Anti-interference radar filtering method and related equipment

Abstract

The embodiment of the invention discloses an anti-interference radar filtering method and related equipment, and the method comprises the steps: a transmitting end can generate a transmitting signal based on a waveform parameter random jitter method; the transmitting end transmits a signal to a real target point, the receiving end receives a returned echo signal, and the echo signal comprises a real echo signal and a false echo signal; determining a matched filter according to the emission signal, performing matched filtering processing on the echo signal based on the matched filter, filtering out a false echo signal and retaining a real echo signal to obtain a filtering signal; and processing the filtering signal according to a preset algorithm to obtain a target parameter corresponding to the real target point. According to the invention, multiple random characteristics are introduced, so that the jammer cannot accurately estimate the key parameters of the signal, the false echo signal obtained by the jammer based on the intercepted emission signal cannot be matched with the matched filter, and the receiver can effectively filter the false echo signal, thereby suppressing the interference and improving the safety of radar detection.

Description

Technical Field

[0001] The present application relates to the technical field of communications, and in particular to an anti-interference radar filtering method and related equipment. Background Art

[0002] With the continuous advancement of radar technology, radar systems are increasingly being used in areas such as range detection, velocity detection, angle detection, and synthetic aperture radar (SAR) imaging. However, radar systems are vulnerable to interference from external signals such as enemy active jammers and wireless communication signals. Deceptive jamming, in particular, poses a major threat to radar systems due to its low jamming power, high flexibility, and high fidelity. Jammers intercept radar transmit signals, modulate them, and retransmit deceptive signals, making it difficult for radar receivers to distinguish between real echoes and forged jammer echoes, thereby misleading the radar system. Specifically, jammers can spoof range, velocity, and angle by manipulating the time delay, frequency, and phase of the echo signal to alter the radar system's target measurement results. Furthermore, with the widespread application of SAR technology, jammers can also forge false echo signals, affecting SAR imaging, inserting false targets into images or altering the imaging characteristics of real targets, severely impacting target recognition and tracking. Therefore, radar systems require effective anti-jamming technologies to combat these complex deceptive jamming techniques and ensure safety and accuracy in a variety of application scenarios.

[0003] Existing deceptive jamming suppression techniques are primarily categorized as multi-channel and time-agile. Multi-channel deceptive jamming suppression employs fixed phase differences between channels and utilizes space-time adaptive processing techniques to perform interference cancellation to suppress interference. However, this technique is highly complex, increasing the processing difficulty and equipment cost of radar receivers. Time-agile deceptive jamming suppression techniques, on the other hand, utilize time-domain parameter agility to suppress deceptive signals transmitted by jammers through techniques such as random initial phase, phase jitter, and orthogonal phase encoding. However, the effectiveness of these techniques relies on the assumption that there is a certain delay between the jammer's interception and forwarding of signals. As jammer equipment improves in performance, or as jammers move beyond their traditional ground-stationary state and are able to track SAR platforms in real time, their real-time processing and forwarding capabilities are significantly enhanced, making these assumptions untenable. Therefore, in this context, the assumptions underlying these existing methods are being challenged, significantly reducing their effectiveness.

[0004] The current time-domain agile anti-interference technology solutions mainly include: random initial phase, orthogonal phase encoding and phase jitter. The random initial phase technology introduces a different initial phase into each transmitted pulse, and the jammer can only intercept the signal before the previous one or more PRIs due to equipment delay to achieve interference signal modulation and forwarding. When the SAR system receives the echo signal, it removes the random initial phase in the echo without affecting the imaging effect of the real echo. However, the jammer can only forward the interference signal based on the phase information of the previous one or more pulses, which causes the interference signal to be defocused in the azimuth direction, ultimately achieving interference signal suppression.

[0005] Orthogonal phase encoding technology utilizes chaotic phase codes and quantization techniques to generate signals with varying amplitudes, and uses chaotic parameters to make different transmitted signals approximately orthogonal. By assuming the jammer's delay, pulse compression gain cannot be achieved at the current pulse instant, thus achieving a suppression effect. Phase dithering technology first constructs a phase-dithered LFM signal model and introduces multiple cosine functions to form a time-varying phase dither function. A genetic algorithm is then used to optimize the phase-dithered signal's parameters, such as amplitude, frequency, and initial phase, to ensure orthogonality between different pulse signals.

[0006] Random initial phase technology has the following drawbacks: First, when jammers are sufficiently advanced to utilize signals intercepted at the current PRI for modulation and retransmission, their deceptive jamming suppression performance is significantly reduced, compromising security. Second, their anti-jamming performance depends on azimuth compression gain. While this can mitigate the effects of deceptive jamming suppression, it does not completely suppress them, and false targets may still remain.

[0007] Quadrature phase coding has the following drawbacks: First, it requires the design of a code set with excellent orthogonality, a process that is computationally complex. The complexity of finding the optimal orthogonal code increases dramatically, especially when the code set is large. Second, as the number of code sets increases, the orthogonality between the individual codes may decrease, leading to reduced system performance. This is particularly true in multi-target or complex interference environments, where orthogonality may not be effectively maintained.

[0008] Phase dithering technology has the following disadvantages: First, it requires pre-optimization of parameters such as amplitude, frequency, and phase, and the joint design of the phases of multiple pulses to ensure orthogonality between them. This significantly increases the complexity of the optimization when a large number of waveforms are optimized and a large number of superimposed sine waves are considered, and orthogonality cannot be guaranteed. Second, if smaller optimization parameters are chosen to reduce complexity and improve orthogonality, the randomness of the waveforms seen by the jammer is significantly reduced, significantly compromising security.

[0009] In summary, anti-interference radar filtering technology is susceptible to interference, and existing deception interference suppression technology has problems such as high technical complexity, poor anti-interference effect, and low security. Summary of the Invention

[0010] In view of this, the embodiments of the present application provide an anti-interference radar filtering method and related equipment, which solve the problems existing in the prior art, such as high complexity of deception interference suppression technology, poor anti-interference effect, and low security.

[0011] In a first aspect, an embodiment of the present application provides an anti-interference radar filtering method, comprising:

[0012] The transmitter generates a transmission signal based on the random dithering method of waveform parameters;

[0013] The receiving end receives an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal obtained by reflection from a true target point and a false echo signal generated by a jammer according to the transmission signal;

[0014] Determining a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal;

[0015] The filtered signal is processed according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0016] In some embodiments, determining a matched filter based on the transmitted signal, and performing matched filtering on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal includes:

[0017] A range filter is determined according to the transmitted signal, and false echo signals in the echo signal are suppressed based on the range filter, while true echo signals are retained to obtain a filtered signal.

[0018] In some embodiments, the target parameters include distance, speed, angle, and imaging, wherein the filtered signal is processed according to a preset algorithm to obtain the imaging corresponding to the real target point, including:

[0019] performing range pulse compression on the real echo signal based on the range filter to obtain a first filtered signal;

[0020] transforming the first filtered signal along the azimuth direction into the azimuth frequency domain, and performing range migration offset correction on the first filtered signal in the azimuth frequency domain;

[0021] An azimuth filter is determined according to the transmitted signal, and azimuth pulse compression is performed on the first focused signal based on the azimuth filter to obtain a radar image corresponding to the real target point.

[0022] In some embodiments, the receiving an echo signal returned based on the transmitted signal includes:

[0023] The transmitting end transmits the transmitting signal to the real target point;

[0024] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0025] The receiving end receives a false echo signal generated by modulating the intercepted transmission signal by the jammer. The false echo signal is obtained by modulating the parameters of the transmission signal estimated and determined by the jammer into a false target template. The false target template is a template of the distance, speed, angle and imaging corresponding to the false target point.

[0026] In some embodiments, generating a transmit signal based on random jittering of waveform parameters includes:

[0027] The transmitting end adjusts parameters such as amplitude, phase, and frequency by forward and backward coding based on a random dithering method of waveform parameters to generate an initial transmitting signal.

[0028] The initial transmission signal is subjected to window filtering by a pulse shaping filter to obtain a transmission signal with limited bandwidth.

[0029] In some embodiments, determining a matched filter based on the transmitted signal, and performing matched filtering on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal includes:

[0030] determining a range matching filter and a pulse shaping filter according to the transmitted signal;

[0031] Performing deconvolution processing on the echo signal to obtain an original echo signal corresponding to the initial transmission signal;

[0032] The original echo signal is subjected to matched filtering processing based on the range matched filter to obtain a true echo signal.

[0033] In some embodiments, the receiving an echo signal returned based on the transmitted signal includes:

[0034] The transmitting end transmits the transmitting signal to the real target point;

[0035] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0036] The receiving end receives the false echo signal generated by the jammer modulating the initial transmission signal. The false echo signal is obtained by the jammer performing deconvolution processing on the intercepted transmission signal, estimating and determining the parameters of the transmission signal, embedding it into a false target template, and performing filtering processing.

[0037] In a second aspect, an embodiment of the present application provides an anti-interference radar filtering device, comprising:

[0038] A generating unit, configured to generate a transmission signal based on a waveform parameter random jitter method;

[0039] a receiving unit, configured to receive an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal reflected from a true target point and a false echo signal generated by a jammer based on the transmission signal;

[0040] a filtering unit, configured to determine a matched filter according to the transmitted signal, and perform matched filtering processing on the echo signal based on the matched filter, thereby filtering out false echo signals and retaining true echo signals to obtain a filtered signal;

[0041] The signal processing unit is used to process the filtered signal according to a preset algorithm to obtain the target parameters corresponding to the real target point.

[0042] In a third aspect, an embodiment of the present application provides a terminal device comprising a memory and a processor; the memory stores an application, and the processor is used to run the application in the memory to execute the above-mentioned radar filtering method.

[0043] In a fourth aspect, an embodiment of the present application provides a radar filtering system, comprising the above-mentioned anti-interference radar filtering device, wherein the anti-interference radar filtering device is integrated in the above-mentioned terminal device to execute the above-mentioned radar filtering method.

[0044] The embodiment of the present application discloses an anti-interference radar filtering method and related equipment, wherein the transmitting end generates a transmission signal based on a waveform parameter random jitter method; the receiving end receives an echo signal returned based on the transmission signal, the echo signal including a real echo signal reflected from a real target point and a false echo signal generated by a jammer based on the transmission signal; a matched filter is determined according to the transmission signal, and the echo signal is matched filtered based on the matched filter to filter out the false echo signal and retain the real echo signal to obtain a filtered signal; the filtered signal is processed according to a preset algorithm to obtain the target parameters corresponding to the real target point. The present application introduces multiple random characteristics to the transmission signal, so that the jammer cannot accurately estimate the key parameters of the signal. Therefore, the false echo signal generated by the jammer based on the intercepted transmission signal cannot match the matched filter, and the false echo signal can be filtered out by the matched filter, thereby effectively suppressing interference and improving the safety of radar detection targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 A schematic diagram of an application scenario of the anti-interference radar filtering method provided by an embodiment of the present invention.

[0047] Figure 2a The figure is a flow chart of an anti-interference radar filtering method provided by an embodiment of the present invention.

[0048] Figure 2b This is another flowchart of the anti-interference radar filtering method provided by an embodiment of the present invention.

[0049] Figure 2c This is a structural diagram of an anti-interference radar filtering device provided by an embodiment of the present invention.

[0050] Figure 3 It is a structural diagram of an electronic device provided by an embodiment of the present invention.

[0051] Figure 4 This is a comparison chart of fuzzy functions of various waveforms provided by the embodiments of the present invention, wherein (a) conventional LFM waveform, (b) waveform with random dithering of waveform parameters, and (c) waveform with random dithering of windowed waveform parameters.

[0052] Figure 5These are delay and Doppler profiles of various waveform ambiguity functions provided by embodiments of the present invention. (a) and (b) correspond to LFM waveforms, (c) and (d) correspond to waveforms with randomized waveform parameters jitter, and (e) and (f) correspond to waveforms with randomized windowed waveform parameters jitter.

[0053] Figure 6 This is a comparison of the cross-ambiguity functions of various waveforms provided by the embodiments of the present invention. (a) corresponds to the traditional LFM waveform, (b) corresponds to the waveform with random dithering of waveform parameters, and (c) corresponds to the waveform with random dithering of windowed waveform parameters.

[0054] Figure 7 These are delay and Doppler profiles of various waveform cross-ambiguity functions provided by embodiments of the present invention. (a) and (b) correspond to waveforms with random jitter of waveform parameters, and (c) and (d) correspond to waveforms with random jitter of windowed waveform parameters.

[0055] Figure 8 This is the imaging result of a point target using an LFM waveform provided by an embodiment of the present invention, where (a) corresponds to the radar image and (b) corresponds to the azimuth profile.

[0056] Figure 9 This is the imaging result of a point target using a random initial phase waveform, provided by an embodiment of the present invention, where the jammer cannot promptly use the signal in the current PRI. (a) corresponds to the radar image, and (b) corresponds to the azimuth profile.

[0057] Figure 10 This is the imaging result of a point target using a random initial phase waveform, provided by an embodiment of the present invention, where the jammer can promptly use the signal in the current PRI. (a) corresponds to the radar image, and (b) corresponds to the azimuth profile.

[0058] Figure 11 This is the imaging result of a point target using an orthogonal phase-coded waveform, provided by an embodiment of the present invention, where the jammer cannot promptly utilize the signal in the current PRI. (a) corresponds to the radar image, and (b) corresponds to the azimuth profile.

[0059] Figure 12 This is the imaging result of a point target using an orthogonal phase-coded waveform according to an embodiment of the present invention, where the jammer can promptly use the signal in the current PRI. (a) corresponds to the radar image, and (b) corresponds to the azimuth profile.

[0060] Figure 13 This is an azimuth cross-sectional diagram of the imaging results of the waveform points using the proposed waveform parameter random jitter according to an embodiment of the present invention. (a) corresponds to the jammer being unable to promptly utilize the signal in the current PRI, and (b) corresponds to the jammer being able to promptly utilize the signal in the current PRI.

[0061] Figure 14 This is an azimuth cross-sectional diagram of the imaging results of the waveform points using the proposed windowed waveform parameters and random jitter, according to an embodiment of the present invention. (a) corresponds to the jammer being unable to promptly utilize the signal in the current PRI, while (b) corresponds to the jammer being able to promptly utilize the signal in the current PRI.

[0062] Figure 15 It is the original image of the real scene imaging simulation of the embodiment of the present invention.

[0063] Figure 16 It is a traditional LFM waveform image of the real scene imaging simulation according to the embodiment of the present invention.

[0064] Figure 17 It is a random initial phase image of the real scene imaging simulation according to the embodiment of the present invention (the signal in the current PRI cannot be used in time).

[0065] Figure 18 It is a random initial phase image of the real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI can be used in time).

[0066] Figure 19 It is an orthogonal phase-encoded image of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI cannot be used in time).

[0067] Figure 20 It is an orthogonal phase-coded image of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI can be used in a timely manner).

[0068] Figure 21 It is a waveform parameter random jitter image of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI cannot be used in time).

[0069] Figure 22 It is a waveform parameter random jitter image of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI can be used in a timely manner).

[0070] Figure 23 It is a random jitter image of windowed waveform parameters of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI cannot be used in a timely manner).

[0071] Figure 24 It is a random jitter image of windowed waveform parameters of a real scene imaging simulation according to an embodiment of the present invention (the signal in the current PRI can be used in a timely manner). DETAILED DESCRIPTION

[0072] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0073] The embodiments of the present invention provide an anti-interference radar filtering method and related equipment.

[0074] An embodiment of the present invention provides an anti-interference radar filtering system, including an anti-interference radar filtering device provided by any embodiment of the present invention. The anti-interference radar filtering device can be specifically integrated in a terminal, which can be a personal computer (PC) or the like.

[0075] The synthetic aperture radar system is an active earth observation system, including a radar platform. The radar platform can be installed on flying platforms such as aircraft, drones, satellites, and spacecraft. It can realize all-day and all-weather earth observation and has a certain surface penetration capability.

[0076] The radar platform mainly includes the following parts: radar transmitter, used to generate high-power radiation signals; antenna, used to radiate signals into space and receive signals reflected from targets; radar receiver, used to amplify, filter and transform weak received signals; radar servo equipment, used to control the rotation of the radar antenna, control and record antenna beam pointing data; frequency synthesizer and timer, used to coordinate the work of various radar subsystems.

[0077] For example, reference Figure 1 The application scenario of the anti-interference radar filtering system in this application is as follows: the radar platform is mounted on a flying platform. The coordinate origin O is the projection of the radar platform on the ground at time zero. The X-axis is parallel to the radar's motion direction, and the Z-axis is perpendicular to the ground. The radar platform moves at a certain height at a uniform linear speed V along the positive direction of the X-axis. The radar platform's motion direction is the azimuth direction, and the direction perpendicular to the radar platform's motion path is the range direction, i.e., the Y-axis. The positions of the true target and false target are marked on the plane where the X-axis and Y-axis are located, respectively.

[0078] Among them, the radar platform can generate a transmission signal through a random jitter method based on waveform parameters at the transmitting end; the receiving end receives an echo signal returned based on the transmission signal, and the echo signal includes a real echo signal reflected from a real target point and a false echo signal generated by a jammer based on the transmission signal; a matched filter is determined according to the transmission signal, and matched filtering processing is performed on the echo signal based on the matched filter to filter out the false echo signal and retain the real echo signal to obtain a filtered signal; the filtered signal is processed according to a preset algorithm to obtain the target parameters corresponding to the real target point.

[0079] It is understandable that the above method of the present invention can also be applied to other sensing systems, such as a wireless sensing system. Accordingly, the wireless sensing system includes a wireless transmitter and a wireless receiver.

[0080] above Figure 1 The example is only an example of a scenario architecture for implementing the embodiment of the present invention. The embodiment of the present invention is not limited to the above Figure 1 The scenario structure shown is based on which various embodiments of the present invention are proposed.

[0081] It should be noted that the serial numbers of the following embodiments are not intended to limit the preferred order of the embodiments.

[0082] This embodiment will be described from the perspective of an anti-interference radar filter device, which can be integrated into a terminal, such as a mobile phone, a tablet computer, a laptop computer, or a personal computer (PC).

[0083] like Figure 2a As shown, an anti-interference radar filtering method is provided. The method can be executed by a processor of a radar platform. The specific process of the anti-interference radar filtering method can be as follows:

[0084] 101. The transmitter generates a transmission signal based on a waveform parameter random jitter method.

[0085] The transmission signal is a pulse signal generated by a radar transmitter, and the random jitter of the waveform parameters is designed to follow the random jitter of the Gaussian distribution.

[0086] The transmission signal generated based on the random jitter of waveform parameters in this application is

[0087]

[0088] Among them, γ is the waveform jitter control factor, For rectangular windows, is the Gaussian jitter waveform, and A0 is the signal amplitude.

[0089] This application adds random waveform parameter jitter to the initial signal, making it impossible for the jammer to accurately determine the amplitude of the signal jitter. As a result, the false echo signal generated by the jammer does not match the matched filter filtering. During the imaging process, the false echo signal is filtered out. This can effectively suppress interference and improve radar safety.

[0090] In some embodiments, since the spectrum of the transmission signal generated based on random jitter of waveform parameters is expanded and the bandwidth is increased compared to the traditional LFM transmission signal, in order to further improve the practicality and applicability of the proposed technical solution and suppress the signal bandwidth, the transmission signal with random jitter of waveform parameters can be windowed.

[0091] Specifically, the transmitting end generates a transmitting signal based on a waveform parameter random jitter method, including the following steps:

[0092] The transmitting end generates an initial signal according to a pulse shaping filter;

[0093] According to the random jitter of the waveform parameters, the amplitude, phase, frequency, and front and back coding of the initial signal are adjusted to obtain the initial transmission signal.

[0094] The initial transmission signal is subjected to window filtering by a pulse shaping filter to obtain a transmission signal with limited bandwidth.

[0095] The transmitted signal based on random jitter of the windowed waveform parameters is:

[0096]

[0097] where g(t) is the pulse shaping filter.

[0098] In this application, the spectrum of the transmitted signal with random jitter of waveform parameters is extended. In practical applications, considering the existence of other radar systems, the frequency band may be affected. Therefore, the bandwidth of the transmitted signal can be limited by windowing the spectrum to further enhance practicality.

[0099] In the present application, the transmission signal is windowed according to the pulse shaping filter, and the pulse shaping filter is used to perform convolution processing on the initial transmission signal in the time domain to intercept the signal within the preset bandwidth as the transmission signal.

[0100] It is understandable that the present invention can select a pulse shaping filter to perform window filtering on the initial transmission signal to obtain an initial transmission signal with limited bandwidth. Of course, the initial transmission signal can also be directly used as the transmission signal.

[0101] 102. A receiving end receives an echo signal returned based on the transmitted signal, where the echo signal includes a true echo signal reflected from a true target point and a false echo signal generated by a jammer according to the transmitted signal.

[0102] The echo signal refers to the signal received by the antenna, including real echo signals and false echo signals.

[0103] Specifically, the receiving of the echo signal returned based on the transmitted signal comprises the following steps:

[0104] The transmitting end transmits the transmitting signal to the real target point;

[0105] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0106] The receiving end receives the false echo signal generated by the jammer modulating the initial transmission signal. The false echo signal is obtained by the jammer performing deconvolution processing on the intercepted transmission signal, estimating and determining the parameters of the transmission signal, embedding it into a false target template, and performing filtering processing.

[0107] The false target template is a template of distance, speed, angle and imaging corresponding to the false target point.

[0108] Assuming that the real target point is point p, the real echo signal received after reflection from the point target is:

[0109]

[0110] Among them, R p (η) is the instantaneous slant range of the point target p relative to the SAR.

[0111] Considering the application of jammers in real-time processing scenarios and relaxing the assumptions of existing waveform agility methods, the processing process can be divided into two cases: one is that the jammer cannot use the current PRI signal in time due to processing delays; the other is that the jammer can use the current PRI signal for modulation and forwarding in time. In order to successfully implement deceptive jamming, the jammer first needs to detect the key parameters of the SAR platform in advance, such as platform altitude, speed and heading, to accurately predict the radar signal characteristics. Secondly, the jammer needs to estimate and analyze parameters such as carrier frequency, modulation frequency and pulse repetition frequency based on the intercepted signal to ensure that the deceptive signal forwarded after modulation can be effective. However, the transmit signal generated based on random jitter of waveform parameters in this application embeds parameter-adjustable random amplitude jitter in the original LFM signal. This amplitude jitter not only affects the signal amplitude, but also causes phase discontinuity, making it difficult for the jammer to accurately estimate the signal parameters, especially the amplitude and phase information, during the interception phase. Since the jammer's DRFM can work by detecting and regenerating the triggered pulse waveform, in order to implement false target template modulation and ensure the jamming effect, the jammer regenerates the LFM signal to restore phase continuity. Therefore, regardless of whether the jammer can utilize the current PRI signal, it can only roughly estimate the amplitude based on the intercepted signal and regenerate a segment of the LFM signal for subsequent modulation and retransmission. To further emphasize the jammer's capabilities, assuming that the carrier frequency and modulation rate of the regenerated signal are the same as the original LFM signal, the specific processing flow of the jammer is as follows.

[0112] (1) When the jammer cannot utilize the signal in the current PRI in time:

[0113] The signal intercepted by the jammer is:

[0114]

[0115] in, is the amplitude estimated by the jammer. Since the amplitude estimated by the jammer has significant estimation errors, it is assumed that the estimated amplitude is obtained by calculating the average amplitude of the transmitted signal.

[0116] Then, the jammer modulates and forwards the signal according to (4):

[0117]

[0118] in, is the false target modulation parameter, R J (η) is the instantaneous slant range of the jammer relative to the SAR platform, σ J Preset reflection coefficient for the jammer.

[0119] (2) When the jammer cannot utilize the signal in the current PRI in time:

[0120] The signal intercepted by the jammer is:

[0121]

[0122] in, is the estimated amplitude of the jammer.

[0123] Then, the jammer modulates and forwards the signal according to (6):

[0124]

[0125] In some embodiments, the transmitted signal is a signal obtained by windowing the initial transmitted signal. In this case, after being reflected by the real target point, the received real echo signal is:

[0126]

[0127] Compared with the waveform parameter random jitter technical solution, the jammer needs to perform deconvolution and reconvolution operations, and the remaining steps are the same as formulas (4) to (7).

[0128] In a security countermeasure scenario, assuming the jammer possesses powerful processing capabilities to maintain effective jamming, the jammer can optionally deconvolve the transmitted signal after intercepting it. The jammer then estimates the parameters of the transmitted signal, embeds it into a false target template, and performs filtering. Without deconvolution, the jammer directly embeds the false target template, significantly reducing the jamming effectiveness.

[0129] Specifically, the receiving of the echo signal returned based on the transmitted signal comprises the following steps:

[0130] The transmitting end transmits the transmitting signal to the real target point;

[0131] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0132] The receiving end receives the false echo signal generated by the jammer modulating the initial transmission signal. The false echo signal is obtained by the jammer performing deconvolution processing on the intercepted transmission signal, estimating and determining the parameters of the transmission signal, embedding it into a false target template, and performing filtering processing.

[0133] The jammer first deconvolutes the transmitted signal to obtain the initial transmitted signal, then estimates the jitter amplitude of the initial transmitted signal, modulates it according to the jitter amplitude of the initial transmitted signal to generate an initial false echo signal, and then convolutes the initial false echo signal to obtain a false echo signal.

[0134] 103. Determine a matched filter according to the transmitted signal, and perform matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal.

[0135] After receiving the echo signal, the radar platform matches it using a matched filter. After the true echo signal passes through the range pulse compression filter, the range resolution is improved. The range migration offset is then corrected in the azimuth frequency domain, and finally, the target is imaged through the azimuth pulse compression filter. False echo signals, however, cannot pass through the matched filter.

[0136] Specifically, the radar platform uses a range Doppler algorithm to perform imaging processing, and the matched filter is determined according to the transmitted signal, and the matched filtering processing is performed on the echo signal based on the matched filter to obtain a true echo signal, including the following steps:

[0137] A range filter is determined according to the transmitted signal, and false echo signals in the echo signal are suppressed based on the range filter to obtain a true echo signal.

[0138] Among them, this application designs a matched filter based on the transmitted signal, and designs a pulse compression filter based on the transmitted signal.

[0139]

[0140] Among them, R(T r -τ) is the flip of R(τ).

[0141] According to the matched filter, since the jammer cannot accurately estimate the amplitude jittered signal, the interference signal generated by the jammer modulation is mismatched with the matched filter (9), so the false echo signal is suppressed in the imaging process.

[0142] In some embodiments, the transmitted signal is a windowed signal. After the radar platform receives the signal, compared to the aforementioned solution, deconvolution is required before imaging using the range-Doppler algorithm. The remaining steps are the same as those in the aforementioned solution based on random waveform parameter dithering.

[0143] Specifically, determining a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal includes the following steps:

[0144] determining a range matching filter and a pulse shaping filter according to the transmitted signal;

[0145] Performing deconvolution processing on the echo signal to obtain an original echo signal corresponding to the initial transmission signal;

[0146] The original echo signal is subjected to matched filtering processing based on the range matched filter to obtain a true echo signal.

[0147] Compared to the waveform parameter random dithering technique described above, the jammer needs to perform deconvolution and reconvolution, and the remaining steps are the same as those in equations (4) to (7). Since the deconvolved signal at the receiver is the same as the waveform parameter random dithering technique, the windowed waveform parameter random dithering technique has the same suppression and imaging effects.

[0148] 104. Process the filtered signal according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0149] This application can use the range Doppler algorithm for imaging processing. The range Doppler algorithm is the most intuitive and classic method in SAR imaging processing.

[0150] In some embodiments, the target parameters include distance, speed, angle, and imaging, wherein processing the filtered signal according to a preset algorithm to obtain the imaging corresponding to the real target point includes the following steps:

[0151] performing range pulse compression on the real echo signal based on the range filter to obtain a first filtered signal;

[0152] transforming the first filtered signal along the azimuth direction into the azimuth frequency domain, and performing range migration offset correction on the first filtered signal in the azimuth frequency domain;

[0153] An azimuth filter is determined according to the transmitted signal, and azimuth pulse compression is performed on the first focused signal based on the azimuth filter to obtain a radar image corresponding to the real target point.

[0154] The core concept of the range-Doppler algorithm is that real targets parallel to the radar platform's track share the same Doppler history, manifesting only as different Doppler signal delays in the azimuth time domain and as linear phases with added delays in the azimuth frequency domain (Doppler domain). Therefore, a matched filter can be designed based on the Doppler history of a reference target. Matched filtering is then performed on the signal within the same range bin to obtain the azimuth positions of other targets at the same distance relative to the reference target. To improve computational efficiency, azimuth pulse compression filtering (azimuth pulse compression) can be performed via multiplication in the azimuth frequency domain. Therefore, this method for simultaneously locating real targets at the same distance in the azimuth frequency domain is called the range-Doppler algorithm. Because the range bins between the radar and the target differ at different azimuths, i.e., range migration occurs, range migration correction is required before performing matched filtering in azimuth. Interpolation is then used to obtain the corrected signal, ensuring that the instantaneous range between the radar and the target remains consistent at different azimuths (the target's range bins remain consistent at different azimuths after range pulse compression).

[0155] The range Doppler algorithm obtains high resolution in range and azimuth through pulse compression. Its correlation is completed by converting the signal and reference function into the frequency domain, and range migration correction is performed at the same time.

[0156] The range compression of the Range Doppler algorithm uses a matched filter to filter out false echo signals and compress the true echo signals in the range direction. Due to range migration, the true echo signals at the same point are placed within a single range gate for easy processing. At this point, the phase of the true echo signal is no longer linearly modulated with the range direction, so azimuth compression can only be achieved by performing range bin correction, straightening the echo signal history curve. This range bin correction can be compensated for using sinc interpolation.

[0157] After range migration correction, the signal trajectory along the azimuth direction changes from a curve to a straight line, and azimuth compression becomes a one-dimensional process. Similar to range compression, azimuth compression can be achieved using an azimuth matched filter. After compression, an image of the true target point can be obtained.

[0158] From the above, it can be seen that the transmitting end of the present application generates a transmitting signal based on the waveform parameter random jitter method; the receiving end receives the echo signal returned based on the transmitting signal, and the echo signal includes the real echo signal reflected from the real target point, and the false echo signal generated by the jammer according to the transmitting signal; the matching filter is determined according to the transmitting signal, and the echo signal is matched and filtered based on the matching filter to filter out the false echo signal and retain the real echo signal to obtain a filtered signal; the filtered signal is processed according to the preset algorithm to obtain the target parameters corresponding to the real target point. The present application introduces a variety of random characteristics to the transmitting signal, so that the jammer cannot accurately estimate the key parameters of the signal. Therefore, the false echo signal generated by the jammer based on the intercepted transmitting signal cannot match the matching filter. The false echo signal can be filtered out by the matching filter, thereby effectively suppressing interference and improving the safety of radar detection targets.

[0159] refer to Figure 2b The specific process of the anti-interference radar filtering method according to the embodiment of the present invention may be as follows:

[0160] 201. The radar transmitter generates a transmission signal based on a random dithering method of waveform parameters.

[0161] 202. A radar receiver receives an echo signal returned based on the transmitted signal, where the echo signal includes a true echo signal reflected from a true target point and a false echo signal generated by a jammer based on the transmitted signal.

[0162] 203. The terminal determines a matched filter according to the transmitted signal, and performs matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal.

[0163] 204. The terminal processes the filtered signal according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0164] The terminal is pre-installed with a signal processing program, including a range Doppler algorithm program.

[0165] As can be seen from the above, the transmitting end generates a transmitting signal based on the random jitter method of the waveform parameters; the receiving end receives the echo signal returned based on the transmitting signal, and the echo signal includes the real echo signal reflected from the real target point, and the false echo signal generated by the jammer according to the transmitting signal; the matching filter is determined according to the transmitting signal, and the echo signal is matched and filtered based on the matching filter to filter out the false echo signal and retain the real echo signal to obtain a filtered signal; the filtered signal is processed according to the preset algorithm to obtain the target parameters corresponding to the real target point. The present application introduces a variety of random characteristics to the transmitting signal, so that the jammer cannot accurately estimate the key parameters of the signal. Therefore, the false echo signal generated by the jammer based on the intercepted transmitting signal cannot match the matching filter. The false echo signal can be filtered out by the matching filter, thereby effectively suppressing interference and improving the safety of radar detection targets.

[0166] In some embodiments, the terminal is also integrated with devices for performing waveform performance analysis and point target imaging simulation experiments.

[0167] 1. Waveform performance analysis

[0168] The waveform performance analysis is used to analyze the waveform performance of the transmission signal used in this application and the LFM signal commonly used in the prior art.

[0169] Specifically, the present application analyzes the waveform performance of the transmitted signal through ambiguity functions and cross-ambiguity functions.

[0170] (1) The ambiguity function is a tool used to evaluate the autocorrelation characteristics of radar signals under time delay and Doppler shift. It can intuitively show the correlation of signals under different time delays and Doppler shifts. The ambiguity function can be used to analyze the time domain and frequency domain resolution performance of the radar waveform, that is, how it can distinguish the speed and distance of different targets. It is defined as follows:

[0171]

[0172] Among them, τ is the distance dimension delay, f d is the Doppler frequency.

[0173] Based on (1) and (10), we derive the fuzzy function based on the waveform parameter random dithering method as follows:

[0174]

[0175] Among them, T s is the sampling interval, N is the number of sampling points, a n is the amplitude value of the nth sampling point, which obeys the Gaussian distribution, and

[0176]

[0177] like Figure 4 and Figure 5 First, Figure 4 It shows that the fuzzy function of the LFM waveform has a slope-shaped fuzziness, while the waveform of the transmitted signal based on the random jitter of the waveform parameters and the random jitter of the windowed waveform parameters proposed in this application has a pin-shaped fuzzy function. Figure 5 The results show that due to the larger bandwidth of the waveform parameter random jitter waveform, the waveform parameter random jitter waveform has better delay resolution and lower sidelobe levels. The waveform parameter random jitter waveform has almost the same performance as the LFM waveform in the Doppler dimension. Because the windowed waveform parameter random jitter waveform is windowed based on the waveform parameter random jitter waveform and its bandwidth is close to the bandwidth of the LFM waveform, the transmitted signal waveform of the windowed waveform parameter random jitter has almost the same performance as the LFM waveform in the delay dimension and Doppler dimension. Fourth, the theoretical results of the ambiguity function of the proposed waveform parameter random jitter and windowed waveform parameter random jitter waveforms are consistent with the simulation results.

[0178] From the above, it can be seen that the transmission signal waveform used in this application is suitable for the range Doppler algorithm, and has higher delay resolution, and the experimental results are consistent with the theoretical results.

[0179] (2) The cross-ambiguity function is a tool used to analyze the correlation between two different signals. It is used to evaluate the similarity between different signals under different time delays and Doppler frequency shifts. It is widely used in interference suppression and deceptive jamming detection. The introduction of the cross-ambiguity function can analyze the anti-interference performance of the waveform.

[0180] The cross fuzzy function is defined as follows:

[0181]

[0182] Among them, x J (t) is the interference signal.

[0183] Based on (1) and (13), this application derives the fuzzy function based on the waveform parameter random dithering method as follows:

[0184] When τ ≥ 0 and

[0185]

[0186] when

[0187]

[0188] When τ<0 and

[0189]

[0190] This application uses the cross ambiguity function to compare the anti-interference performance of various waveforms. Figure 6 and 7 As shown in the figure, it can be seen that the waveform parameter random jitter and the windowed waveform parameter random jitter waveform have obvious anti-interference performance compared with the LFM waveform. Figure 6 (b) and (c), the overall suppression performance of the waveform parameter random jitter waveform is slightly better than that of the windowed waveform parameter random jitter waveform. This is because the windowed waveform parameter random jitter waveform is windowed on the basis of the waveform parameter random jitter waveform, and the waveform agility is slightly reduced. Figure 7 It can be seen that the theoretical results and simulation results of the waveform parameter random jitter waveform and the cross ambiguity function are consistent. The same is true for the windowed waveform parameter random jitter waveform.

[0191] From the above, it can be seen that the waveform parameter random dithering and windowed waveform parameter random dithering waveforms used in this application have obvious anti-interference performance compared with the LFM waveform, and the experimental results are consistent with the theoretical results.

[0192] 2. Point target simulation experiment

[0193] In some embodiments, several point target simulation experiments can be constructed to verify the interference suppression performance of the technical solution proposed in this application, where the simulation parameters are shown in the following table.

[0194]

[0195] For point target imaging simulation experiments, a combination of synthetic and real data was used. The data preparation process includes the following steps:

[0196] Radar signal generation: First, a standard radar echo signal is created using the generation unit to simulate the actual echo signal reflected from radar targets in different scenarios. This signal is typically a linear frequency modulated (LFM) signal or other type of modulated signal, and the frequency and time range can be customized based on the actual application requirements.

[0197] Interference signal generation: To verify the effectiveness of the interference suppression algorithm, a jitter interference signal is generated in the simulation experiment. This interference signal is modeled using a Gaussian random process or other jitter characteristics to simulate electromagnetic interference or electronic warfare interference in a real environment.

[0198] Noise data generation: Generate background noise signals based on the radar operating environment. Gaussian white noise models are often used in simulation experiments to simulate the noise background in real environments, further enhancing the authenticity of the simulation results.

[0199] Data Format and Storage: Signal and interference data generated during simulations are saved in standardized formats, such as MAT files (MATLAB), CSV files, or HDF5 files. This standardized data format ensures efficient subsequent algorithm testing, validation, and performance analysis. Data is stored by timestamp or frequency band, facilitating rapid recall and analysis across multiple simulations.

[0200] Introducing Real Radar Datasets: In the later stages of the simulation experiment, a real radar echo signal dataset will be introduced to provide a more realistic evaluation of the jamming algorithm. The real datasets are sourced from public radar signal libraries or radar measurement equipment in specific laboratories. By combining real and simulated data, the feasibility and robustness of the algorithm in practical applications are enhanced.

[0201] In addition to the above data preparation, the point target imaging simulation experiment also requires hardware environment preparation, as follows:

[0202] (1) Server environment

[0203] Linux Server: The simulation environment runs on the Linux operating system, providing a stable computing and resource management platform suitable for the development and testing of complex signal processing algorithms.

[0204] GPU Accelerator: Use NVIDIA GPU graphics cards (such as Tesla V100 and A100) for simulation acceleration. The GPU's parallel computing capabilities enable rapid processing of radar signal amplitude jitter, interference suppression, and large-scale matrix operations and convolution operations required for anti-interference radar filtering simulations.

[0205] (2) Simulation and processing platform

[0206] MATLAB or Python: Used to write simulation scripts and signal processing algorithms. MATLAB's SignalProcessing toolbox or Python's NumPy and SciPy libraries provide efficient signal processing and data analysis capabilities.

[0207] Radar simulation tools: Dedicated radar signal processing and imaging simulation software (such as Simulink, STK, etc.) used for radar system performance evaluation and interference suppression strategy verification.

[0208] In some embodiments, the simulation results were run on MATLAB R2019a and the experimental results of the independent experiments were averaged. Figures 8 to 14 shown.

[0209] Figure 8The figure shows the point target imaging results of the LFM waveform when there is a deceptive jamming signal. There are three false targets at different azimuth angles. Figure 9 This is the suppression result of the random initial phase waveform when the jammer cannot use the current PRI signal. The false target is suppressed to a certain extent, but there are still some residues in the azimuth. When the jammer can use the current PRI signal, Figure 10 It can be seen that the suppression effect of the random initial phase method is invalid. Figure 11 is the suppression result of the orthogonal phase coding method when the jammer cannot use the current PRI signal. Figure 11 (b) It can be seen that the false target can still be seen with the naked eye at azimuths of -10m, 40m, and 90m. When the jammer can use the current PRI signal, Figure 12 It can be seen that the suppression effect of the orthogonal phase encoding method has failed. This is the same conclusion as the random initial phase method, because both the random initial phase waveform and the orthogonal phase encoding method assume that the jammer cannot use the current PRI signal. Once the jammer equipment is advanced enough to use the current PRI signal, the random initial phase waveform and the orthogonal phase encoding waveform will not achieve the suppression effect. Figure 13 and Figure 14 These are the suppression effects of the waveform parameter random jitter waveform and the windowed waveform parameter random jitter waveform proposed in this application. It can be found that regardless of whether the jammer can use the current PRI signal, the false target is completely suppressed.

[0210] The anti-interference radar filtering method proposed in this application breaks the strong assumptions of traditional methods. It uses random jitter of waveform parameters to enable the jammer to only roughly estimate the amplitude and cannot accurately estimate the jitter amplitude and other key parameters of the transmitted signal, thereby improving the interference suppression performance and the security of the radar system.

[0211] 3. Real scene imaging simulation experiment

[0212] In some embodiments, a real scene imaging simulation experiment can also be performed to construct Figure 1 In the real-world scenario shown, the radar platform is mounted on a flying platform. The coordinate origin, O, is the radar platform's projection on the ground at time zero. The X-axis is parallel to the radar's direction of motion, and the Z-axis is perpendicular to the ground. The radar platform is moving at a constant speed V along the positive X-axis at a given height. The radar's direction of motion is the azimuth, and the direction perpendicular to the radar platform's trajectory is the range, or Y-axis. The positions of true and false targets are marked on the planes containing the X and Y axes, respectively.

[0213] Figure 15 The original image, i.e., the real scene without the deceptive interference, is shown. Figure 16This is an imaging scenario using a traditional LFM waveform. Due to the lack of deceptive interference suppression, a false target area appears, that is, the vehicle in the red box is a false target. Figure 17 When the jammer cannot use the current PRI signal, the random initial phase waveform is suppressed. The false target is suppressed to a certain extent, but there are still residual traces on the image. A few outlines of the false target are observed by zooming in. When the jammer can use the current PRI signal, Figure 18 It can be seen that the suppression effect of the random initial phase method fails and false targets appear normally in the image. Figure 19 It shows that when the jammer cannot use the current PRI signal, the orthogonal phase encoding method has a certain suppression effect, but it can be clearly seen that there are still residual false targets. This is because the orthogonality between pulses cannot be perfectly satisfied. Figure 20 It can be seen that the suppression effect of the orthogonal phase encoding method is invalid, which is the same conclusion as the random initial phase method. Figures 21 to 24 These are the suppression effects of the waveform parameter random jitter waveform and the windowed waveform parameter random jitter waveform proposed in this paper. It can be found that regardless of whether the jammer can use the current PRI signal, the false target is completely suppressed.

[0214] It can be seen that the anti-interference radar filtering method proposed in this application breaks the strong assumptions of the traditional method. It uses random jitter of waveform parameters to make the jammer only roughly estimate the amplitude and cannot accurately estimate the jitter amplitude and other key parameters of the transmitted signal, thereby improving the interference suppression performance and improving the security of the radar system.

[0215] This application addresses the common deception jamming issues in current synthetic aperture radar (SAR) systems and the shortcomings of existing time-domain agility technologies. It proposes an interference suppression solution using random waveform parameter jitter. By introducing a strategy to suppress the amplitude jitter jamming feature, the radar system's anti-jamming capability and security are significantly improved when facing deception jamming. Specific benefits include:

[0216] (1) Significantly improve the ability to suppress deceptive interference: This technology can accurately distinguish true and false signals under deceptive interference by analyzing and identifying the characteristics of amplitude jitter in deceptive interference signals, thereby effectively suppressing the impact of interference signals on the system. Compared with traditional anti-interference technologies, this application can more accurately deal with complex situations in deceptive interference, especially in strong interference environments, and can significantly reduce the false detection rate and false judgment rate of the radar system, enhancing the accuracy and stability of signal recognition.

[0217] (2) Improve the security and reliability of radar systems: Amplitude jitter interference suppression technology greatly improves the system's anti-interference performance and increases the difficulty of detecting deceptive interference signals, making radar systems safer in high-security application scenarios such as military and national defense. This application can effectively respond to enemy deceptive interference, ensure the robustness of the system in complex electromagnetic environments, and provide higher security for national defense communications and radar detection missions.

[0218] (3) Improve system real-time performance and response speed: By effectively extracting and rapidly detecting amplitude jitter features, this application reduces algorithm complexity while ensuring interference suppression effectiveness and improves the system's real-time response capability. Compared with other complex anti-interference technologies, amplitude jitter interference suppression technology reduces signal processing delays and can maintain real-time processing capabilities in harsh interference environments, effectively improving the system's response speed and ensuring the system's rapid response in complex battlefield environments.

[0219] (4) Reduce system hardware complexity and cost: This application mainly relies on feature extraction and algorithm optimization of amplitude jitter, reducing the reliance on complex hardware equipment. By improving the interference suppression effect through software algorithms, the overall hardware cost of the system is reduced, and the hardware architecture design of the radar system is simplified. This application brings convenience to the subsequent maintenance and upgrade of the system and lays the foundation for its wide application in radar systems of different scales.

[0220] Promoting the Development of Military Communications and Radar Detection Applications: This technical solution is highly practical and particularly suitable for military and defense applications with demanding communications and radar detection requirements. By effectively suppressing amplitude jitter interference, it provides military radars with more stable and reliable target detection and interference identification capabilities, enhancing system communication confidentiality and data transmission security, meeting the demands for efficient operations in complex battlefield environments.

[0221] In order to better implement the above method, an embodiment of the present invention can also provide an anti-interference radar filtering device, which can be specifically integrated into a radar platform. The radar platform may include a radar transmitter, a radar receiver, a radar servo device, a frequency synthesizer and a timer, as well as a terminal integrated with a signal analysis and processing program, etc. The terminal may include: a mobile phone, a tablet computer, a laptop computer, a personal computer (PC), a wearable device such as a smart watch, and other smart devices.

[0222] For example, Figure 2c As shown, the anti-interference radar filtering device may include a generating unit 301, a receiving unit 302, a filtering unit 303 and a signal processing unit 304, as follows:

[0223] (1) A generating unit 301 is used at the transmitting end to generate a transmitting signal based on a waveform parameter random jitter method.

[0224] In some embodiments, the generating unit 301 may be specifically configured to:

[0225] The transmitting end generates an initial signal according to a pulse shaping filter;

[0226] According to random jitter of waveform parameters, the amplitude, phase, frequency, and front and back coding of the initial signal are adjusted to obtain an initial transmission signal;

[0227] The initial transmission signal is subjected to window filtering by a pulse shaping filter to obtain a transmission signal with limited bandwidth.

[0228] (2) A receiving unit 302, configured to receive an echo signal returned based on the transmitted signal, wherein the echo signal includes a true echo signal reflected from a true target point and a false echo signal generated by a jammer based on the transmitted signal.

[0229] The receiving unit 302 is used for frequency conversion processing and sampling output, and can receive the echo signal returned based on the transmission signal, perform sampling processing on the echo signal, and output the echo signal to the filtering unit.

[0230] The echo signal includes a true echo signal and a false echo signal. In some embodiments, the receiving unit 302 may be specifically configured to:

[0231] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0232] The receiving end receives a false echo signal generated by modulating the intercepted transmission signal by the jammer. The false echo signal is obtained by modulating the parameters of the transmission signal estimated and determined by the jammer into a false target template. The false target template is a template of the distance, speed, angle and imaging corresponding to the false target point.

[0233] In some embodiments, the receiving unit 302 may further be configured to:

[0234] The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal;

[0235] The receiving end receives the false echo signal generated by the jammer modulating the initial transmission signal. The false echo signal is obtained by the jammer performing deconvolution processing on the intercepted transmission signal, estimating and determining the parameters of the transmission signal, embedding it into a false target template, and performing filtering processing.

[0236] (3) A filtering unit 303 is configured to determine a matched filter according to the transmitted signal, and perform matched filtering on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal.

[0237] In some embodiments, the filtering unit 303 may be specifically configured to:

[0238] A matched filter is determined according to the transmission signal, and matched filtering is performed on the echo signal output by the receiving unit 302 based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal.

[0239] (4) A signal processing unit 304 is used to process the filtered signal according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0240] In some embodiments, the target parameters include distance, speed, angle, and imaging. Processing the filtered signal according to a preset algorithm to obtain the imaging corresponding to the real target point may include:

[0241] performing range pulse compression on the real echo signal based on the range filter to obtain a first filtered signal;

[0242] transforming the first filtered signal along the azimuth direction into the azimuth frequency domain, and performing range migration offset correction on the first filtered signal in the azimuth frequency domain;

[0243] An azimuth filter is determined according to the transmitted signal, and azimuth pulse compression is performed on the first focused signal based on the azimuth filter to obtain a radar image corresponding to the real target point.

[0244] As can be seen from the above, the present application can generate a transmission signal based on a waveform parameter random jitter method through a generating unit 301; a receiving unit 302 for receiving an echo signal returned based on the transmission signal, wherein the echo signal includes a real echo signal reflected from a real target point, and a false echo signal generated by a jammer based on the transmission signal; a filtering unit 303 for determining a matching filter based on the transmission signal, and performing matching filtering on the echo signal based on the matching filter, filtering out false echo signals and retaining real echo signals to obtain a filtered signal; a signal processing unit 304 for processing the filtered signal according to a preset algorithm to obtain target parameters corresponding to the real target point. The present application introduces a variety of random characteristics into the transmission signal, so that the jammer cannot accurately estimate the key parameters of the signal. Therefore, the false echo signal generated by the jammer based on the intercepted transmission signal cannot match the matching filter, and the false echo signal can be filtered out by the matching filter, thereby effectively suppressing interference and improving the safety of radar detection targets.

[0245] An embodiment of the present invention further provides a radar platform, including a radar transmitter, a radar receiver, and a terminal integrated with an anti-interference radar filtering device. The terminal of the radar platform can integrate any anti-interference radar filtering device provided by the embodiment of the present invention.

[0246] For example, Figure 3 FIG. 1 is a schematic diagram showing the structure of a terminal device according to an embodiment of the present invention, specifically:

[0247] The terminal device may include one or more processing core processors 401, one or more storage media memories 402, a power supply 403, an input unit 404 and other components. Those skilled in the art will understand that Figure 4 The terminal structure shown in the figure does not constitute a limitation on the terminal device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0248] Processor 401 is the control center of the terminal device. It connects all components of the terminal device using various interfaces and circuits. By running or executing software programs and / or modules stored in memory 402 and accessing data stored in memory 402, it performs various terminal functions and processes data, thereby providing overall terminal monitoring. Optionally, processor 401 may include one or more processing cores. Preferably, processor 401 may integrate an application processor and a modem processor. The application processor primarily handles the operating system, user interface, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into processor 401.

[0249] The memory 402 can be used to store software programs and modules. The processor 401 executes various functional applications and data processing by running the software programs and modules stored in the memory 402. The memory 402 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 402 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage device. Accordingly, the memory 402 may also include a memory controller to provide the processor 401 with access to the memory 402.

[0250] The terminal device also includes a power supply 403 for supplying power to various components. Preferably, the power supply 403 can be logically connected to the processor 401 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 403 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0251] The terminal device may further include an input unit 404, which may be used to receive input digital or character information and generate keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0252] Although not shown, the terminal device may further include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 401 in the terminal will load the executable files corresponding to the processes of one or more application programs into the memory 402 according to the following instructions, and the processor 401 will run the application programs stored in the memory 402 to implement various functions as follows:

[0253] The transmitter generates a transmission signal based on the random dithering method of waveform parameters;

[0254] The receiving end receives an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal obtained by reflection from a true target point and a false echo signal generated by a jammer according to the transmission signal;

[0255] Determining a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal;

[0256] The filtered signal is processed according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0257] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0258] As can be seen from the above, this embodiment can generate a transmission signal based on the random jitter method of waveform parameters by the transmitting end; the receiving end receives the echo signal returned based on the transmission signal, and the echo signal includes the real echo signal reflected from the real target point, and the false echo signal generated by the jammer according to the transmission signal; the matching filter is determined according to the transmission signal, and the echo signal is matched and filtered based on the matching filter to filter out the false echo signal and retain the real echo signal to obtain a filtered signal; the filtered signal is processed according to the preset algorithm to obtain the target parameters corresponding to the real target point. This application introduces a variety of random characteristics to the transmission signal, so that the jammer cannot accurately estimate the key parameters of the signal. Therefore, the false echo signal generated by the jammer based on the intercepted transmission signal cannot match the matched filter. The false echo signal can be filtered out by the matched filter, thereby effectively suppressing interference and improving the safety of radar detection targets. This application adds random jitter to the waveform parameters of the transmitted signal, making it impossible for the jammer to determine the true jitter amplitude and other key parameters of the transmitted signal. Therefore, the false echo signal obtained by the jammer based on the modulation of the intercepted transmitted signal cannot be matched with the matched filter. In this way, this application can filter out the false echo signal through the matched filter, thereby effectively suppressing interference and improving the security of the radar system.

[0259] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0260] To this end, an embodiment of the present invention provides a storage medium disposed in a radar device, which stores a plurality of instructions. The instructions can be loaded by a processor to cause the radar device to execute the steps of any of the anti-interference radar filtering methods provided in the embodiments of the present invention. For example, the instructions can execute the following steps:

[0261] The transmitter generates a transmission signal based on the random dithering method of waveform parameters;

[0262] The receiving end receives an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal obtained by reflection from a true target point and a false echo signal generated by a jammer according to the transmission signal;

[0263] Determining a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal;

[0264] The filtered signal is processed according to a preset algorithm to obtain target parameters corresponding to the real target point.

[0265] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0266] The storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. The instructions stored in the storage medium can execute the steps of any of the anti-interference radar filtering methods provided in the embodiments of the present invention. Therefore, the beneficial effects achievable by any of the anti-interference radar filtering methods provided in the embodiments of the present invention can be achieved. See the previous embodiments for details and will not be repeated here.

[0267] The above describes in detail an anti-interference radar filtering method and related equipment provided by an embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will appreciate that, based on the concepts of the present invention, there may be changes in the specific implementation methods and scope of application. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An anti-interference radar filtering method, characterized in that: include: The transmitter generates a transmission signal based on the random dithering method of waveform parameters; The receiving end receives an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal obtained by reflection from a true target point and a false echo signal generated by a jammer according to the transmission signal; Determining a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal; The filtered signal is processed according to a preset algorithm to obtain target parameters corresponding to the real target point.

2. The anti-interference radar filtering method according to claim 1, wherein: The determining of a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal, includes: A range filter is determined according to the transmitted signal, and false echo signals in the echo signal are suppressed based on the range filter, while true echo signals are retained to obtain a filtered signal.

3. The anti-interference radar filtering method according to claim 2, wherein: The target parameters include distance, speed, angle and imaging, wherein the filtered signal is processed according to a preset algorithm to obtain the imaging corresponding to the real target point, including: performing range pulse compression on the real echo signal based on the range filter to obtain a first filtered signal; transforming the first filtered signal along the azimuth direction into the azimuth frequency domain, and performing range migration offset correction on the first filtered signal in the azimuth frequency domain; An azimuth filter is determined according to the transmitted signal, and azimuth pulse compression is performed on the first focused signal based on the azimuth filter to obtain a radar image corresponding to the real target point.

4. The anti-interference radar filtering method according to claim 1, wherein: The receiving an echo signal returned based on the transmitted signal includes: The transmitting end transmits the transmitting signal to the real target point; The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal; The receiving end receives a false echo signal generated by modulating the intercepted transmission signal by the jammer. The false echo signal is obtained by modulating the parameters of the transmission signal estimated and determined by the jammer into a false target template. The false target template is a template of the distance, speed, angle and imaging corresponding to the false target point.

5. The anti-interference radar filtering method according to claim 1, wherein: The transmitter generates a transmission signal based on the waveform parameter random jitter method, including: The transmitting end adjusts parameters such as amplitude, phase, and frequency by forward and backward coding based on a random dithering method of waveform parameters to generate an initial transmitting signal; The initial transmission signal is subjected to window filtering by a pulse shaping filter to obtain a transmission signal with limited bandwidth.

6. The anti-interference radar filtering method according to claim 5, characterized in that: The determining of a matched filter according to the transmitted signal, and performing matched filtering processing on the echo signal based on the matched filter to filter out false echo signals and retain true echo signals to obtain a filtered signal, includes: determining a range matching filter and a pulse shaping filter according to the transmitted signal; Performing deconvolution processing on the echo signal to obtain an original echo signal corresponding to the initial transmission signal; The original echo signal is subjected to matched filtering processing based on the range matched filter to obtain a true echo signal.

7. The anti-interference radar filtering method according to claim 6, characterized in that: The receiving an echo signal returned based on the transmitted signal includes: The transmitting end transmits the transmitting signal to the real target point; The receiving end receives a real echo signal of the real target point obtained based on the reflection of the transmitted signal; The receiving end receives the false echo signal generated by the jammer modulating the initial transmission signal. The false echo signal is obtained by the jammer performing deconvolution processing on the intercepted transmission signal, estimating and determining the parameters of the transmission signal, embedding it into a false target template, and performing filtering processing.

8. An anti-interference radar filter device, characterized in that: include: A generating unit, configured to generate a transmission signal based on a waveform parameter random jitter method; a receiving unit, configured to receive an echo signal returned based on the transmission signal, wherein the echo signal includes a true echo signal reflected from a true target point and a false echo signal generated by a jammer based on the transmission signal; a filtering unit, configured to determine a matched filter according to the transmitted signal, and perform matched filtering processing on the echo signal based on the matched filter, thereby filtering out false echo signals and retaining true echo signals to obtain a filtered signal; The signal processing unit is used to process the filtered signal according to a preset algorithm to obtain the target parameters corresponding to the real target point.

9. A terminal device, characterized in that: The system comprises a memory and a processor; the memory stores an application program, and the processor is configured to run the application program in the memory to execute the radar filtering method according to any one of claims 1 to 7.

10. A radar filtering system, comprising the anti-interference radar filtering device according to claim 8, wherein the anti-interference radar filtering device is integrated into the terminal device according to claim 9 to execute the radar filtering method according to any one of claims 1 to 7.

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