Terminal positioning method, device and equipment based on cooperation of multiple base stations

Abstract

The invention provides a terminal positioning method, device and equipment based on cooperation of multiple base stations, and relates to the technical field of wireless communication. The method comprises the following steps: after a to-be-positioned terminal obtains a plurality of receiving signals, performing segmented self-correlation on each receiving signal in a time domain, and determining an arrival time coarse synchronization result of each receiving signal according to a segmented self-correlation result; for each received signal, taking a preset number of sampling points before and after the arrival time coarse synchronization result of the received signal as target sampling points, carrying out self-correlation on a signal with a symbol length behind each target sampling point, and determining an arrival time fine synchronization result of the received signal according to a self-correlation result; and according to the arrival time fine synchronization result of each received signal and the position coordinate of each base station in the plurality of base stations, resolving an arrival time difference equation to obtain a positioning result of the to-be-positioned terminal. The problems that the dynamic terminal positioning precision is greatly influenced by Doppler frequency offset and the power consumption is high can be solved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a terminal positioning method, apparatus, and device based on multi-base station collaboration. Background Technology

[0002] The Internet of Things (IoT), as a core direction of the development of next-generation information technology, is a key technology driving future digital and intelligent development. IoT terminals are responsible for sensing the environment and collecting information, forming the most fundamental layer of the IoT. Through wireless or wired communication protocols, IoT terminals upload the collected data to the cloud, edge servers, or other devices in real time or periodically, building an ubiquitous network and enabling intelligent interaction between devices.

[0003] Public network IoT is a licensed frequency band narrowband IoT technology, evolved from the Long-Term Evolution (LTE) system. Compared to LTE, public network IoT features key technological advantages such as low power consumption, high connection density, wide-area coverage, and ultra-low cost. The uplink signal employs single-carrier frequency division multiplexing (FDM) technology, supporting single-subcarrier and multi-subcarrier transmission. Compared to other IoT technologies, public network IoT has lower costs, primarily due to its narrowband signal, spectrum reuse, and low power consumption of terminal devices, reducing infrastructure construction costs. Specifically, narrowband signals significantly reduce transmission bandwidth and signal processing costs; spectrum reuse fully utilizes limited spectrum resources, improving spectrum utilization efficiency; and low power consumption of terminal devices extends device lifespan and reduces manufacturing costs.

[0004] To achieve public network IoT, terminal devices must first perform downlink synchronization after powering on. The downlink synchronization signal includes a narrowband primary synchronization signal (NPSS), which the terminal detects to perform downlink synchronization. Then, in some scenarios, terminal location is required to further utilize the information sensed and collected by the terminal, such as in asset tracking and management (e.g., electric bicycle anti-theft, medical equipment management), or in monitoring widely distributed public facilities (e.g., manhole covers, fire hydrants, etc.). However, the process of downlink synchronization by detecting the NPSS signal and the terminal location process have the following shortcomings: 1. Poor dynamic resistance: Traditional methods often employ downlink synchronization methods based on local signal time-domain autocorrelation. For example, the receiver stores the same primary synchronization signal (NPSS) as the transmitted signal and performs correlation detection to find peak values. This method lacks the ability to resist dynamic changes in terminals, and the positioning accuracy of dynamic terminals is greatly affected by Doppler frequency offset.

[0005] 2. High terminal power consumption: Traditional terminals that rely on external systems for positioning need to install a power-intensive Global Navigation Satellite System (GNSS) module. During GNSS positioning, the Radio Resource Control (RRC) connection needs to be disconnected. According to data in the 3GPP standard, this part of the power consumption accounts for 30%-50% of the total power consumption of the terminal, which is not suitable for power-sensitive IoT terminals. Summary of the Invention

[0006] This invention provides a terminal positioning method, apparatus, and device based on multi-base station collaboration to solve the problems of high power consumption and significant impact of Doppler frequency offset on dynamic terminal positioning accuracy.

[0007] In a first aspect, embodiments of the present invention provide a terminal positioning method based on multi-base station collaboration, comprising: After the terminal to be located acquires multiple received signals, each received signal is segmented autocorrelation in the time domain. The arrival time of each received signal is determined based on the segmented autocorrelation results. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. For each received signal, a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal are taken as target sampling points. Autocorrelation is performed on the signal one symbol length after each target sampling point, and the fine synchronization result of the arrival time of the received signal is determined based on the autocorrelation result. Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, the time difference of arrival equation is solved to obtain the positioning result of the terminal to be located.

[0008] Secondly, embodiments of the present invention provide a terminal positioning device based on multi-base station cooperation, comprising: The coarse synchronization module is used to perform segmented autocorrelation on each received signal in the time domain after the terminal to be located acquires multiple received signals, and to determine the coarse synchronization result of the arrival time of each received signal based on the segmented autocorrelation result. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. The fine synchronization module is used to take a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal as target sampling points for each received signal, perform autocorrelation on the signal one symbol length after each target sampling point, and determine the fine synchronization result of the arrival time of the received signal based on the autocorrelation result. The positioning module is used to solve the time difference of arrival equation based on the precise synchronization result of the arrival time of each received signal and the location coordinates of each of the multiple base stations, and to obtain the positioning result of the terminal to be located.

[0009] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect or any possible implementation thereof.

[0010] In this embodiment of the invention, after acquiring multiple received signals at the terminal to be located, segmented autocorrelation is performed on each received signal in the time domain. Based on the segmented autocorrelation results, the coarse synchronization result of the arrival time of each received signal is determined. Here, the received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. Then, for each received signal, a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal are taken as target sampling points. Autocorrelation is performed on the signal one symbol length after each target sampling point. Based on the autocorrelation result, the fine synchronization result of the arrival time of the received signal is determined. Then, based on the fine synchronization result of the arrival time of each received signal and the position coordinates of each of the multiple base stations, the time difference of arrival equation is solved to obtain the positioning result of the terminal to be located. This can overcome the problem that the dynamic terminal positioning accuracy is greatly affected by Doppler frequency offset, and accurate positioning can be performed without a GNSS module, solving the problem of high power consumption in terminal positioning. Attached Figure Description

[0011] Figure 1 This is an application scenario diagram of the terminal positioning method based on multi-base station collaboration provided in the embodiments of the present invention; Figure 2 This is a flowchart illustrating the implementation of the terminal positioning method based on multi-base station collaboration provided in this embodiment of the invention. Figure 3 This is a comparison chart of the RMSE of the proposed method and the comparison method for estimating time delay observations under different Doppler frequency offsets and signal-to-noise ratios provided in the embodiments of the present invention. Figure 4 This is a comparison chart of the positioning accuracy RMSE of the proposed method and the comparison method under different Doppler frequency offsets and signal-to-noise ratios provided in the embodiments of the present invention. Figure 5 This is a power consumption comparison chart between the terminal positioning method based on multi-base station collaboration and the GNSS method provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of a terminal positioning device based on multi-base station collaboration provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0012] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0013] Figure 1 This diagram illustrates an application scenario of the terminal positioning method based on multi-base station collaboration provided in an embodiment of the present invention. Figure 1 As shown, this embodiment is applied to a scenario where the terminal can receive NPSS signals from at least three base stations.

[0014] See Figure 2 The document illustrates a flowchart of the implementation of the terminal positioning method based on multi-base station collaboration provided in an embodiment of the present invention, which is described in detail below: Step 201: After the terminal to be located acquires multiple received signals, perform segmented autocorrelation on each received signal in the time domain, and determine the arrival time coarse synchronization result of each received signal based on the segmented autocorrelation result. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located.

[0015] In one embodiment, step 201 may include: For each received signal, the signal after each sampling point of the received signal is divided into 11 equal parts, and 11 segmented signals corresponding to each sampling point are obtained.

[0016] For each of the 11 segmented signals corresponding to each sampling point, a cross-correlation operation is performed between each segmented signal and its own conjugate, and a cross-correlation operation is performed between each segmented signal and the conjugate of other segmented signals. Based on the cross-correlation operation results, the first metric value corresponding to each sampling point is determined as the segmented autocorrelation result for each sampling point.

[0017] Based on the piecewise autocorrelation results corresponding to each sampling point, the coarse synchronization result of the arrival time of the received signal is obtained.

[0018] For example, for each of the 11 segmented signals corresponding to each sampling point, a cross-correlation operation can be performed between each segmented signal and its own conjugate, and a cross-correlation operation can be performed between each segmented signal and the conjugate of other segmented signals. The sum of the results of each cross-correlation operation is then used as the correlation value corresponding to each segmented signal.

[0019] The minimum value among the correlation values ​​of each of the 11 segmented signals corresponding to each sampling point is used to determine the first metric value corresponding to each sampling point.

[0020] For example, for each received signal, the sampling point corresponding to the maximum value of the first metric value among the sampling points of that received signal can be selected as the coarse synchronization sampling point.

[0021] The time corresponding to the coarse synchronization sampling point is determined as the arrival time of the received signal, which is the coarse synchronization result.

[0022] In this embodiment, the process of establishing the main synchronization signal NPSS transmission model for the ground terminal (i.e., the terminal to be located) is first introduced: The length of each radio frame (RF) period in the public network IoT signal is 10ms. Each RF consists of 10 subframes (SF) of 1ms each. Each SF includes two 0.5ms slots, and each slot consists of 7 OFDM symbols (Sysmol). Among them, the NPSS is transmitted in the 5th subframe of the radio frame with a period of 10ms. It occupies the last 11 OFDM symbols of the 5th subframe in the time domain and 11 subcarriers in the frequency domain. It is transmitted by the base station to the terminal to be located.

[0023] NPSS is generated based on short ZC sequences, according to the formula for generating 11-bit short ZC sequences: ; in: Indicates the sequence number. For physical root index, , This represents the time-domain spreading code. The resulting 11-bit short ZC sequence is transformed to the time domain using an inverse Fourier transform (IFFT), and then the CP is added to obtain the NPSS signal. .

[0024] The corresponding signal received by the terminal to be located (i.e., the received signal). Represented as: ; in: The normalized sign indicates the time difference. Indicates the normalized carrier bias. Indicates the first One sampling point, The mean is 0 and the variance is Additive white Gaussian noise, This represents the number of IFFT points when the sampling frequency is 1.92MHz. .

[0025] In this embodiment, considering that the NPSS signal is generated based on an 11-bit short ZC sequence, the autocorrelation function of the ZC sequence is almost zero at all points except zero, exhibiting good correlation characteristics. However, under the presence of a Doppler frequency offset, its cross-correlation peak is significantly affected, and the signal bandwidth is only 180kHz. Therefore, more symbols need to be used in the time domain to ensure that the NPSS has sufficient time domain resources for synchronous detection.

[0026] Therefore, a time-domain segmented autocorrelation downlink NPSS coarse synchronization algorithm is designed to perform segmented autocorrelation on the received NPSS signal (i.e., the received signal) of the dynamic terminal: 1. At the terminal, receive the signal. Perform detection on the received signal Each sampling point The signal, which is the length of the next NPSS signal, is divided into 11 equal parts to obtain : ; 2. The conjugate of each segmented signal with itself and the conjugate of the other 10 segmented signals. Performing cross-correlation calculations yielded 11 correlation values. : ; in, This indicates the cross-correlation displacement.

[0027] Transmitted signal Substituting the values ​​into the calculation, we get: .

[0028] When accurate synchronization is achieved, the result is... Unaffected by dynamics: ; in, , represents a constant.

[0029] For each sampling point According to different It is worth 11 different correlation values. Each sampling point First metric The minimum value among these 11 relevant values: ; 3. Based on each sampling point First metric Selecting coarse synchronization sampling points means determining the peak position in the first metric as the coarse synchronization sampling point. : ; This embodiment designs a downlink NPSS coarse synchronization algorithm with time-domain segmentation correlation. The received NPSS signal is segmented, and the coarse synchronization observation value is obtained by using the time-domain repetition characteristic for correlation detection.

[0030] Step 202: For each received signal, take a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal as target sampling points, perform autocorrelation on the signal one symbol length after each target sampling point, and determine the fine synchronization result of the arrival time of the received signal based on the autocorrelation result.

[0031] In one embodiment, step 202 may include: The signal after each target sampling point is divided into two equal parts by one symbol length. Autocorrelation is then performed on the two segments of the signal after the division. The result of the autocorrelation operation is determined as the second metric value corresponding to each target sampling point.

[0032] Based on the second metric value corresponding to each target sampling point, the arrival time of the received signal is determined as a precise synchronization result.

[0033] For example, the target sampling point corresponding to the maximum value of the second metric value of each target sampling point can be selected as the fine synchronization sampling point.

[0034] The time corresponding to the fine synchronization sampling point is determined as the arrival time of the received signal, which is the fine synchronization result.

[0035] In this embodiment, the delay observations are further refined using the downlink NPSS signal based on the coarse synchronization observation results, so as to use a more accurate synchronization algorithm to detect the accurate arrival time of the NPSS signal.

[0036] Therefore, the results of the coarse estimation algorithm are used as coarse synchronization observations, and correlation operations are performed using the favorable properties of the ZC sequence to reduce the interference of multipath and noise.

[0037] Considering the multipath effect of ground base station signals, the received signal after coarse synchronization can be written as: ; (1) First, take the coarse synchronous observation values. front and back 1 sampling point is used as the target sampling point, where It can be determined based on actual needs.

[0038] (2) Take a signal of one symbol length (i.e., OFDM symbol length) from the target sampling point and divide it into two equal parts to obtain the first half of the symbol length. The signal and the length of the second half of the symbol The two signal segments are autocorrelation-based to reduce the effects of multipath and noise. Specifically, the metric function for the fine synchronization method is: ; in, For the first Impact response of multiple path effects for conjugate, for conjugate, For the first The time delay of a multipath effect path. The calculation results of the metric function include: The first represents the component with the same radius, that is: .

[0039] The second equation represents the cross component, that is: .

[0040] The third equation is the noise part, that is... .

[0041] (3) Take the maximum value of the metric function as the precise synchronization observation value. : ; Since the paths are independent of each other, all of them except the first one can be regarded as noise. Therefore, the entire metric function can only reach its peak when the sampling point is the starting position of the synchronization signal.

[0042] Based on the coarse synchronization results, this embodiment designs a fine synchronization algorithm for downlink NPSS signals, which calculates the autocorrelation of sampling points near the coarse synchronization observation to complete the fine synchronization observation.

[0043] Step 203: Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, solve the time difference of arrival equation to obtain the positioning result of the terminal to be located.

[0044] In one embodiment, step 203 may include: Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, the time difference of arrival equation is obtained.

[0045] The arrival time difference equation is solved using the chan method to obtain the positioning result of the terminal to be located.

[0046] For example, three base stations can be selected from multiple base stations, referred to as the first base station, the second base station, and the third base station.

[0047] Based on the precise synchronization results of the arrival time of each received signal, the arrival time difference between the precise synchronization results of the arrival time of the received signal corresponding to the second base station and the precise synchronization results of the arrival time of the received signal corresponding to the first base station is calculated and denoted as the first arrival time difference. The arrival time difference between the precise synchronization results of the arrival time of the received signal corresponding to the third base station and the precise synchronization results of the arrival time of the received signal corresponding to the first base station is calculated and denoted as the second arrival time difference.

[0048] Based on the location coordinates of each base station, calculate the difference between the distance between the second base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the first distance difference. Also calculate the difference between the distance between the third base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the second distance difference.

[0049] Based on the first arrival time difference, the first distance difference, the second arrival time difference, and the second distance difference, the arrival time difference equation is obtained.

[0050] In this embodiment, a method for estimating the signal arrival time observation of a dynamic terminal in a multi-base station coverage scenario is designed so that the terminal to be located can obtain the delay observation by detecting the primary synchronization signal (NPSS) emitted by multiple base stations. Then, a multi-base station collaborative terminal location calculation (TDOA) equation is established to solve for the terminal location information.

[0051] Specifically, to calculate the location of the terminal to be located, the TDOA equation is established using the acquired NPSS signal delay observations: In a ground base station scenario, assume the location coordinates of the terminal to be located are: You can see , , The three base stations (i.e., the first base station, the second base station, and the third base station) have the following location coordinates: , , When data upload is required, the terminal to be located begins detecting the downlink NPSS signals sent by the base station, recording the arrival times of the three NPSS signals and the location of each terminal to establish the TDOA equation. The terminal to be located needs to be equipped with a height sensor. The distances from the three base stations to the ground terminal are... , , Represented as: ; use These represent the difference between the arrival time of the second NPSS signal detected by the terminal to be located and the arrival time of the first NPSS signal (i.e., the first arrival time difference), and the difference between the arrival time of the third NPSS signal and the arrival time of the first NPSS signal (i.e., the second arrival time difference). Let represent the arrival times of the three NPSS signals (i.e., the precise synchronization results of the arrival times of the received signals corresponding to the first base station, the second base station, and the third base station, respectively). Then, the time difference of arrival is: ; ; Therefore, the following set of TDOA equations can be listed: ; in: For the Earth's radius, This refers to the terminal height.

[0052] The terminal position is obtained by solving the TDOA equation using the chan method: use Let represent the distance difference between the second base station and the first base station at the time the NPSS signal is transmitted (i.e., the first distance difference), and let represent the distance difference between the third base station and the first base station at the time the NPSS signal is transmitted (i.e., the second distance difference). Then the distance difference equation can be: ; ; From the first equation in the TDOA system, we can obtain: ; ; In the solution process, it is necessary to first use To represent with a linear expression Find Ultimately, we can arrive at the conclusion use The solution is: ; in: , .

[0053] Figure 3 The simulation conducted for the method of this invention shows that the accuracy of the NPSS detection algorithm directly affects the acquisition process and synchronization accuracy of TDOA observations. Figure 3The MSA method proposed in this invention is compared with the maximum likelihood method. The vertical axis represents the RMSE of the observation estimation error relative to the OFDM symbol spacing normalization, and the CFO represents the Doppler frequency offset relative to the subcarrier spacing normalization. It can be seen that both the MSA and maximum likelihood algorithms can effectively perform time delay observations without Doppler frequency offset, with little difference in accuracy. However, when the Doppler frequency offset is 0.4 subcarrier spacings, the MSA method of this invention still maintains good detection accuracy, while the detection error of the maximum likelihood algorithm increases sharply, demonstrating the anti-Doppler performance of the proposed method in time delay observation estimation.

[0054] Figure 4 Simulations of the method of this invention demonstrate how the positioning error varies with Doppler frequency offset and signal-to-noise ratio. In the absence of Doppler frequency offset, both the method of this invention and the comparative algorithm achieve positioning accuracy of tens of meters. When the Doppler frequency offset is 0.4 subcarrier intervals, the anti-Doppler performance of the NPSS detection algorithm of this invention allows the time delay observation to maintain a small error, while the positioning accuracy of the traditional algorithm increases significantly, even reaching several kilometers. This proves that the algorithm of this invention can enable dynamic terminals to achieve accurate self-localization in multi-base station coverage scenarios.

[0055] Figure 5 Simulations of the method of this invention demonstrate a comparison of terminal power consumption between the method of this invention and the GNSS method. The terminal needs to perform GNSS positioning before each uplink data transmission, and the RRC connection needs to be disconnected during the GNSS positioning process. This portion of power consumption accounts for 30%-50% of the total UE power consumption, and is affected by the GNSS acquisition time. The impact. The longer the signal, the greater the power consumption of the GNSS method. Using its own signal allows for positioning calculations without interrupting the RRC connection, saving a significant amount of power in this process. The IoT terminal positioning method using the base station downlink synchronization signal of this invention is more power-efficient than the GNSS method.

[0056] This invention proposes a dynamic method for estimating signal arrival time (TDOA) observations of terminals in multi-base station coverage scenarios. This method utilizes the good correlation properties of ZC sequences and the repetitive characteristics of NPSS signals for primary synchronization signal detection, and consists of two parts: coarse estimation and fine estimation, to obtain the time delay observations of base station signals. Based on the above algorithm, a multi-base station collaborative terminal location calculation TDOA equation is established, and the Chan method is used to solve the TDOA equation to obtain the terminal location coordinates. This method is suitable for achieving dynamic IoT terminal self-localization in multi-base station coverage scenarios and can meet the needs of dynamic IoT terminal location information acquisition in GNSS-free scenarios.

[0057] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0058] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0059] Figure 6 A schematic diagram of a terminal positioning device based on multi-base station collaboration provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below: like Figure 6 As shown, the terminal positioning device based on multi-base station collaboration includes: The coarse synchronization module 61 is used to perform segmented autocorrelation on each received signal in the time domain after the terminal to be located acquires multiple received signals, and determine the arrival time coarse synchronization result of each received signal based on the segmented autocorrelation result. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. The fine synchronization module 62 is used to take a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal as target sampling points for each received signal, perform autocorrelation on the signal one symbol length after each target sampling point, and determine the fine synchronization result of the arrival time of the received signal based on the autocorrelation result. The positioning module 63 is used to solve the time difference of arrival equation based on the precise synchronization result of the arrival time of each received signal and the position coordinates of each base station among multiple base stations, and to obtain the positioning result of the terminal to be positioned.

[0060] In one possible implementation, the coarse synchronization module 61 is specifically used for: For each received signal, the signal after each sampling point of the received signal is divided into 11 equal parts, and 11 segmented signals corresponding to each sampling point are obtained. For each sampling point, the 11 segmented signals are cross-correlated with each segmented signal and its own conjugate, and cross-correlated with the conjugates of each segmented signal and other segmented signals. The first metric value corresponding to each sampling point is determined based on the cross-correlation result, which is used as the segmented autocorrelation result for each sampling point. Based on the piecewise autocorrelation results corresponding to each sampling point, the coarse synchronization result of the arrival time of the received signal is obtained.

[0061] In one possible implementation, the coarse synchronization module 61 is specifically used for: For each sampling point, cross-correlation is performed between each segment signal and its own conjugate, and cross-correlation is performed between each segment signal and the conjugate of other segment signals. The sum of the cross-correlation results is calculated as the correlation value for each segment signal. The minimum value among the correlation values ​​of each of the 11 segmented signals corresponding to each sampling point is used to determine the first metric value corresponding to each sampling point.

[0062] In one possible implementation, the coarse synchronization module 61 is specifically used for: For each received signal, the sampling point corresponding to the maximum value of the first metric value among the sampling points of the received signal is selected as the coarse synchronization sampling point; The time corresponding to the coarse synchronization sampling point is determined as the arrival time of the received signal, which is the coarse synchronization result.

[0063] In one possible implementation, the fine synchronization module 62 is specifically used for: The signal after each target sampling point is divided into two equal parts by one symbol length. The two segments of the signal after the division are then subjected to autocorrelation. The result of the autocorrelation is determined as the second metric value corresponding to each target sampling point. Based on the second metric value corresponding to each target sampling point, the arrival time of the received signal is determined as a precise synchronization result.

[0064] In one possible implementation, the fine synchronization module 62 is specifically used for: Select the target sampling point corresponding to the maximum value of the second metric value of each target sampling point as the fine synchronization sampling point; The time corresponding to the fine synchronization sampling point is determined as the arrival time of the received signal, which is the fine synchronization result.

[0065] In one possible implementation, the positioning module 63 is specifically used for: Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, the arrival time difference equation is obtained; The arrival time difference equation is solved using the chan method to obtain the positioning result of the terminal to be located.

[0066] In one possible implementation, the positioning module 63 is specifically used for: Select three base stations from the multiple base stations, and denote them as the first base station, the second base station, and the third base station; Based on the fine synchronization results of the arrival time of each received signal, calculate the arrival time difference between the fine synchronization results of the arrival time of the received signal corresponding to the second base station and the fine synchronization results of the arrival time of the received signal corresponding to the first base station, and record it as the first arrival time difference. Also calculate the arrival time difference between the fine synchronization results of the arrival time of the received signal corresponding to the third base station and the fine synchronization results of the arrival time of the received signal corresponding to the first base station, and record it as the second arrival time difference. Based on the location coordinates of each base station, calculate the difference between the distance between the second base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the first distance difference. Also calculate the difference between the distance between the third base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the second distance difference. The arrival time difference equation is obtained based on the first arrival time difference, the first distance difference, the second arrival time difference, and the second distance difference.

[0067] Figure 7 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. For example... Figure 7 As shown, the electronic device 7 of this embodiment includes a processor 70 and a memory 71. The memory 71 stores a computer program 72. When the processor 70 executes the computer program 72, it implements the steps in the various method embodiments described above. Alternatively, when the processor 70 executes the computer program 72, it implements the functions of each module / unit in the various device embodiments described above.

[0068] For example, computer program 72 may be divided into one or more modules / units, which are stored in memory 71 and executed by processor 70 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 72 in electronic device 7.

[0069] Electronic device 7 may include, but is not limited to, processor 70 and memory 71. Those skilled in the art will understand that... Figure 7 This is merely an example of electronic device 7 and does not constitute a limitation on electronic device 7. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 7 may also include input / output devices, network access devices, buses, etc.

[0070] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0071] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0072] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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. Such 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, and should all be included within the protection scope of the present invention.

Claims

1. A terminal positioning method based on multi-base station collaboration, characterized in that, include: After the terminal to be located acquires multiple received signals, each received signal is segmented autocorrelation in the time domain. The arrival time of each received signal is determined based on the segmented autocorrelation results. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. For each received signal, a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal are taken as target sampling points. Autocorrelation is performed on the signal one symbol length after each target sampling point, and the fine synchronization result of the arrival time of the received signal is determined based on the autocorrelation result. Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, the time difference of arrival equation is solved to obtain the positioning result of the terminal to be located.

2. The terminal positioning method based on multi-base station collaboration according to claim 1, characterized in that, For each received signal, perform piecewise autocorrelation in the time domain. Based on the piecewise autocorrelation results, determine the coarse synchronization result of the arrival time of each received signal, including: For each received signal, the signal after each sampling point of the received signal is divided into 11 equal parts, and 11 segmented signals corresponding to each sampling point are obtained. For each sampling point, the 11 segmented signals are cross-correlated with each segmented signal and its own conjugate, and cross-correlated with the conjugates of each segmented signal and other segmented signals. The first metric value corresponding to each sampling point is determined based on the cross-correlation result, which is used as the segmented autocorrelation result for each sampling point. Based on the piecewise autocorrelation results corresponding to each sampling point, the coarse synchronization result of the arrival time of the received signal is obtained.

3. The terminal positioning method based on multi-base station collaboration according to claim 2, characterized in that, For each sampling point corresponding to 11 segmented signals, a cross-correlation operation is performed between each segmented signal and its own conjugate, and a cross-correlation operation is performed between each segmented signal and the conjugates of other segmented signals. Based on the cross-correlation results, the first metric value corresponding to each sampling point is determined, including: For each sampling point, cross-correlation is performed between each segment signal and its own conjugate, and cross-correlation is performed between each segment signal and the conjugate of other segment signals. The sum of the cross-correlation results is calculated as the correlation value for each segment signal. The minimum value among the correlation values ​​of each of the 11 segmented signals corresponding to each sampling point is used to determine the first metric value corresponding to each sampling point.

4. The terminal positioning method based on multi-base station collaboration according to claim 2, characterized in that, Based on the piecewise autocorrelation results corresponding to each sampling point, the coarse synchronization results of the arrival time of the received signal are obtained, including: For each received signal, the sampling point corresponding to the maximum value of the first metric value among the sampling points of the received signal is selected as the coarse synchronization sampling point; The time corresponding to the coarse synchronization sampling point is determined as the arrival time of the received signal, which is the coarse synchronization result.

5. The terminal positioning method based on multi-base station collaboration according to claim 1, characterized in that, Autocorrelation is performed on the signal one symbol length after each target sampling point. Based on the autocorrelation result, the arrival time of the received signal is determined to achieve precise synchronization, including: The signal after each target sampling point is divided into two equal parts by one symbol length. The two segments of the signal after the division are then subjected to autocorrelation. The result of the autocorrelation is determined as the second metric value corresponding to each target sampling point. Based on the second metric value corresponding to each target sampling point, the arrival time of the received signal is determined as a precise synchronization result.

6. The terminal positioning method based on multi-base station collaboration according to claim 5, characterized in that, Based on the second metric value corresponding to each target sampling point, the arrival time precision synchronization result of the received signal is determined, including: Select the target sampling point corresponding to the maximum value of the second metric value of each target sampling point as the fine synchronization sampling point; The time corresponding to the fine synchronization sampling point is determined as the arrival time of the received signal, which is the fine synchronization result.

7. The terminal positioning method based on multi-base station cooperation according to claim 1, characterized in that, Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each of the multiple base stations, the time difference of arrival equation is solved to obtain the positioning result of the terminal to be located, including: Based on the precise synchronization results of the arrival time of each received signal and the location coordinates of each base station among multiple base stations, the arrival time difference equation is obtained; The arrival time difference equation is solved using the chan method to obtain the positioning result of the terminal to be located.

8. The terminal positioning method based on multi-base station cooperation according to claim 7, characterized in that, Based on the precise synchronization results of the arrival time of each received signal, and the location coordinates of each of the multiple base stations, the time difference of arrival equation is obtained, including: Select three base stations from the multiple base stations, and denote them as the first base station, the second base station, and the third base station; Based on the fine synchronization results of the arrival time of each received signal, calculate the arrival time difference between the fine synchronization results of the arrival time of the received signal corresponding to the second base station and the fine synchronization results of the arrival time of the received signal corresponding to the first base station, and record it as the first arrival time difference. Also calculate the arrival time difference between the fine synchronization results of the arrival time of the received signal corresponding to the third base station and the fine synchronization results of the arrival time of the received signal corresponding to the first base station, and record it as the second arrival time difference. Based on the location coordinates of each base station, calculate the difference between the distance between the second base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the first distance difference. Also calculate the difference between the distance between the third base station and the terminal to be located and the distance between the first base station and the terminal to be located, and record it as the second distance difference. The arrival time difference equation is obtained based on the first arrival time difference, the first distance difference, the second arrival time difference, and the second distance difference.

9. A terminal positioning device based on multi-base station collaboration, characterized in that, include: The coarse synchronization module is used to perform segmented autocorrelation on each received signal in the time domain after the terminal to be located acquires multiple received signals, and to determine the coarse synchronization result of the arrival time of each received signal based on the segmented autocorrelation result. The received signal is the NPSS signal sent by each of the multiple base stations received by the terminal to be located. The fine synchronization module is used to take a preset number of sampling points before and after the coarse synchronization result of the arrival time of the received signal as target sampling points for each received signal, perform autocorrelation on the signal one symbol length after each target sampling point, and determine the fine synchronization result of the arrival time of the received signal based on the autocorrelation result. The positioning module is used to solve the time difference of arrival equation based on the precise synchronization result of the arrival time of each received signal and the location coordinates of each of the multiple base stations, and to obtain the positioning result of the terminal to be located.

10. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method as described in any one of claims 1 to 8.

Images