Anti-interference and anti-cheating method and equipment for civil aviation satellite navigation

Abstract

The invention relates to the technical field of satellite navigation, and particularly discloses an anti-interference and anti-cheating method and equipment for civil aviation satellite navigation, and the method comprises the steps: constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, solving an optimal anti-interference weight vector under the significance of a maximum output signal to interference plus noise ratio, and obtaining an optimal anti-interference weight vector under the significance of a maximum output signal to interference plus noise ratio; the maximum interference suppression degree and the minimum satellite signal receiving signal-to-noise ratio loss are considered; detecting whether deception exists in the captured signal after interference resistance through a correlation peak ternary detection and attitude position auxiliary detection method; if deception exists, deception is inhibited through a deception regeneration cancellation method, and satellite signal purification is achieved. Aiming at the anti-interference and anti-cheating requirements of civil aviation, a multi-beam pointing and multi-stage Wiener filtering anti-interference method, a correlation peak ternary detection method, an attitude position auxiliary detection method and a cheating regeneration fire-fighting cheating method are constructed; the method has the advantages of being universal for various kinds of interference, high in anti-interference capability, adaptive to forwarding / generation type deception, high in deception prevention capability, high in engineering practicability and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite navigation, in particular to a civil aviation satellite navigation anti-interference and anti-deception method and device. BACKGROUND

[0002] Satellite navigation equipment in practical application is faced with unintentional interference and intentional interference. Unintentional interference mainly comes from satellite positioning system multiple access interference and adjacent navigation band channel interference, etc. Intentional interference can be divided into suppression interference and deception interference from the interference mechanism.

[0003] Suppression interference (hereinafter referred to as interference) can be divided into continuous type and pulse type from the type. Continuous interference types include single tone, multi-tone, sweep, amplitude modulation, phase modulation, frequency modulation, etc. The main characteristic parameters of pulse interference include pulse repetition frequency, duty cycle, carrier frequency, etc. Interference causes the equivalent carrier-to-noise ratio of satellite navigation equipment to decrease, and then the position, velocity and time (PVT) accuracy to deteriorate, even the loop to lose lock, and the equipment to be unable to locate.

[0004] Deception interference (hereinafter referred to as deception) can be divided into repeater type and generator type from the generation mode. Repeater deception is obtained by receiving-amplifying-delaying-transmitting satellite signals. Relative to satellite signals, the time delay is positive, and the power can be strong or weak. Generator deception needs to know satellite signal carrier frequency, modulation mode, spread spectrum code and navigation text, etc. Based on this, deception similar to satellite signal structure but different in time delay and text is generated. Relative to satellite signals, the time delay can be positive or negative, and the power can be strong or weak.

[0005] Satellite navigation anti-interference and anti-deception is one of the important contents of the protection policy in the navigation war "protection, prevention and preservation", and has been a research hotspot in the field of military satellite navigation. Many research results have been successfully transformed and applied on a large scale. However, the research results of military satellite navigation anti-interference and anti-deception are not suitable for civil use, and there is an urgent need for commercialization of mature research results suitable for civil use.

[0006] Existing satellite navigation anti-interference and anti-deception methods are mostly military satellite navigation anti-interference and anti-deception methods for satellite navigation authorized service signals.

[0007] The BDS B1A, B2b, B3A and B3AE satellite navigation authorized service signals adopt a spread spectrum modulation mode, and a non-periodic spread spectrum code used for spreading is generated by a military code level PRM chip which is a core component of a Beidou independently controllable security system, and the generation mode is not disclosed to the outside, and the generated spread spectrum code stream is not output to the outside. Since the PRM chip (first phase) supports a limited number of beams, the existing military satellite navigation anti-jamming method adopts an adaptive zero anti-jamming method, and does not adopt a multi-beam pointing anti-jamming method which has stronger anti-jamming capability. Since the PRM chip avoids generating type deception, only retransmission type deception needs to be considered, and therefore the existing military satellite navigation anti-deception method adopts a related peak detection and identification anti-deception method.

[0008] The existing military satellite navigation anti-jamming and anti-deception method is not suitable for being applied to civil aviation satellite navigation anti-jamming and anti-deception, and the main reason is that: The civil aviation satellite navigation signals BDS B1C, B2a and GPS L1C / A are public service signals, and a short period spread spectrum code used for spreading is disclosed in a space signal interface control document, and does not need to be generated by a PRM chip. For example, the spread spectrum code generation mode of the Beidou navigation civil signal B1C, B2a is disclosed in the Beidou Satellite Navigation System Space Signal Interface Control Document Public Service Signal B1C (1.0 version) and the Beidou Satellite Navigation System Space Signal Interface Control Document Public Service Signal B2a (1.0 version) issued by the China Satellite Navigation System Management Office.

[0009] In this way, on the one hand, it is not limited by the support capability of the number of beams of the PRM chip, and a multi-beam pointing anti-jamming method which has stronger anti-jamming capability can be adopted. On the other hand, it does not enjoy the privilege of avoiding the generation type deception of the PRM chip, and both the retransmission type deception and the generation type deception need to be considered. Compared with the retransmission type deception, the generation type deception has positive or negative time delay relative to the satellite signal, and has stronger deception (no positive time delay prior information is available), so that the conventional related peak detection and identification method is invalid, and more strict signal detection, information verification and other technologies need to be combined.

[0010] Based on this technical background, the present application studies a civil aviation satellite navigation anti-jamming and anti-deception method and device. SUMMARY

[0011] In view of the deficiencies of the prior art, the present application provides a civil aviation satellite navigation anti-jamming and anti-deception method and device. The method constructs a multi-beam pointing and multi-level Wiener filtering anti-jamming method for civil aviation anti-jamming and anti-deception requirements, has the advantages of being suitable for multiple types of interference, having strong anti-jamming capability, and having strong engineering practicability; and by constructing a related peak three-element detection, an attitude and position auxiliary detection, and a deception regeneration counter deception method, the method has the advantages of adapting to retransmission / generation type deception, having strong anti-deception capability, and having strong engineering practicability.

[0012] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a civil aviation satellite navigation anti-jamming and anti-deception method, comprising: By constructing a multi-beam pointing, multi-stage Wiener filtering anti-jamming method, the optimal anti-jamming weight vector under the maximum output signal-to-interference-and-noise ratio is solved, so as to maximize the interference suppression degree and minimize the loss of satellite signal reception signal-to-noise ratio; By the correlation peak ternary detection method and the attitude position auxiliary detection method, it is detected whether there is deception in the captured signal after anti-jamming; if there is deception, the deception in the captured signal is suppressed by the deception regeneration cancellation method, so as to realize the purification of the satellite signal.

[0013] The second aspect of the present application provides a civil aviation satellite navigation anti-jamming and anti-deception device used in the above-mentioned, comprising: The array antenna comprises 4 B1C frequency band antenna array elements, 4 B2a frequency band antenna array elements, a feed network and an array surface. The radio frequency channel comprises 4 B1C frequency band down-conversion units and 4 B2a frequency band down-conversion units, and is used for filtering, frequency conversion and amplification processing of the satellite signals and / or interference and / or deception received by the 4 B1C frequency band antenna array elements and the 4 B2a frequency band antenna array elements to obtain 8 analog signals. The digital processing unit is connected with the output of the radio frequency channel, and is used for converting the 8 analog signals transmitted by the radio frequency channel into 8 digital intermediate frequency signals, and performing multi-beam anti-jamming, navigation signal processing, navigation information processing and anti-deception processing on the 8 digital intermediate frequency signals. The interface unit comprises a radio frequency interface, a data interface and a power supply interface, the radio frequency interface is used for radio frequency input and feed output, the data interface is used for data transmission and information injection, and the power supply interface is used for external power supply input and isolation processing. The power supply unit is used for converting an external power supply voltage into voltages required by the array antenna, the radio frequency channel and the digital processing unit.

[0014] The beneficial effects of the present application include: (1) The civil aviation satellite navigation anti-jamming and anti-deception method provided by the present application is suitable for civil aviation anti-jamming and anti-deception requirements, and has the advantages of being suitable for multiple types of interference, having strong anti-jamming ability, and being strong in engineering practicability; at the same time, by constructing the correlation peak ternary detection, the attitude position auxiliary detection and the deception regeneration cancellation anti-deception method, the method has the advantages of being suitable for retransmission / formation deception, having strong anti-deception ability and being strong in engineering practicability.

[0015] (2) The civil aviation satellite navigation anti-interference and anti-deception method provided by the application firstly establishes a multi-beam pointing anti-interference model based on minimum variance distortionless response, so that the minimum output variance is subordinate to the single satellite signal upward gain, and the optimal anti-interference weight vector ensures the interference suppression and the high signal-to-noise ratio reception of the satellite navigation; then, the multi-stage Wiener filtering is used to quickly solve the noise subspace projection matrix and the multi-beam pointing optimal anti-interference weight vector; finally, the multi-beam pointing optimal anti-interference weight vector is used for weighted summation of the array signal vector, so that the interference suppression and the high-quality satellite signal reception are realized.

[0016] (3) The civil aviation satellite navigation anti-interference and anti-deception method provided by the application constructs a correlation peak ternary detection, an attitude position auxiliary detection and a deception regeneration countermeasure deception method according to the civil aviation satellite navigation anti-deception demand; the correlation peak ternary detection method and the attitude position auxiliary detection method are used to detect whether there is deception; if there is deception, the deception regeneration countermeasure method is used to suppress the deception in the captured signal, so that the satellite signal is purified, and the method has the advantages of adaptive retransmission / generation deception, strong anti-deception ability and strong engineering practicability.

[0017] (4) The civil aviation satellite navigation anti-interference and anti-deception equipment provided by the application designs a hardware platform of the civil aviation satellite navigation anti-interference and anti-deception equipment as a parallel processing and expandable platform of a dual-frequency 8-channel low-noise radio frequency front end, an extensible FPGA+DSP heterostructure and a modular interface, a software architecture as a layered modular architecture of independent hardware processing in the business layer and standard protocol support in the interface layer, and an appearance structure as a airworthiness compliance structure of a low-profile streamline, no protruding structure, lightweight weather-resistant aluminum alloy material and anti-impact and vibration, so that the equipment supports multi-frequency multi-mode multi-channel signal processing, cross-platform transplantation, expansion and integration.

[0018] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[0020] Figure 1 A flowchart of the civil aviation satellite navigation anti-interference and anti-deception method provided by the application.

[0021] Figure 2 A specific embodiment of the civil aviation satellite navigation anti-interference and anti-deception equipment provided by the application is a whole hardware architecture schematic diagram.

[0022] Figure 3A software composition schematic diagram of a specific embodiment of a civil aviation satellite navigation anti-interference and anti-deception device according to the present application is shown.

[0023] Figure 4 A specific embodiment of a civil aviation satellite navigation anti-interference and anti-deception device according to the present application is shown. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0025] The present application provides a civil aviation satellite navigation anti-interference and anti-deception method, as shown, comprising: Figure 1 By constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, the optimal anti-interference weight vector under the maximum output signal-to-interference-and-noise ratio is solved to balance the maximum interference suppression degree and the minimum satellite signal reception signal-to-noise ratio loss. By a correlation peak ternary detection method and an attitude position auxiliary detection method, it is detected whether there is deception in the captured signal after anti-interference; if there is deception, the deception in the captured signal is suppressed by a deception regeneration cancellation method to realize satellite signal purification.

[0026] In the present application, for the civil aviation anti-interference and anti-deception requirements, a multi-beam pointing and multi-stage Wiener filtering anti-interference method is constructed, which has the advantages of being suitable for multiple types of interference, strong anti-interference ability, and strong engineering practicability; at the same time, by constructing a correlation peak ternary detection, an attitude position auxiliary detection, and a deception regeneration cancellation anti-deception method, it has the advantages of adapting to the retransmission / generation type deception, strong anti-deception ability, and strong engineering practicability.

[0027] According to the present application, by constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, the optimal anti-interference weight vector under the maximum output signal-to-interference-and-noise ratio is solved to balance the maximum interference suppression degree and the minimum satellite signal reception signal-to-noise ratio loss, comprising: A multi-beam pointing anti-interference model is constructed, and the optimal anti-interference weight vector under the maximum output signal-to-interference-and-noise ratio is the projection of the steering vector in the expected satellite signal direction on the noise subspace; A projection matrix of the noise subspace is obtained by multi-stage Wiener filtering; Based on the projection matrix, the optimal anti-interference weight vector of the anti-interference model is calculated; The array signal vector of the anti-interference model is weighted and summed using the optimal anti-interference weight vector, which minimally affects the satellite signal while maximally suppressing the interference.

[0028] ​According to the application, the anti-interference model is a minimum variance distortionless response constraint optimization model, and the expression of the constraint optimization model is: ; Wherein, is a covariance matrix of the array signal vector , is a steering vector in the expected satellite signal direction, is an anti-interference weight vector, is a conjugate transpose symbol of a vector or a matrix; The expression of the optimal anti-interference weight vector is: ; Wherein, is the optimal anti-interference weight vector, is a unit matrix, is an interference steering vector matrix, is a projection matrix of a noise subspace, is an inverse symbol of a matrix, is the number of interferences, is the dimension of a vector; The projection matrix of the noise subspace is obtained through a multi-stage Wiener filter, and the corresponding initialization and iteration process are as follows: Initialization: , ; Iteration times: ; ; ; ; ; Take the first large values corresponding to to constitute the projection matrix of the noise subspace ; Wherein, , is an initial value of iteration, is the first element of the vector , is the first standard orthogonal basis vector of the interference subspace, is a mathematical expectation operator, and the symbol is a conjugate operator, is a modulus operator, is a conjugate transpose operator, , , are the first and the second interference steering vectors, respectively. , expected signal of the (i-1)th iteration, , input vector of the i th iteration, , input vector of the (i-1)th iteration, mean square value of the i th expected signal. According to the application, the correlation peak ternary detection method comprises:

[0029] proposing ternary hypotheses of H0, H1 and H2, determining a test statistic and a probability distribution thereof obeyed, and giving a significance level; determining a critical point of a rejection region under the significance level according to the probability distribution obeyed by the test statistic; correlating the captured signal after interference rejection with a local spreading code; if there is no correlation peak value greater than the critical point in a two-dimensional search space of carrier Doppler frequency shift-spreading code phase, it is determined that there is no expected satellite signal, and the capturing continues; if there is only one correlation peak value greater than the critical point, it is determined that there is only an expected satellite signal and no deception, and the tracking stage is directly entered; if there are multiple correlation peak values greater than the critical point, it is determined that there is an expected satellite signal and deception, and the deception regeneration cancellation stage is entered; wherein the test statistic obeys a centralized chi-square distribution when the H0 hypothesis is true, and obeys a non-centralized chi-square distribution when the H1 and H2 hypotheses are true; The attitude and position aided detection method comprises: determining an acceptable false alarm rate, and solving a detection threshold corresponding to the false alarm rate; calculating carrier phase double difference predicted values of all visible satellites by using attitude and position information, wherein the maximum carrier phase double difference predicted value is denoted as ; making a decision according to whether the difference between the carrier phase double difference observation value and exceeds the detection threshold, i.e., if the difference between the carrier phase double difference observation value and does not exceed the detection threshold, it is determined that there is only an expected satellite signal and no deception, and the tracking stage is directly entered; if the difference between the carrier phase double difference observation value and exceeds the detection threshold, it is determined that there is deception, and the deception regeneration cancellation stage is entered; the formula used for solving the detection threshold is: ; wherein is the detection threshold, is the false alarm rate,​ The probability cumulative distribution function corresponding to the carrier phase double difference observation noise distribution function of the satellite signal is as follows: The expression of the probability cumulative distribution function is as follows: Wherein, The carrier phase observation noise variance is σ 2.

[0030] According to the present application, the deception in the captured signal after the anti-jamming is suppressed by the deception regenerating cancellation method, and the satellite signal purification is realized, including: The deception in the current captured signal is tracked to obtain the amplitude estimation value and the phase estimation value of the deception; The regenerating deception is obtained according to the amplitude estimation value, the phase estimation value, and the spread spectrum code of the deception generated by the local interface control file; The regenerating deception is subtracted from the captured signal after the anti-jamming, and the satellite signal purification is transferred to the tracking unit.

[0031] In the present application, firstly, a multi-beam pointing anti-jamming model based on minimum variance distortionless response is established, so that the minimum output variance is subordinate to the single satellite signal upward gain, and the optimal anti-jamming weight vector ensures the interference suppression and the satellite navigation low signal-to-noise ratio loss reception; then, a multi-stage Wiener filter is used to quickly solve the noise subspace projection matrix and the multi-beam pointing optimal anti-jamming weight vector; finally, the multi-beam pointing optimal anti-jamming weight vector is used for weighted summation of the array signal vector, so that the interference suppression and the satellite signal high-quality reception are realized.

[0032] In the present application, aiming at the civil aviation satellite navigation anti-deception demand, a related peak ternary detection, attitude position auxiliary detection and deception regenerating cancellation deception prevention method are constructed; whether there is deception is detected through the related peak ternary detection method and the attitude position auxiliary detection method; if there is deception, the deception in the captured signal is suppressed by the deception regenerating cancellation method, and the satellite signal purification is realized, which has the advantages of strong anti-deception ability, strong engineering practicability and the like.

[0033] The present application also provides a civil aviation satellite navigation anti-jamming anti-deception device used in the above method, including: The array antenna includes 4 B1C frequency band antenna array elements, 4 B2a frequency band antenna array elements, a feed network and an array surface. The radio frequency channel includes 4 B1C frequency band down-conversion units and 4 B2a frequency band down-conversion units, and is used for filtering, frequency conversion and amplification processing of the satellite signals and / or interference and / or deception received by the 4 B1C frequency band antenna array elements and the 4 B2a frequency band antenna array elements to obtain 8 analog signals. ​The digital processing unit is connected with the output of the radio frequency channel, and is used for converting the 8 analog signals transmitted by the radio frequency channel into 8 digital intermediate frequency signals, and performing multi-beam anti-interference, navigation signal processing, navigation information processing and anti-deception processing on the 8 digital intermediate frequency signals. The interface unit comprises a radio frequency interface, a data interface and a power supply interface, the radio frequency interface is used for radio frequency input and power output, the data interface is used for data transmission and information injection, and the power supply interface is used for external power input and isolation processing. The power supply unit is used for converting an external power voltage into voltages required by the array antenna, the radio frequency channel and the digital processing unit.

[0034] According to the application, the input end of each B1C frequency band down conversion unit is connected with the output of one B1C frequency band antenna array element, and the input end of each B2a frequency band down conversion unit is connected with the output of one B2a frequency band antenna array element. The 4 B1C frequency band down conversion units and the 4 B2a frequency band down conversion units are used for filtering, frequency converting and amplifying satellite signals and / or interference and / or deception received by the 4 B1C frequency band antenna array elements and the 4 B2a frequency band antenna array elements respectively to obtain 8 analog intermediate frequency signals.

[0035] According to the application, the digital processing unit comprises 8 analog-to-digital converters, a field programmable gate array chip and a digital signal processing chip. The input end of each analog-to-digital converter is connected with the output end of one B1C frequency band down conversion unit or one B2a frequency band down conversion unit, and the output end outputs a digital intermediate frequency signal. The field programmable gate array chip performs multi-beam anti-interference, navigation signal processing, correlation peak triad detection and deception regeneration counter deception processing on the 8 digital intermediate frequency signals. The digital signal processing chip performs navigation information processing and attitude position auxiliary detection anti-deception processing.

[0036] According to the application, the software running on the field programmable gate array chip comprises an anti-interference module, a capture module, a tracking module, a data demodulation module, a TIXX module, an observation quantity extraction module and a correlation peak triad detection and deception regeneration counter deception module. The software running on the digital signal processing chip comprises an attitude position auxiliary detection anti-deception module, a PVT solution module, an integrity monitoring module and a self-checking module. The anti-interference module comprises multi-stage Wiener filtering, optimal anti-interference weight vector calculation and weighted summation processing on an array signal vector. The navigation signal processing comprises capturing, tracking, data demodulation, TIXX and observation quantity extraction on satellite signals. The navigation information processing comprises PVT solution, integrity monitoring and self-checking. Anti-spoofing processing includes correlation peak ternary detection, attitude position auxiliary detection and deception regeneration cancellation; Anti-interference processing, navigation signal processing, correlation peak ternary detection and deception regeneration for fire deception processing are implemented in VHDL language, and the rest of the processing is implemented in C language.

[0037] According to the present invention, the device is in the shape of a cuboid; The structural parts of the equipment are made of 5A06 aluminum alloy plates and assembled by screws; GP5000 thermal pads are installed on the heating components of the equipment, and thermal bosses are set at the corresponding positions on the bottom of the equipment shell; The heat dissipation path of the equipment is components → thermal pad → housing → aircraft; The design parameters of the device's power supply, power consumption, interface, dimensions, and weight are shown in Table 1. Table 1 Design parameters for installation of anti-interference and anti-spoofing equipment for civil aviation satellite navigation

[0038] In the present invention, in response to the gap in civil aviation satellite navigation anti-interference and anti-deception equipment, the hardware platform of the civil aviation satellite navigation anti-interference and anti-deception equipment is designed as a parallel processing and scalable platform of "dual-frequency 8-channel low-noise RF front-end, scalable FPGA+DSP heterogeneous, and modular interface", the software architecture is a layered modular architecture of "business layer processing is independent of hardware, and interface layer supports standard protocols", and the appearance structure is an airworthiness and compliant structure of "low-profile streamlined, no protruding structure, lightweight weather-resistant aluminum alloy material, impact and vibration resistance", which supports multi-frequency, multi-mode, multi-channel signal processing, cross-platform transplantation, expansion and integration.

[0039] The present invention will be described in more detail below through examples.

[0040] Example 1: like Figure 1 As shown, this embodiment proposes an anti-interference and anti-spoofing method for civil aviation satellite navigation. By constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, correlation peak ternary detection, attitude and position auxiliary detection, and deception regeneration to prevent deception, it meets the security requirements of civil aviation satellite navigation applications. The specific process is as follows: 1) Constructing multi-beam pointing and multi-stage Wiener filtering anti-interference method: Multi-beam pointing anti-interference modeling is a minimum variance distortionless response (MVDR) constrained optimization model as follows: ; Where, is the array signal vector The covariance matrix of is a steering vector in the desired satellite signal direction, is an anti-jamming weight vector, is a conjugate transpose symbol of vector or matrix; The reason why the multi-beam pointing anti-jamming method is superior to the adaptive nulling anti-jamming method is that the former restricts the gain of the satellite signal coming direction , which can ensure to suppress interference and receive satellite signals with high quality; the latter restricts the first element of the weight vector to be 1, which only ensures to suppress interference; The optimal anti-jamming weight vector of the above constraint optimization problem is : ; In the formula, is an identity matrix, is an interference steering vector matrix, is a projection matrix of noise subspace, is an inverse symbol of matrix; The projection matrix can be obtained by multi-stage Wiener filtering, and the corresponding initialization and iteration process is as follows: Initialization: , ; Iteration times: ; ; ; ; ; Take the first large values corresponding to to form the projection matrix of the noise subspace , wherein is the number of interferences, is the dimension of the vector, , is the initial value of iteration, is the first element of the vector , is the first standard orthogonal basis vector of the interference subspace, is a mathematical expectation operator, and the symbol is a conjugate operator, is a modulus operator, is a conjugate transpose operator, , are the first , , The expected signal of the next iteration, ,The input vector of the first , The input vector of the first , The input vector of the first , The mean square value of the first , The mean square value of the first , The optimal anti-interference weight vector is: ; The array signal vector is weighted and summed with the optimal anti-interference weight vector to suppress interference therein and obtain a satellite signal with good reception quality (i.e., high reception signal-to-noise ratio); 2) Correlation peak ternary detection, attitude position auxiliary detection, and deception regeneration countermeasure deception method: The correlation peak ternary detection and attitude position auxiliary detection methods are used to detect whether there is deception. If there is deception, the deception regeneration countermeasure method is used to suppress the deception in the captured signal to achieve satellite signal purification. (1) Correlation peak ternary detection method: The spread spectrum code of the public service signal mainly used by civil aviation is a short-period spread spectrum code, which has the characteristics of sharp autocorrelation function and flat cross-correlation function. Based on this, the correlation peak ternary detection method is constructed as follows: H0: There is no expected satellite signal at the current carrier Doppler frequency shift-spread spectrum code phase search unit; H1: There is only expected satellite signal at the current carrier Doppler frequency shift-spread spectrum code phase search unit; H2: There are expected satellite signal and deception at the current carrier Doppler frequency shift-spread spectrum code phase search unit; The test statistic under the H0 assumption is subject to a centralized chi-square distribution. The test statistic under the H1 and H2 assumptions is subject to a non-centralized chi-square distribution. According to the probability distribution of the test statistic, the critical point of the rejection region at the significance level is determined. The significance level is usually 0.05, 0.01, or 0.005.

[0041] Correlate the captured signal after anti-interference with the local spread spectrum code. In the (carrier Doppler frequency shift, spread spectrum code phase) two-dimensional search space, if there is no correlation peak value greater than the critical point, it is determined that there is no expected satellite signal, and the acquisition continues. If there is only one correlation peak value greater than the critical point, it is determined that there is only expected satellite signal and no deception, and the tracking phase is directly entered. If there are multiple correlation peak values greater than the critical point, it is determined that there are expected satellite signal and deception, and the deception regeneration countermeasure phase is entered. (2) Attitude position auxiliary detection method: If other navigation systems such as inertial navigation system providing attitude and position information are available, the carrier phase double difference method assisted by attitude and position information can be used for spoofing detection. The carrier phase double difference method assisted by attitude and position information makes full use of the differences between spoofing signals and satellite signals in carrier phase single difference and double difference observations to realize spoofing detection. The differences between spoofing signals and satellite signals in carrier phase single difference and double difference observations are as follows. Each spoofing signal is transmitted via a pair of repeater antennas, and the angles of arrival at the satellite navigation equipment are exactly the same. Therefore, the carrier phase single difference observations of each spoofing signal fluctuate around a constant, and the double difference observations of each spoofing signal fluctuate around zero. Each satellite signal is transmitted via different satellite antennas, and the angles of arrival at the satellite navigation equipment are different. Therefore, the carrier phase single difference and double difference observations of different satellite signals are related to satellite motion, integer ambiguity and baseline vector, and are different for different satellites. Accordingly, the spoofing detection process of the attitude and position assisted detection method is as follows. First, determine the acceptable false alarm rate, and solve the detection threshold corresponding to the false alarm rate The solving formula is as follows: ; In the formula, is the false alarm rate, is the probability cumulative distribution function corresponding to the carrier phase double difference observation noise distribution function of the satellite signal, and is defined as ; In the formula, is the carrier phase observation noise variance; Then, the carrier phase double difference prediction values of all visible satellites are calculated using the attitude and position information, wherein the maximum carrier phase double difference prediction value is denoted as ; Finally, a decision is made according to whether the difference between the carrier phase double difference observation value and exceeds the threshold; that is, if the difference between the carrier phase double difference observation value and the prediction value does not exceed the detection threshold, it is determined that only the satellite signal exists and there is no spoofing, and the process directly enters the tracking phase; if the difference between the carrier phase double difference observation value and the prediction value exceeds the detection threshold, it is determined that spoofing exists, and the process enters the spoofing regeneration and cancellation phase. (3) Spoofing regeneration and cancellation method: The spread spectrum code of the public service signal used by civil aviation is publicly disclosed, and its generation method can be found in the space signal interface control document (ICD) of each satellite navigation system. Accordingly, the spoofing regeneration and cancellation method suppresses the spoofing in the captured signal after anti-jamming according to the following process. First, the deception in the currently captured signal is tracked to obtain the amplitude and phase estimates of the deception; then, based on the amplitude and phase estimates of the deception and the deception spread spectrum code generated locally according to the ICD, the regenerated deception is obtained; then, the regenerated deception is subtracted from the captured signal after anti-interference to achieve deception cancellation; finally, all deception is cancelled and the satellite signal is purified and transferred to the tracking unit.

[0042] This embodiment provides a civil aviation satellite navigation anti-interference and anti-deception device, such as Figure 2 As shown, it is mainly composed of array antenna, RF channel, digital processing unit, power supply unit, interface unit, etc., including: 1) Hardware design: Considering that the primary satellite navigation signals used in civil aviation are BDS B1C, B2a, and GPS L1C / A, and that BDS B1C and GPS L1C / A have the same carrier frequency and overlapping signal bands; The array antenna mainly consists of four B1C band antenna elements, four B2a band antenna elements, a feed network, and an array surface. The four B1C band antenna elements simultaneously receive, interfere with, and deceive B1C and L1C / A satellite signals, while the four B2a band antenna elements receive, interfere with, and deceive B2a satellite signals. The RF channel is mainly composed of four B1C band down-conversion units and four B2a band down-conversion units. The four B1C band down-conversion units filter, convert, and amplify B1C and L1C / A satellite signals, interference, and deception. The four B2a band down-conversion units filter, convert, and amplify B2a satellite signals, interference, and deception. The digital processing unit is mainly composed of a field programmable gate array (FPGA) chip and a digital signal processing (DSP) chip. The FPGA performs multi-beam anti-interference, navigation signal processing, correlation peak ternary detection, and deception regeneration for firefighting deception on 8-channel digital intermediate frequency signals; the DSP performs navigation information processing, attitude and position auxiliary detection and anti-deception processing; 2) Software Design: The software running on FPGA and DSP chips mainly consists of anti-interference processing, navigation signal processing, navigation information processing, and anti-deception processing software, such as Figure 3 As shown; The anti-interference processing mainly includes multistage Wiener filtering (obtaining a projection matrix of a noise subspace), optimal anti-interference weight vector calculation, weighted sum of array signal vectors and the like processing; the navigation signal processing mainly includes satellite signal acquisition, tracking, data demodulation, TIXX, observation extraction and the like processing; the navigation information processing mainly includes PVT solution, integrity monitoring and the like processing; the anti-deception processing mainly includes correlation peak ternary detection, attitude position auxiliary detection, deception regeneration cancellation and the like processing; The anti-interference processing, the navigation signal processing, the correlation peak ternary detection and the deception regeneration cancellation anti-deception processing are realized by using VHDL language, and the rest processing is realized by using C language; 3) Appearance structure design: According to the requirement of the civil aviation aircraft installation equipment, the structural member of the civil aviation satellite navigation anti-interference anti-deception equipment is processed by using 5A06 aluminum alloy plate, and is combined into shape by screw mode; the heating component is installed with GP5000 heat conduction pad, and there is a heat conduction boss at the corresponding position of the bottom of the shell, and the heat dissipation path is component→heat conduction pad→shell→aircraft; the appearance structure of the civil aviation satellite navigation anti-interference anti-deception equipment is shown as Figure 4 (Figure (a), left (b), (c), (d) view (d)); 4) Other design: The power supply, power consumption, interface, appearance size and weight of the civil aviation satellite navigation anti-interference anti-deception equipment are shown in Table 1; Table 1 Civil aviation satellite navigation anti-interference anti-deception equipment installation design parameters

[0043] The civil aviation satellite navigation anti-interference anti-deception method provided by the embodiment of the application is constructed according to the civil aviation anti-interference anti-deception demand, and a multibeam pointing and multistage Wiener filtering anti-interference method is constructed, which has the advantages of being suitable for multiple types of interference, having strong anti-interference ability, and being strong in engineering practicability; meanwhile, a correlation peak ternary detection, attitude position auxiliary detection and deception regeneration cancellation anti-deception method is constructed, which has the advantages of being suitable for retransmission / generation type deception, having strong anti-deception ability, and being strong in engineering practicability.

[0044] The above has described the embodiments of the application, and the above description is exemplary, is not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A civil aviation satellite navigation anti-interference and anti-deception method, characterized in that: include: By constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, the optimal anti-interference weight vector is solved in terms of maximum output signal-to-interference-noise ratio, so as to achieve the maximum interference suppression and the minimum loss of satellite signal reception signal-to-noise ratio. Through the correlation peak ternary detection method and the posture position auxiliary detection method, it is possible to detect whether there is deception in the captured signal after anti-interference; If deception exists, the deception in the captured signal is suppressed by a deception regeneration cancellation method to achieve satellite signal purification.

2. The method according to claim 1, characterized in that By constructing a multi-beam pointing and multi-stage Wiener filtering anti-interference method, the optimal anti-interference weight vector in the sense of maximum output signal-to-interference-noise ratio is solved to achieve the maximum interference suppression and the minimum loss of satellite signal reception signal-to-noise ratio. A multi-beam pointing anti-interference model is constructed, and the optimal anti-interference weight vector in terms of maximum output signal-to-interference-noise ratio is obtained as the projection of the steering vector in the direction of the desired satellite signal onto the noise subspace. Obtaining a projection matrix of the noise subspace by multi-stage Wiener filtering; Based on the projection matrix, obtaining the optimal anti-interference weight vector of the anti-interference model; The optimal anti-interference weight vector is used to perform weighted summation on the array signal vector of the anti-interference model, thereby suppressing the interference therein to the greatest extent while affecting the satellite signal therein to the least extent.

3. The method according to claim 2, characterized in that The anti-interference model is a minimum variance undistorted response constrained optimization model, and the expression of the constrained optimization model is: ； in, is the array signal vector The covariance matrix of is the steering vector in the direction of the desired satellite signal, is the anti-interference weight vector, is the conjugate transpose symbol of a vector or matrix; The expression of the optimal anti-interference weight vector is: ； in, is the optimal anti-interference weight vector, is the identity matrix, is the interference steering vector matrix, is the projection matrix of the noise subspace, is the matrix inverse symbol, is the number of interferences, is the dimension of the vector; The projection matrix of the noise subspace is obtained by multi-stage Wiener filtering, and the corresponding initialization and iteration process is as follows: initialization: , ; Iteration Second-rate: ; ； ； ； ； Pick Center front The corresponding large value The projection matrix that forms the noise subspace ; in, 、 is the initial value of the iteration, is a vector The first element of is the first interference subspace orthonormal basis vectors, is the mathematical expectation operator, symbol is the conjugate operator, is the modulo operator, is the conjugate transpose operator, 、 Respectively 、 The expected signal of the iteration, 、 Respectively 、 The input vector for the iteration, For the The mean square value of the expected signal.

4. The method according to claim 1, wherein The correlation peak ternary detection method comprises: Propose the three hypotheses of H0: no expected satellite signal, H1: only expected satellite signal, H2: expected satellite signal and deception, determine the test statistic and its probability distribution, and give a significance level; According to the probability distribution obeyed by the test statistic, determine the critical point of the rejection region at the significance level; Correlating the captured signal after anti-interference with a local spreading code; In the two-dimensional search space of carrier Doppler frequency shift and spread spectrum code phase, if there is no correlation peak greater than the critical point, it is determined that there is no desired satellite signal and acquisition continues; If there is only one correlation peak greater than the critical point, it is determined that only the desired satellite signal exists and there is no deception, and the tracking phase is directly entered; If there are multiple correlation peaks greater than the critical point, it is determined to be a desired satellite signal and deception, and the process enters the deception regeneration cancellation stage; Among them, when the H0 hypothesis is true, the test statistic obeys the centralized chi-square distribution; when the H1 and H2 hypotheses are true, the test statistic obeys the non-central chi-square distribution; The posture position auxiliary detection method comprises: Determine the acceptable false alarm rate and solve the detection threshold corresponding to the false alarm rate; The attitude and position information are used to calculate the carrier phase double difference prediction value of all visible satellites, where the largest carrier phase double difference prediction value is recorded as ; According to the carrier phase double difference observation value and the The difference between the carrier phase double difference observation value and the If the difference between the carrier phase double difference observation value and the If the difference exceeds the detection threshold, it is determined that there is deception and the process enters the deception regeneration and cancellation stage; The formula used to solve the detection threshold is: ； in, is the detection threshold, is the false alarm rate, is the probability cumulative distribution function corresponding to the double-difference observation noise distribution function of the carrier phase of the satellite signal; The expression of the probability cumulative distribution function is: ； in, is the carrier phase observation noise variance.

5. The method according to claim 4, characterized in that Suppressing deception in the captured signal after anti-interference by using a deception regeneration cancellation method to achieve satellite signal purification includes: Track the deception in the currently captured signal to obtain the amplitude estimation value and phase estimation value of the deception; Obtaining a regenerative spoof based on the amplitude estimate, the phase estimate, and a spoofed spread spectrum code generated locally according to an interface control file; The regenerated deception is subtracted from the anti-interference, captured signal, and the satellite signal is purified and transferred to the tracking unit.

6. A civil aviation satellite navigation anti-interference and anti-deception device used in the method according to any one of claims 1 to 5, characterized in that: include: Array antenna, including 4 B1C band antenna elements, 4 B2a band antenna elements, feed network, and array surface; The radio frequency channel includes four B1C band down-conversion units and four B2a band down-conversion units, which are used to filter, frequency-convert, and amplify satellite signals and / or interference and / or spoofing received by the four B1C band antenna array elements and the four B2a band antenna array elements to obtain eight analog signals; a digital processing unit connected to the output of the radio frequency channel, configured to convert the eight analog signals transmitted by the radio frequency channel into eight digital intermediate frequency signals, and perform multi-beam anti-interference, navigation signal processing, navigation information processing, and anti-spoofing processing on the eight digital intermediate frequency signals; The interface unit includes a radio frequency interface, a data interface, and a power interface. The radio frequency interface is used for radio frequency input and power output, the data interface is used for data transmission and information addition, and the power interface is used for external power input and isolation processing; The power supply unit is used to convert the external power supply voltage into the voltage required by the array antenna, radio frequency channel, and digital processing unit.

7. The device according to claim 6, characterized in that The input end of each B1C band down-conversion unit is connected to the output of a B1C band antenna array element, and the input end of each B2a band down-conversion unit is connected to the output of a B2a band antenna array element; The four B1C band down-conversion units and the four B2a band down-conversion units are used to filter, convert and amplify the satellite signals and / or interference and / or deception received by the four B1C band antenna array elements and the four B2a band antenna array elements to obtain 8 analog intermediate frequency signals.

8. The device according to claim 6, characterized in that The digital processing unit includes an 8-channel analog-to-digital converter, a field programmable gate array chip and a digital signal processing chip; The input end of each analog-to-digital converter is connected to the output end of a B1C frequency band down-conversion unit or the output end of a B2a frequency band down-conversion unit, and the output end outputs a digital intermediate frequency signal; The field programmable gate array chip performs multi-beam anti-interference, navigation signal processing, correlation peak ternary detection and deception regeneration on 8-channel digital intermediate frequency signals to process fire deception; The digital signal processing chip performs navigation information processing and posture position auxiliary detection and anti-deception processing.

9. The device according to claim 8, characterized in that The software running on the field programmable gate array chip includes an anti-interference module, a capture module, a tracking module, a data demodulation module, a TIXX module, an observation quantity extraction module, and a correlation peak ternary detection and deception regeneration module for fire deception; The software running on the digital signal processing chip includes an attitude position auxiliary detection anti-spoofing module, a PVT solution module, an integrity monitoring module and a self-test module; The anti-interference module includes multi-stage Wiener filtering, optimal anti-interference weight vector calculation and weighted summation processing of array signal vectors; Said navigation signal processing includes capturing, tracking, data demodulation, TIXX and observation quantity extraction of satellite signals; Said navigation information processing includes PVT solution, integrity monitoring and self-test; The anti-spoofing process includes performing correlation peak ternary detection, posture position auxiliary detection and deception regeneration cancellation; The anti-interference processing, navigation signal processing, correlation peak ternary detection and deception regeneration for fire deception processing are implemented in VHDL language, and the remaining processing is implemented in C language.

10. The device according to claim 6, characterized in that The device is in the shape of a cuboid; The structural parts of the equipment are made of 5A06 aluminum alloy plates and assembled by screws; The heating components of the device are installed with GP5000 thermal pads, and a thermal boss is set at the corresponding position on the bottom of the device shell; The heat dissipation path of the device is components → thermal pad → housing → aircraft; The design parameters of the equipment, including power supply, power consumption, interface, dimensions and weight, are as follows: 。

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