Main lobe intermittent sampling and forwarding interference suppression method and system based on high-dimensional feature correlation filtering

Abstract

The invention discloses a main lobe intermittent sampling and forwarding interference suppression method and system based on high-dimensional feature correlation filtering, and the method comprises the steps: carrying out the super-resolution processing of a monopulse echo signal in a time-frequency domain, and extracting a high-dimensional time-frequency feature spectrum; performing time-frequency correlation analysis on the high-dimensional time-frequency characteristic spectrum to identify correlation characteristics between a target signal and an interference signal; designing an FIR band-pass filter based on high-dimensional characteristics by adopting a Parks-McClellan algorithm, filtering a time-frequency domain of an original signal, and filtering out-of-band noise and interference; and performing inverse short-time Fourier transform on the filtered time-frequency domain signal, and reconstructing a target signal, thereby realizing effective suppression of main lobe intermittent sampling forwarding interference. Experiments verify that the method can significantly improve the signal to interference ratio, has good anti-interference performance in a complex electromagnetic environment, can realize real-time processing, and provides reliable technical support for radar target detection.

Description

Technical Field

[0001] The present invention relates to the technical field of radar anti-intermittent sampling and repeater jamming, and particularly to a method and system for suppressing main lobe intermittent sampling and repeater jamming based on high-dimensional feature correlation filtering. Background Art

[0002] Currently, radar systems generally use linear frequency modulation signals as transmitted signals and utilize pulse compression technology to achieve high-resolution target detection. However, such radars are vulnerable to interference in complex electromagnetic environments. In recent years, the interfering party has intercepted the radar transmitted signal through a digital radio frequency memory, and through high-speed sampling and slicing processing, the sampled signal is modulated, amplified, and then forwarded, thus generating intermittent sampling and repeater jamming. This interference method combines suppression and deception. It shows a dense short-time narrow pulse impact effect in the time domain and is prone to false alarms in CFAR detection after pulse compression, seriously interfering with the target detection and tracking of the radar.

[0003] Especially when the interference signal is directly facing the main lobe of the radar receiver, traditional side lobe anti-jamming techniques often fail to work, resulting in a significant decline in radar performance and an inability to accurately identify the target position. Therefore, aiming at the problem of suppressing main lobe intermittent sampling and repeater jamming, it is urgent to develop new anti-jamming methods. In recent years, by means of time-frequency analysis, super-resolution technology, and high-dimensional feature correlation filtering, processing radar echo signals has become an effective way to improve anti-jamming capabilities. By performing super-resolution processing on the echo signal in the time-frequency domain, extracting high-dimensional time-frequency features, and then combining with the design of an advanced FIR band-pass filter, the interference signal can be effectively separated and suppressed while retaining the target signal information, thereby achieving effective suppression of main lobe intermittent sampling and repeater jamming. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method and system for suppressing main lobe intermittent sampling and repeater jamming based on high-dimensional feature correlation filtering. By comprehensively using high-dimensional feature time-frequency correlation filtering technology, it realizes the efficient suppression of main lobe intermittent sampling and repeater jamming in complex electromagnetic environments, and significantly improves the signal-to-interference ratio and target detection ability of the radar system.

[0005] In order to achieve the above invention objectives, the technical solutions adopted by the present invention are as follows:

[0006] A method for suppressing main lobe intermittent sampling and repeater jamming based on high-dimensional feature correlation filtering includes the following steps:

[0007] S1, perform super-resolution processing on the monopulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum;

[0008] S2, perform high-dimensional time-frequency correlation on the high-dimensional time-frequency feature spectrum;

[0009] S3, the Parks-McClellan algorithm is used to design a FIR bandpass filter based on high-dimensional features to filter the original signal in the time-frequency domain;

[0010] S4, performing an inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, thereby suppressing the main lobe intermittent sampling forwarding interference.

[0011] Furthermore, in step S1, the radar transmission signal is a linear frequency modulation signal with a large time width, and its expression is:

[0012]

[0013] Among them, t represents the time variable, t represents the pulse width, represents a rectangular pulse function with a width of t, f represents the carrier frequency, K represents the frequency modulation slope, and exp[j2π(·)] represents the complex exponential function.

[0014] Using the jammer’s sampling interval T J The transmission signal and the target echo signal are segmented by the sampling pulse width τ to form an intermittent sampling signal and a corresponding sliced ​​interference signal.

[0015] Furthermore, in step S1, a frequency domain MUSIC estimation method is used to perform super-resolution processing on the single pulse echo signal, and the steps include:

[0016] S11, constructing a covariance matrix for the echo signal and performing eigendecomposition to obtain all eigenvalues ​​and eigenvectors;

[0017] S12, separate the signal subspace and the noise subspace;

[0018] S13, utilizing the principle that the input vector is orthogonal to the noise subspace, by scanning the frequency variable f in each frame of the time-frequency diagram, a high-dimensional time-frequency characteristic spectrum is obtained.

[0019] Furthermore, in step S2, by adopting a logic method based on multiple hypotheses, using prediction and correlation gates to perform time-frequency correlation on the high-dimensional time-frequency spectrum after super-resolution, the steps include:

[0020] S21, defining the components of the measured values ​​at each moment and the distance vectors between them;

[0021] S22, according to the normalized distance square (subject to the chi-square with p degrees of freedom 2 The distribution) is compared with the preset threshold γ to determine the correlation between adjacent scanning moments.

[0022] Furthermore, in step S3, the FIR bandpass filter is designed using the Parks-McClellan algorithm.

[0023] And the time-frequency domain of the original signal is retained within the band and attenuated outside the band by using the FIR band-pass filter.

[0024] Furthermore, the design parameters of the FIR band-pass filter include: the filter bandwidth is 0.4 MHz; the filter slope matches the frequency modulation slope of the transmitted signal; the filter order is 256.

[0025] Furthermore, in step S4, after the filtered time-frequency domain undergoes inverse short-time Fourier transform, the reconstructed target signal is further subjected to pulse compression processing, and the interference suppression effect is verified by comparing the signal-to-interference ratio of the target signal and the interference signal before and after interference suppression.

[0026] Furthermore, the interference signal is a slice-and-forward interference, and its formation process includes:

[0027] 1) The radar transmitted signal S0(t) is sampled by a rectangular pulse to obtain the sampled signal J1(t) = S0(t)P(t);

[0028] 2) The jammer multiplies the sampled signal by the noise signal n(t) to obtain the slice interference J(t) = J1(t)n(t);

[0029] 3) After amplification, the interference signal overlaps with the target echo signal in the time domain to form the received signal S r (t) = A·J(t - τ) + S t (t);

[0030] where, represents the convolution operation of signals, δ(.) represents the impulse function, is a rectangular pulse function with width τ, n(t) represents the noise signal, A represents the amplification factor of the interference signal, and S t (t) represents the target echo signal.

[0031] The present invention also discloses a main lobe intermittent sampling and forwarding interference suppression system, which can be used to implement the above-mentioned main lobe intermittent sampling and forwarding interference suppression method. Specifically, it includes:

[0032] A time-frequency super-resolution processing module: used to perform super-resolution processing on the monopulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum;

[0033] A time-frequency correlation module: used to perform high-dimensional time-frequency correlation on the high-dimensional time-frequency feature spectrum;

[0034] FIR Filter Design and Filtering Module: It is used to design a FIR band-pass filter based on high-dimensional features by using the Parks-McClellan algorithm and filter the time-frequency domain of the original signal;

[0035] Target Signal Reconstruction Module: It is used to perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, so as to realize the suppression of main lobe intermittent sampling and repeater jamming; and

[0036] Display and Interaction Module: It is used to display the processing results and provide a user interaction interface to realize the input of operation instructions and the output of feedback information.

[0037] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the above-mentioned method for suppressing main lobe intermittent sampling and repeater jamming is realized.

[0038] The present invention also discloses a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for suppressing main lobe intermittent sampling and repeater jamming is realized.

[0039] Compared with the prior art, the advantages of the present invention are as follows:

[0040] 1. By using high-dimensional time-frequency super-resolution processing technology, the high-dimensional time-frequency features of the echo signal are extracted, and through time-frequency correlation analysis, the target signal and the interference signal can be effectively distinguished. After filtering and reconstruction, the signal-to-interference ratio of the monopulse echo can be significantly improved (for example, increased by about 17.4 dB), thereby improving the accuracy and reliability of radar target detection.

[0041] 2. An FIR band-pass filter designed based on the Parks-McClellan algorithm is used to accurately filter the original signal in the time-frequency domain. It can not only retain the effective information of the target signal, but also effectively suppress out-of-band interference and noise, ensuring stable anti-jamming in a complex electromagnetic environment.

[0042] 3. Through super-resolution processing and high-dimensional time-frequency correlation analysis of the monopulse echo signal, the present invention can more accurately identify the difference between the interference signal and the target signal, providing a more reliable basis for subsequent filtering and signal reconstruction.

[0043] 4. The present invention realizes the efficient processing and reconstruction of signals, has good real-time performance, and provides strong technical support for the application of radar systems in actual combat environments. Description of the Drawings

[0044] Figure 1 It is a flowchart of the method for suppressing main lobe intermittent sampling and repeater jamming according to the embodiment of the present invention;

[0045] Figure 2 This is the monopulse time-domain diagram of the main-lobe intermittent sampling and forwarding jamming in the embodiment of the present invention;

[0046] Figure 3 This is the monopulse time-frequency diagram of the main-lobe intermittent sampling and forwarding jamming in the embodiment of the present invention;

[0047] Figure 4 This is the monopulse high-dimensional time-frequency feature spectrogram of the main-lobe intermittent sampling and forwarding jamming in the embodiment of the present invention;

[0048] Figure 5 This is the monopulse high-dimensional time-frequency feature correlation spectrogram of the main-lobe intermittent sampling and forwarding jamming in the embodiment of the present invention;

[0049] Figure 6 This is the phase-frequency characteristic diagram of the FIR filter in the embodiment of the present invention;

[0050] Figure 7 This is the time-frequency diagram after FIR processing in the embodiment of the present invention;

[0051] Figure 8 This is the comparison diagram of the time-domain echo before and after interference suppression in the embodiment of the present invention;

[0052] Figure 9 This is the comparison diagram of the pulse compression results before and after interference suppression in the embodiment of the present invention. Detailed implementation manners

[0053] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention with reference to the accompanying drawings and by way of examples.

[0054] As Figure 1 shown, the present invention provides a method for suppressing main-lobe intermittent sampling and forwarding jamming based on high-dimensional feature correlation filtering, including:

[0055] Step 1: Perform time-frequency domain super-resolution processing on the monopulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum with higher spectral resolution than the short-time Fourier transform spectrum.

[0056] Step 1 specifically includes:

[0057] Assume that the transmitted signal of the radar is a large time-bandwidth linear frequency modulation signal,

[0058]

[0059] And assume that there is a target and a jammer in space at the same distance from the radar. Only considering the waveform, the target echo S t (t) formed by the target reflecting the radar transmitted signal can be expressed as:

[0060] S t (t) = S0(t)

[0061] Let the sampling interval (period) of the jammer be T J , the sampling pulse width be τ, and the sampling repetition frequency f J be the reciprocal of T J Using the jammer sampling interval T J and the jammer sampling time width τ to segment the transmitted signal and the target echo signal

[0062] After receiving the transmitted signal of the radar, the jammer will perform intermittent sampling processing, multiply the sampled signal by noise to form a sliced interference of the noise product. Assuming the noise signal is n(t), the intermittent sampling pulse train of the jammer is:

[0063]

[0064] where represents the convolution operation of signals, and δ(g) represents the impulse function. Then the sampled signal (intermittent sampling signal) can be obtained as:

[0065] J1(t) = S0(t)P(t)

[0066] Then the sliced interference J(t) generated by the jammer can be expressed as:

[0067] J(t) = J1(t)n(t)

[0068] The formed sliced interference is amplified and immediately forwarded, covering the target echo signal in the time domain. The echo signal S r (t) can be expressed as:

[0069] S r (t) = A·J(t - τ) + S t (t)

[0070] First, use an equally spaced rectangular pulse train to sample the radar signal S t (t) at equal intervals to obtain the interference sample signal J1(t), which is the chopping stage here; then through several times of replication and filling processing, make the interference sample signal completely fill the adjacent empty time slots on the right and generate the interference signal J(t), which is the interleaving stage here. Through replication, the expression of the sliced combined interference can be obtained as:

[0071]

[0072] where is the number of replications

[0073] In the simulation experiment, a linear frequency modulation signal with a center frequency of 5 GHz is selected as the radar transmission signal. The signal time width is 100 microseconds, and each intermittent sampling interference period is 4.5 microseconds. The time domain of the echo signal is as shown in Figure 2 shown; perform a short-time Fourier transform on the original echo monopulse signal to obtain a time-frequency diagram as shown in Figure 3 shown.

[0074] In this embodiment, step one further includes:

[0075] Adopt an estimation method based on frequency-domain MUSIC to perform time-frequency domain super-resolution processing on the echo signal of the monopulse:

[0076] Separate the signal from the noise through eigenvalue decomposition. Find all the eigenvalues and eigenvectors of matrix R, which can be expressed as:

[0077]

[0078] Obtain the signal subspace and the noise subspace, which are respectively:

[0079]

[0080] Assume the input vector is:

[0081] s = [1e -j2πf L e -j2π(N-1)f

[0082] The vector is orthogonal to the noise subspace. Since s is a function of f, the function of the variable frequency f is:

[0083]

[0084] If the value of f is equal to the input signal frequency, because s is orthogonal to V n orthogonal, therefore, when the denominator is 0, the output peak represents the input frequency in the signal. Scan the frequency dimension of the time-frequency diagram frame by frame. After performing MUSIC for all times, finally obtain a high-dimensional time-frequency feature spectrum with a higher spectral resolution than the short-time Fourier transform spectrum, as shown in Figure 4 shown.

[0085] Step two: Perform high-dimensional time-frequency correlation on the super-resolved high-dimensional time-frequency spectrum;

[0086] Step two specifically includes:

[0087] Perform high-dimensional time-frequency correlation on the super-resolved high-dimensional time-frequency spectrum: Adopt a logical method to identify possible associated track points through prediction and correlation gates in a multiple hypothesis manner.

[0088] Let ​is the l-th component of the measurement i at time k, where l = 1, ..., p, i = 1, ..., m k 。The distance vector d i (k) between the observations z j (k) and z ij (k + 1) can be defined as follows:

[0089]

[0090] where t is the time interval between two scans. If it is assumed that the observation error is independent, zero-mean, and Gaussian distributed, with the covariance matrix being R i (k), then the normalized squared distance is:

[0091] D ij (k) @ d i ' j [R i (k) + R j (k + 1)] -1 d ij

[0092] where D ij (k) is a random variable following a chi-square 2 distribution with p degrees of freedom. By looking up the chi-square 2 distribution table with the given threshold probability for p degrees of freedom, the threshold γ can be obtained. If D ij (k) ≤ γ, then it can be determined that z i (k) and z j (k + 1) are interconnected on both sides.

[0093] According to the association result, high-dimensional time-frequency association is realized on the high-dimensional spectrum, and the result is as Figure 5 shown, where the longest association segment represents the target, and the discrete shorter association segments represent the respective forwarding periods of the intermittent sampling and forwarding interference.

[0094] Step 3: Design an FIR band-pass filter under high-dimensional features by using the Parks-McClellan algorithm to filter the time-frequency domain of the original signal.

[0095] Step 3 specifically includes:

[0096] First, design an FIR band-pass filter under high-dimensional features by using the Parks-McClellan algorithm. Since the impulse response of the ideal filter is non-causal and infinite in length, the window function method is used. Starting from the time domain, a causal and finite-length impulse response is used to approximate the non-causal and infinite-length ideal filter, and filter design is carried out through convolution in the frequency domain, and lower side lobes are designed to achieve characteristics close to the impulse function for efficient filtering. The phase-frequency characteristic of the designed FIR filter is as Figure 6As shown in the figure. Among them, the core parameters of the designed filter are as follows: 1) Filter width: 0.4 MHz; 2) Filter slope: the frequency modulation slope of the transmitted signal; 3) Filter order: 256th order.

[0097] Then, through the designed band-pass filter, the time-frequency domain of the original signal is filtered to obtain the filtered time-frequency domain, as Figure 7 shown. It can be seen that the longest correlation segment mentioned in step two is completely retained, and the remaining intermittent interference segments are filtered out of the band by the filter. In addition to the interference being filtered out, the noise outside the target area is also successfully filtered out.

[0098] Step 4: Perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal and complete interference suppression.

[0099] Step 4 specifically includes:

[0100] First, perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, and obtain the time-domain echo signal as Figure 8 shown. From the time-domain signal after anti-interference, it can be seen that most of the interference has been suppressed, and compared with the target signal in the original echo, its energy loss is very small.

[0101] Secondly, perform pulse compression on the reconstructed signal again. After interference suppression, most of the false spikes caused by interference have disappeared, and the noise floor has also been reduced, and the signal-to-interference ratio of the overall echo has been significantly improved.

[0102] Finally, evaluate the signal-to-interference ratio before and after interference suppression. Calculate the ratio of the position of the target to the position of the maximum value in the interference area as the signal-to-interference ratio, and calculate the difference in the signal-to-interference ratio before and after interference suppression. By comparing the pulse compression results before and after interference suppression, the experimental results are as Figure 9 shown. After interference suppression, the signal-to-interference ratio of the single-pulse echo can be increased by 17.4 dB, and the main-lobe intermittent sampling and forwarding interference suppression can be successfully achieved.

[0103] In another embodiment of the present invention, a main-lobe intermittent sampling and forwarding interference suppression system is provided. This system can be used to implement the above-mentioned main-lobe intermittent sampling and forwarding interference suppression method. Specifically, it includes:

[0104] Time-frequency super-resolution processing module: used to perform super-resolution processing on the single-pulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum;

[0105] Time-frequency correlation module: used to perform high-dimensional time-frequency correlation on the high-dimensional time-frequency feature spectrum;

[0106] FIR Filter Design and Filtering Module: It is used to design a FIR band-pass filter based on high-dimensional features by using the Parks-McClellan algorithm and filter the time-frequency domain of the original signal;

[0107] Target Signal Reconstruction Module: It is used to perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, so as to realize the suppression of main lobe intermittent sampling and forwarding interference; and

[0108] Display and Interaction Module: It is used to display the processing results and provide a user interaction interface to realize the input of operation instructions and the output of feedback information.

[0109] In another embodiment of the present invention, a terminal device is provided. The terminal device includes a processor and a memory. The memory is used to store a computer program. The computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the main lobe intermittent sampling and forwarding interference suppression method.

[0110] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in the terminal device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and, of course, the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, and this storage space stores the operating system of the terminal. And, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory.

[0111] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the main lobe intermittent sampling and forwarding interference suppression method in the above embodiments; the one or more instructions in the computer-readable storage medium are loaded and executed by the processor.

[0112] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program code.

[0113] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0114] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0116] Those of ordinary skill in the art will realize that the embodiments described herein are to assist the reader in understanding the implementation methods of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not depart from the essence of the present invention based on these technical revelations disclosed in the present invention, and these deformations and combinations are still within the scope of protection of the present invention.

Claims

1. A method for suppressing main lobe intermittent sampling and repeater jamming based on high-dimensional feature correlation filtering, characterized in that It includes the following steps: S1. Perform super-resolution processing on the single-pulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum; S2. Perform high-dimensional time-frequency correlation on the high-dimensional time-frequency feature spectrum; S3. Design a FIR band-pass filter based on high-dimensional features using the Parks-McClellan algorithm to filter the time-frequency domain of the original signal; S4. Perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, realizing the suppression of main-lobe intermittent sampling and forwarding interference.

2. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: In step S1, the radar transmitting signal is a linear frequency modulation signal with a large time width, and its expression is: where t represents the time variable, T represents the pulse width, represents a rectangular pulse function with a width of T, f represents the carrier frequency, K represents the frequency modulation slope, and exp[j2π(·)] represents the complex exponential function; Using the sampling interval T of the jammer J and the sampling pulse width τ to slice the transmitted signal and the target echo signal, forming an intermittent sampling signal and the corresponding sliced interference signal.

3. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: In step S1, a super-resolution processing is performed on the single-pulse echo signal using a frequency-domain MUSIC estimation method. The steps include: S11. Construct a covariance matrix for the echo signal and perform eigenvalue decomposition to obtain all eigenvalues and eigenvectors; S12. Separate the signal subspace and the noise subspace; S13. Utilize the principle that the input vector is orthogonal to the noise subspace, and by scanning the frequency variable f in each frame of the time-frequency diagram, obtain the high-dimensional time-frequency feature spectrum.

4. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: In step S2, by adopting a logic method based on multiple hypotheses, use prediction and correlation gates to perform time-frequency correlation on the high-dimensional time-frequency spectrum after super-resolution. The steps include: S21. Define the components of the measurement values at each moment and the distance vectors therebetween; S22. Compare the normalized squared distance with a preset threshold γ to determine the correlation relationship between adjacent scanning moments.

5. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: In step S3, use the Parks-McClellan algorithm to design a FIR band-pass filter, and use the FIR band-pass filter to retain the in-band part and attenuate the out-of-band part of the time-frequency domain of the original signal.

6. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 5, wherein: The design parameters of the FIR band-pass filter include: the filter bandwidth is 0.4 MHz; the filter slope matches the frequency modulation slope of the transmitting signal; the filter order is 256.

7. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: In step S4, after the filtered time-frequency domain undergoes inverse short-time Fourier transform, the reconstructed target signal is further subjected to pulse compression processing, and by comparing the signal-to-interference ratio of the target signal and the interference signal before and after interference suppression, verify the interference suppression effect.

8. The method for suppressing main-lobe intermittent sampling and forwarding interference according to claim 1, wherein: The interference signal is a slice and forward interference, and its formation process includes: 1) The radar transmit signal S0(t) is sampled by a rectangular pulse to obtain the sampled signal J1(t) = S0(t)P(t); 2) The jammer multiplies the sampling signal with the noise signal n(t) to obtain a slice interference J(t) = J1(t)n(t); 3) After amplification, the interference signal overlaps with the target echo signal in the time domain to form a received signal S r (t) = A·J(t - τ) + S t (t); Among them, represents the convolution operation of signals, δ(.) represents the impulse function, is a rectangular pulse function with a width of τ, n(t) represents the noise signal, A represents the amplification factor of the interference signal, and S t (t) represents the target echo signal.

9. A main lobe intermittent sampling and repeater jamming suppression system, characterized in that: The system can be used to implement the main lobe intermittent sampling and forwarding interference suppression method described in any one of claims 1 to 8. Specifically, it includes: A time-frequency super-resolution processing module: used to perform super-resolution processing on the monopulse echo signal in the time-frequency domain to obtain a high-dimensional time-frequency feature spectrum; A time-frequency correlation module: used to perform high-dimensional time-frequency correlation on the high-dimensional time-frequency feature spectrum; An FIR filter design and filtering module: used to design an FIR band-pass filter based on high-dimensional features using the Parks-McClellan algorithm and filter the time-frequency domain of the original signal; A target signal reconstruction module: used to perform inverse short-time Fourier transform on the filtered time-frequency domain to reconstruct the target signal, thereby realizing the suppression of main lobe intermittent sampling and forwarding interference; and A display and interaction module: used to display the processing results and provide a user interaction interface to implement the input of operation instructions and the output of feedback information.

10. A computer-readable storage medium, characterized in that: It stores a computer program, and when the program is executed by a processor, it realizes the main lobe intermittent sampling and forwarding interference suppression method described in any one of claims 1 to 8.

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