DCI), the base station schedules the PRB (Physical Resource Block) and MCS (Modulation and Coding Scheme) information of the PUSCH (Physical Uplink Shared Channel) to be transmitted by the UE. Then the UE sends service data on the PUSCH.

[0075] This invention proposes a terminal positioning method, device, electronic device, storage medium, and program product, which are described below in conjunction with... Figures 1-7 Describe it.

[0076] Figure 1 This is a flowchart illustrating the terminal positioning method provided by the present invention, as shown below. Figure 1 As shown, the terminal positioning method includes steps S110, S120, S130, S140 and S150.

[0077] Step S110: Identify and lock the target terminal, and listen to the uplink time domain signal of the target terminal.

[0078] In this embodiment of the invention, the executing entity is a positioning device, and the target terminal is the terminal that needs to be located.

[0079] In one embodiment, the target terminal identification process is as follows: Downlink synchronization is established with the target base station; the physical downlink control channel of the target base station is monitored and decoded to obtain the Transport Block Size (TBS) in the downlink control information; when no inducement message is sent to the target terminal, the average value of all TBS obtained within a preset time window is calculated as the background TBS baseline; an inducement message is sent to the target terminal, and a listening timer is started. During the duration of the listening timer, the maximum value of the TBS is monitored as the candidate TBS peak value; when the candidate TBS peak value is detected to be greater than the background TBS baseline and the preset TBS threshold, it is determined as a valid identification event; the steps of sending the inducement message, starting the listening timer, and detecting the candidate TBS peak value are repeated N times. If the number of valid identification events reaches M, the target terminal is determined to be identified; where N and M are both positive integers, and M ≤ N. The specific execution process can be referred to in the following embodiments, which will not be elaborated here.

[0080] In another embodiment, the target terminal identification process is as follows: Downlink synchronization is established with the target base station; inducement messages are sent to the target terminal at preset fixed time intervals; the physical downlink control channel of the target base station is monitored and decoded to obtain the Transport Block Size (TBS) set in the downlink control information, and the timestamp corresponding to each TBS is recorded. The TBS set is matched with the preset inducement message TBS length to obtain a valid timestamp sequence; interval analysis and periodic detection are performed on this valid timestamp sequence; when the detected time interval pattern matches the sending interval of the inducement message, the target terminal is identified.

[0081] After successfully identifying the target terminal, the system locks onto the target terminal and listens to its uplink time-domain signal. The uplink time-domain signal refers to the baseband IQ (In-phase Quadrature) sampling data transmitted by the target terminal, which is received by the antenna of the positioning device after propagation through the wireless channel.

[0082] Step S120: Based on the downlink frame synchronization point and uplink parameters, perform timing processing on the uplink time domain signal, and calculate the time domain timing advance (TA) value and the frequency domain timing advance (TA) value based on the processing result.

[0083] The downlink frame synchronization point is the start time of the downlink frame obtained by decoding the primary synchronization signal (PSS) and secondary synchronization signal (SSS) of the 5G cell.

[0084] Uplink parameters include, but are not limited to: uplink time slot interval and uplink time advance relative to downlink. The uplink time slot interval refers to the configuration pattern and periodicity of uplink time slots on the time axis as defined in the TDD system, obtained by decoding the SIB1 (System Information Block 1) message in the PDSCH. The uplink time advance relative to downlink refers to the time offset by which the base station commands the terminal to send uplink signals in advance, used to compensate for radio wave propagation delay, obtained through DCI. Based on this time advance, the one-way propagation distance from the target terminal to the base station can be calculated.

[0085] Based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is processed for timing. Based on the processing results, the Time Advance (TA) value is calculated in both the time and frequency domains, denoted as the time-domain TA value and the frequency-domain TA value, respectively. The time-domain TA value represents the number of sampling points, i.e., the sampling point deviation, while the frequency-domain TA value represents the angle value, i.e., the phase deviation.

[0086] The calculation process for the time-domain TA value is as follows: Based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is processed to locate and extract the uplink time-domain data; based on the uplink time-domain data, the first received DMRS (DeModulation Reference Signal) frequency-domain data is extracted; based on the DCI parameters, the local DMRS frequency-domain data is calculated; conjugate correlation operations are performed on the first received DMRS frequency-domain data and the local DMRS frequency-domain data to obtain the frequency-domain channel response; the frequency-domain channel response is converted into the time-domain channel impulse response through inverse fast Fourier transform (IFFT); the modulus square operation is performed on the time-domain channel impulse response, and the peak position is determined based on the operation result; based on the peak position, the time-domain TA value is calculated.

[0087] The calculation process of the frequency domain TA value is as follows: Based on the downlink frame synchronization point and uplink parameters, the uplink time domain signal is processed to locate and extract the uplink time domain data; based on the uplink time domain data, the first received DMRS frequency domain data is extracted; based on the DCI parameters, the local DMRS frequency domain data is calculated; conjugate correlation operation is performed on the first received DMRS frequency domain data and the local DMRS frequency domain data to obtain the frequency domain channel response; transpose-misaligned multiplication operation is performed on the frequency domain channel response to obtain a complex scalar; based on the angle value of the complex scalar and the IFFT transform length, the frequency domain TA value is calculated.

[0088] The specific calculation process for the time-domain TA value and the frequency-domain TA value can be found in the following embodiments, which will not be elaborated here.

[0089] Step S130: When the TA verification is determined to be successful based on the time-domain TA value and the frequency-domain TA value, the target distance information is calculated based on the time-domain TA value.

[0090] After calculating the time-domain TA value and the frequency-domain TA value, TA verification is performed based on the time-domain TA value and the frequency-domain TA value.

[0091] In one embodiment, time-domain compensation is performed on the first received DMRS frequency domain data based on the time-domain TA value to obtain the second received DMRS frequency domain data; normalized energy calculation is performed on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy; frequency-domain compensation is performed on the first received DMRS frequency domain data based on the frequency-domain TA value to obtain the third received DMRS frequency domain data; normalized energy calculation is performed on the third received DMRS frequency domain data and the local DMRS frequency domain data to obtain the second energy; the average value of the first energy and the second energy is calculated to obtain the average energy; whether the average energy is greater than a preset threshold is detected to determine whether the TA verification passes. If the average energy is greater than the preset threshold, the TA verification is determined to pass; if the average energy is less than or equal to the preset threshold, the TA verification is determined to fail. The specific execution process can be referred to in the following embodiments, which will not be elaborated here.

[0092] In another embodiment, time-domain compensation is performed on the first received DMRS frequency domain data based on the time-domain TA value to obtain the second received DMRS frequency domain data; normalized energy calculation is performed on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy; frequency-domain compensation is performed on the first received DMRS frequency domain data based on the frequency-domain TA value to obtain the third received DMRS frequency domain data; normalized energy calculation is performed on the third received DMRS frequency domain data and the local DMRS frequency domain data to obtain the second energy. The first energy is checked to see if it is greater than a first preset threshold, and the second energy is checked to see if it is greater than a second preset threshold, to determine whether the TA verification passes. If the first energy is greater than the first preset threshold and the second energy is greater than the second preset threshold, the TA verification is determined to pass; if the first energy is less than or equal to the first preset threshold, and / or the second energy is less than or equal to the second preset threshold, the TA verification is determined to fail.

[0093] Of course, it is understandable that TA verification can be performed based solely on the time-domain TA value or solely on the frequency-domain TA value, and other verification methods can be used. For example, reasonable time-domain TA and frequency-domain TA ranges can be set according to the physical environment. When the time-domain TA value is within the expected time-domain TA range, or when the frequency-domain TA value is within the expected frequency-domain TA range, the verification is considered successful.

[0094] By performing joint TA verification on the time-domain TA value and the frequency-domain TA value, erroneous measurements caused by multipath interference and other factors can be effectively eliminated, ensuring the reliability of the time-domain TA value used and thus improving the accuracy of distance estimation.

[0095] When determining that the TA verification has passed based on the time-domain TA value and the frequency-domain TA value, the target distance information is calculated based on the time-domain TA value. The target distance information refers to the distance between the target terminal and the positioning device, and the specific calculation formula is as follows:

[0096] D=T s • Time-domain TA value • c;

[0097] Where D is the target distance, T s The sampling period for the signal received by the positioning device is in seconds. The time-domain TA value is the number of sampling points, and c is the speed of light, with a value of 3.0 × 10⁻⁶. 8 m / s.

[0098] Step S140: Calculate the target direction information based on the uplink time domain signal using the phase comparison method.

[0099] The target orientation information is calculated based on the uplink time-domain signal using the phase comparison method. The target orientation information is the orientation angle of the target terminal relative to the positioning device, characterized by AoA (Angle of Arrival), denoted as θ'.

[0100] Specifically, the process involves acquiring the frequency to be measured, constructing a theoretical phase difference sample based on the frequency, antenna spacing, and rotational incident angle; acquiring the complex signals corresponding to the uplink time-domain signal in each antenna of the antenna array, and calculating the true phase difference based on the complex signals; calculating the average cosine similarity between the true phase difference and the theoretical phase difference sample; and determining the rotational incident angle corresponding to the maximum value in the average cosine similarity as the azimuth angle of the incoming wave. The specific execution process can be found in the following embodiment, and will not be elaborated upon here.

[0101] It should be noted that the execution order of steps S140 and S120-S130 is not important and they can be executed in parallel.

[0102] Step S150: Determine the location of the target terminal based on the target distance information and the target direction information.

[0103] After obtaining the target distance information and target direction information, the position of the target terminal is determined based on the target distance information D and the target direction information θ.

[0104] Assuming the positioning device is the origin of the coordinate system, the position of the target terminal is: (x,y)=(D×cosθ',D×sinθ').

[0105] Assuming the geographic coordinates of the positioning device are (x0, y0), the location of the target terminal can be determined by a simple coordinate transformation as: (x, y) = (x0 + D × cosθ', y0 + D × sinθ').

[0106] The terminal positioning method provided in this invention identifies and locks onto the target terminal and listens to its uplink time-domain signal. Then, based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is processed at regular intervals. The time-domain TA value and frequency-domain TA value are calculated based on the processing results, and TA verification is performed. When the TA verification passes, the target distance information is calculated based on the time-domain TA value. This joint verification method effectively eliminates erroneous measurements caused by multipath interference and other factors, ensuring the reliability of TA value measurement and improving the accuracy of target distance estimation. Simultaneously, by using the phase comparison method to calculate target direction information based on the uplink time-domain signal, high-precision direction positioning can be achieved. Finally, based on the highly reliable target distance information and high-precision target direction information, the location of the target terminal is determined. Compared to the coarse positioning based on the ID of the serving cell where the target terminal is located in the prior art, this invention significantly improves the positioning accuracy of the target terminal. Furthermore, this invention requires only a single positioning device to complete distance and direction measurements and achieve target terminal positioning, greatly reducing the complexity and cost of system deployment.

[0107] Based on any of the above embodiments, refer to Figure 2 , Figure 2 This is a second schematic flowchart of the terminal positioning method provided by the present invention. The above step S120 includes: step S121, step S122, step S123, step S124, step S125, step S126, step S127, step S128 and step S129.

[0108] Step S121: Based on the downlink frame synchronization point and the uplink parameters, perform timing processing on the uplink time domain signal to locate and extract the uplink time domain data;

[0109] The positioning device detects the downlink synchronization signal, obtains downlink synchronization by decoding PSS and SSS, and obtains the downlink frame synchronization point.

[0110] Decode the SIB1 message in PDSCH to obtain the uplink parameters, which include, but are not limited to: uplink time slot interval and uplink time advance relative to downlink.

[0111] By using the downlink frame synchronization point and uplink parameters, the uplink time domain signal can be processed in a timely manner, that is, the time domain position of the uplink signal can be found, and the complete uplink time domain data can be extracted based on this.

[0112] Furthermore, the uplink time-domain data is stored in DDR (Double Data Rate) memory in units of time slots.

[0113] Step S122: Extract the frequency domain data of the first received demodulation reference signal (DMRS) based on the uplink time domain data.

[0114] First, extract DMRS symbol data from the uplink time domain data. DMRS symbol data is time domain data, which includes CP (Cyclic Prefix) and OFDM (Orthogonal Frequency Division Multiplexing) data.

[0115] It should be noted that since the time-domain TA value is not yet known at this time, it is assumed to be 0. DMRS symbol data is extracted from DDR memory based on the time-domain TA value of 0. Assuming the second symbol is a DMRS symbol, at a sampling rate of 122.88M, the CP length of the second symbol in a 5G system is 140 sampling points, and the data length is 4096 points. Therefore, the total length of the DMRS symbol data is 140 + 4096 points.

[0116] After extracting the DMRS symbol data, the CP processing is removed from the DMRS symbol data, and then the obtained valid data is processed by FFT (Fast Fourier Transform). Then, the DMRS frequency domain data is extracted according to the position and length of the DMRS frequency domain data, which is recorded as the first received DMRS frequency domain data.

[0117] Furthermore, the extracted first DMRS frequency domain data can be stored in local memory A.

[0118] Step S123: Calculate the local DMRS frequency domain data based on the downlink control information DCI parameters.

[0119] DCI parameters include uplink RB (Resource Block) index, uplink RB resource size, number of uplink RBs, and DMRS configuration type.

[0120] Based on the DCI parameters, and in accordance with the sequence generation rules specified in the 3GPP (3rd Generation Partnership Project) protocol, a DMRS frequency domain sequence is generated, which is denoted as local DMRS frequency domain data.

[0121] Furthermore, the calculated local DMRS frequency domain data can be stored in local memory B.

[0122] It should be noted that storing the first received DMRS frequency domain data and the local DMRS frequency domain data in different memories is primarily based on considerations such as data characteristics, parallel processing requirements, and data security. Specifically, the local DMRS frequency domain data is calculated based on DCI parameters; that is, once the DCI parameters are decoded, the local DMRS frequency domain data can be calculated. However, the first received DMRS frequency domain data depends on the target terminal's actual uplink transmission, and its generation is later than the local DMRS frequency domain data. If they shared memory, complex logic would be needed to manage these two asynchronous write processes, increasing design complexity. By storing the first received DMRS frequency domain data and the local DMRS frequency domain data in different memories, parallel operation can be achieved, significantly improving processing speed and meeting the stringent real-time requirements of 5G systems. Furthermore, storing the local DMRS frequency domain data in a separate memory B, compared to storing it together with the first DMRS frequency domain data in memory A, avoids accidental overwriting or interference during frequent writes of received data, ensuring the security and stability of the reference data.

[0123] Step S124: Calculate the frequency domain channel response based on the first received DMRS frequency domain data and the local DMRS frequency domain data.

[0124] First received DMRS frequency domain data is read from memory A, and local DMRS frequency domain data is read from memory B. Conjugate correlation operation is performed on the first received DMRS frequency domain data and the local DMRS frequency domain data to obtain the frequency domain channel response.

[0125] Specifically, the conjugates of the first received DMRS frequency domain data (denoted as Rdmrs) and the local DMRS frequency domain data (denoted as Ldmrs) are multiplied point-by-point to obtain the initial frequency domain channel response (denoted as Hest1) at the DMRS subcarrier positions. Then, the length of the initial frequency domain channel response is doubled, and a zero-value vector is initialized. Next, using a frequency domain interpolation method, the initial frequency domain channel response is simultaneously assigned to all odd-numbered index positions and all even-numbered index positions of the extended vector. Through the above method, a dense, artificial frequency domain channel response (denoted as Hest2) can be constructed.

[0126] The specific calculation formula is as follows:

[0127] Hest1=Rdmrs. conj(Ldmrs) (1)

[0128] Hest2=zeros(2 len,1) (2)

[0129] Hest2(1:2:end)=Hest1 (3);

[0130] Hest2(2:2:end)=Hest1 (4).

[0131] in,. This indicates element-wise multiplication (dot product); conj(Ldmrs) indicates taking the complex conjugate of Ldmrs; len is the number of DMRS received, i.e., the length of Hest1; Hest2(1:2:end)=Hest1 means assigning the value of Hest1 to the odd-numbered index position of Hest2 (i.e., the 1st, 3rd, 5th, ... position), and Hest2(2:2:end)=Hest1 means assigning the value of Hest1 to the even-numbered index position of Hest2 (i.e., the 2nd, 4th, 6th, ... position).

[0132] It should be noted that the initial frequency domain channel response, Hest1, is sparse and discontinuous. If a large-point IFFT (Inverse Fast Fourier Transform) is directly performed on the sparse Hest1, extensive zero-padding in the frequency domain is required, resulting in numerous spurious sidelobes in the time domain response. This severely impacts resolution and leads to poor time-domain transformation. Constructing a dense, artificial frequency domain channel response, Hest2, typically yields a closer approximation to the true channel characteristics than the zero-padding method described above. Therefore, the time-domain channel impulse response obtained by IFFT using Hest2 will be of higher quality than the result obtained by IFFT using Hest1 after zero-padding, thus optimizing the time-domain transformation effect.

[0133] Step S125: The frequency domain channel response is converted into the time domain channel impulse response by inverse fast Fourier transform (IFFT).

[0134] Then, the frequency-domain channel response is transformed into a time-domain channel impulse response (denoted as Hest3) using IFFT. Specifically, a 4096-point IFFT is performed to obtain 4096 points of time-domain data, and the result is assigned to the even-numbered index position of Hest3. The related calculation formulas below are also explained with an IFFT transform length of 4096.

[0135] The specific calculation formula is as follows:

[0136] Hest3(2:2:end)=IFFT(Hest2,4096) (5).

[0137] By assigning an even-numbered index position to Hest3, downsampling can be performed, reducing the amount of data and facilitating subsequent processing.

[0138] Step S126: Perform a modulus square operation on the time-domain channel impulse response, and determine the peak position based on the operation result.

[0139] Step S127: Calculate the time-domain TA value based on the peak position.

[0140] Next, a modulus square operation is performed on the time-domain channel impulse response to find the position corresponding to the maximum value, denoted as the peak position pos. Then, the time-domain TA value is calculated based on the peak position pos.

[0141] The specific calculation formula is as follows:

[0142] Hest4 = [abs(Hest3)] 2 (6);

[0143] [~,pos]=max(Hest4) (7;

[0144] T ta =(pos<=2048)?pos-1:pos-1-4096 (8).

[0145] Where Hest4 represents the result of the modular square operation; [abs(Hest3)] 2 This indicates that the modulus square operation is performed on the time-domain channel impulse response Hest3; [~,pos] indicates that the maximum value itself is ignored, and only the peak position pos is output; T ta This represents the time-domain TA value; (pos<=2048)?pos-1:pos-1-4096 is a conditional assignment statement. If the peak position is less than or equal to 2048, then the time-domain TA value = pos-1; if the peak position is greater than 2048, then the time-domain TA value = pos-1-4096.

[0146] Step S128: Perform a transpose-misaligned multiplication operation on the frequency domain channel response to obtain a complex scalar.

[0147] Step S129: Calculate the frequency domain TA value based on the angle value of the complex scalar and the IFFT transform length.

[0148] The calculation process for the frequency domain TA value is as follows:

[0149] First, perform a transpose-misaligned multiplication operation on the frequency domain channel response to obtain a complex scalar.

[0150] Assuming that the array M = [C0, C1, C2, ..., Cn] is obtained through the conjugate correlation operation of formula (1), the transpose-misplaced multiplication formula is as follows:

[0151] M dat =C0 C1+C1 C2+C2 C3......+Cn-1 Cn;

[0152] Among them, M dat Represents a complex scalar; C0, C1, C2, ..., Cn are consecutive elements in the initial frequency domain channel response Hest1, where C0 = Hest1[0] represents the channel response of the first subcarrier; C1 = Hest1[1] represents the channel response of the second subcarrier; C2 = Hest1[2] represents the channel response of the third subcarrier; C3 = Hest1[3] represents the channel response of the fourth subcarrier; Cn-1 = Hest1[n-1] represents the channel response of the nth subcarrier; Cn = Hest1[n] represents the channel response of the (n+1)th subcarrier.

[0153] Then, the angle value of the complex scalar is calculated, and the frequency domain TA value is calculated based on the angle value of the complex scalar and the IFFT transform length. The specific calculation formula is as follows:

[0154] F ta =angle(M dat ) / 2 / pi / 4096;

[0155] Among them, F ta Represents the frequency domain TA value, angle() is the complex phase extraction function, angle(M dat ) represents the complex scalar M dat The angle value, pi is the mathematical constant pi, and 4096 represents the IFFT transform length.

[0156] The terminal positioning method provided in this invention calculates the frequency domain channel response by combining the first received DMRS frequency domain data and the local DMRS frequency domain data. This response is then transformed into a time domain channel impulse response via IFFT, followed by modulus-square operation and peak detection. This achieves high-precision, multipath-resistant measurement of signal propagation delay. By transforming delay measurement into finding the precise location of the main path in the time domain channel impulse response, multipath interference is effectively suppressed, providing reliable absolute delay information for high-precision distance calculation. Simultaneously, by performing a transpose-misaligned multiplication operation on the frequency domain channel response and extracting its complex angle to calculate the frequency domain TA value, the Doppler frequency shift caused by the relative motion between the target terminal and the positioning device can be accurately estimated. TA verification based on the time domain TA value and frequency domain TA value calculated in the above manner can effectively reduce the probability of false alarms and misjudgments.

[0157] Based on any of the above embodiments, refer to Figure 3 , Figure 3This is the third flowchart of the terminal positioning method provided by the present invention. Before step S130, it also includes steps S161, S162, S163, S164, S165 and S166.

[0158] It should be noted that the execution order of steps S161-S162 and steps S163-S164 is not important and they can be executed in parallel.

[0159] Step S161: Based on the time domain TA value, perform time domain compensation on the first received DMRS frequency domain data to obtain the second received DMRS frequency domain data.

[0160] Step S162: Perform normalized energy calculation on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy.

[0161] The calculation process for the first energy is as follows:

[0162] The calculated time-domain TA value is used to compensate for the received DMRS sampling point offset in the time domain. This is because the physical meaning of the time-domain TA value is the sampling point offset; therefore, when compensating for the received DMRS frequency domain data using the time-domain TA value, it needs to be done in the time domain.

[0163] Specifically, based on the time-domain TA value, the starting address of the DMRS symbol data is calculated; based on the starting address, the DMRS symbol data is extracted; the DMRS symbol data is then subjected to cyclic prefix removal and Fast Fourier Transform processing sequentially to extract the second received DMRS frequency domain data. The specific execution process can be found in the following embodiments, which will not be elaborated here.

[0164] Then, normalized energy calculations are performed on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy.

[0165] Specifically, after transposing the local DMRS frequency domain data, it is multiplied by the second received DMRS frequency domain data to obtain the first calculation result; the first calculation result is then subjected to a modulo-square operation to obtain the signal-aligned total energy, denoted as the first signal-aligned total energy; after transposing the second received DMRS frequency domain data, it is multiplied by the second received DMRS frequency domain data to obtain the received signal total energy, denoted as the first received signal total energy; based on the first signal-aligned total energy, the first received signal total energy, and the total number of DMRS subcarriers, the first energy is calculated. The specific execution process can be found in the following embodiment, which will not be elaborated here.

[0166] Step S163: Based on the frequency domain TA value, perform frequency domain compensation on the first received DMRS frequency domain data to obtain the third received DMRS frequency domain data.

[0167] Step S164: Perform normalized energy calculation on the third received DMRS frequency domain data and the local DMRS frequency domain data to obtain the second energy.

[0168] The calculation process for the second energy is as follows:

[0169] Based on the frequency domain TA value, frequency domain compensation is performed on the first received DMRS frequency domain data to obtain the third received DMRS frequency domain data.

[0170] Specifically, the location index of the DMRS subcarrier is first calculated. Then, based on this location index, the first received DMRS frequency domain data, and the frequency domain TA value, the third received DMRS frequency domain data is calculated. The specific calculation formula is as follows:

[0171] indx=mod(4096-bwpSize 6+rbStart 12+[1:2:rbSize 12]'-1,4096);

[0172] Rdmrs3=Rdmrs. exp(1i 2 pi indx F ta / 4096);

[0173] Where Rdmrs3 represents the third received DMRS frequency domain data, exp(1i) represents complex exponentiation, indx represents the position index of the DMRS subcarrier, bwpSize represents the frequency domain bandwidth allocated to the target terminal, rbSize represents the working frequency domain bandwidth of the target terminal (i.e., the number of resource blocks allocated to the target terminal), rbStart represents the starting position of the frequency domain resources, ' represents the transpose operation, and F ta Rdmrs is the frequency domain TA value, and Rdmrs is the received DMRS frequency domain data (i.e., the first received DMRS frequency domain data) based on the time domain TA value being equal to 0.

[0174] Then, normalized energy calculations are performed on the third received DMRS frequency domain data and the local DMRS frequency domain data to obtain the second energy.

[0175] Specifically, after transposing the local DMRS frequency domain data, it is multiplied by the third received DMRS frequency domain data to obtain the second calculation result; the second calculation result is then subjected to a modulo-square operation to obtain the total signal-aligned energy, which is denoted as the second signal-aligned total energy; after transposing the third received DMRS frequency domain data, it is multiplied by the third received DMRS frequency domain data to obtain the total received signal energy, which is denoted as the second received signal total energy; based on the second signal-aligned total energy, the second received signal total energy, and the total number of DMRS subcarriers, the second energy is calculated. The specific execution process can be found in the following embodiment, which will not be elaborated here.

[0176] Step S165: Calculate the average value of the first energy and the second energy to obtain the average energy;

[0177] Step S166: Detect whether the average energy is greater than a preset threshold to determine whether the TA verification is passed.

[0178] After obtaining the first energy and the second energy, calculate the average value of the first energy EnergeA and the second energy EnergeB to obtain the average energy, which is (EnergeA+EnergeB) / 2.

[0179] Then, the average energy is checked to see if it exceeds a preset threshold to determine whether the time-domain (TA) verification passes. If the average energy exceeds the preset threshold, the calculated time-domain and frequency-domain TA values ​​are reliable, and the TA verification passes. If the average energy is less than or equal to the preset threshold, the calculated time-domain and frequency-domain TA values ​​are unreliable, and the TA verification fails. In this case, the result can be sent to the user terminal for expert analysis.

[0180] The terminal positioning method provided in this invention calculates the normalized energy (i.e., first energy) of the second received DMRS signal and the local DMRS signal after time-domain TA value compensation, and the normalized energy (i.e., second energy) of the third received DMRS signal and the local DMRS signal after frequency-domain TA value compensation, and takes their average value as the final evaluation index. This TA compensation and re-extraction method can resist the influence of single estimation errors and noise, significantly improving the robustness of TA verification in interference environments. Subsequently, the average energy is compared with a preset threshold to reliably verify the effects of time-domain and frequency-domain TA compensation, greatly reducing the risk of misjudgment and achieving closed-loop optimization of the verification process with low computational complexity.

[0181] Based on any of the above embodiments, step S161 includes: step S1611, step S1612 and step S1613.

[0182] Step S1611: Calculate the starting address of the DMRS symbol data based on the time-domain TA value.

[0183] Step S1612: Extract DMRS symbol data based on the starting address.

[0184] Step S1613: Perform cyclic prefix removal and fast Fourier transform processing on the DMRS symbol data in sequence to extract the second received DMRS frequency domain data.

[0185] It should be noted that the uplink time domain data is stored in DDR memory, and receiving DMRS time domain compensation involves readjusting the position of the uplink time domain data. An example is given below:

[0186] When the default time-domain TA value is 0, the starting address of the DMRS symbol data in DDR is at the beginning of the CP, and the DMRS symbol data is read from this point. If the calculated time-domain TA value is -3, the signal is advanced by 3 sampling points, and the starting address of the DMRS symbol data is shifted backward by 3 sampling points; if the calculated time-domain TA value is +3, the signal is delayed by 3 sampling points, and the starting address of the DMRS symbol data is shifted forward by 3 sampling points.

[0187] Specifically, the starting address of the DMRS symbol data in DDR is calculated based on the aforementioned time-domain TA value, i.e., the storage address of the uplink time-domain data in DDR is adjusted. Then, based on the starting address calculated above, the DMRS symbol data is re-extracted. Next, the re-extracted DMRS symbol data is sequentially processed by deCP and FFT transformation, and then the DMRS frequency domain data is extracted according to the position and length of the DMRS frequency domain data, which is denoted as the second received DMRS frequency domain data.

[0188] Furthermore, the extracted second received DMRS frequency domain data is stored in local memory A for updating.

[0189] The terminal positioning method provided in this embodiment of the invention can accurately calculate the received DMRS frequency domain data (i.e., the second received DMRS frequency domain data) after time domain compensation based on the time domain TA value through the above method, thereby achieving accurate time domain compensation.

[0190] Furthermore, step S162 above includes: step S1621, step S1622, step S1623 and step S1624.

[0191] Step S1621: After transposing the local DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the first calculation result.

[0192] Step S1622: Perform a modular square operation on the first calculation result to obtain the total energy of the first signal alignment.

[0193] Step S1623: After transposing the second received DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the total energy of the first received signal.

[0194] Step S1624: Calculate the first energy based on the first signal alignment total energy, the first received signal total energy, and the total number of DMRS subcarriers.

[0195] After transposing the local DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the first calculation result. Then, perform a modulo-square operation on the first calculation result to obtain the total energy of the local DMRS frequency domain data and the second received DMRS frequency domain data when they are aligned, which is denoted as the first signal alignment total energy.

[0196] Meanwhile, after transposing the second received DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the total energy corresponding to the second received DMRS frequency domain data itself, which is denoted as the total energy of the first received signal.

[0197] Then, the first energy is calculated based on the total energy of the first signal alignment, the total energy of the first received signal, and the total number of DMRS subcarriers. First energy = Total energy of the first signal alignment / Total energy of the first received signal / Total number of DMRS subcarriers.

[0198] The specific calculation formula is as follows:

[0199] EnergeA=abs(Ldmrs' Rdmrs2) 2 / (Rdmrs2' Rdmrs2) / (6 rbSize).

[0200] Where EnergyA represents the first energy, Rdmrs2 is the second received DMRS frequency domain data, Ldmrs represents the local DMRS frequency domain data, and ' indicates transpose operation, Ldmrs' Rdmrs2 represents the first calculation result, abs(Ldmrs' Rdmrs2) 2 Rdmrs2' represents the total energy of the first signal alignment obtained by performing a modular square operation on the first calculation result, rbSize is the number of resource blocks allocated to the target terminal, and Rdmrs2' is the total energy of the first signal alignment obtained by performing a modular square operation on the first calculation result. Rdmrs2 represents the total energy of the first received signal, 6 rbSize represents the total number of DMRS subcarriers, which is because a typical DMRS configuration uses 6 subcarriers to carry DMRS signals.

[0201] The terminal positioning method provided in this embodiment of the invention normalizes the signal energy by calculating the total energy of the first signal alignment and the total energy of the first received signal, and then dividing the two. The normalized energy is then divided by the total number of DMRS subcarriers to normalize the resource scale. In this way, the first energy calculated at the end is a dimensionless, normalized quality indicator, which provides a stable and reliable basis for subsequent TA verification.

[0202] Furthermore, the above step S164 includes: step S1641, step S1642, step S1643 and step S1644.

[0203] Step S1641: After transposing the local DMRS frequency domain data, multiply it with the third received DMRS frequency domain data to obtain the second calculation result.

[0204] Step S1642: Perform a modular square operation on the second calculation result to obtain the total energy of the second signal alignment.

[0205] Step S1643: After transposing the third received DMRS frequency domain data, multiply it with the third received DMRS frequency domain data to obtain the total energy of the second received signal.

[0206] Step S1644: Calculate the second energy based on the second signal alignment total energy, the second received signal total energy, and the total number of DMRS subcarriers.

[0207] After transposing the local DMRS frequency domain data, multiply it with the third received DMRS frequency domain data to obtain the second calculation result. Then, perform a modulo-square operation on the second calculation result to obtain the total energy of the local DMRS frequency domain data and the third received DMRS frequency domain data when aligned, which is denoted as the second signal alignment total energy.

[0208] Meanwhile, after transposing the third received DMRS frequency domain data, it is multiplied with the third received DMRS frequency domain data to obtain the total energy corresponding to the third received DMRS frequency domain data itself, which is denoted as the total energy of the second received signal.

[0209] Then, the second energy is calculated based on the total energy of the second signal alignment, the total energy of the second received signal, and the total number of DMRS subcarriers. Second energy = Total energy of the second signal alignment / Total energy of the second received signal / Total number of DMRS subcarriers.

[0210] The specific calculation formula is as follows:

[0211] EnergeB=abs(Ldmrs' Rdmrs3) 2 / (Rdmrs3' Rdmrs3) / (6 rbSize).

[0212] Where EnergeB represents the second energy, Rdmrs3 is the third received DMRS frequency domain data, Ldmrs represents the local DMRS frequency domain data, and ' indicates transpose operation, Ldmrs' Rdmrs3 represents the second calculation result, abs(Ldmrs' Rdmrs3) 2 Rdmrs3' represents the total energy of the second signal alignment obtained by performing a modular square operation on the second calculation result. Rdmrs3 represents the total energy of the second received signal.

[0213] The terminal positioning method provided in this embodiment of the invention normalizes the signal energy by calculating the total energy of the second signal alignment and the total energy of the second received signal, and then dividing the two. Furthermore, the normalized energy is divided by the total number of DMRS subcarriers to normalize the resource scale. In this way, the second energy calculated at the end is a dimensionless, normalized quality indicator, which provides a stable and reliable basis for subsequent TA verification.

[0214] Based on any of the above embodiments, refer to Figure 4 , Figure 4 This is the fourth flowchart of the terminal positioning method provided by the present invention. The above step S140 includes: step S141, step S142, step S143 and step S144.

[0215] Step S141: Obtain the frequency point to be measured, and construct a theoretical phase difference sample based on the frequency point to be measured, the antenna spacing, and the rotational incident angle.

[0216] The frequency to be tested is the operating frequency of the target terminal.

[0217] Antenna spacing is the distance between each directional antenna (also called an array element) in the antenna array of a positioning device.

[0218] The rotational incident angle is the current rotational signal incident angle.

[0219] The phase comparison method of a correlated interferometer can be used to construct a theoretical phase difference sample based on the frequency to be measured, the antenna spacing, and the rotational incident angle.

[0220] Specifically, taking the use of a 4-antenna non-uniform linear array in a positioning device as an example, the process of obtaining theoretical phase difference samples will be explained.

[0221] When the positioning device uses a 4-antenna non-uniform linear array, which includes array element 1, array element 2, array element 3 and array element 4, the array elements are directional antennas with a coverage range of ≤120 degrees.

[0222] When the signal is a narrowband far-field plane wave, the path difference between the two array elements is:

[0223] ;

[0224] in, This represents the distance between two array elements, where θ is the signal incident angle. The phase difference between the signals of the two array elements. Let be the wavelength of the sinusoidal signal, c be the speed of light, and f be the frequency of the sinusoidal signal. Transforming the above formula, we obtain:

[0225] ;

[0226] Extending to all phase differences, there are a total of 4 × (4-1) / 2 = 6 phase differences, as detailed below:

[0227] ;

[0228] ;

[0229] ;

[0230] ;

[0231] ;

[0232] ;

[0233] in, This represents the signal phase difference between array element 1 and array element 2. This represents the signal phase difference between array element 1 and array element 3. This represents the signal phase difference between array element 1 and array element 4. This represents the signal phase difference between array element 2 and array element 3. This represents the signal phase difference between array element 2 and array element 4. This indicates the signal phase difference between array element 3 and array element 4. This represents the distance between array element 1 and array element 2. This indicates the distance between array element 2 and array element 3. This indicates the distance between array element 3 and array element 4.

[0234] Each time, the incident angle is rotated k times at a fixed frequency point f. The above phase difference is saved as a theoretical phase difference sample. The details are as follows:

[0235] ;

[0236] in, This represents the frequency of the i-th partition. This indicates the current angle of incidence during rotation.

[0237] It should be noted that the final number of theoretical phase difference samples is the number of frequency points divided, and the number of rows in each sample is the number of divisions k by rotating the incident angle, and the number of columns is the total number of phase differences 6.

[0238] Step S142: Obtain the complex signal corresponding to the uplink time domain signal in each antenna of the antenna array, and calculate the true phase difference based on the complex signal.

[0239] When performing direction finding, the complex signals corresponding to the uplink time domain signals in each antenna (element) of the antenna array are obtained, and the true phase difference between each pair of antennas is calculated based on the complex signals.

[0240] Taking a 4-antenna setup as an example, the complex signals corresponding to the uplink time-domain signal in array elements 1, 2, 3, and 4 are denoted as S1, S2, S3, and S4, respectively. The true phase difference is calculated using the following formula:

[0241] P 12 =arg(S1×conj(S2));

[0242] P 13 =arg(S1×conj(S3));

[0243] P 14 =arg(S1×conj(S4));

[0244] P 23 =arg(S2×conj(S3));

[0245] P 24 =arg(S2×conj(S4));

[0246] P 34 =arg(S3×conj(S4));

[0247] Among them, P 12 P represents the true phase difference of the uplink time-domain signal between array element 1 and array element 2. 13 P represents the true phase difference of the uplink time-domain signal between array element 1 and array element 3. 14 P represents the true phase difference of the uplink time-domain signal between array element 1 and array element 4.23 P represents the true phase difference of the uplink time-domain signal between array element 2 and array element 3. 24 P represents the true phase difference of the uplink time-domain signal between array element 2 and array element 4. 34 This represents the true phase difference between array element 3 and array element 4 in the uplink time domain signal.

[0248] Step S143: Calculate the average cosine similarity between the actual phase difference and the theoretical phase difference sample;

[0249] Step S144: The rotational incident angle corresponding to the maximum value in the average cosine similarity is determined as the azimuth angle of the incoming wave from the target.

[0250] Calculate the average cosine similarity between the actual phase difference and the theoretical phase difference samples, and determine the rotational incident angle corresponding to the maximum value in the average cosine similarity as the azimuth angle of the incoming wave of the target.

[0251] Specifically, for each rotating incident angle in the theoretical phase difference sample, the cosine of the difference between the true phase difference and the theoretical phase difference is calculated, and the average value is obtained to get the mean cosine similarity of that rotating incident angle. The mean cosine similarity of all rotating incident angles is compared, and the rotating incident angle corresponding to the maximum value is determined as the azimuth angle of the incoming wave from the target. The specific calculation formula is as follows:

[0252] ;

[0253] Where cos() represents the cosine function, and P represents the true phase difference. The mean cosine similarity is represented by k values. The maximum value among the k mean cosine similarities is the azimuth of the incoming wave.

[0254] The terminal positioning method provided in this invention pre-acquires the frequency point to be measured and constructs a theoretical phase difference sample by combining the antenna spacing and a series of known rotational incident angles to achieve adaptive calibration, laying a reliable benchmark for high-precision direction finding. In the actual measurement stage, by acquiring the complex signals of the uplink time-domain signal in each antenna and calculating the true phase difference, direct and non-destructive measurement of the target signal is achieved, ensuring the accuracy and reliability of the original data. Then, by calculating the average cosine similarity between the true phase difference and the theoretical phase difference sample, the periodicity of the cosine function is cleverly utilized to overcome the abrupt change problem caused by phase difference cycle slip, significantly improving the stability and robustness of the matching process. Furthermore, by determining the rotational incident angle corresponding to the maximum value in the average cosine similarity as the target's azimuth angle, a precise mapping from the similarity space to the physical space is achieved, ensuring the optimality and determinism of the azimuth angle estimation result, thereby realizing high-precision and high-reliability positioning of the target terminal's azimuth.

[0255] Based on any of the above embodiments, the step "identifying the target terminal" includes: step S111, step S112, step S113, step S114 and step S115.

[0256] Step S111: Establish downlink synchronization with the target base station, and monitor and decode the physical downlink control channel of the target base station to obtain the transport block size (TBS) in the downlink control information.

[0257] The positioning device tunes to the operating frequency of the target base station and receives its downlink signals. By decoding the synchronization signal block SSB, including the primary synchronization signal PSS and the secondary synchronization signal SSS, it achieves time-frequency synchronization with the target base station and obtains the physical cell identifier (PCI) of the cell.

[0258] Subsequently, a demodulation reference signal DMRS is generated based on this PCI, and the physical downlink control channel (PDCCH) of the target base station is continuously monitored. By performing blind detection on the PDCCH, the downlink control information (DCI) within it is decoded. For each successfully decoded DCI, the positioning device calculates the corresponding TBS (Transport Block Size) based on the modulation and coding scheme (MCS) and resource allocation parameters indicated within it.

[0259] Step S112: When no inducement message is sent to the target terminal, the average value of all TBSs obtained within a preset time window is calculated and used as the background TBS baseline.

[0260] The positioning device maintains a heartbeat interval and calculates the average TBS length of received SMS messages within the heartbeat interval, which serves as the background TBS baseline. The preset time window is this heartbeat interval.

[0261] It should be noted that no inducement messages are sent to the target terminal when measuring the background TBS baseline. This ensures that the background TBS baseline always reflects the purest background traffic, completely unaffected by deliberate inducement, thus making the comparison between the candidate TBS peak and the background TBS baseline more accurate and further reducing the false positive rate.

[0262] Step S113: Send an inducement message to the target terminal and start a listening timer. During the duration of the listening timer, monitor the maximum value of TBS as a candidate TBS peak value.

[0263] Step S114: When the peak value of the candidate TBS is detected to be greater than the background TBS baseline and the preset TBS threshold, it is determined to be a valid identification event.

[0264] Step S115: Repeat the steps of sending the inducement message, starting the listening timer, and detecting the candidate TBS peak a total of N times. If the number of valid event identifications reaches M, the target terminal is determined to be identified. Wherein, N and M are both positive integers, and M≤N.

[0265] When target terminal identification is required, the positioning device sends a prompting message at preset time intervals, and stops measuring the heartbeat interval during the sending of the prompting message. The preset time interval can be fixed or random. Random preset time intervals, on the other hand, enhance the robustness of detection.

[0266] For each induced message sent, the positioning device starts a listening timer to obtain the maximum TBS length within this time period, i.e., the maximum value of TBS, and uses it as a candidate TBS peak value. After the listening interval ends, the measurement of the average TBS value within the heartbeat interval continues.

[0267] When sending inducement messages, SMS messages can be sent to the target terminal via SMS modem to trigger the 5G target base station to send downlink broadcast messages, control information and service information to the target number corresponding to the target terminal, thereby inducing the target terminal to maintain regular communication with the target base station.

[0268] When a candidate TBS peak is detected to be greater than the background TBS baseline and the preset TBS threshold, it is determined as a valid identification event.

[0269] Repeat steps S113 and S114 above, sending the inducement message, starting the listening timer, and detecting the candidate TBS peak a total of N times. If the number of valid event identifications reaches M, the target terminal is determined to be identified; where N and M are both positive integers, and M≤N. It should be noted that the time interval between each repetition of steps S113 and S114 is the preset time interval mentioned above.

[0270] The terminal positioning method provided in this invention identifies the target terminal in the manner described above. The entire process only requires passively listening to the air interface signal, does not rely on the cooperation of the terminal, does not require the target terminal to install any specific application, and does not require modification of the existing network infrastructure. It has wide applicability and is crucial for application scenarios in special fields.

[0271] Based on any of the above embodiments, the terminal positioning method provided in this embodiment of the invention is applied to a terminal positioning system, with reference to... Figure 5The system includes a radio frequency processing subsystem, a positioning device, and a control and management subsystem. The positioning device is implemented based on an FPGA (Field Programmable Gate Array) architecture, while the control and management subsystem can be implemented based on an ARM (Advanced RISC (Reduced Instruction Set Computer) architecture.

[0272] The radio frequency processing subsystem receives 5G air interface wireless signals through the antenna, completes radio frequency signal filtering, mixing, and digital processing of intermediate frequency analog signals to finally obtain digital intermediate frequency signals. Then, the digital intermediate frequency signals are transmitted to the positioning equipment for digital preprocessing.

[0273] After receiving the digital intermediate frequency (IF) signal, the positioning device first performs digital down-conversion processing, transforming the high-sampling-rate IF signal into a low-sampling-rate baseband signal. For example, taking a 15kHz subcarrier as an example, the 5G system's SSB synchronization block occupies 240 PRBs in the frequency domain, with a total bandwidth of 3.6MHz = 240 × 15. Under IQ sampling, the sampling rate for SSB synchronization search is at least 3.6MHz, and the system design specifies a sampling rate of 3.84MHz for SSB synchronization search. At frequencies below 6GHz, the 5G system bandwidth is 100MHz, and the system design specifies a sampling rate of 122.88MHz for the 5G digital IF signal. Therefore, during SSB synchronization search, the digital preprocessing function transforms the 122.88MHz 5G digital IF signal into a 3.84MHz baseband signal through multiple decimation filters.

[0274] Then, downlink synchronization and decoding are performed to obtain uplink parameters, including but not limited to uplink synchronization point, uplink time slot index, uplink demodulation reference signal (DMRS) symbol index, and uplink resource configuration, which are then stored in the DDR database.

[0275] The target terminal is identified and locked using the aforementioned target terminal identification method. The uplink time-domain signal of the target terminal is then monitored. Based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is processed at regular intervals. Target transfer (TA) calculation is performed based on the processing results, including the calculation of time-domain and frequency-domain TA values, followed by TA verification. If the TA verification passes, distance is measured based on the time-domain TA value to calculate the target distance information. Simultaneously, direction finding is performed using phase comparison to calculate the target direction information. Finally, the location of the target terminal is determined based on the target distance and direction information.

[0276] The control and management subsystem is the core control unit of the entire terminal positioning system. It is responsible for coordinating the data flow and control signals between various modules in the positioning device to ensure that each module works together in accordance with the predetermined process.

[0277] The terminal positioning device provided by the present invention is described below. The terminal positioning device described below and the terminal positioning method described above can be referred to in correspondence.

[0278] Figure 6 This is a schematic diagram of the terminal positioning device provided by the present invention, as shown below. Figure 6 As shown, the device includes a terminal identification module 610, a TA value calculation module 620, a distance calculation module 630, a direction calculation module 640, and a position determination module 650; wherein:

[0279] The terminal identification module 610 is used to identify and lock the target terminal, and to listen to the uplink time domain signal of the target terminal;

[0280] The TA value calculation module 620 is used to perform timing processing on the uplink time domain signal according to the downlink frame synchronization point and uplink parameters, and calculate the time domain timing advance TA value and the frequency domain TA value based on the processing result;

[0281] The distance calculation module 630 is used to calculate the target distance information based on the time-domain TA value when the TA verification is determined to be passed based on the time-domain TA value and the frequency-domain TA value.

[0282] The direction calculation module 640 is used to calculate the target direction information based on the uplink time domain signal using the phase comparison method;

[0283] The location determination module 650 is used to determine the location of the target terminal based on the target distance information and the target direction information.

[0284] It should be noted that the terminal positioning device provided in this embodiment of the invention can implement all the method steps implemented in the above-mentioned terminal positioning method embodiment and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiment and the beneficial effects will not be described in detail.

[0285] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7As shown, the electronic device may include a processor 710, a communications interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communications interface 720, and the memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute the terminal positioning method provided in the above embodiments.

[0286] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0287] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the terminal positioning method provided in the above embodiments.

[0288] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the terminal positioning methods provided in the above embodiments.

[0289] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0290] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0291] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A terminal positioning method, characterized in that, include: The target terminal is identified and locked, and the uplink time domain signal of the target terminal is monitored; Based on the downlink frame synchronization point and uplink parameters, the uplink time-domain signal is subjected to timing processing, and the time-domain timing advance (TA) value and frequency-domain TA value are calculated based on the processing results. When the TA verification is deemed successful based on the time-domain TA value and the frequency-domain TA value, the target distance information is calculated based on the time-domain TA value. The target direction information is calculated based on the uplink time-domain signal using the phase comparison method. The location of the target terminal is determined based on the target distance information and the target direction information.

2. The terminal positioning method according to claim 1, characterized in that, The step of performing timing processing on the uplink time-domain signal based on the downlink frame synchronization point and uplink parameters, and calculating the time-domain timing advance (TA) value and the frequency-domain TA value based on the processing results, includes: Based on the downlink frame synchronization point and the uplink parameters, the uplink time domain signal is processed in a timing manner to locate and extract the uplink time domain data; Based on the uplink time domain data, extract the frequency domain data of the first received demodulation reference signal (DMRS); Calculate the local DMRS frequency domain data based on the downlink control information (DCI) parameters; The frequency domain channel response is calculated based on the first received DMRS frequency domain data and the local DMRS frequency domain data; The frequency domain channel response is converted into the time domain channel impulse response by using the inverse fast Fourier transform (IFFT). The time-domain channel impulse response is subjected to modulus square operation, and the peak position is determined based on the operation result; Calculate the time-domain TA value based on the peak position; Perform a transpose-misaligned multiplication operation on the frequency domain channel response to obtain a complex scalar; The frequency domain TA value is calculated based on the angle value of the complex scalar and the IFFT transform length.

3. The terminal positioning method according to claim 2, characterized in that, Before calculating the target distance information based on the time-domain TA value and the frequency-domain TA value when determining that the TA verification has passed, the method further includes: Based on the time-domain TA value, time-domain compensation is performed on the first received DMRS frequency-domain data to obtain the second received DMRS frequency-domain data. Normalized energy calculations are performed on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy; Based on the frequency domain TA value, the first received DMRS frequency domain data is frequency domain compensated to obtain the third received DMRS frequency domain data. The second energy is obtained by performing normalized energy calculation on the third received DMRS frequency domain data and the local DMRS frequency domain data; Calculate the average value of the first energy and the second energy to obtain the average energy; The average energy is checked to see if it is greater than a preset threshold in order to determine whether the TA verification is successful.

4. The terminal positioning method according to claim 3, characterized in that, The step of performing time-domain compensation on the first received DMRS frequency-domain data based on the time-domain TA value to obtain the second received DMRS frequency-domain data includes: Calculate the starting address of the DMRS symbol data based on the time-domain TA value; Extract DMRS symbol data based on the starting address; The DMRS symbol data is sequentially processed by decyclic prefix removal and Fast Fourier Transform to extract the second received DMRS frequency domain data; and / or, The step of performing normalized energy calculation on the second received DMRS frequency domain data and the local DMRS frequency domain data to obtain the first energy includes: After transposing the local DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the first calculation result; Perform a modular square operation on the first calculation result to obtain the total energy of the first signal alignment; After transposing the second received DMRS frequency domain data, multiply it with the second received DMRS frequency domain data to obtain the total energy of the first received signal; The first energy is calculated based on the first signal alignment total energy, the first received signal total energy, and the total number of DMRS subcarriers.

5. The terminal positioning method according to any one of claims 1 to 4, characterized in that, The step of calculating target direction information based on the uplink time-domain signal using the phase comparison method includes: Obtain the frequency point to be measured, and construct a theoretical phase difference sample based on the frequency point to be measured, the antenna spacing, and the rotational incident angle; Obtain the complex signal corresponding to the uplink time-domain signal in each antenna of the antenna array, and calculate the true phase difference based on the complex signal; Calculate the mean cosine similarity between the actual phase difference and the theoretical phase difference sample; The rotational incident angle corresponding to the maximum value in the average cosine similarity is determined as the azimuth angle of the incoming wave from the target.

6. The terminal positioning method according to any one of claims 1 to 4, characterized in that, The identification of the target terminal includes: Establish downlink synchronization with the target base station, and monitor and decode the physical downlink control channel of the target base station to obtain the transport block size (TBS) in the downlink control information; When no inducement message is sent to the target terminal, the average value of all TBSs obtained within a preset time window is calculated and used as the background TBS baseline. Send an inducement message to the target terminal and start a listening timer. During the duration of the listening timer, monitor the maximum value of TBS as a candidate TBS peak value. When the peak value of the candidate TBS is detected to be greater than the background TBS baseline and the preset TBS threshold, it is determined to be a valid identification event; The steps of sending the inducement message, starting the listening timer, and detecting the candidate TBS peak are repeated N times. If the number of times the effective event is identified reaches M, the target terminal is determined to be identified. Where N and M are both positive integers, and M≤N.

7. A terminal positioning device, characterized in that, include: The terminal identification module is used to identify and lock the target terminal, and to listen to the uplink time domain signal of the target terminal; The TA value calculation module is used to perform timing processing on the uplink time domain signal based on the downlink frame synchronization point and uplink parameters, and calculate the time domain timing advance TA value and the frequency domain TA value based on the processing results; The distance calculation module is used to calculate the target distance information based on the time-domain TA value when the TA verification is determined to be passed based on the time-domain TA value and the frequency-domain TA value. The direction calculation module is used to calculate the target direction information based on the uplink time-domain signal using the phase comparison method; The location determination module is used to determine the location of the target terminal based on the target distance information and the target direction information.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the terminal positioning method as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the terminal positioning method as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the terminal positioning method as described in any one of claims 1 to 6.

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