KR20210120499A - Beam forming anti-jamming processing apparatus capable of eliminating spoofing signal using array antenna - Google Patents

Abstract

The present invention relates to a beam-forming anti-jamming apparatus capable of removing a spoofing signal by using an array antenna. The beam-forming anti-jamming apparatus capable of removing a spoofing signal by using an array antenna comprises: an array antenna; a frequency down conversion unit converting an RF satellite navigation signal received by the array antenna into a digital IF signal to output the digital IF signal; an interference signal processing means simulating a jamming signal based on spoofing signal direction information to generate a spoofing signal direction jamming signal, removing a jamming signal from the spoofing signal direction jamming signal and the digital IF signal based on satellite direction information, and forming a beam in a satellite direction to output a jamming-removed signal; a navigation calculation unit including a correlation processing unit determining the tracking status of a satellite and reflecting a code and a carrier wave corresponding to a tracking satellite in the jamming-removed signal to extract correlation peak value information, and generating the satellite direction information of a tracking satellite through navigation solution calculation; and a spoofing signal sensing unit receiving the satellite direction information and the correlation peak value information to sense a spoofing signal, and outputting the spoofing signal direction information. A spoofing signal can be searched and detected in all directions to be removed, and navigation performance can be improved by minimizing loss for a tracking satellite.

Description

A beam-forming anti-jamming device capable of removing deceptive signals using an array antenna {BEAM FORMING ANTI-JAMMING PROCESSING APPARATUS CAPABLE OF ELIMINATING SPOOFING SIGNAL USING ARRAY ANTENNA}

The present invention relates to a beam-forming anti-jamming technology capable of removing a spoof signal using an array antenna, and more particularly, omnidirectional detection of a spoof signal in the interference signal removal for a satellite navigation signal received through an array antenna, The present invention relates to a beamforming anti-jamming device capable of removing a spoofing signal by using an array antenna capable of removing the spoofing signal.

A global navigation satellite system (GNSS) is a system that calculates a user's location by triangulation using a plurality of satellites orbiting the earth. Such a satellite navigation system can be used for a long time because there is no divergence of errors according to usage time, and has the advantage of being able to accurately position the entire earth.

On the other hand, when the GNSS signal transmitted from the satellite at an altitude of about 20,000 km reaches the receiver, it becomes a signal of about -128.5 dBm, which is lower than the thermal noise at room temperature. That is, since the GNSS signal is lower than the thermal noise, it can be easily affected by the interference signal. The interference signal can be largely classified into two types: a jamming signal and a spoofing signal. The jamming signal is a signal input to the receiver with a much stronger strength than the GNSS signal in order to prevent reception of the GNSS signal. This signal does not contain navigation data or Pseudo-Random Noise (PRN) codes. Although the GNSS signal has a processing gain of direct spread, it is particularly vulnerable to intentional or military jamming, so a receiver in which a jamming countermeasure algorithm is not reflected falls into a navigational failure state.

On the other hand, the spoof signal has the same PRN as the GNSS receiving satellite PRN in order to navigate the receiver to a deliberate position, and is transmitted to be a signal of higher power than the GNSS received signal of the target GNSS receiver. This signal contains the PRN code as well as the navigation data. An example of a deceptive signal is a rebroadcast signal. The rebroadcast signal is a signal that stores a satellite signal actually received by a receiver in an environment without an interference signal, and broadcasts the signal to a target receiver by giving a sufficient gain to the stored signal. The receiver, to which the deception response algorithm is not reflected, performs navigation using an actual GNSS signal, and when receiving such a spoof signal, the receiver performs navigation using the spoof signal instead of using the satellite signal being used for the existing navigation.

Meanwhile, in order to remove the spoofing signal from the signal received through the antenna, the detection and removal of the spoofing signal must be performed after the detection and removal of the jamming signal is preceded. In order to detect a spoofing signal, it is searched for whether a jump occurs without reason in the amplitude and phase of the carrier, or the phase of the bit carrier, which is the difference between the carrier itself copied by the receiver in the carrier of the received signal. In general, since the spoof signal is received several dB higher than the power of the actual receiving satellite, it can be detected by searching whether the total reception strength of the signal has suddenly increased.

In general, in the case of a receiver using a single antenna, since it is not easy to distinguish a deceptive signal from a satellite signal, the correlation value for each PRN of the satellite is checked and, if two or more peak values are detected in one PRN at the same time, the corresponding PRN is transmitted. satellites are not used for navigation. However, these existing deceptive detection and removal methods do not distinguish between a deceptive signal and a normal satellite signal despite the presence of a normally operating satellite signal. there is a problem.

Registered Patent No. 10-2042104 (2019.11.01)

An embodiment of the present invention provides a beam-forming anti-jamming device capable of removing a spoofing signal using an array antenna capable of omnidirectionally detecting a spoofing signal and removing the spoofing signal in jamming removal for a satellite navigation signal through an array antenna. would like to provide

An embodiment of the present invention performs navigation using a beamforming algorithm, and at the same time allocates a part of a signal acquisition channel for spoofing signal detection, so that spoofing signals are constantly searched for each search area to effectively remove spoofing signals. An object of the present invention is to provide a beamforming anti-jamming device capable of removing a deceptive signal using an antenna.

In one embodiment of the present invention, a null is formed in the direction of the jamming signal by simulating the jamming signal incident in the direction of the array antenna in the direction of the corresponding search area in which the spoofing signal is detected, and the beam is steered in the direction of the satellite to steer the spoof signal. An object of the present invention is to provide a beamforming anti-jamming device capable of effectively removing a spoofing signal and removing a spoofing signal by using an array antenna that can improve navigation performance and at the same time.

In embodiments, a beamforming anti-jamming device capable of removing a spoof signal using an array antenna converts an array antenna and a radio frequency (RF) satellite navigation signal received from the array antenna into a digital intermediate frequency (IF) signal and outputs it frequency down converter to generate a spoof signal direction jamming signal by simulating a jamming signal based on the spoof signal direction information, and remove the jamming signal from the digital IF signal and the spoof signal direction jamming signal based on the satellite direction information, Interference signal processing means that forms a beam in the direction of a satellite to output a signal from which the jamming is removed, a correlation for determining whether to track a satellite, and reflecting the carrier wave and code corresponding to the tracking satellite to the signal from which the jamming is removed to extract correlation peak value information a navigation calculator comprising a processing unit, generating the satellite direction information of the tracking satellite through a navigation solution operation, and receiving the satellite direction information and the correlation peak value information to detect a spoof signal and output the spoof signal direction information It includes a deceptive signal detection unit.

The frequency down converter is connected to each of the antennas arranged in the array antenna, and an RF/IF converter that converts the inputted RF satellite navigation signal to IF and analog-digitally converts the converted IF signal to output ADC may be included.

The interference signal processing means includes: a jamming signal generator for generating a spoof signal direction jamming signal based on the spoof signal direction information; A summing unit for adding a signal to the input digital IF signal; A steering vector is calculated for the regions, an output signal of the summing unit and the steering vector are received, the beam of the array antenna is steered in the direction of a satellite signal, and a null is formed in the direction of a deceptive signal and a jamming signal to remove the jamming signal. It may include a beam former to generate the.

The jamming signal generator simulates a signal generator and a signal generated by the signal generator based on the spoof signal direction information as a jamming signal received by each antenna of the array antenna in the spoofing signal direction to generate a jamming signal in the spoofing signal direction. It may include a phase shifter that outputs

The beam forming unit receives the output signal of the summing unit and receives a covariance matrix calculator for calculating a covariance matrix, receives the covariance matrix and the satellite direction steering vector to steer the beam of the array antenna in the satellite direction, and null in the jamming signal direction A weight calculator for navigation that calculates a weight to form, divides the receivable space of the array antenna into a plurality of search areas for spoofing signal search, and calculates direction information of each search area and a steering vector suitable for the structure of the array antenna a search area steering vector calculator that receives the covariance matrix and the search area steering vector and calculates a weight for steering the beam of the array antenna to the search area, a weight calculator for detecting a spoofing signal, the weight for navigation and the spoof signal and a multiplier for applying a weight by multiplying an output signal of the summing unit by a weight for detection, and a summer for outputting a signal from which the jamming is removed by summing the output signals to which the weight has been applied by the multiplier.

The correlation processor includes a carrier signal generator for generating a carrier signal corresponding to a tracking satellite based on the frequency of the IF signal, a multiplier that multiplies the jammed signal with the carrier signal, and a code signal for each Pseudo-Random Noise (PRN) phase. A C/A code generator that generates by delaying, and correlating the de-jammed signal multiplied by the carrier and the code signal so that the frequency of the carrier signal and the phase of the code signal coincide with the de-jammed signal It may include a correlator for detecting peak values.

The spoof signal detection unit receives the satellite direction information and the correlation peak value information, and a peak value checker that checks whether there is peak value information including a PRN that matches the PRN included in the satellite direction information, and a PRN of the satellite direction information If there is matching peak value information, the angle between the two direction vectors is calculated based on the satellite direction information and the direction information of the peak value detection search area. It may include a spoof signal detector for generating direction information.

When the number of the peak value information exceeding the threshold in the corresponding search region is greater than a specific number, the spoofing signal detector may determine the corresponding search region as the direction in which the spoofing signal exists.

The disclosed technology may have the following effects. However, this does not mean that a specific embodiment should include all of the following effects or only the following effects, so the scope of the disclosed technology should not be construed as being limited thereby.

A beamforming anti-jamming device capable of removing a spoof signal using an array antenna according to an embodiment of the present invention can detect a spoof signal in all directions and remove the spoofing signal in jamming removal for a satellite navigation signal through the array antenna. have.

A beamforming anti-jamming apparatus capable of removing a spoofing signal using an array antenna according to an embodiment of the present invention performs navigation using a beamforming algorithm and allocates a part of a signal acquisition channel for spoofing signal detection to detect a spoofing signal. It is possible to effectively remove the deceptive signal by constantly searching for each search area.

The beam forming anti-jamming device capable of removing a spoof signal using an array antenna according to an embodiment of the present invention simulates a jamming signal incident in the direction of the array antenna in the direction of the corresponding search area in which the spoofing signal is detected, and in the direction of the jamming signal A null is formed and the beam is steered in the direction of the satellite to effectively remove the deceptive signal and improve the navigation performance.

1 is a diagram illustrating a satellite navigation system to which a beamforming anti-jamming apparatus capable of removing a deceptive signal using an array antenna according to an embodiment of the present invention is applied.
2 is a block diagram illustrating a beamforming anti-jamming apparatus capable of removing a deceptive signal using an array antenna according to an embodiment of the present invention.
3 is a detailed configuration diagram showing the interference signal processing means shown in FIG.
FIG. 4 is a detailed configuration diagram showing the correlation processing unit and the deception signal detecting unit shown in FIG. 2 .
FIG. 5 is a view for explaining the principle of detecting a deception signal of the deception signal detecting unit of FIG. 2 .

Since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiment described in the text. That is, since the embodiment may have various changes and may have various forms, it should be understood that the scope of the present invention includes equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only such effects, it should not be understood that the scope of the present invention is limited thereby.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

Terms such as “first” and “second” are for distinguishing one component from another, and the scope of rights should not be limited by these terms. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component.

When a component is referred to as being “connected to” another component, it should be understood that the component may be directly connected to the other component, but other components may exist in between. On the other hand, when it is mentioned that a certain element is "directly connected" to another element, it should be understood that the other element does not exist in the middle. Meanwhile, other expressions describing the relationship between elements, that is, “between” and “immediately between” or “neighboring to” and “directly adjacent to”, etc., should be interpreted similarly.

The singular expression is to be understood to include the plural expression unless the context clearly dictates otherwise, and terms such as "comprises" or "have" refer to the embodied feature, number, step, action, component, part or these It is intended to indicate that a combination exists, and it should be understood that it does not preclude the possibility of the existence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms defined in general used in the dictionary should be interpreted as being consistent with the meaning in the context of the related art, and cannot be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present application.

1 is a diagram illustrating a satellite navigation system to which a beamforming anti-jamming apparatus capable of removing a deceptive signal using an array antenna according to an embodiment of the present invention is applied.

Referring to FIG. 1 , the satellite navigation system 100 receives the satellite signals of k GNSS satellites 110 , the jamming signals of the jamming signal transmitter 120 , and the spoofing signals of the spoofing signal transmitter 130 at the antenna 141 . Thus, a satellite signal, a jamming signal, and a spoofing signal are output as an RF signal of a radio frequency band through the antenna 141 . Here, k denotes the maximum number of receivable satellites.

Here, the antenna 141 is configured as an array antenna in which N (N is a natural number) antennas ANT1 to ANTN are combined. An output terminal of the array antenna 141 is connected to an input terminal of the beam forming anti-jamming apparatus 140 according to an exemplary embodiment, so that an RF signal output from the array antenna 141 is input to the beam forming anti-jamming apparatus 140 .

The beamforming anti-jamming apparatus 140 according to an embodiment may be configured separately from the satellite navigation receiver 150 so that an output terminal of the beamforming anti-jamming apparatus 140 may be connected to an input terminal of the satellite navigation receiver 150 . The beamforming anti-jamming apparatus 140 according to an embodiment may be configured to be included in the satellite navigation receiver 150 . That is, the beamforming anti-jamming apparatus 140 may be connected between the array antenna 141 and the satellite navigation receiver 150 to provide an anti-jamming function. In this case, the beamforming anti-jamming apparatus 140 may detect and remove the deceptive signal during the anti-jamming process.

The beam forming anti-jamming apparatus 140 according to an embodiment forms a beam in the direction of the satellite signal with respect to the RF signal output from the array antenna 141 and forms a null in the direction of the jamming signal and the deceptive signal to form a satellite. The quality of a signal input to the navigation receiver 150 may be improved. Here, the beamforming anti-jamming apparatus 140 performs navigation using a beamforming algorithm, detects the direction of the spoofing signal, and simulates the jamming signal in the direction of the spoofing signal to remove the spoofing signal.

2 is a block diagram illustrating a beamforming anti-jamming apparatus 140 capable of removing a deceptive signal using an array antenna according to an embodiment of the present invention.

Referring to FIG. 2 , the beamforming anti-jamming apparatus 140 includes N frequency down-converters 210 , an interference signal processing unit 220 , a navigation calculator 230 , a correlation processing unit 240 , and a deceptive signal detection unit. 250 may be included. Here, N is a natural number and may correspond to the number of antennas constituting the array antenna 141 .

N frequency down converters 210 are provided to correspond to each channel of the array antenna 141 . Each frequency down-converter 210 receives an RF signal output from the array antenna 141 as its front end is connected to one output end of the array antenna 141 .

The frequency down-converter 210 includes an RF/IF converter and an Analog-Digital Converter (ADC), converts an input RF signal into an IF signal of an intermediate frequency band, and converts it back to a high-resolution digital IF signal. It converts the signal into a signal.

The interference signal processing means 220 generates an anti-jamming signal by forming a null in the direction of the jamming signal and the deceptive signal and forming a beam in the direction of the satellite. In one embodiment, the interference signal processing means 220 receives the N digital IF signals output from the frequency down converter 220 and the direction information of the spoofing signal detected by the spoofing signal detecting unit 250, and receiving the jamming signal and A signal applied by calculating a weight for forming a null in the direction of the deceptive signal and forming a beam in the direction of the satellite signal is provided to the navigation calculator 230 . The interference signal processing means 220 removes the jamming signal from the digital satellite signal of the IF band until the spoof signal is detected by the spoof signal detection unit 250 and outputs it. A detailed configuration of the interference signal processing means 220 will be described later with reference to FIG. 3 .

The navigation calculator 230 calculates satellite information and position, speed, and time information of the receiver based on the signal output from the interference signal processing unit 220 . The navigation calculator 230 determines whether to track the satellite and updates the change in the code phase increase value and the carrier phase increase value of the tracking satellite in order to track the satellite signal. In this case, a method of determining whether to track a satellite and a method of updating a code and a carrier change for tracking a satellite is obvious to those skilled in the art, and a detailed description thereof will be omitted.

In an embodiment, the navigation calculator 230 calculates an error of the code phase information and a carrier phase error to correct the error, and navigates through a navigation solution (eg, current position, movement speed, time information, etc.) calculation. extract data. Here, the navigation calculator 230 may analyze the direction of each tracking satellite through a navigation solution to generate satellite direction information, and output it to the interference signal processing unit 220 .

In particular, the navigation calculator 230 may include a correlation processor 240 for correlating signals of some channels acquired in the signal acquisition and tracking processes to detect a deceptive signal.

The correlation processing unit 240 reflects the carrier wave and code corresponding to the tracking satellite to the jammed-removed signal input from the interference signal processing unit 220, performs correlation processing, detects the peak value, and outputs correlated peak value information.

The spoofing signal detecting unit 250 searches for a spoofing signal based on the satellite direction information provided by the navigation calculator 230 and the correlation peak value information provided by the correlation processing unit 240 , and when the spoofing signal is detected, the direction of the spoofing signal The information is transmitted to the interference signal processing means 230 .

3 is a block diagram showing the interference signal processing means 220 shown in FIG.

Referring to FIG. 3 , the interference signal processing unit 220 may include a jamming signal generating unit 310 , a summing unit 320 , a steering vector calculating unit 330 , and a beam forming unit 340 .

The jamming signal generator 310 may generate a jamming signal in the spoofing signal direction based on the spoofing signal direction information. In an embodiment, the jamming signal generator 310 may include a signal generator 311 and a phase shifter 312 . Here, the jamming signal generator 310 generates a signal for generating a jamming signal from the signal generator 311 , and based on the spoof signal direction information output from the spoof signal detector 250 from the phase shifter 312 . The generated signal is simulated as a jamming signal received by each antenna of the array antenna 141 in the spoofing signal direction to generate a jamming signal in the spoofing signal direction. That is, the jamming signal generator 310 generates a simulated jamming signal with respect to the spoofing signal in the direction of the corresponding search area in which the spoofing signal is detected.

The summing unit 320 is provided at the input terminal of the interference signal processing unit 220 to receive the digital IF signal output from the frequency down-converter 210 and output it to the beam forming unit 240 . When the jamming signal generating unit 310 generates the spoofing signal direction jamming signal, the summing unit 320 adds the generated spoofing signal direction jamming signal to the input digital IF signal and outputs the summed signal.

The steering vector calculator 330 calculates a steering vector based on the satellite direction information output from the navigation calculator 230 . The steering vector calculator 330 calculates a steering vector of the received signal based on the satellite direction information and the position of each antenna according to the arrangement shape of the array antenna 141 .

The beam former 340 calculates a weight to be applied to the N channels based on the digital IF signal to which the digital IF signal input through the summing unit 320 or the deceptive signal direction jamming signal is summed, and weights each digital IF signal. By synthesizing N digital IF signals to which weights are applied, an anti-jamming signal in which nulls are formed in the jamming direction and the beam is steered in the satellite direction can be generated. In one embodiment, the beam former 340 includes a covariance matrix calculator 341 , a weight calculator for navigation 342 , a search area steering vector calculator 343 , a weight calculator for detecting a deceptive signal 344 , and a multiplier 345 . and a summer 346 .

The covariance matrix calculator 341 calculates a covariance matrix based on the frequency down-converted N digital IF signals received from the array antenna 141 . Here, the equation for calculating the covariance matrix is as follows.

where R is the covariance matrix and x is the input signal vector.

The covariance matrix calculator 341 calculates the covariance matrix through the following equation when the digital IF signal is summed with the deceptive signal direction jamming signal.

Here, Rs is a covariance matrix for spoofing signal removal, x is an input signal vector, and js is a jamming signal in the spoofing signal direction.

The calculated covariance matrix is input to a weight calculator 342 for navigation and a weight calculator 344 for detecting a deceptive signal for weight calculation.

The navigation weight calculator 342 receives the covariance matrix and the steering vector calculated by the covariance matrix calculator 341 and the steering vector calculator 330, respectively, and calculates weights. Here, the weight is determined such that the signal corresponding to the satellite direction is strengthened and the signal corresponding to the jamming direction is suppressed. The navigation weight calculator 342 calculates a weight based on the satellite direction steering vector because the satellite direction is different for each tracking satellite, and the equation for calculating the weight is as follows.

Here, d is a satellite direction steering vector, R is a covariance matrix calculated for an array antenna reception input signal, and (·) ^H denotes Hermitian operation. Hermitian operation means calculating the complex conjugate transpose of a vector or matrix.

Here, d is a satellite direction steering vector, Rs is a covariance matrix calculated for a signal in which a jamming signal in the direction of a deceptive signal is added to an array antenna reception input signal, and (·) ^H denotes Hermitian operation.

The calculated navigation weights w _{11 to w 1n} are multiplied by the multiplier 345 to each digital IF signal. The weighted N digital IF signals are summed by summer 346 to generate a jammed-free digital IF sum signal. Here, if the jamming signals in the spoofing direction are added by applying a weight to the summed signals, nulls are formed in the jamming and spoofing directions and an IF signal in which the beam is steered in the satellite direction can be generated. That is, the beam former 340 may perform high-performance navigation by IF outputting the anti-jamming signal from which the deceptive signal is removed.

The search area steering vector calculator 343 calculates a search area steering vector based on the search area direction information designated by the designer in order to detect a deceptive signal while the navigation weight is calculated. The calculated steering vector information is input to the weight calculator 344 for detecting a deceptive signal to calculate a weight similar to the weight calculator 342 for navigation. The weight calculation for detecting a deceptive signal can be obtained by the following equation.

Here, s is the search area direction steering vector.

_{The calculated weights w 21 to w 2n} for detecting the deceptive signal are multiplied by the multiplier 345 by the digital IF signal. The weighted N digital IF signals are summed by a summer 346 to generate an IF signal for spoofing detection. This signal is output to the correlation processing unit 240 for detecting a deceptive signal.

The correlation processing unit 240 detects a peak value by changing the code delay value and the Doppler value for each PRN from the input IF signal for detecting a spoofing signal, and correlating it. When information on the peak value is transmitted to the spoofing signal detecting unit 250, the spoofing signal detecting unit 250, when there is peak value information having the same PRN as the satellite direction information input from the navigation calculator 230, the corresponding search area and satellite Calculate the angle between the signal directions. When the number of satellites having an angle greater than or equal to the threshold set by the user is greater than a specific number in one search area, it is determined that a deceptive signal exists in the corresponding search area. When a deceptive signal is detected, the direction of the corresponding search area is recognized as the deceit signal direction, and direction information of the search area is transmitted to the phase shifter 312 .

FIG. 4 is a configuration diagram illustrating the correlation processing unit 240 and the deception signal detecting unit 250 shown in FIG. 2 .

Referring to FIG. 4 , the correlation processing unit 240 receives the IF signal for detecting the dejammed signal and performs correlation processing to output correlation peak value information. The correlation processing unit 240 may include a carrier signal generator 410 , a multiplier 420 , a C/A code generator 430 , and a correlator 440 .

The carrier signal generator 410 generates a carrier wave corresponding to the tracking satellite by reflecting the carrier phase increase value of the tracking satellite for tracking the phase signal. Here, the carrier wave may be generated while gradually changing the frequency of the IF signal. The de-jammed signal is multiplied by the carrier wave of the tracking satellite by the multiplier 420 and transmitted to the correlator 440 .

The C/A code generator 430 generates a code of the tracking satellite by reflecting a code phase increase value of the tracking satellite. The C/A code generator 430 generates a code signal for each PRN by phase delay. The C/A code (Coarse Acquisition-Code) is a navigation message signal carried on the L1 carrier, and the PRN with a bandwidth of 1 MHz is repeated. Since this PRN is different for each satellite, a unique number of each satellite is an indicator that can identify the satellite.

The correlator 440 performs Fast Fourier Transform (FFT) on the carrier-multiplied, de-jammed signal and the code signal for each PRN, and conjugate-complexes the FFT-transformed code signal, multiplies the two signals, and then performs inverse FFT transformation. . The inverse FFT-transformed signal produces the same result as correlating the two signals, and when the frequency and code phase of the generated carrier signal coincide with the input intermediate frequency signal, a peak value is detected in the code phase delay-Doppler frequency plane. The detected correlation peak value information is output to the deception signal detection unit 250 .

Meanwhile, the deception signal detector 250 may include a peak value information checker 450 and a deception signal detector 460 . The deception signal detection unit 250 checks the peak value information in the peak value information checker 450 . The peak value information checker 450 receives satellite direction information from the navigation calculator 230 and receives correlation peak value information detected by the correlation processing unit 240 to check whether there is peak value information that matches the PRN of the satellite direction information. The deceptive signal detector 460 calculates an angle between the two direction vectors based on the satellite direction information and the search region direction information in which the peak value is detected, if there is peak value information that matches the PRN of the satellite direction information as a result of the inspection. The spoofing signal detector 460 detects a spoofing signal by determining that a spoofing signal exists in the corresponding search area when the angular difference between the satellite direction and the direction vector of the search area exceeds a specific number of satellite information. When the spoofing signal is detected, direction information of the spoofing signal is output to the interference signal processing means 220 to simulate the spoofing signal direction jamming signal.

FIG. 5 is a view for explaining the principle of detecting a deception signal of the deception signal detecting unit in FIG. 4 .

In FIG. 5 , a hemispherical skyplot centered on the array antenna 141 is divided into a plurality of predefined search areas 510 . When the spoof signal is transmitted through the spoof signal transmitter 130 , a satellite signal having the same PRN as the visible satellite of the receiver exists. Assuming that the spoof signal whose PRNs of visible satellites a and b match are transmitted from the spoof signal transmitter 130 located in the direction of search area 5, the correlation peak value information of search area 5 detected in satellite signal tracking includes satellite a' and b' information will be present. This coincides with the PRNs of satellites a and b, respectively.

The spoof signal detection unit 250 calculates the angle difference a and the angle difference b between the satellite a and b directions and the direction vector of the search area 5, respectively, and when the calculated angle differences a and b exceed the threshold, the search area 5 determines that there are two over-threshold satellites, satellite a' and satellite b'. When the number of satellites is greater than or equal to a certain number in the search area 5, the deceptive signal detecting unit 250 defines the search area 5 as the deceitful signal detecting area 520 and sets the search area direction information as the deceit signal direction to the interference signal processing means 220 ) to pass

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be done.

100: satellite navigation system
110: GNSS satellite 120: jamming signal transmitter
130: deception signal transmitter 140: beam forming anti-jamming device
141: array antenna 150: satellite navigation receiver
210: frequency down-converter 220: interference signal processing means
230: navigation calculator 240: correlation processing unit (Acquisition)
250: deception signal detection unit
310: jamming signal generator
311: signal generator 312: phase shifter
320: summing unit 330: steering vector calculation unit
340: beam forming unit
341: Covariance Matrix Calculator 342: Weight Calculations for Navigation
343: search area steering vector calculator 344: weight calculator for detecting fraudulent signals
345: multiplier 346: summer
410: carrier signal generator 420: multiplier
430: C/A code generator 440: correlator
450: peak value information checker 460: deception signal detector
510: a plurality of search areas 520: a deceptive signal detection area

Claims (8)

array antenna;
a frequency down converter for converting a radio frequency (RF) satellite navigation signal received from the array antenna into a digital intermediate frequency (IF) signal and outputting;
A spoof signal direction jamming signal is generated by simulating a jamming signal based on the spoof signal direction information, and a jamming signal is removed from the digital IF signal and the spoofing signal direction jamming signal based on the satellite direction information, and a beam is formed in the satellite direction. an interference signal processing means for outputting a signal from which the jamming is removed;
and a correlation processing unit for determining whether to track a satellite and extracting correlation peak value information by reflecting a carrier wave and a code corresponding to the tracking satellite to the signal from which the jamming is removed, and generating the satellite direction information of the tracking satellite through a navigation solution operation a navigation calculator; and
A beamforming anti-jamming device capable of removing a spoofing signal using an array antenna including a spoofing signal detecting unit receiving the satellite direction information and the correlation peak value information, detecting a spoofing signal, and outputting the spoofing signal direction information.
The method of claim 1, wherein the frequency down-converting unit
An RF/IF converter that is connected to each of the antennas arranged in the array antenna and converts the inputted RF satellite navigation signal into IF, and an ADC that converts the converted IF signal to analog-digital and outputs it A beam-forming anti-jamming device capable of removing a deceptive signal using an array antenna, which is characterized.
According to claim 1, wherein the interference signal processing means
a jamming signal generator for generating a spoof signal direction jamming signal based on the spoof signal direction information;
a summing unit for receiving the digital IF signal and generating the spoofing signal direction jamming signal to the digital IF signal;
a steering vector calculation unit for calculating a satellite direction steering vector based on the satellite direction information and a position of each antenna according to an arrangement shape of the array antenna; and
A steering vector is calculated for the spoofing signal search areas, the output signal of the summing unit and the steering vector are received, the beam of the array antenna is steered in the direction of the satellite signal, A beam-forming anti-jamming device capable of removing a deceptive signal using an array antenna, comprising a beam-forming unit generating a removed signal.
The method of claim 3, wherein the jamming signal generator
signal generator; and
A phase shifter for simulating a signal generated by the signal generator based on the spoof signal direction information as a jamming signal received by each antenna of the array antenna in a spoofing signal direction and outputting a jamming signal in the spoofing signal direction A beam-forming anti-jamming device capable of removing a deceptive signal using an array antenna, which is characterized.
The method of claim 3, wherein the beam forming unit
a covariance matrix calculator that receives the output signal of the summing unit and calculates a covariance matrix;
a weight calculator for navigation that receives the covariance matrix and the satellite direction steering vector, steers the beam of the array antenna in the satellite direction, and calculates weights for forming nulls in the jamming signal direction;
a search area steering vector calculator that divides the receivable space of the array antenna into a plurality of search areas for searching for a spoof signal, and calculates a steering vector matching direction information of each search area and a structure of the array antenna;
a weight calculator for detecting a deceptive signal that receives the covariance matrix and the search area steering vector and calculates a weight for steering the beam of the array antenna to the search area;
a multiplier for applying a weight by multiplying the weight for the navigation and the weight for detecting the spoofing signal by the output signal of the summing unit; and
and a summer for outputting a signal from which the jamming has been removed by summing the output signals weighted by the multiplier, respectively.
The method of claim 2, wherein the correlation processing unit
a carrier signal generator for generating a carrier signal corresponding to the tracking satellite based on the frequency of the IF signal;
a multiplier that multiplies the de-jammed signal and the carrier signal;
a C/A code generator that generates a phase-delayed code signal for each Pseudo-Random Noise (PRN); and
and a correlator for correlating the de-jammed signal multiplied by the carrier and the code signal to detect a peak value when the frequency of the carrier signal and the phase of the code signal coincide with the de-jammed signal A beam-forming anti-jamming device that can remove deceptive signals using an array antenna.
The method of claim 2, wherein the deception signal detection unit
a peak value checker that receives the satellite direction information and the correlated peak value information and checks whether there is peak value information including a PRN that matches the PRN included in the satellite direction information; and
If there is peak value information that matches the PRN of the satellite direction information, the angle between the two direction vectors is calculated based on the satellite direction information and the direction information of the peak value detection search region. A beamforming anti-jamming device capable of removing a spoofing signal using an array antenna, characterized in that it includes a spoofing signal detector for generating spoofing signal direction information by determining the signal direction.
The method of claim 7, wherein the spoof signal detector is
If the number of the peak value information exceeding the threshold in the corresponding search region is greater than a specific number, the corresponding search region is determined as the direction in which the spoofing signal is present. jamming device.

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