Detection and Suppression Method for Suppression Deception Combined Interference in High-Precision Anti-Interference Navigation

Abstract

The present invention relates to the field of high-precision anti-jamming satellite navigation technology, and specifically discloses a method for detecting and suppressing combined jamming of suppression and spoofing in high-precision anti-jamming navigation, including: for combined jamming of suppression and spoofing, one or at least two of the methods of space-frequency joint - multi-beam / beam nulling - noise subspace projection, correlation peak detection and screening, true suppression and false spoofing interference detection, spoofing interference recovery and cancellation, improved PAC, and fast solution method for interference subspace of dense suppression / isolation suppression spoofing / dense suppression spoofing are deeply fused to achieve the detection and suppression of combined jamming. The present invention solves the problems of detecting and suppressing combined jamming such as isolated suppression and weak spoofing, dense suppression and weak spoofing, isolated suppression and stronger spoofing, dense suppression and stronger spoofing, isolated suppression and strong spoofing, and dense suppression and strong spoofing.

Description

Technical Field

[0001] The present invention relates to the field of high-precision anti-interference satellite navigation technology, and particularly to a method for detecting and suppressing combined jamming of suppression and deception in high-precision anti-interference navigation. Background Art

[0002] Outstanding features of high-precision anti-interference satellite navigation applications such as precision approach and landing of aircraft, carrier-based aircraft landing on aircraft carriers, formation flight of aircraft and automatic in-air refueling, and rapid direction finding and autonomous north seeking of missile launch vehicles / aircraft are complex interference environments and high positioning and orientation requirements.

[0003] The complexity of the interference environment is mainly manifested in the variety and variability of interference types. From the perspective of interference mechanisms, interference types are divided into suppression interference, deception interference, and combined jamming of suppression and deception, among which deception interference is further divided into regenerative and retransmitted types; interference variability mainly includes rapid or slow changes over time in the number, direction of arrival, modulation, frequency, intensity, etc. of interference. Positioning and orientation requirements include providing decimeter / centimeter-level positioning services in real time or near real time and orientation services better than 1 degree / 0.5 degree, etc.

[0004] High-precision positioning and orientation in complex interference environments need to solve three strongly coupled problems - complex interference detection and real-time suppression, satellite signal distortion source tracing and control, and high-precision positioning and orientation under low distortion.

[0005] Through theoretical derivation, simulation analysis and experimental verification, the inventor decoupled and disassembled the above three problems into three categories, seven sub-categories, and 10 sequential topics shown in the following table.

[0006] Accordingly, 10 high-precision anti-interference navigation invention patents corresponding to the above topics were planned and laid out, as shown in Table 1.

[0007] Table 1 List of decoupling and disassembly of high-precision positioning and orientation problems in complex interference environments

[0008]

[0009] In the present invention, the method for detecting and suppressing combined jamming of suppression and deception in high-precision anti-interference navigation, which is the first category, the third sub-category, and the 5th invention listed in Table 1, is analyzed and elaborated.

[0010] Combined jamming of suppression and deception is composed of suppression interference and deception interference. Existing interference detection and suppression methods mainly include adaptive nulling anti-suppression interference based on array antennas, multi-beam anti-suppression interference methods, deception interference suppression methods based on narrow correlation, deception interference detection and suppression methods based on correlation peak detection and screening, etc.

[0011] Combined interference can be subdivided into isolated suppression and weak deception combined interference, dense suppression and weak deception combined interference, isolated suppression and stronger deception combined interference, dense suppression and stronger deception combined interference, isolated suppression and strong deception combined interference, dense suppression and strong deception combined interference, etc. Here, isolated interference and dense interference are divided according to spatial distribution. Dense interference means that many point interference sources are distributed within a small angular domain, and the spatial distribution is very close. More complex combined interference should be dealt with in combination with interference source positioning and orientation, radar detection and warning, etc., which are not considered in the present invention.

[0012] Among the existing interference detection and suppression methods, adaptive nulling anti-suppression interference and multi-beam anti-suppression interference based on array antennas are applicable to suppression interference and strong deception interference; deception interference suppression based on narrow correlation and deception interference detection and suppression based on correlation peak detection and screening are applicable to weak deception interference; none of them can detect and suppress the above 6 types of combined interference.

[0013] Based on this technical background, the present invention studies the detection and suppression method for suppression and deception combined interference in high-precision anti-interference navigation. Summary of the Invention

[0014] Aiming at the deficiencies of the existing technology, the present invention provides a detection and suppression method for suppression and deception combined interference in high-precision anti-interference navigation, which deeply integrates methods such as space-frequency joint - multi-beam / zeroing - noise subspace projection, correlation peak detection and screening, true-suppressing and false-convex deception interference detection, deception interference recovery and cancellation, improved PAC, and fast solution of interference subspace, etc., to achieve the detection and suppression of combined interference.

[0015] To achieve the above purpose, the present invention provides a detection and suppression method for suppression and deception combined interference in high-precision anti-interference navigation, including: for suppression and deception combined interference, one or at least two of the methods of space-frequency joint - multi-beam / zeroing - noise subspace projection, correlation peak detection and screening, true-suppressing and false-convex deception interference detection, deception interference recovery and cancellation, improved PAC, and fast solution of dense suppression / isolation suppression deception / dense suppression deception interference subspace are deeply integrated to achieve the detection and suppression of combined interference.

[0016] The beneficial effects of the present invention include:

[0017] The detection and suppression method for suppression and deception combined interference in high-precision anti-interference navigation proposed by the present invention deeply integrates methods such as space-frequency joint - multi-beam / zeroing - noise subspace projection, correlation peak detection and screening, true-suppressing and false-convex deception interference detection, deception interference recovery and cancellation, improved PAC, and fast solution of interference subspace; systematically solves the problems of detection and suppression of combined interference such as isolated suppression and weak deception, dense suppression and weak deception, isolated suppression and stronger deception, dense suppression and stronger deception, isolated suppression and strong deception, and dense suppression and strong deception.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By describing the exemplary embodiments of the present invention in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more apparent.

[0020] Figure 1 It is a schematic flow chart of the detection and suppression method for suppressing spoofing combined interference in high-precision anti-interference navigation proposed by the present invention. DETAILED IMPLEMENTATION MANNER

[0021] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0022] The present invention provides a detection and suppression method for suppressing spoofing combined interference in high-precision anti-interference navigation, as Figure 1 shown, including:

[0023] For the suppressing spoofing combined interference, one or at least two of the methods of joint space-frequency - multi-beam / beamforming nulling - noise subspace projection, correlation peak detection and screening, true suppression and false spoofing interference detection, spoofing interference recovery and cancellation, improved PAC, and fast solution method for the interference subspace of dense suppression / isolation suppression spoofing / dense suppression spoofing interference are deeply integrated to achieve the detection and suppression of the combined interference.

[0024] In the present invention, methods such as joint space-frequency - multi-beam / beamforming nulling - noise subspace projection, correlation peak detection and screening, true suppression and false spoofing interference detection, spoofing interference recovery and cancellation, improved PAC, and fast solution of the interference subspace are deeply integrated; systematically solving the problems of detecting and suppressing combined interference such as isolation suppression and weak spoofing, dense suppression and weak spoofing, isolation suppression and stronger spoofing, dense suppression and stronger spoofing, isolation suppression and strong spoofing, and dense suppression and strong spoofing.

[0025] According to the present invention, the suppressing spoofing combined interference includes isolation suppression and weak spoofing combined interference, dense suppression and weak spoofing combined interference, isolation suppression and stronger spoofing combined interference, dense suppression and stronger spoofing combined interference, isolation suppression and strong spoofing combined interference, and dense suppression and strong spoofing combined interference;

[0026] For the combined interference of isolated jamming and weak deception, the method of joint spatio-frequency - multi-beam / beamforming - noise subspace projection, correlation peak detection and screening is deeply integrated to achieve the detection and suppression of combined interference. Among them, the method of joint spatio-frequency - multi-beam / beamforming - noise subspace projection is used to suppress isolated jamming, and the method of correlation peak detection and screening is used to detect and suppress weak deception interference;

[0027] The method of joint spatio-frequency - multi-beam - noise subspace projection is used for the case where the satellite position, the phase center position of the array antenna, and the attitude of the antenna array surface are known, and includes the following steps:

[0028] The first step: The space signal is sequentially received, amplified, down-converted, filtered, and analog-to-digital converted by the antenna elements, radio frequency channels, and analog-to-digital conversion units, and then outputs multiple digital intermediate frequency signals; each digital intermediate frequency signal is divided into two paths after serial / parallel conversion and fast Fourier transform, one path is sent to the FIFO buffer, and the other path is sent to the weight vector calculation unit;

[0029] The second step: The weight vector calculation unit uses the forward decomposition of multi-stage Wiener filtering to obtain the noise subspace and the projection matrix;

[0030] The third step: Multiply the L desired satellite steering vectors by the noise subspace projection matrix respectively, and normalize the multiplication results in amplitude to obtain L optimal weight vectors for the array antenna beams pointing to L satellites respectively;

[0031] The fourth step: Match the L optimal weight vectors with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position and depth of the array antenna match the interference direction and intensity, and at the same time ensure that the synthesized beam points to the desired satellite to achieve high-quality reception of the desired satellite signal.

[0032] According to the present invention, the method of joint spatio-frequency - beamforming - noise subspace projection is used for the case where the satellite position, the phase center position of the array antenna, and the attitude of the antenna array surface are unknown, and includes the following steps:

[0033] The first step: The same as the first step of the method of joint spatio-frequency - multi-beam - noise subspace projection;

[0034] The second step: The same as the second step of the method of joint spatio-frequency - multi-beam - noise subspace projection;

[0035] The third step: Multiply the vector with only the first element non-zero by the noise subspace projection matrix, and normalize the multiplication result in amplitude to obtain 1 optimal weight vector for the array antenna null to align with the interference direction;

[0036] The fourth step: Match the optimal weight vector with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position and depth of the array antenna match the interference direction and intensity;

[0037] The related peak detection and screening method includes:

[0038] 1) The mechanism and decision criterion of related peak detection:

[0039] The satellite signal adopts the direct sequence spread spectrum system, where the spreading sequence is a pseudo-random code sequence with sharp autocorrelation characteristics and flat cross-correlation characteristics. If there is weak spoofing interference, the number of sharp correlation peaks in the two-dimensional search space of pseudo-random code phase and Doppler frequency shift is more than one;

[0040] If the detected number of related peaks is 1, it is determined that there is no spoofing interference;

[0041] If the number of related peaks is greater than 1, it is determined that there is spoofing interference.

[0042] 2) The mechanism and processing method of related peak screening:

[0043] After detecting spoofing interference, that is, when the number of related peaks is greater than 1, spoofing interference, especially repeater interference, usually lags behind the satellite signal.

[0044] Screen out the related peak with the forward pseudo-code delay and transfer it to the tracking link; discard the related peak with the backward pseudo-code delay and do not transfer it to the tracking link.

[0045] According to the present invention, for the combined interference of dense jamming and weak spoofing, the space-frequency joint - multi-beam / beam nulling - noise subspace projection, the fast solution of the dense jamming subspace, and the related peak detection and screening method are deeply integrated to achieve the detection and suppression of the combined interference. Among them, the space-frequency joint - multi-beam / beam nulling - noise subspace projection and the fast solution of the dense jamming subspace deep integration method are used to suppress dense jamming, and the related peak detection and screening method is used to detect and suppress weak spoofing interference;

[0046] The steps of the space-frequency joint - multi-beam / beam nulling - noise subspace projection and the fast solution of the dense jamming subspace deep integration method are the same as the first, third, and fourth steps of the space-frequency joint - multi-beam / beam nulling - noise subspace projection method, only the second step is different; the second step includes: obtaining the dense jamming subspace, noise subspace, and projection matrix by using the fast solution method of the dense jamming subspace, that is, first expanding the covariance matrix in the interference incident direction to obtain the expanded covariance matrix; then using the multi-stage Wiener filtering based on the covariance matrix hierarchy to perform forward decomposition on the expanded covariance matrix to quickly solve the dense jamming subspace, and further obtain the noise subspace and projection matrix.

[0047] According to the present invention, for the combined interference of isolated suppression and strong deception, if the direction of the deception interference is unknown, the space-frequency joint - multi-beam / beamforming - noise subspace projection is deeply integrated with the true signal suppression convex false deception interference detection, deception interference recovery cancellation, and improved PAC method to achieve the detection and suppression of the combined interference; if the direction of the deception interference is known, the space-frequency joint - multi-beam / beamforming - noise subspace projection and the fast solution of the isolated suppression deception interference subspace are deeply integrated to achieve the detection and suppression of the combined interference;

[0048] The true signal suppression convex false deception interference detection, deception interference recovery cancellation, and improved PAC method include:

[0049] 1) True signal suppression convex false deception interference detection:

[0050] First, determine the visible satellite set according to the ephemeris and approximate position, and select the satellite to be detected from the visible satellite set;

[0051] Then, virtually generate medium-intensity interference in the direction of the signal of the satellite to be detected. Through the fast solution method of the virtual interference subspace, that is, obtain the virtual interference subspace and the noise subspace according to the steering vector in the direction of the satellite to be detected and the anti-jamming degrees of freedom of the array antenna, so that the array antenna forms a null in the direction of the satellite to be detected to suppress the signal of the satellite to be detected;

[0052] Finally, if the navigation processing unit can capture and track the satellite to be detected or non-visible satellite, it is determined that there is deception interference; otherwise, it is determined that there is no deception interference;

[0053] 2) Deception interference recovery cancellation, improved PAC:

[0054] First, estimate the amplitude and phase of the deception interference according to the deception interference detection situation, and recover the deception interference;

[0055] Then, subtract it from the received signal to suppress the deception interference below -10 dB;

[0056] Finally, use the improved PAC method, that is, add 1 correlator to search for correlation peaks in the ~ chip region in the conventional PAC method, correct the phase discrimination function, and suppress the residual deception interference.

[0057] Steps of the method for deeply integrating spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection and fast solution of isolated suppression spoofing interference subspace are the same as the first, third, and fourth steps of the spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection method, only the second step is different; the second step: using the fast solution method for isolated suppression spoofing interference subspace to obtain the isolated suppression spoofing interference subspace, noise subspace, and projection matrix, that is, using forward decomposition of multistage Wiener filtering based on the data hierarchy and Schmidt orthogonalization of the spoofing interference steering vector to quickly solve the isolated suppression spoofing interference subspace, and then obtaining the noise subspace and projection matrix.

[0058] According to the present invention, for combined interference of dense suppression and strong spoofing, if the direction of arrival of the spoofing interference is unknown, deeply integrate spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection, fast solution of dense suppression interference subspace, true suppression and false spoofing interference detection, spoofing interference recovery cancellation, and improved PAC to realize the detection and suppression of combined interference; if the direction of arrival of the spoofing interference is known, deeply integrate spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection and fast solution of dense suppression spoofing interference subspace to realize the detection and suppression of combined interference;

[0059] Steps of the method for deeply integrating spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection and fast solution of dense suppression spoofing interference subspace are the same as the first, third, and fourth steps of the spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection method, only the second step is different; the second step includes: using the fast solution method for dense suppression spoofing interference subspace to obtain the dense suppression spoofing interference subspace, noise subspace, and projection matrix, that is, using forward decomposition of multistage Wiener filtering based on the covariance matrix hierarchy after expanding the direction of arrival of the interference and Schmidt orthogonalization of the spoofing interference steering vector to quickly solve the dense suppression spoofing interference subspace, and then obtaining the noise subspace and projection matrix.

[0060] According to the present invention, for combined interference of isolated suppression and strong spoofing, use the spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection method to realize the detection and suppression of combined interference;

[0061] For combined interference of dense suppression and strong spoofing, deeply integrate spatial-frequency joint multi-beam / beamforming nulling-noise subspace projection and fast solution of dense suppression interference subspace to realize the detection and suppression of combined interference.

[0062] The present invention will be described in more detail below through embodiments.

[0063] Embodiment 1:

[0064] As Figure 1As shown in the figure, this embodiment proposes a method for detecting and suppressing combined spoofing interference in high-precision anti-jamming navigation. Aiming at the characteristics of six types of combined interference, it organically integrates the methods of spatio-frequency joint - multi-beam - noise subspace projection, fast solution method for interference subspace, suppression of true convex false spoofing interference detection, spoofing interference recovery cancellation, improved micro-pulse correlation (PAC) method, and correlation peak detection and screening, etc., to effectively detect and suppress six types of combined interference;

[0065] In this embodiment, the method for detecting and suppressing combined interference that organically integrates the above methods is shown in Table 2;

[0066] Table 2 Detection and suppression methods for six types of combined interference

[0067]

[0068] In this embodiment, the method specifically includes:

[0069] 1. Spatio-frequency joint - multi-beam / beam nulling - noise subspace projection method:

[0070] For the isolated jamming of combined interference 1 and 3 and combined interference 5, if the satellite position, array antenna phase center position, antenna array attitude, etc. are known, the spatio-frequency joint - multi-beam - noise subspace projection method is adopted; otherwise, the spatio-frequency joint - beam nulling - noise subspace projection method is adopted;

[0071] 1) The spatio-frequency joint - multi-beam - noise subspace projection method includes:

[0072] The first step: The spatial signal is processed by the antenna elements, radio frequency channels, analog-to-digital conversion units for reception, amplification, down-conversion, filtering, analog-to-digital conversion, etc., and then outputs multiple digital intermediate frequency signals; each digital intermediate frequency signal is divided into two paths after serial / parallel conversion (S / P) and fast Fourier transform (FFT), one path is sent to the first-in first-out (FIFO) buffer, and the other path is sent to the weight vector calculation unit;

[0073] The second step: The weight vector calculation unit uses eigen-decomposition such as forward decomposition of multistage Wiener filtering to obtain the noise subspace and projection matrix;

[0074] The third step: The L desired satellite steering vectors are multiplied by the noise subspace projection matrix respectively, and then amplitude-normalized to obtain L optimal weight vectors with the array antenna beams respectively pointing to L satellites;

[0075] The fourth step: The L optimal weight vectors are matched with the data to be weighted in the FIFO buffer, weighted and summed, ensuring that the null position and depth of the array antenna match the interference direction of arrival and intensity, realizing the effective suppression of isolated jamming and combined interference 5; at the same time, ensuring that the synthesized beam points to the desired satellite, realizing the high-quality reception of the desired satellite signal;

[0076] 2) The spatial-frequency joint-nulling-noise subspace projection method includes:

[0077] The first step: the same as the first step of the above spatial-frequency joint-multi-beam-noise subspace projection method;

[0078] The second step: the same as the second step of the above spatial-frequency joint-multi-beam-noise subspace projection method;

[0079] The third step: multiply with a vector whose only first element is non-zero and the noise subspace projection matrix, and then perform amplitude normalization to obtain 1 optimal weight vector for the null of the array antenna to align with the interference direction;

[0080] The fourth step: match the optimal weight vector with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position and depth of the array antenna match the interference direction and intensity, so as to effectively suppress isolated jamming and combined jamming 5;

[0081] 2. Fusion of spatial-frequency joint-multi-beam / zeroing-noise subspace projection and fast solution of dense jamming subspace:

[0082] For the dense jamming of combined jamming 2 and 4 and combined jamming 6, if the satellite position, the phase center position of the array antenna, the antenna array attitude, etc. are known, fuse the spatial-frequency joint-multi-beam-noise subspace projection method and the fast solution method of the dense jamming subspace; otherwise, fuse the spatial-frequency joint-nulling-noise subspace projection method and the fast solution method of the dense jamming subspace;

[0083] The processing procedure of the fusion method of spatial-frequency joint-multi-beam / zeroing-noise subspace projection and fast solution of dense jamming subspace is as follows;

[0084] The first step: the same as the first step of the above spatial-frequency joint-multi-beam-noise subspace projection method;

[0085] The second step: adopt the fast solution method of the dense jamming subspace to obtain the dense jamming subspace, the noise subspace and the projection matrix; that is, expand the covariance matrix in the interference incident direction to obtain the expanded covariance matrix; adopt the multi-stage Wiener filtering based on the covariance matrix hierarchy to perform forward decomposition on the expanded covariance matrix, quickly solve the dense jamming subspace, and then obtain the noise subspace and the projection matrix;

[0086] The third step: if the satellite position, the phase center position of the array antenna, the antenna array attitude, etc. are known, then multiply the L desired satellite steering vectors with the noise subspace projection matrix respectively, and perform amplitude normalization to obtain L optimal weight vectors for the array antenna beams to point to L satellites respectively; otherwise, the vector Multiply it with the noise subspace projection matrix, and then perform amplitude normalization to obtain one optimal weight vector for aligning the null of the array antenna with the interference direction.

[0087] Step 4: Match the L optimal weight vectors with the data to be weighted cached in the FIFO, and perform weighted summation to ensure that the null position, depth, and width of the array antenna match the interference direction, intensity, and spatial distribution, so as to effectively suppress the dense jamming and combined interference 6; at the same time, ensure that the synthesized beam points to the desired satellite to achieve high-quality reception of the desired satellite signal; or, match one optimal weight vector with the data to be weighted and perform weighted summation to ensure that the null position, depth, and width of the array antenna match the interference direction, intensity, and spatial distribution, so as to effectively suppress the dense jamming and combined interference 6.

[0088] 3. Correlation peak detection and screening:

[0089] In the case of weak spoofing interference of combined interference 1 and 2, the correlation peak at the true pseudocode delay of the satellite signal is prominent and the main peak is easy to distinguish from the sidelobes, and there is a correlation peak at the spoofing pseudocode delay but it is not prominent; for this reason, the correlation peak detection and screening method is used for suppression.

[0090] 1) Correlation peak detection includes:

[0091] The satellite signal adopts a direct sequence spread spectrum system, where the spreading sequence is a pseudorandom code sequence with sharp autocorrelation characteristics and flat cross-correlation characteristics; if there is weak spoofing interference, the number of sharp correlation peaks in the two-dimensional search space of (pseudorandom code phase, Doppler frequency shift) is more than one; if the detected number of correlation peaks is 1, it is determined that there is no spoofing interference; if the number of correlation peaks is greater than 1, it is determined that there is spoofing interference.

[0092] 2) Correlation peak screening includes:

[0093] After detecting spoofing interference (that is, the case where the number of correlation peaks is greater than 1), considering that spoofing interference, especially repeat-back interference, usually lags behind the satellite signal; therefore, screen out the correlation peak with the earlier pseudocode delay and transfer it to the tracking link; discard the correlation peak with the later pseudocode delay and do not transfer it to the tracking link.

[0094] 4. Detection of suppressing true and convex false spoofing interference, spoofing interference recovery cancellation, and improved PAC:

[0095] In the case where the direction of the stronger spoofing interference in combined interference 3 and 4 is unknown, the method of detecting suppressing true and convex false spoofing interference, spoofing interference recovery cancellation, and improved PAC is adopted, including;

[0096] 1) Detection of suppressing true and convex false spoofing interference includes:

[0097] First, determine the visible satellite set according to the almanac, approximate position, etc., and select the satellite to be inspected from the visible satellite set; then, virtually impose medium-intensity interference on the signal direction of the satellite to be inspected, and quickly solve for the virtual interference subspace and noise subspace through virtual interference subspace, so that the array antenna forms a null in the direction of the satellite to be inspected to suppress the signal of the satellite to be inspected; finally, judge whether there is spoofing interference according to whether the navigation processing unit can capture and track the satellite to be inspected or non-visible satellites.

[0098] 2) Spoofing interference recovery cancellation and improved PAC include:

[0099] First, estimate the amplitude, phase, etc. of the spoofing interference according to the spoofing interference detection situation, and recover the spoofing interference; then subtract it from the received signal to suppress the spoofing interference below -10 dB; finally, use the improved PAC method - add 1 correlator to search ~ for the correlation peaks within a chip region and use them to correct the phase discrimination function to suppress the residual spoofing interference, where is the narrow correlator interval;

[0100] 5. Fusion of space-frequency joint - multi-beam / beam nulling - noise subspace projection and fast solution of isolated suppression spoofing interference subspace:

[0101] For combined interference 3 with known spoofing interference direction, fuse the space-frequency joint - multi-beam / beam nulling - noise subspace projection method and the fast solution method of isolated suppression spoofing interference subspace. The processing procedure is as follows;

[0102] The first step: The same as the first step of the above space-frequency joint - multi-beam - noise subspace projection method;

[0103] The second step: Adopt the fast solution method of isolated suppression spoofing interference subspace to obtain the isolated suppression spoofing interference subspace, noise subspace and projection matrix; that is, use the forward decomposition of multi-stage Wiener filtering based on data hierarchy and the Schmidt orthogonalization of the spoofing interference steering vector to quickly solve the isolated suppression spoofing interference subspace, and then obtain the noise subspace and projection matrix;

[0104] The third step: If the satellite position, array antenna phase center position, antenna array attitude, etc. are known, multiply the L desired satellite steering vectors by the noise subspace projection matrix respectively, and then normalize the amplitude to obtain L optimal weight vectors of the array antenna beams pointing to L satellites; otherwise, the vector is multiplied by the noise subspace projection matrix, and then the amplitude is normalized to obtain 1 optimal weight vector of the array antenna null pointing to the interference direction;

[0105] Step 4: Match the L optimal weight vectors with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position and depth of the array antenna match the interference direction of arrival and intensity, so as to effectively suppress the combined interference 3; at the same time, ensure that the synthesized beam points to the desired satellite to achieve high-quality reception of the desired satellite signal; alternatively, match 1 optimal weight vector with the data to be weighted and perform weighted summation to ensure that the null position and depth of the array antenna match the interference direction of arrival and intensity, so as to effectively suppress the combined interference 3;

[0106] 6. Fusion of space-frequency joint - multi-beam / beam nulling - noise subspace projection and fast solution of the dense suppression spoofing interference subspace:

[0107] For the combined interference 4 with known directions of arrival of strong spoofing interference, fuse the space-frequency joint - multi-beam / beam nulling - noise subspace projection method and the fast solution method of the dense suppression spoofing interference subspace. The processing procedure is as follows;

[0108] Step 1: The same as the first step of the above space-frequency joint - multi-beam - noise subspace projection method;

[0109] Step 2: Adopt the fast solution method of the dense suppression spoofing interference subspace to obtain the dense suppression spoofing interference subspace, the noise subspace, and the projection matrix; that is, use the forward decomposition of the multi-stage Wiener filter based on the covariance matrix hierarchy after expanding the direction of arrival of the interference and the Schmidt orthogonalization of the spoofing interference steering vector to quickly solve the dense suppression spoofing interference subspace, and then obtain the noise subspace and the projection matrix;

[0110] Step 3: If the satellite position, the phase center position of the array antenna, the antenna array attitude, etc. are known, multiply the L desired satellite steering vectors by the noise subspace projection matrix respectively, and then perform amplitude normalization to obtain the L optimal weight vectors for the array antenna beams pointing to L satellites respectively; otherwise, Multiply the vector by the noise subspace projection matrix, and then perform amplitude normalization to obtain 1 optimal weight vector for the array antenna null to align with the interference direction of arrival;

[0111] Step 4: Match the L optimal weight vectors with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position, depth, and width of the array antenna match the interference direction of arrival, intensity, and spatial distribution, so as to effectively suppress the combined interference 4; at the same time, ensure that the synthesized beam points to the desired satellite to achieve high-quality reception of the desired satellite signal; alternatively, match 1 optimal weight vector with the data to be weighted and perform weighted summation to ensure that the null position, depth, and width of the array antenna match the interference direction of arrival, intensity, and spatial distribution, so as to effectively suppress the combined interference 4.

[0112] The detection and suppression method for suppressing spoofing combined interference in high-precision anti-interference navigation proposed by the embodiments of the present invention deeply integrates methods such as spatio-frequency joint - multi-beam / beam nulling - noise subspace projection, correlation peak detection and screening, true spoofing convex false spoofing interference detection, spoofing interference recovery cancellation, improved PAC, and fast solution of interference subspace; systematically solves the detection and suppression problems of combined interference such as isolated suppression and weak spoofing, dense suppression and weak spoofing, isolated suppression and stronger spoofing, dense suppression and stronger spoofing, isolated suppression and strong spoofing, and dense suppression and strong spoofing.

[0113] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for detecting and suppressing combined interference of high-precision anti-interference navigation, characterized in that: include: For suppression deception combined interference, one or two of the following methods are used: space-frequency joint-multi-beam / zeroing-noise subspace projection, or space-frequency joint-multi-beam / zeroing-noise subspace projection combined with correlation peak detection and screening, true convex false deception interference detection, deception interference recovery cancellation, improved PAC, dense suppression / isolated suppression deception / dense suppression deception interference subspace fast solution method to achieve detection and suppression of combined interference; The space-frequency joint-multi-beam-noise subspace projection method is used in the case where the satellite position, the phase center position of the array antenna, and the antenna array attitude are known, and includes the following steps: Step 1: The spatial signal is received, amplified, down-converted, filtered, and processed by the antenna array element, RF channel, and analog-to-digital conversion unit in sequence, and then multiple digital intermediate frequency signals are output; each digital intermediate frequency signal is then divided into two paths after serial / parallel conversion and fast Fourier transform, one path is sent to the FIFO buffer, and the other path is sent to the weight vector calculation unit; Step 2: The weight vector calculation unit uses multi-level Wiener filtering to perform forward decomposition to obtain the noise subspace and projection matrix; Step 3: multiply the L desired satellite steering vectors by the noise subspace projection matrix respectively, and normalize the multiplication results to obtain L optimal weight vectors for the array antenna beam to point to the L satellites respectively; Step 4: Match the L optimal weight vectors with the weighted data in the FIFO buffer and perform weighted summation to ensure that the null position and depth of the array antenna match the direction and strength of the interference, and ensure that the synthetic beam points to the desired satellite to achieve high-quality reception of the desired satellite signal; The space-frequency joint-zeroing-noise subspace projection method is used in the case where the satellite position, the phase center position of the array antenna, and the antenna array attitude are unknown, and includes the following steps: The first step is the same as the first step of the space-frequency joint-multi-beam-noise subspace projection method; The second step is the same as the second step of the space-frequency joint-multi-beam-noise subspace projection method; Step 3: multiply the noise subspace projection matrix by a vector whose only first element is non-zero, and normalize the multiplication result to obtain an optimal weight vector for aligning the array antenna null with the interference direction; Step 4: Match the optimal weight vector with the data to be weighted in the FIFO buffer, and perform weighted summation to ensure that the null position and depth of the array antenna match the direction and strength of the interference.

2. The method according to claim 1, characterized in that The suppression and deception combination interference includes isolated suppression and weak deception combination interference, intensive suppression and weak deception combination interference, isolated suppression and relatively strong deception combination interference, intensive suppression and relatively strong deception combination interference, isolated suppression and strong deception combination interference and intensive suppression and strong deception combination interference; For the isolated suppression and weak deception combined interference, the space-frequency joint-multi-beam / zeroing-noise subspace projection, correlation peak detection and screening method are deeply integrated to realize the detection and suppression of combined interference, wherein the space-frequency joint-multi-beam / zeroing-noise subspace projection method is used to suppress isolated suppression interference, and the correlation peak detection and screening method is used to detect and suppress weak deception interference.

3. The method according to claim 2, characterized in that The correlation peak detection and screening method comprises: 1) Mechanism and decision criteria of correlation peak detection: The satellite signal adopts a direct sequence spread spectrum system, in which the spread spectrum sequence is a pseudo-random code sequence with sharp autocorrelation characteristics and flat cross-correlation characteristics. If there is weak deception interference, there will be more than one sharp correlation peak in the two-dimensional search space of pseudo-random code phase and Doppler frequency shift; If the number of correlation peaks detected is 1, it is determined that there is no deceptive interference; If the number of correlation peaks is greater than 1, it is judged that there is deceptive interference; 2) Mechanism and processing method of relevant peak screening: After deceptive interference is detected, that is, the number of correlation peaks is greater than 1, the deceptive interference lags behind the satellite signal; The correlation peaks with earlier pseudo code delay are selected and transferred to the tracking stage; the correlation peaks with later pseudo code delay are discarded and not transferred to the tracking stage.

4. The method according to claim 3, characterized in that For the combined interference of dense suppression and weak deception, the space-frequency joint-multi-beam / zeroing-noise subspace projection, the dense suppression interference subspace fast solution, and the correlation peak detection and screening method are deeply integrated to achieve the detection and suppression of combined interference, wherein the space-frequency joint-multi-beam / zeroing-noise subspace projection and the dense suppression interference subspace fast solution deep fusion method are used to suppress dense suppression interference, and the correlation peak detection and screening method is used to detect and suppress weak deception interference; The steps of the space-frequency joint-multi-beam / zeroing-noise subspace projection and densely suppressed interference subspace fast solution deep fusion method are the same as the first step, the third step and the fourth step of the space-frequency joint-multi-beam / zeroing-noise subspace projection method, and only the second step is different; the second step includes: using the densely suppressed interference subspace fast solution method to obtain the densely suppressed interference subspace, the noise subspace and the projection matrix, that is, first expanding the covariance matrix in the interference incident direction to obtain the expanded covariance matrix; then using a multi-level Wiener filter based on the covariance matrix hierarchy to forward decompose the expanded covariance matrix, quickly solve the densely suppressed interference subspace, and then obtain the noise subspace and the projection matrix.

5. The method according to claim 3, characterized in that: For the isolated suppression and strong deception combined interference, if the direction of the deception interference is unknown, the space-frequency joint-multi-beam / zeroing-noise subspace projection is deeply integrated with the true convex false deception interference detection, deception interference recovery cancellation, and improved PAC method to achieve detection and suppression of combined interference; if the direction of the deception interference is known, the space-frequency joint-multi-beam / zeroing-noise subspace projection and the isolated suppression deception interference subspace fast solution are deeply integrated to achieve detection and suppression of combined interference; The true convex false deception interference detection, deception interference recovery cancellation and improved PAC method include: 1) Suppressing true convexity and false deception interference detection: First, determine the visible satellite set according to the almanac and the approximate position, and select the satellite to be detected from the visible satellite set; Then, a virtual medium-intensity interference is created in the direction of the signal from the satellite to be detected, and a virtual interference subspace and a noise subspace are obtained by a fast solution method of a virtual interference subspace, that is, according to the upward steering vector of the satellite to be detected and the anti-interference freedom degree of the array antenna, so that the array antenna forms a null in the direction of the satellite to be detected to suppress the signal of the satellite to be detected; Finally, if the navigation processing unit can capture and track the satellite to be detected or the non-visible satellite, it is determined that there is deception interference; otherwise, it is determined that there is no deception interference; 2) Deception jamming recovery cancellation, improved PAC: Firstly, according to the deception interference detection situation, the amplitude and phase of the deception interference are estimated, and the deception interference is recovered; This is then subtracted from the received signal, suppressing the spoofing jammer to below -10dB; Finally, the improved PAC method is used, that is, a correlator search is added to the conventional PAC method. ~ Correlation peaks in the chip area are used to correct the phase detection function and suppress residual deception interference; The steps of the space-frequency joint-multi-beam / zeroing-noise subspace projection and isolated suppression deception interference subspace rapid solution deep fusion method are the same as the first, third and fourth steps of the space-frequency joint-multi-beam / zeroing-noise subspace projection method, with only the second step being different; the second step: adopting the isolated suppression deception interference subspace rapid solution method to obtain the isolated suppression deception interference subspace, the noise subspace and the projection matrix, that is, adopting the multi-level Wiener filtering forward decomposition based on data hierarchy and the Schmidt orthogonalization of the deception interference guidance vector to quickly solve the isolated suppression deception interference subspace, and then obtain the noise subspace and the projection matrix.

6. The method according to claim 3, characterized in that For the intensive suppression and strong deception combined interference, if the direction of the deception interference is unknown, the space-frequency joint-multi-beam / zeroing-noise subspace projection and the intensive suppression interference subspace are quickly solved, and deeply integrated with the true convex false deception interference detection, deception interference recovery cancellation, and improved PAC to achieve the detection and suppression of combined interference; if the direction of the deception interference is known, the space-frequency joint-multi-beam / zeroing-noise subspace projection and the intensive suppression deception interference subspace are quickly solved to achieve the detection and suppression of combined interference; The steps of the space-frequency joint-multi-beam / zeroing-noise subspace projection and intensive suppression deception interference subspace rapid solution deep fusion method are the same as the first step, the third step, and the fourth step of the space-frequency joint-multi-beam / zeroing-noise subspace projection method, and only the second step is different; The second step includes: using the densely suppressed deception interference subspace fast solution method to obtain the densely suppressed deception interference subspace, noise subspace and projection matrix, that is, using interference-based multi-level Wiener filtering forward decomposition of the expanded covariance matrix level and Schmidt orthogonalization of the deception interference guidance vector to quickly solve the densely suppressed deception interference subspace, and then obtain the noise subspace and projection matrix.

7. The method according to claim 3, characterized in that For the isolated suppression and strong deception combined interference, the space-frequency joint-multi-beam / zeroing-noise subspace projection method is used to achieve detection and suppression of the combined interference; For the dense suppression and strong deception combined interference, the space-frequency joint-multi-beam / zeroing-noise subspace projection and the dense suppression interference subspace fast solution are deeply integrated to realize the detection and suppression of the combined interference.

Images