Satellite navigation positioning receiver and use method thereof

Abstract

The invention relates to the technical field of satellite navigation, in particular to a use method of a satellite navigation positioning receiver, which comprises the following steps: S1, performing FFT (Fast Fourier Transform) on data sampled by a 2-cycle local code 1 / 4 chip to obtain local code spectrum data, performing intermediate frequency down-conversion on satellite data according to intermediate frequency values of satellites with different channel numbers, and then performing 1 / 4 chip resampling to obtain local code spectrum data; performing frequency mixing on the resampled satellite data and a local carrier of a preset specified Doppler frequency to complete Doppler down-conversion, performing FFT on the data subjected to Doppler down-conversion to obtain satellite spectrum data, performing bidirectional cyclic shift on the satellite spectrum data, performing conjugate multiplication on the satellite spectrum data subjected to cyclic shift and the local spectrum data, and performing frequency multiplication on the satellite spectrum data subjected to cyclic shift and the local spectrum data. The satellite navigation positioning receiver can effectively solve the problem that an existing satellite navigation positioning receiver can only passively receive the navigation signal and cannot correct the navigation signal, so that the precision of the navigation signal is poor.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to a satellite navigation positioning receiver and a use method thereof. Background Art

[0002] Satellite navigation positioning receivers are devices used to receive satellite navigation signals. However, existing satellite navigation positioning receivers still have shortcomings. Specifically, existing satellite navigation positioning receivers can only passively receive navigation signals and cannot correct navigation signals, resulting in poor accuracy of navigation signals.

[0003] Therefore, a satellite navigation positioning receiver and a method of using the same are needed to solve the problems raised in the above background technology. Summary of the invention

[0004] The object of the present invention is to provide a satellite navigation positioning receiver and a method of using the same to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for using a satellite navigation positioning receiver comprises the following steps:

[0007] S1, perform FFT on the data sampled by 1 / 4 chip of 2-cycle local code to obtain local code spectrum data, perform 1 / 4 chip re-sampling on the satellite data after IF down-conversion according to the IF value of satellites with different channel numbers, mix the re-sampled satellite data with the local carrier of the preset Doppler frequency to complete Doppler down-conversion, perform FFT on the data after Doppler down-conversion to obtain satellite spectrum data, perform bidirectional cyclic shift on the satellite spectrum data, perform conjugate multiplication on the satellite spectrum data after cyclic shift and the local code spectrum data, perform IFFT on the product, take the modulus of the output result after IFFT, search for the maximum value, if the maximum value is greater than the preset threshold, it is determined that the capture is successful, repeat the above process to complete the capture of multiple navigation satellites;

[0008] S2, obtain reference ephemeris, record the update time of the reference ephemeris, receive and track the captured satellite navigation signal, obtain ephemeris from the satellite navigation signal and record the acquisition time of the satellite ephemeris, calculate the update time interval between the satellite ephemeris and the reference ephemeris, judge whether the time interval conforms to the broadcast ephemeris update frequency value, and when the judgment result is no, determine that the satellite navigation signal is a false signal, repeat the navigation satellite capture and time interval judgment operation until the judgment result is yes, and then calculate the reference space position of the corresponding satellite according to the reference ephemeris, and then calculate the current space position of the navigation satellite according to the current ephemeris in the navigation signal, and calculate the error distance between the reference space position and the current space position, when the error distance is greater than the threshold value, determine that the satellite navigation signal is a false signal, when the error distance is less than or equal to the threshold value, determine that the satellite navigation signal is a true signal, and replace the reference ephemeris with the current ephemeris;

[0009] S3, using a wavelet noise reduction algorithm to perform denoising on the received real navigation signal to obtain a denoised signal, using a digital bandpass filter to filter the denoised signal to obtain a filtered signal, establishing a space-time filter model, using the space-time filter model to construct a multipath interference model, using the multipath interference model to perform interference estimation, multiplying the estimated interference signal by a corresponding coefficient, subtracting it from the received signal to obtain an interference-eliminated signal, performing time domain or frequency domain processing on the interference-eliminated signal to optimize signal quality and restore navigation information;

[0010] S4, obtaining the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver from the restored navigation position information, solving the deviation prediction value between the receiver clock and the global positioning system GPS time at the different time points according to the position information and the pseudorange, and calculating the position of the receiver according to the deviation prediction value;

[0011] As a preferred solution of the present invention, the specific method of multipath interference in S3 is to assume that the interference signal is composed of N paths, and the delay and amplitude of each path are τ_i and α_i respectively, then the modeling of the interference signal can be expressed as: d(t) = Σα_i*x_filtered(t-τ_i), x_filtered is the filtered signal, d(t) represents the weighted sum of the signal on each path and the corresponding delay and amplitude, and the coefficient vector expression formula in S3 is: w = (R_x)^(-1)*r_x, R_x is the autocorrelation matrix of the filtered signal x_filtered, and r_x is the cross-correlation vector of the received signal and the interference signal modeling.

[0012] As a preferred solution of the present invention, the broadcast ephemeris update frequency value in S2 is 2 hours / time, and the threshold value is 10 meters.

[0013] As a preferred solution of the present invention, the number of FFT points in S1 is 4096, the resampling frequency is 2044000 Hz, and the intermediate frequency value expression formula of satellites with different channel numbers is fi=f0+i×562500, wherein fi refers to the intermediate frequency value of the satellite signal with channel number i, and f0 refers to the intermediate frequency value of the satellite signal with channel number 0.

[0014] As a preferred solution of the present invention, the navigation position information in S4 includes the navigation satellite number, the reference time of the ephemeris, the square root of the semi-major axis, the eccentricity, the inclination, the longitude of the ascending node on each weekly epoch, the perigee argument, the mean perigee angle, the rate of change of the inclination, the rate of change of the longitude of the ascending node, the correction value for the average motion, the correction value for the cosine of the latitude argument, the correction value for the sine of the latitude argument, the correction value for the cosine of the orbital radius, the correction value for the sine of the orbital radius, the correction value for the cosine of the inclination, the correction value for the sine of the inclination, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite group delay difference, the health status of the satellite, and the GPS time when the auxiliary information is obtained.

[0015] As a preferred solution of the present invention, when the Doppler down-conversion is performed in S1, the range of the preset Doppler frequency fd is -250<fd≤250Hz, the step search interval of the preset Doppler frequency fstep=50Hz, and the Doppler search range is ±5250Hz; for the satellite signal with channel i, the search range is expanded by cyclically shifting k spectral lines, wherein the value range of k is k=0,±1,±2,...,±1, after obtaining the Doppler spectrum of the satellite signal with channel number i, the spectrum of the satellite signal with channel number i±1 can be obtained by cyclically shifting 1127±k spectral lines to the right or left, and when performing cyclic shift of N=1127 spectral lines to perform Doppler calculation for channel number i±1, 100Hz needs to be compensated, and the values ​​of channel number i are -6, -3, 0, 3.

[0016] As a preferred solution of the present invention, the method for determining the pseudorange in S4 is to determine the transmission time of the signal transmitted by each satellite to the receiver based on the pre-acquired transmission time of the signal transmitted by each satellite to the reference server, and determine the pseudorange from each satellite to the receiver based on the transmission time of the signal transmitted by each satellite to the receiver and the speed of light.

[0017] As a preferred solution of the present invention, the method for solving the deviation prediction value in S4 is to obtain a pseudorange equation group based on the relationship between the pseudorange from each navigation satellite to the receiver and the true distance from each satellite to the receiver, perform series expansion on the position and clock deviation of the receiver in the pseudorange equation group around the approximate position value of the receiver and the predicted value of the clock deviation, eliminate nonlinear terms in the equation group after the series expansion, and solve the approximate position value of the receiver and the predicted value of the clock deviation based on the equation group after eliminating the nonlinear terms and the known position information of at least five satellites and the pseudorange from each satellite to the receiver.

[0018] As a preferred solution of the present invention, the specific method for calculating the position of the receiver according to the deviation prediction value in S4 is to use the solved position approximation value and clock deviation prediction value to iteratively operate the pseudorange equation group until the difference between the position approximation value obtained after the iterative operation and the position approximation value obtained after the previous iterative operation is less than a threshold value, and then determine the clock deviation between the receiver clock and the GPS time and the position of the receiver according to the position approximation value and the clock deviation prediction value obtained by the iterative operation.

[0019] A satellite navigation positioning receiver, comprising:

[0020] A capture module is used to capture multiple groups of navigation satellite signals. The capture module includes an FFT unit, a resampling unit, a cyclic shift unit, a down-conversion unit, and a capture decision unit. The FFT unit is used to perform FFT operations. The resampling unit is used to perform 1 / 4 chip resampling after performing intermediate frequency down-conversion on satellite data according to intermediate frequency values ​​of satellites with different channel numbers. The down-conversion unit is used to mix the resampled satellite data with a local carrier of a preset Doppler frequency and complete Doppler down-conversion. The cyclic shift unit is used to perform bidirectional cyclic shift on satellite spectrum data. The capture decision unit is used to take the modulus of the output result and search for the maximum value. If the maximum value is greater than a preset threshold, it is determined that the capture is successful and the satellite capture is completed.

[0021] A signal detection module, used to detect whether the navigation satellite signal is a false signal, the signal detection module includes a signal unit, a judgment unit and an execution unit, the signal unit is used to obtain a reference ephemeris, a reference ephemeris update time, a current ephemeris and a current ephemeris acquisition time, the judgment unit is used to calculate a time interval between the current ephemeris acquisition time and the reference ephemeris update time and judge whether the time interval conforms to a broadcast ephemeris update frequency value, and the execution unit is used to determine that the satellite navigation signal is a false signal when the judgment result of the judgment unit is no;

[0022] A signal processing module is used to perform denoising and filtering on real navigation satellite signals and eliminate interference. The signal processing module includes a denoising and filtering unit, an interference elimination unit, and an optimization and restoration unit. The denoising and filtering unit is used to perform denoising and filtering on the navigation signal. The interference elimination unit is used to construct a multipath interference model and use the model to eliminate interference on the navigation signal after the denoising and filtering process. The optimization and restoration unit is used to optimize the signal quality of the signal after the interference elimination and restore the navigation information.

[0023] The positioning calculation module is used to calculate the position of the receiver. The positioning calculation module includes an acquisition unit and a calculation unit. The acquisition unit is used to obtain the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver. The calculation unit is used to calculate the position of the receiver.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In the present invention, a capture module is used to capture multiple groups of navigation satellite signals, and then the judgment unit and the execution unit in the signal detection module are used to determine whether the navigation signal is a false signal and eliminate the false navigation signal. Then, the signal processing module is used to perform denoising and filtering on the real navigation satellite signal and eliminate interference, thereby optimizing the signal quality and restoring the navigation information. The positioning calculation module calculates the position of the receiver based on the optimized signal quality and restored navigation information, and can judge and process the navigation signal to improve the positioning accuracy, thereby solving the problem that the existing satellite navigation positioning receiver can only passively receive the navigation signal and cannot correct the navigation signal, resulting in poor accuracy of the navigation signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0029] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be a central element. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] For examples, see Figure 1 , the present invention provides a technical solution:

[0032] A method for using a satellite navigation positioning receiver comprises the following steps:

[0033] S1, perform FFT on the data sampled by 1 / 4 chip of 2-cycle local code to obtain local code spectrum data, perform 1 / 4 chip re-sampling on the satellite data after IF down-conversion according to the IF value of satellites with different channel numbers, mix the re-sampled satellite data with the local carrier of the preset Doppler frequency to complete Doppler down-conversion, perform FFT on the data after Doppler down-conversion to obtain satellite spectrum data, perform bidirectional cyclic shift on the satellite spectrum data, perform conjugate multiplication on the satellite spectrum data after cyclic shift and the local code spectrum data, perform I FFT on the product, take the modulus of the output result after I FFT, search for the maximum value, if the maximum value is greater than the preset threshold, it is determined that the capture is successful, repeat the above process to complete the capture of multiple navigation satellites;

[0034] S2, obtain reference ephemeris, record the update time of the reference ephemeris, receive and track the captured satellite navigation signal, obtain ephemeris from the satellite navigation signal and record the acquisition time of the satellite ephemeris, calculate the update time interval between the satellite ephemeris and the reference ephemeris, judge whether the time interval conforms to the broadcast ephemeris update frequency value, and when the judgment result is no, determine that the satellite navigation signal is a false signal, repeat the navigation satellite capture and time interval judgment operation until the judgment result is yes, and then calculate the reference space position of the corresponding satellite according to the reference ephemeris, and then calculate the current space position of the navigation satellite according to the current ephemeris in the navigation signal, and calculate the error distance between the reference space position and the current space position, when the error distance is greater than the threshold value, determine that the satellite navigation signal is a false signal, when the error distance is less than or equal to the threshold value, determine that the satellite navigation signal is a true signal, and replace the reference ephemeris with the current ephemeris;

[0035] S3, using a wavelet noise reduction algorithm to perform denoising on the received real navigation signal to obtain a denoised signal, using a digital bandpass filter to filter the denoised signal to obtain a filtered signal, establishing a space-time filter model, using the space-time filter model to construct a multipath interference model, using the multipath interference model to perform interference estimation, multiplying the estimated interference signal by a corresponding coefficient, subtracting it from the received signal to obtain an interference-eliminated signal, performing time domain or frequency domain processing on the interference-eliminated signal to optimize signal quality and restore navigation information;

[0036] S4, obtaining the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver from the restored navigation position information, solving the deviation prediction value between the receiver clock and the global positioning system GPS time at the different time points according to the position information and the pseudorange, and calculating the position of the receiver according to the deviation prediction value;

[0037] Furthermore, the specific method of multipath interference in S3 is to assume that the interference signal is composed of N paths, and the delay and amplitude of each path are τ_i and α_i respectively, then the modeling of the interference signal can be expressed as: d(t) = Σα_i*x_filtered(t-τ_i), x_filtered is the filtered signal, d(t) represents the weighted sum of the signal on each path and the corresponding delay and amplitude, and the coefficient vector expression formula in S3 is: w = (R_x)^(-1)*r_x, R_x is the autocorrelation matrix of the filtered signal x_filtered, and r_x is the cross-correlation vector of the received signal and the interference signal modeling.

[0038] Furthermore, the broadcast ephemeris update frequency value in S2 is 2 hours / time, and the threshold value is 10 meters.

[0039] Furthermore, the number of FFT points in S1 is 4096, the resampling frequency is 2044000 Hz, and the intermediate frequency value expression formula of satellites with different channel numbers is fi=f0+i×562500, where fi refers to the intermediate frequency value of the satellite signal with channel number i, and f0 refers to the intermediate frequency value of the satellite signal with channel number 0.

[0040] Furthermore, the navigation position information in S4 includes the navigation satellite number, the reference time of the ephemeris, the square root of the semi-major axis, the eccentricity, the inclination, the longitude of the ascending node on each weekly epoch, the perigee angle, the mean perigee angle, the rate of change of the inclination, the rate of change of the longitude of the ascending node, the correction value for the average motion, the correction value for the cosine of the latitude angle, the correction value for the sine of the latitude angle, the correction value for the cosine of the orbital radius, the correction value for the sine of the orbital radius, the correction value for the cosine of the inclination, the correction value for the sine of the inclination, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite group delay difference, the health status of the satellite, and the GPS time when the auxiliary information is obtained.

[0041] Furthermore, when the Doppler down-conversion is performed in S1, the range of the preset Doppler frequency fd is -250<fd≤250Hz, the step search interval of the preset Doppler frequency fstep=50Hz, and the Doppler search range is ±5250Hz; for the satellite signal with channel i, the search range is expanded by cyclically shifting k spectral lines, wherein the value range of k is k=0,±1,±2,...,±1. After obtaining the Doppler spectrum of the satellite signal with channel number i, the spectrum of the satellite signal with channel number i±1 can be obtained by cyclically shifting 1127±k spectral lines to the right or left. When performing cyclic shift of N=1127 spectral lines for Doppler calculation of channel number i±1, 100Hz needs to be compensated, and the values ​​of channel number i are -6, -3, 0, 3.

[0042] Furthermore, the method for determining the pseudorange in S4 is to determine the transmission time of the signal transmitted by each satellite to the receiver based on the transmission time of the signal transmitted by each satellite to the reference server obtained in advance, and determine the pseudorange from each satellite to the receiver based on the transmission time of the signal transmitted by each satellite to the receiver and the speed of light.

[0043] Furthermore, the method for solving the deviation prediction value in S4 is to obtain a pseudorange equation group based on the relationship between the pseudorange from each navigation satellite to the receiver and the true distance from each satellite to the receiver, perform series expansion on the position and clock deviation of the receiver in the pseudorange equation group around the approximate position value of the receiver and the predicted value of the clock deviation, eliminate nonlinear terms in the equation group after the series expansion, and solve the approximate position value of the receiver and the predicted value of the clock deviation based on the equation group after eliminating the nonlinear terms and the known position information of at least five satellites and the pseudorange from each satellite to the receiver.

[0044] Furthermore, the specific method for calculating the position of the receiver according to the deviation prediction value in S4 is to use the solved position approximation value and the clock deviation prediction value to iteratively operate the pseudorange equation group until the difference between the position approximation value obtained after the iterative operation and the position approximation value obtained after the previous iterative operation is less than the threshold value, and then determine the clock deviation between the receiver clock and the GPS time and the position of the receiver according to the position approximation value and the clock deviation prediction value obtained by the iterative operation.

[0045] A satellite navigation positioning receiver, comprising:

[0046] A capture module is used to capture multiple groups of navigation satellite signals. The capture module includes an FFT unit, a resampling unit, a cyclic shift unit, a down-conversion unit, and a capture decision unit. The FFT unit is used to perform FFT operations. The resampling unit is used to perform 1 / 4 chip resampling after performing intermediate frequency down-conversion on satellite data according to intermediate frequency values ​​of satellites with different channel numbers. The down-conversion unit is used to mix the resampled satellite data with a local carrier of a preset Doppler frequency and complete Doppler down-conversion. The cyclic shift unit is used to perform bidirectional cyclic shift on satellite spectrum data. The capture decision unit is used to take the modulus of the output result and search for the maximum value. If the maximum value is greater than a preset threshold, it is determined that the capture is successful and the satellite capture is completed.

[0047] A signal detection module, used to detect whether the navigation satellite signal is a false signal, the signal detection module includes a signal unit, a judgment unit and an execution unit, the signal unit is used to obtain a reference ephemeris, a reference ephemeris update time, a current ephemeris and a current ephemeris acquisition time, the judgment unit is used to calculate a time interval between the current ephemeris acquisition time and the reference ephemeris update time and judge whether the time interval conforms to a broadcast ephemeris update frequency value, and the execution unit is used to determine that the satellite navigation signal is a false signal when the judgment result of the judgment unit is no;

[0048] A signal processing module is used to perform denoising and filtering on real navigation satellite signals and eliminate interference. The signal processing module includes a denoising and filtering unit, an interference elimination unit, and an optimization and restoration unit. The denoising and filtering unit is used to perform denoising and filtering on the navigation signal. The interference elimination unit is used to construct a multipath interference model and use the model to eliminate interference on the navigation signal after the denoising and filtering process. The optimization and restoration unit is used to optimize the signal quality of the signal after the interference elimination and restore the navigation information.

[0049] The positioning calculation module is used to calculate the position of the receiver. The positioning calculation module includes an acquisition unit and a calculation unit. The acquisition unit is used to obtain the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver. The calculation unit is used to calculate the position of the receiver.

[0050] The working process of the present invention is as follows: when the satellite navigation positioning receiver designed by the present invention is in operation, FFT is performed on the data sampled by 1 / 4 chip of the 2-cycle local code to obtain the local code spectrum data, the number of FFT points is 4096, the satellite data is subjected to intermediate frequency down-conversion according to the intermediate frequency values ​​of satellites with different channel numbers, and then 1 / 4 chip resampling is performed, the resampling frequency is 2044000 Hz, and the intermediate frequency values ​​of satellites with different channel numbers are expressed by the formula fi=f0+i×562500, wherein fi refers to the intermediate frequency value of the satellite signal with channel number i, and f0 refers to the intermediate frequency value of the satellite signal with channel number 0;

[0051] The resampled satellite data is mixed with the local carrier of the preset Doppler frequency to complete the Doppler down-conversion. During the Doppler down-conversion, the preset range of the Doppler frequency fd is -250<fd≤250Hz, the preset step search interval of the Doppler frequency fstep=50Hz, and the Doppler search range is ±5250Hz; for the satellite signal with channel number i, the search range is expanded by cyclically shifting k spectral lines, where the value range of k is k=0,±1,±2,...,±1, and the satellite signal with channel number i is obtained. After the Doppler spectrum, the satellite signal spectrum of the channel number i±1 can be obtained by cyclically shifting 1127±k spectral lines to the right or left. When performing cyclic shift of N=1127 spectral lines for i±1 channel number Doppler calculation, 100Hz needs to be compensated. The values ​​of channel number i are -6, -3, 0, 3. The data after Doppler down-conversion is FFT-ed to obtain satellite spectrum data. The satellite spectrum data is bidirectionally cyclically shifted. The satellite spectrum data after cyclic shift and the local code spectrum data are conjugate multiplied, and the product is subjected to I FFT. The output result after I FFT is modulo-ed to search for the maximum value. If the maximum value is greater than the preset threshold, it is determined that the capture is successful. The above process is repeated to complete the capture of multiple navigation satellites.

[0052] Get the reference ephemeris, record the update time of the reference ephemeris, receive and track the captured satellite navigation signal, the broadcast ephemeris update frequency value is 2 hours / time, obtain the ephemeris from the satellite navigation signal and record the acquisition time of the satellite ephemeris, calculate the update time interval between the satellite ephemeris and the reference ephemeris, judge whether the time interval conforms to the broadcast ephemeris update frequency value, when the judgment result is no, determine that the satellite navigation signal is a false signal, repeat the navigation satellite capture and time interval judgment operation until the judgment result is yes, then calculate the reference space position of the corresponding satellite according to the reference ephemeris, then calculate the current space position of the navigation satellite according to the current ephemeris in the navigation signal, and calculate the error distance between the reference space position and the current space position, when the error distance is greater than the threshold value, determine that the satellite navigation signal is a false signal, when the error distance is less than or equal to the threshold value, the threshold value is 10 meters, determine that the satellite navigation signal is a true signal, and replace the reference ephemeris with the current ephemeris;

[0053] The received real navigation signal is denoised using a wavelet denoising algorithm to obtain a denoised signal. The denoised signal is filtered using a digital bandpass filter to obtain a filtered signal. A space-time filter model is established. The space-time filter model is used to construct a multipath interference model. Assuming that the interference signal consists of N paths, the time delay and amplitude of each path are τ_i and α_i respectively, the modeling of the interference signal can be expressed as: d(t) = Σα_i*x_filtered(t-τ_i), x_filtered is the filtered signal, d(t) represents the weighted sum of the signal on each path and the corresponding time delay and amplitude, the multipath interference model is used to estimate the interference, the estimated interference signal is multiplied by the corresponding coefficient, and subtracted from the received signal. The coefficient vector expression formula in S3 is: w = (R_x)^(-1)*r_x, R_x is the filtered signal x_fil tered's autocorrelation matrix, r_x is the cross-correlation vector of the received signal and the interference signal modeling, and the interference-eliminated signal is obtained. The interference-eliminated signal is processed in the time domain or frequency domain to optimize the signal quality and restore the navigation information;

[0054] Obtain the position information of the corresponding navigation satellite and the pseudorange of each navigation satellite to the receiver from the restored navigation position information, the navigation position information including the navigation satellite number, the reference time of the ephemeris, the square root of the semi-major axis, the eccentricity, the inclination, the longitude of the ascending node on each weekly epoch, the argument of perigee, the mean anomaly, the rate of change of the inclination, the rate of change of the longitude of the ascending node, the correction value for the mean motion, the correction value for the cosine of the argument of latitude, the correction value for the sine of the argument of latitude, the correction value for the cosine of the orbital radius, the correction value for the sine of the orbital radius, the correction value for the cosine of the inclination, the correction value for the sine of the inclination, the satellite clock correction parameter, the satellite clock correction parameter, the satellite clock correction parameter, the satellite clock correction parameter, the satellite group delay difference, the health status of the satellite, and the GPS time when the auxiliary information is obtained;

[0055] According to the relationship between the pseudorange from each navigation satellite to the receiver and the true distance from each satellite to the receiver, a pseudorange equation group is obtained, and the position and clock deviation of the receiver in the pseudorange equation group are expanded in series around the approximate position value of the receiver and the predicted value of the clock deviation, and the nonlinear terms are eliminated in the equation group after the series expansion. According to the equation group after the nonlinear terms are eliminated and the known position information of at least five satellites and the pseudorange from each satellite to the receiver, the pseudorange equation group is iteratively calculated using the solved approximate position value and the predicted value of the clock deviation, until the difference between the approximate position value obtained after the iterative calculation and the approximate position value obtained after the previous iterative calculation is less than a threshold value, and then the clock deviation between the receiver clock and the GPS time and the position of the receiver are determined according to the approximate position value obtained by the iterative calculation and the predicted value of the clock deviation.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for using a satellite navigation positioning receiver, characterized in that: The following steps are involved: S1, perform FFT on the data sampled by 1 / 4 chip of 2-cycle local code to obtain local code spectrum data, perform 1 / 4 chip re-sampling on the satellite data after IF down-conversion according to the IF value of satellites with different channel numbers, mix the re-sampled satellite data with the local carrier of the preset Doppler frequency to complete Doppler down-conversion, perform FFT on the data after Doppler down-conversion to obtain satellite spectrum data, perform bidirectional cyclic shift on the satellite spectrum data, perform conjugate multiplication on the satellite spectrum data after cyclic shift and the local code spectrum data, perform IFFT on the product, take the modulus of the output result after IFFT, search for the maximum value, if the maximum value is greater than the preset threshold, it is determined that the capture is successful, repeat the above process to complete the capture of multiple navigation satellites; S2, obtain reference ephemeris, record the update time of the reference ephemeris, receive and track the captured satellite navigation signal, obtain ephemeris from the satellite navigation signal and record the acquisition time of the satellite ephemeris, calculate the update time interval between the satellite ephemeris and the reference ephemeris, judge whether the time interval conforms to the broadcast ephemeris update frequency value, and when the judgment result is no, determine that the satellite navigation signal is a false signal, repeat the navigation satellite capture and time interval judgment operation until the judgment result is yes, and then calculate the reference space position of the corresponding satellite according to the reference ephemeris, and then calculate the current space position of the navigation satellite according to the current ephemeris in the navigation signal, and calculate the error distance between the reference space position and the current space position, when the error distance is greater than the threshold value, determine that the satellite navigation signal is a false signal, when the error distance is less than or equal to the threshold value, determine that the satellite navigation signal is a true signal, and replace the reference ephemeris with the current ephemeris; S3, using a wavelet noise reduction algorithm to perform denoising on the received real navigation signal to obtain a denoised signal, using a digital bandpass filter to filter the denoised signal to obtain a filtered signal, establishing a space-time filter model, using the space-time filter model to construct a multipath interference model, using the multipath interference model to perform interference estimation, multiplying the estimated interference signal by a corresponding coefficient, subtracting it from the received signal to obtain an interference-eliminated signal, performing time domain or frequency domain processing on the interference-eliminated signal to optimize signal quality and restore navigation information; S4, obtaining the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver from the restored navigation position information, solving the deviation prediction value between the receiver clock and the global positioning system GPS time at different times according to the position information and the pseudorange, and calculating the position of the receiver according to the deviation prediction value.

2. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The specific method of multipath interference in S3 is to assume that the interference signal is composed of N paths, and the delay and amplitude of each path are τ_i and α_i respectively. Then the modeling of the interference signal can be expressed as: d(t) = Σα_i*x_filtered(t-τ_i), x_filtered is the filtered signal, d(t) represents the weighted sum of the signal on each path and the corresponding delay and amplitude, and the coefficient vector expression formula in S3 is: w = (R_x)^(-1)*r_x, R_x is the autocorrelation matrix of the filtered signal x_filtered, and r_x is the cross-correlation vector of the received signal and the interference signal modeling.

3. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The broadcast ephemeris update frequency value in S2 is 2 hours / time, and the threshold value is 10 meters.

4. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The number of FFT points in S1 is 4096, the resampling frequency is 2044000 Hz, and the intermediate frequency value expression formula of satellites with different channel numbers is fi=f0+i×562500, where fi refers to the intermediate frequency value of the satellite signal with channel number i, and f0 refers to the intermediate frequency value of the satellite signal with channel number 0.

5. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The navigation position information in S4 includes the navigation satellite number, the reference time of the ephemeris, the square root of the semi-major axis, the eccentricity, the inclination, the longitude of the ascending node on each weekly epoch, the perigee argument, the mean perigee angle, the rate of change of the inclination, the rate of change of the longitude of the ascending node, the correction value for the mean motion, the correction value for the cosine of the latitude argument, the correction value for the sine of the latitude argument, the correction value for the cosine of the orbital radius, the correction value for the sine of the orbital radius, the correction value for the cosine of the inclination, the correction value for the sine of the inclination, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite clock correction parameters, the satellite group delay difference, the health status of the satellite, and the GPS time when the auxiliary information is obtained.

6. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: When the Doppler down-conversion is performed in S1, the range of the preset Doppler frequency fd is -250<fd≤250Hz, the step search interval of the preset Doppler frequency fstep=50Hz, and the Doppler search range is ±5250Hz; for the satellite signal with channel i, the search range is expanded by cyclically shifting k spectral lines, wherein the value range of k is k=0,±1,±2,...,±1. After obtaining the Doppler spectrum of the satellite signal with channel number i, the spectrum of the satellite signal with channel number i±1 can be obtained by cyclically shifting 1127±k spectral lines to the right or left. When performing cyclic shift of N=1127 spectral lines to perform Doppler calculation for channel number i±1, 100Hz needs to be compensated, and the values ​​of channel number i are -6, -3, 0, 3.

7. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The method for determining the pseudorange in S4 is to determine the transmission time of the signal transmitted by each satellite to the receiver based on the transmission time of the signal transmitted by each satellite to the reference server obtained in advance, and determine the pseudorange from each satellite to the receiver based on the transmission time of the signal transmitted by each satellite to the receiver and the speed of light.

8. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The method for solving the deviation prediction value in S4 is to obtain a pseudorange equation group based on the relationship between the pseudorange from each navigation satellite to the receiver and the true distance from each satellite to the receiver, perform series expansion on the position and clock deviation of the receiver in the pseudorange equation group around the approximate position value of the receiver and the predicted value of the clock deviation, eliminate nonlinear terms in the equation group after the series expansion, and solve the approximate position value of the receiver and the predicted value of the clock deviation based on the equation group after eliminating the nonlinear terms and the known position information of at least five satellites and the pseudorange from each satellite to the receiver.

9. The method for using a satellite navigation positioning receiver according to claim 1, characterized in that: The specific method for calculating the position of the receiver according to the deviation prediction value in S4 is to use the solved position approximation value and the clock deviation prediction value to iteratively operate the pseudorange equation group until the difference between the position approximation value obtained after the iterative operation and the position approximation value obtained after the previous iterative operation is less than the threshold value, and then determine the clock deviation between the receiver clock and the GPS time and the position of the receiver according to the position approximation value and the clock deviation prediction value obtained by the iterative operation.

10. A satellite navigation positioning receiver, characterized in that: include: A capture module is used to capture multiple groups of navigation satellite signals. The capture module includes an FFT unit, a resampling unit, a cyclic shift unit, a down-conversion unit, and a capture decision unit. The FFT unit is used to perform FFT operations. The resampling unit is used to perform 1 / 4 chip resampling after performing intermediate frequency down-conversion on satellite data according to intermediate frequency values ​​of satellites with different channel numbers. The down-conversion unit is used to mix the resampled satellite data with a local carrier of a preset Doppler frequency and complete Doppler down-conversion. The cyclic shift unit is used to perform bidirectional cyclic shift on satellite spectrum data. The capture decision unit is used to take the modulus of the output result and search for the maximum value. If the maximum value is greater than a preset threshold, it is determined that the capture is successful and the satellite capture is completed. A signal detection module, used to detect whether the navigation satellite signal is a false signal, the signal detection module includes a signal unit, a judgment unit and an execution unit, the signal unit is used to obtain a reference ephemeris, a reference ephemeris update time, a current ephemeris and a current ephemeris acquisition time, the judgment unit is used to calculate a time interval between the current ephemeris acquisition time and the reference ephemeris update time and judge whether the time interval conforms to a broadcast ephemeris update frequency value, and the execution unit is used to determine that the satellite navigation signal is a false signal when the judgment result of the judgment unit is no; A signal processing module is used to perform denoising and filtering on real navigation satellite signals and eliminate interference. The signal processing module includes a denoising and filtering unit, an interference elimination unit, and an optimization and restoration unit. The denoising and filtering unit is used to perform denoising and filtering on the navigation signal. The interference elimination unit is used to construct a multipath interference model and use the model to eliminate interference on the navigation signal after the denoising and filtering process. The optimization and restoration unit is used to optimize the signal quality of the signal after the interference elimination and restore the navigation information. The positioning calculation module is used to calculate the position of the receiver. The positioning calculation module includes an acquisition unit and a calculation unit. The acquisition unit is used to obtain the position information of the corresponding navigation satellite and the pseudorange from each navigation satellite to the receiver. The calculation unit is used to calculate the position of the receiver.

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