A method, device, equipment and medium for extracting a direct-diameter component

Abstract

A method, apparatus, device, and medium for extracting direct path components are disclosed, relating to the field of communication technology. The method includes: acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include a reference station and at least one non-reference station; comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival (TDOA) spectrum between each non-reference station and the reference station; for each observation time, extracting multiple spectral peaks and corresponding time delay differences from the TDOA spectrum; tracking the trajectory of multiple propagation paths evolving over time based on the time delay differences at multiple observation times to obtain the time delay difference trajectory of each propagation path; and extracting the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory. Therefore, this application can improve the accuracy of direct path component extraction, thereby reducing positioning and tracking errors.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method, apparatus, device and medium for extracting the direct path component. Background Technology

[0002] In wireless positioning systems, extracting the line-of-sight (LOS) component from the wireless signal is a core prerequisite for achieving high-precision ranging and positioning. However, in complex real-world positioning scenarios, such as densely built-up urban areas or indoor environments, wireless signals undergo extensive reflection, diffraction, and scattering, generating numerous non-line-of-sight (NLOS) components with delays close to or even larger than the LOS components. This makes it easy to mistake NLOS components for LOS components, resulting in low accuracy in LOS component extraction and consequently, significant errors in positioning and tracking results. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a method, apparatus, device, and medium for extracting the direct path component, which can improve the extraction accuracy of the direct path component and thereby reduce the error in positioning and tracking results.

[0004] The embodiments of this application disclose the following technical solutions: In a first aspect, this application discloses a method for extracting a direct path component, the method comprising: The method involves acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include one reference station and at least one non-reference station. The wireless signal of each non-reference station is compared with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station. For each observation time, multiple spectral peaks and time delay differences corresponding to the multiple spectral peaks are extracted from the arrival time difference spectrum; Based on the time delay difference values ​​at multiple observation times, the trajectory of multiple propagation paths that evolve over time is tracked to obtain the time delay difference trajectory of each propagation path; Based on the stability index of the time delay difference trajectory, the direct path component is extracted from the multiple propagation paths.

[0005] Secondly, this application discloses a device for extracting the direct diameter component, the device comprising: The signal acquisition module is used to acquire wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include one reference station and at least one non-reference station; The signal comparison module is used to compare the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station. The peak extraction module is used to extract multiple spectral peaks and time delay differences corresponding to the multiple spectral peaks from the arrival time difference spectrum for each observation time. The trajectory acquisition module is used to track the trajectories of multiple propagation paths that evolve over time based on the time delay difference values ​​of multiple observation times, and obtain the time delay difference trajectory of each propagation path; The component extraction module is used to extract the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory.

[0006] Thirdly, this application discloses an electronic device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the program, when executed, implements the method described in the first aspect.

[0007] Fourthly, this application discloses a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0008] Compared with the prior art, this application has the following beneficial effects: This application provides a method, apparatus, device, and medium for extracting the direct path component. The method includes: acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmission source; the multiple receiving stations include a reference station and at least one non-reference station; comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station; for each observation time, extracting multiple spectral peaks and corresponding time delay differences from the arrival time difference spectrum; tracking the trajectory of multiple propagation paths evolving over time based on the time delay differences at multiple observation times to obtain the time delay difference trajectory of each propagation path; and extracting the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory. Thus, this application utilizes the different characteristics of direct paths and reflection paths in terms of time evolution. By tracking the trajectory of observation data from multiple consecutive moments, a time delay difference trajectory for each propagation path is constructed, and the stability index of the time delay difference trajectory for each propagation path is calculated. This mathematically quantifies the degree of fluctuation in the propagation path, effectively distinguishing between the smoothly fluctuating direct path and the drastically changing reflection path. Therefore, this application improves the accuracy of extracting the direct path component, thereby reducing the error in the positioning and tracking results. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A flowchart illustrating a method for extracting the direct path component provided in an embodiment of this application; Figure 2 A schematic diagram of multiple receiving stations and a transmitting source provided for an embodiment of this application; Figure 3 A flowchart for obtaining the time difference of arrival spectrum in the frequency domain is provided as an embodiment of this application; Figure 4 A flowchart for obtaining the delay difference trajectory of each propagation path is provided in an embodiment of this application; Figure 5 This is a schematic diagram of a device for extracting the direct diameter component according to an embodiment of this application. Detailed Implementation

[0011] As described earlier, in complex real-world positioning scenarios, such as densely built-up urban areas or indoor environments, wireless signals undergo extensive reflection, diffraction, and scattering, generating numerous reflected path components with delays close to or even larger than the direct path components. This makes it easy to mistake reflected path components for direct path components, resulting in low accuracy in extracting direct path components and consequently, larger errors in positioning and tracking results.

[0012] The inventors, through research, have provided a method, apparatus, device, and medium for extracting the direct path component. The method includes: acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include a reference station and at least one non-reference station; comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station; for each observation time, extracting multiple spectral peaks and corresponding time delay differences from the arrival time difference spectrum; based on the time delay differences at multiple observation times, tracing the trajectory of multiple propagation paths evolving over time to obtain the time delay difference trajectory of each propagation path; and extracting the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory. Thus, this application utilizes the different characteristics of direct paths and reflection paths in terms of temporal evolution. By tracking the trajectory of observation data from multiple consecutive moments, a time delay difference trajectory for each propagation path is constructed, and the stability index of the time delay difference trajectory for each propagation path is calculated. This mathematically quantifies the degree of fluctuation in the propagation path, effectively distinguishing between the smoothly fluctuating direct path and the drastically changing reflection path. Therefore, this application improves the accuracy of extracting the direct path component, thereby reducing the error in the positioning and tracking results.

[0013] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0014] See Figure 1 The figure is a flowchart of a method for extracting a direct path component according to an embodiment of this application. This method is applied to computing devices with data processing capabilities, such as a central processing station or any receiving station. The method includes: S101: Acquire the wireless signals received by multiple receiving stations at multiple observation times; the wireless signals come from the same transmission source; the multiple receiving stations include one reference station and at least one non-reference station.

[0015] See Figure 2 This figure is a schematic diagram of multiple receiving stations and a transmitting source provided in an embodiment of this application. Multiple receiving stations (such as...) Figure 2 (There are 3) are receiving stations whose spatial locations are known and whose time is synchronized with the reference station. The receiving stations can be ground base stations, sensor nodes, etc. The multiple receiving stations include one reference station and at least one non-reference station. The reference station *r* can be a geographically centrally located receiving station (e.g.,...). Figure 2 (Receiving station 2 in the middle).

[0016] It should be noted that although this embodiment uses multiple receiving stations as an example, only one reference station and one non-reference station (i.e., two receiving stations) are needed to achieve the direct path extraction function of this technical solution. The number of receiving stations can be expanded according to the actual application scenario, for example, by increasing the number of non-reference stations to improve positioning accuracy or coverage. This application does not limit the specific method for determining the reference station.

[0017] The emission source emits at fixed time intervals. It transmits radio signals to one reference station and at least one non-reference station. The transmitting source is numbered... Secondary non-reference station Taking the transmission of wireless signals as an example, non-reference station After being processed by the radio frequency front end, the received wireless signal is The wireless signal As shown in the following formula (1):

[0018] in, In the first During the transmission of the secondary signal, the non-reference station At any moment Received wireless signal, Non-reference station The number of observable propagation paths (including direct paths and reflection paths). In the first During the second signal transmission, via the first The propagation path reaches the non-reference station The complex amplitude of the wireless signal (including propagation path loss, phase shift, and other effects). This is the baseband waveform of the wireless signal. In the first During the second signal transmission, via the first The propagation path reaches the non-reference station The propagation delay of wireless signals, In the first During the transmission of the secondary signal, the non-reference station The noise of the wireless signal received at time t.

[0019] It should be noted that this application does not limit the specific implementation method of the radio frequency front-end. For example, radio frequency or intermediate frequency quadrature sampling, digital downconversion and other receiving schemes can be adopted.

[0020] S102: Compare the radio signal of each non-reference station with the radio signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station.

[0021] To eliminate measurement uncertainties caused by clock asynchrony between the transmitter and receiver, and to enable stable path tracking using timing information, this step compares the signals from the non-reference station with those from the reference station to obtain a stable time difference of arrival spectrum. In one specific implementation, the time difference of arrival spectrum between each non-reference station and the reference station is obtained in the time domain by performing cross-correlation between the radio signals received by each non-reference station and the radio signals received by the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station.

[0022] In the first During the secondary signal transmission, for non-reference stations Received wireless signals and reference station Taking the cross-correlation operation of received wireless signals as an example, for non-reference stations... m and reference station r cross-correlation function As shown in formula (2) below:

[0023] in, In the first During the transmission of the secondary signal, the non-reference station Received wireless signals and reference station The cross-correlation function of the received wireless signals, In the first During the transmission of the secondary signal, the non-reference station At any moment Received wireless signal, In the first During the transmission of the next signal, the reference station At any moment Received wireless signal, superscript For conjugate, The time delay difference variable.

[0024] It is understandable that the magnitude of the cross-correlation function changes with the time delay difference variable. The changing curve is the arrival time difference spectrum, and its peak position corresponds to the arrival time difference (i.e., the delay difference) between the two stations.

[0025] See Figure 3 The figure is a flowchart illustrating how to obtain the time difference of arrival spectrum in the frequency domain according to an embodiment of this application. In another specific implementation, the method for obtaining the time difference of arrival spectrum between each non-reference station and the reference station in the frequency domain is shown in steps A1-A3 below: A1: For the digital baseband signal sequence corresponding to the wireless signal received by each non-reference station and the digital baseband signal sequence corresponding to the wireless signal received by the reference station, perform discrete Fourier transform processing respectively to obtain the frequency domain representation of the received signal sequence of each non-reference station and the frequency domain representation of the received signal sequence of the reference station.

[0026] Non-reference station , No. Taking the next signal transmission as an example, firstly, the wireless signal received by the non-reference station... Perform analog-to-digital conversion to obtain the corresponding digital baseband signal sequence. Subsequently, the digital baseband signal sequence was analyzed. Perform Discrete Fourier Transform to obtain the result at the 1st... During the transmission of the secondary signal, the non-reference station Frequency domain representation of the received signal sequence .in, Frequency Index , is the number of points in the Discrete Fourier Transform.

[0027] Understandably, each frequency index Corresponding to a specific frequency value Frequency value The calculation formula is shown in formula (3) below:

[0028] in, For the first The center frequency of each sub-band The starting frequency of the signal. This refers to the subcarrier spacing or frequency resolution.

[0029] A2: Determine the spectral complex ratio sequence for each non-reference station based on the ratio of the frequency domain representation of the received signal sequence of each non-reference station to the frequency domain representation of the received signal sequence of the reference station.

[0030] With the first Taking the next signal transmission as an example, based on the non-reference station Frequency domain representation of the received signal sequence and reference station Frequency domain representation of the received signal sequence The ratio of the non-reference stations is used to determine the non-reference stations. Spectral complex ratio sequence Specifically, the spectral complex ratio sequence The calculation formula is shown in formula (4) below:

[0031] in, In the first During the transmission of the secondary signal, the non-reference station The spectrum of complex ratios, In the first During the transmission of the secondary signal, the non-reference station The frequency domain representation of the received signal sequence. In the first During the transmission of the next signal, the reference station The frequency domain representation of the received signal sequence.

[0032] Specifically, , In the first The transmitted signal spectrum during the next signal transmission. In the first During the transmission of the secondary signal, the non-reference station The channel frequency domain response. If channel fading is not considered, then in the... During the transmission of the secondary signal, the non-reference station Channel frequency domain response , In the first When the signal is transmitted, it reaches the non-reference station. The complex amplitude of the wireless signal, For the first The center frequency of each sub-band In the first When the signal is transmitted, it reaches the non-reference station. The propagation delay of wireless signals.

[0033] It is understandable that the spectral complex ratio sequence in the above formula (4) Eliminated the transmitted signal spectrum The impact (because the numerator and denominator can be directly simplified).

[0034] A3: Perform inverse discrete Fourier transform or super-resolution spectral estimation on the spectral complex ratio sequence of each non-reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station.

[0035] The spectral ratio is a complex number, including phase information. and amplitude information Specifically, in the first During the transmission of the secondary signal, the non-reference station Phase information of the complex ratio of the spectrum As shown in the following formula (5):

[0036] in, In the first During the transmission of the secondary signal, the non-reference station The spectral complexity ratio in the th Phase information in each sub-band For the first The center frequency of each sub-band In the first When the signal is transmitted, the wireless signal reaches the non-reference station. Time and Arrival Reference Station The time difference (instant delay difference). The phase shift is constant.

[0037] As can be seen from formula (5), phase information It is about the first The center frequency of each sub-band A linear function whose slope is related to the arrival of the radio signal at the non-reference station. The difference between the time and the time of arrival at reference station r Proportional.

[0038] In one specific implementation, an inverse discrete Fourier transform can be performed on the spectral complex ratio sequence of each non-reference station to obtain the function in the time-delay domain. The function in the time delay domain is the function in the first time delay domain. During the transmission of the secondary signal, the non-reference station and reference station The arrival time difference spectrum between them. The function in the time extension domain. The independent variable in With the When the signal is transmitted, the wireless signal reaches the non-reference station. Time and Arrival Reference Station Time difference When they are aligned, the phases of each frequency component are corrected and aligned, thus forming an energy peak at the corresponding time delay. The position of this peak is the [missing information - likely a specific time delay]. Estimated delay during secondary signal transmission .

[0039] In another specific implementation, to further improve the time delay resolution capability in complex multipath environments (e.g., dense propagation paths, low signal-to-noise ratio), super-resolution spectral estimation can be performed on the spectral complex ratio sequence of each non-reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station: First, the spectral complex ratio sequence of each non-reference station is converted into... 1D spectral complex ratio vector As shown in the following formula (6):

[0040] Where γ is A dimensional complex ratio vector, The superscript T stands for transpose, and x is... The complex amplitude vector of the propagation path in dimension, whose elements Indicates the first The complexity of the propagation path, G is A dimensional manifold matrix, where each column corresponds to a steering vector of a potential propagation path, the th column being... p A column can be represented as (The colon represents all lines) The number of propagation path components, For noise vectors, For the first The time delay corresponding to each propagation path.

[0041] Subsequently, according to Using a spectral complex ratio vector of dimension 1, at least one of the following algorithms is employed: Multiple Signal Classification (MUSIC), Rotation Invariant Technique (ESPRIT), and Sparse Reconstruction Algorithm, the arrival time difference spectrum between each non-reference station and the reference station is obtained.

[0042] S103: For each observation time, extract multiple spectral peaks and the time delay difference values ​​corresponding to the multiple spectral peaks from the arrival time difference spectrum.

[0043] Each spectral peak represents a possible propagation path, such as a direct path, a primary reflection path, a secondary reflection path, etc. In one specific implementation, peak detection is performed on the arrival time difference spectrum obtained in step S102. Specifically, firstly, an amplitude threshold is preset, and only spectral peaks greater than this threshold are retained; then, the retained spectral peaks are sorted according to their amplitude, and the peaks at the beginning of the path are extracted. The most prominent spectral peaks form a spectral peak set. Among them, This represents the preset maximum number of propagation paths.

[0044] For example, in the first During the transmission of the secondary signal, the non-reference station Relative reference station The resulting spectral peak set can be ,in, This is the time delay difference. The amplitude of the arrival time difference spectrum.

[0045] S104: Based on the time delay difference at multiple observation times, track the trajectory of multiple propagation paths that evolve over time to obtain the time delay difference trajectory of each propagation path.

[0046] Because direct paths are time-continuous, while noise peaks or certain reflection paths may be caused by sudden interference, trajectory tracing can distinguish the nature of the propagation path. See also Figure 4 This figure is a flowchart illustrating how to obtain the delay difference trajectory for each propagation path according to an embodiment of this application. This step utilizes the Kalman filter concept to design methods for predicting, estimating, and matching the delay difference: B1: Based on the time delay difference and time delay change rate of the propagation path at the previous observation time, predict the time delay difference and time delay change rate of the propagation path at the current observation time.

[0047] Based on the temporal continuity of the propagation path, this step uses the path state (time delay difference and time delay change rate) from the previous observation time to predict the path state at the current observation time: Based on the first-order motion model, the formula for predicting the time delay difference at the current observation time is shown in the following formula (7):

[0048] in, For the first The observation time of the transmission of the second signal (the current observation time) is related to the first... The predicted value of the delay difference of each propagation path. For the first The observation time of the next signal transmission (the previous observation time), the... The final estimate of the time delay of each propagation path. For the first The observation time of the next signal transmission The rate of change of time delay of each propagation path, The time interval between the two measurements.

[0049] Based on the first-order motion model, the formula for predicting the rate of change of time delay at the current observation moment is shown in formula (8):

[0050] in, For the first The observation time of the second signal transmission is related to the first The predicted value of the rate of change of time delay for each propagation path. For the first The observation time of the next signal transmission, the first The final estimate of the rate of change of time delay for each propagation path.

[0051] B2: The multiple spectral peaks extracted from the arrival time difference spectrum at the current observation time will be matched with the predicted time delay difference to determine the propagation path corresponding to each of the multiple spectral peaks.

[0052] This step minimizes the difference between the predicted and observed time delays by matching multiple spectral peaks extracted from the arrival time difference spectrum at the current observation time with the predicted time delay differences, thereby determining the propagation paths corresponding to each of the multiple spectral peaks: The matching adopts the criterion of minimizing the cost function, as shown in the following formula (9):

[0053] in, In the first At that moment, the extracted first The time delay difference of each spectral peak, For the first Time for the first The prediction results of the time delay difference of each propagation path. For the new interest, Let be the cost function.

[0054] It should be noted that if the cost function value is greater than the preset value, then the observed spectral peak is considered not to belong to the first... The propagation path is defined, and the cumulative number of lost paths is increased. If the cost function value is less than or equal to a preset value, the observed spectral peak is considered to belong to the [number]th [path]. Establish a propagation path and execute step B3.

[0055] B3: Using the time delay difference and time delay change rate of the propagation path corresponding to the successfully matched spectral peak, update the predicted time delay difference and time delay change rate of the propagation path at the current observation time.

[0056] This step uses the state of the propagation path corresponding to the successfully matched spectral peak to update the state of the propagation path at the current observation time, obtaining a more accurate time delay difference and time delay change rate of the propagation path at the current observation time: Specifically, the Kalman filter update method is adopted, as shown in the following formula (10):

[0057] in, For the first Time of the first The estimated time delay of the output of each propagation path (posterior estimate). For the first Time of the first The difference in prediction delay for each propagation path. The difference between the successfully matched spectral peak delay difference and the predicted delay difference, The Kalman gain (0-1) is the delay difference. For the first Time of the first The final rate of change estimate for each propagation path, For the first Time of the first The predicted rate of change of each propagation path, The Kalman gain is the rate of change. For the first Time of the first Uncertainty in predicting the propagation path This is the preset value for process noise. For the measurement time interval, The intensity coefficient is updated for the rate.

[0058] S105: Extract the direct path component from multiple propagation paths based on the stability index of the time delay difference trajectory.

[0059] Given that direct paths are stable and continuous in time, while reflection paths often fluctuate significantly or appear intermittently, this step evaluates the time delay difference trajectory of each propagation path by constructing a stability scoring formula that integrates the posterior variance of the propagation path, the number of times the propagation path occurs continuously, and the number of times the propagation path is lost. The propagation path with the highest stability score is selected as the direct path component. First, for each maintained propagation path, its posterior variance is calculated. Specifically, the formula for calculating the posterior variance is shown in formula (11) below:

[0060] in, For the first Time of the first The final uncertainty (posterior variance) of each propagation path. For the first Time of the first The prediction uncertainty (prior variance) of a propagation path. Kalman gain for delay difference For new information.

[0061] Specifically, no. Time of the first The prediction uncertainty (prior variance) of the propagation path is equal to the first... q -1 moment p The sum of the final uncertainty (i.e., posterior variance) of the propagation path and the preset value of the process noise is shown in the following formula (12):

[0062] in, For the first At that moment, for the first The uncertainty (i.e., prior variance) in predicting a propagation path. For the first Time of the first The ultimate uncertainty (i.e., posterior variance) of each propagation path. This is the preset value for process noise.

[0063] Subsequently, based on the posterior variance, the first... Stability score at any time As shown in the following formula (13):

[0064] in, For the first Time of the first The final uncertainty (posterior variance) of each propagation path. and These represent the number of times the trajectory continues (including the lost portions) and the number of times it is lost, respectively. This represents the number of valid observations in the trajectory. Therefore, the stability score is correlated with the posterior variance of the propagation path, the number of times the propagation path repeatedly appears, and the number of times the propagation path is lost.

[0065] For each moment Select stability score The highest trajectory is taken as the direct path trajectory, and the updated time delay difference of the direct path trajectory at the current observation time is used as the positioning parameter measurement value of the direct path.

[0066] In one specific implementation, the position coordinates of the transmitting source can also be determined based on the position parameter measurements (i.e., delay difference) of the direct path between multiple non-reference stations and the reference station, as shown in the following formula (14):

[0067] in, This represents the time delay difference of the direct route. As the source of launch Location to non-reference station The distance of the location, As the source of launch Location to reference station The distance of the location, This refers to the speed of radio wave propagation.

[0068] By solving this system of equations (such as using the least squares method or Taylor series expansion), the precise position coordinates of the emission source can be calculated.

[0069] In summary, this application provides a method for extracting the direct path component. The method includes: acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include a reference station and at least one non-reference station; comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station; for each observation time, extracting multiple spectral peaks and corresponding time delay differences from the arrival time difference spectrum; tracking the trajectory of multiple propagation paths evolving over time based on the time delay differences at multiple observation times to obtain the time delay difference trajectory of each propagation path; and extracting the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory. Thus, this application utilizes the different characteristics of direct paths and reflection paths in terms of temporal evolution. By tracking the trajectory of observation data from multiple consecutive moments, a time delay difference trajectory for each propagation path is constructed, and the stability index of the time delay difference trajectory for each propagation path is calculated. This mathematically quantifies the degree of fluctuation in the propagation path, effectively distinguishing between the smoothly fluctuating direct path and the drastically changing reflection path. Therefore, this application improves the accuracy of extracting the direct path component, thereby reducing the error in the positioning and tracking results.

[0070] See Figure 5 This figure is a schematic diagram of a device for extracting a direct diameter component according to an embodiment of this application. The device 500 for extracting the direct diameter component includes: The signal acquisition module 501 is used to acquire wireless signals received by multiple receiving stations at multiple observation times; the wireless signals come from the same transmitting source; the multiple receiving stations include one reference station and at least one non-reference station; The signal comparison module 502 is used to compare the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station. The peak extraction module 503 is used to extract multiple peaks and the time delay difference values ​​corresponding to the multiple peaks from the arrival time difference spectrum for each observation time. The trajectory acquisition module 504 is used to track the trajectory of multiple propagation paths that evolve over time based on the time delay difference values ​​at multiple observation times, and obtain the time delay difference trajectory of each propagation path. The component extraction module 505 is used to extract the direct path component from multiple propagation paths based on the stability index of the time delay difference trajectory.

[0071] In one specific implementation, the signal comparison module 502 is specifically used to: perform cross-correlation calculations on the wireless signals received by each non-reference station and the wireless signals received by the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station.

[0072] In one specific implementation, the signal comparison module 502 is specifically used to: perform Discrete Fourier Transform processing on the digital baseband signal sequence corresponding to the wireless signal received by each non-reference station and the digital baseband signal sequence corresponding to the wireless signal received by the reference station, respectively, to obtain the frequency domain representation of the received signal sequence of each non-reference station and the frequency domain representation of the received signal sequence of the reference station; determine the spectral complex ratio value sequence of each non-reference station based on the ratio of the frequency domain representation of the received signal sequence of each non-reference station and the frequency domain representation of the received signal sequence of the reference station; and perform inverse Discrete Fourier Transform or super-resolution spectral estimation on the spectral complex ratio value sequence of each non-reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station.

[0073] In one specific implementation, the signal comparison module 502 is specifically used to: convert the spectral complex ratio sequence of each non-reference station into a spectral complex ratio vector; the formula for the spectral complex ratio vector is as follows: γ = Gx + n; Wherein, γ is the complex ratio vector of the spectrum, x is the complex amplitude vector of the propagation path, G is the manifold matrix, and n is the noise vector; based on the complex ratio vector of the spectrum, at least one of the following algorithms is used: multiple signal classification, rotation invariant technology, and sparse reconstruction algorithm, to obtain the time difference spectrum of arrival between each of the non-reference stations and the reference station.

[0074] In one specific implementation, the trajectory acquisition module 504 is specifically used to: predict the time delay difference and time delay change rate of the propagation path at the current observation time based on the time delay difference and time delay change rate of the propagation path at the previous observation time; match multiple spectral peaks extracted from the arrival time difference spectrum for the current observation time with the predicted time delay difference to determine the propagation paths corresponding to the multiple spectral peaks respectively; and update the predicted time delay difference and time delay change rate of the propagation path at the current observation time using the time delay difference and time delay change rate of the propagation path corresponding to the successfully matched spectral peaks.

[0075] In one specific implementation, the component extraction module 505 is specifically used to: determine the stability score corresponding to each propagation path; the stability score is related to the posterior variance of the propagation path, the number of times the propagation path continues to appear, and the number of times the propagation path is lost; select the propagation path with the highest stability score as the direct path trajectory, and use the updated time delay difference of the direct path trajectory at the current observation time as the positioning parameter measurement value of the direct path.

[0076] In one specific implementation, the device 500 for extracting the direct path component further includes a coordinate determination module; the coordinate determination module is used to determine the position coordinates of the transmitting source based on the measured values ​​of the positioning parameters of the direct path.

[0077] In summary, this application provides a device for extracting the direct path component. This application utilizes the different characteristics of direct paths and reflection paths in terms of temporal evolution. By tracking the trajectory of observation data from multiple consecutive time points, a time delay difference trajectory for each propagation path is constructed, and the stability index of the time delay difference trajectory for each propagation path is calculated. This mathematically quantifies the degree of fluctuation in the propagation path, thereby effectively distinguishing between the gently fluctuating direct path and the drastically changing reflection path. Therefore, this application improves the accuracy of direct path component extraction, thereby reducing the error in positioning and tracking results.

[0078] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components indicated 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 the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0079] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for extracting a direct diameter component, characterized in that, The method includes: The method involves acquiring wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include one reference station and at least one non-reference station. The wireless signal of each non-reference station is compared with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station. For each observation time, multiple spectral peaks and time delay differences corresponding to the multiple spectral peaks are extracted from the arrival time difference spectrum; Based on the time delay difference values ​​at multiple observation times, the trajectory of multiple propagation paths that evolve over time is tracked to obtain the time delay difference trajectory of each propagation path; Based on the stability index of the time delay difference trajectory, the direct path component is extracted from the multiple propagation paths.

2. The method according to claim 1, characterized in that, The step of comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station includes: The radio signals received by each non-reference station are cross-correlated with the radio signals received by the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station.

3. The method according to claim 1, characterized in that, The step of comparing the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station includes: For each of the non-reference station's received wireless signal corresponding digital baseband signal sequences and the reference station's received wireless signal corresponding digital baseband signal sequences, discrete Fourier transform processing is performed to obtain the frequency domain representation of each non-reference station's received signal sequence and the frequency domain representation of the reference station's received signal sequence. Based on the ratio of the frequency domain representation of the received signal sequence of each non-reference station to the frequency domain representation of the received signal sequence of the reference station, a spectral complex ratio sequence for each non-reference station is determined. Perform inverse discrete Fourier transform or super-resolution spectral estimation on the spectral complex ratio sequence of each non-reference station to obtain the arrival time difference spectrum between each non-reference station and the reference station.

4. The method according to claim 3, characterized in that, The step of performing super-resolution spectral estimation on the spectral complex ratio sequence of each non-reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station includes: The sequence of spectral complex ratio values ​​for each non-reference station is converted into a spectral complex ratio value vector; the formula for the spectral complex ratio value vector is as follows: γ = Gx + n; Where γ is the complex ratio vector of the spectrum, x is the complex amplitude vector of the propagation path, G is the manifold matrix, and n is the noise vector; Based on the spectral complex ratio vector, at least one of the following algorithms is used: multiple signal classification, rotation invariant technique, and sparse reconstruction algorithm, to obtain the arrival time difference spectrum between each of the non-reference stations and the reference station.

5. The method according to claim 1, characterized in that, The step of tracing the trajectory of multiple propagation paths evolving over time based on the time delay difference values ​​at multiple observation times, and obtaining the time delay difference trajectory of each propagation path, includes: Based on the delay difference and delay change rate of the propagation path at the previous observation time, predict the delay difference and delay change rate of the propagation path at the current observation time. The multiple spectral peaks extracted from the arrival time difference spectrum at the current observation time are matched with the predicted time delay difference to determine the propagation paths corresponding to the multiple spectral peaks respectively. Using the time delay difference and time delay change rate of the propagation path corresponding to the successfully matched spectral peak, update the predicted time delay difference and time delay change rate of the propagation path at the current observation time.

6. The method according to claim 1, characterized in that, The step of extracting the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory includes: Determine the stability score for each propagation path; the stability score is related to the posterior variance of the propagation path, the number of times the propagation path occurs continuously, and the number of times the propagation path is lost; The propagation path with the highest stability score is selected as the direct path trajectory, and the updated time delay difference of the direct path trajectory at the current observation time is used as the positioning parameter measurement value of the direct path.

7. The method according to claim 6, characterized in that, The method further includes: The position coordinates of the transmitting source are determined based on the measured values ​​of the positioning parameters of the direct path.

8. A device for extracting a direct diameter component, characterized in that, The device includes: The signal acquisition module is used to acquire wireless signals received by multiple receiving stations at multiple observation times; the wireless signals originate from the same transmitting source; the multiple receiving stations include one reference station and at least one non-reference station; The signal comparison module is used to compare the wireless signal of each non-reference station with the wireless signal of the reference station to obtain the time difference of arrival spectrum between each non-reference station and the reference station. The peak extraction module is used to extract multiple spectral peaks and time delay differences corresponding to the multiple spectral peaks from the arrival time difference spectrum for each observation time. The trajectory acquisition module is used to track the trajectories of multiple propagation paths that evolve over time based on the time delay difference values ​​of multiple observation times, and obtain the time delay difference trajectory of each propagation path; The component extraction module is used to extract the direct path component from the multiple propagation paths based on the stability index of the time delay difference trajectory.

9. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the program, when executed, implements the method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 7.

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