A method to combat main lobe interference based on signal separation

Abstract

The present invention discloses a method for resisting mainlobe interference based on signal separation, comprising: performing de-skewing processing on an echo signal received by a radar system to obtain the real and imaginary parts of the de-skewing signal; performing L-layer wavelet decomposition on the real and imaginary parts of the de-skewing signal to obtain M sub-modes of the de-skewing signal; calculating the matching degree of the M sub-modes with the radar matching coefficient, and selecting the sub-mode corresponding to the target signal component; using the sub-mode corresponding to the target signal component as the mode to be reconstructed, and obtaining a reconstructed signal through wavelet reconstruction; performing an inverse de-skewing operation on the reconstructed signal to obtain a reconstructed echo signal. Aiming at the situation of low interference-to-signal ratio and low signal-to-noise ratio, the present invention divides the echo into interference and target components according to wavelet decomposition and retains the target component to reconstruct the echo, thereby removing the interference components entering the radar mainlobe, ensuring the integrity of the target information as much as possible, and reducing the energy loss of the target.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar, and in particular relates to a main lobe interference resistance method based on signal separation. Background Art

[0002] Ensuring survival and completing detection missions in complex electromagnetic environments has always been a key concern in the radar field. Radar jamming technology has evolved from simple methods such as noise blocking and artificial jammer placement to complex forms of deceptive jamming or the coexistence of multiple jammers. Furthermore, if the jammer enters the radar's mainlobe beam, it will gain the radar's mainlobe gain, making it impossible to filter out the jammer using methods such as sidelobe cancellation or sidelobe blanking, significantly impacting target detection.

[0003] Digital Radio Frequency Memory (DRFM) jammers are commonly used to generate deceptive jamming. These jamming types include full-pulse store-and-forward, intermittent sampling store-and-forward, and intermittent sampling store-and-forward with convolutional modulation. Intermittent sampling store-and-forward mainly includes three types: Interrupted Sampling and Repeater Jamming (ISRJ), Interrupted Sampling and Direct Jamming (ISDJ), and Intermittent Sampling and Cyclic Jamming (ISCJ). The ISRJ samples the transmitted signal and then repeatedly forwards it before sampling the next segment. This jamming pattern generates multiple primary false targets, but because the jamming segments are identical, their correlation with the target is relatively weak. The ISDJ samples the transmitted signal and then directly forwards it. This jamming pattern generates a single primary false target and multiple secondary false targets. Because the forwarded jamming segments contain different targets, they have strong correlation with the target. The ISCJ forwards the previously sampled signal slice in reverse order after forwarding the currently sampled signal slice. Furthermore, after the radar pulse ends, it continues forwarding the previously sampled signal segment until all sampled signals have reached the same forwarding number. This type of jamming creates multiple primary and secondary false targets. Intermittent sampling and forwarding jamming with convolution modulation superimposes convolution noise on intermittent sampling and forwarding jamming. The resulting jamming signal combines the strong deceptiveness of intermittent sampling jamming with the strong suppressiveness of noise jamming. After pulse compression, it forms energy peaks over a large area. The multiple intermittent sampling jamming within this large area overwhelms the target, preventing the radar from effectively filtering out the jamming and detecting its location.

[0004] Among the related technologies, one type is a time domain, frequency domain, or time-frequency domain masking method based on mainlobe interference identification. In the case of low interference-to-signal ratio and low signal-to-noise ratio, the interference energy is relatively low. Since there is no obvious high-energy area in the echo, the masking method cannot remove the interference. At the same time, if the sidelobes of the interference cover the target, it will also cause energy loss of the target. In the case of low signal-to-noise ratio, it will lead to missed detection of the target. There is also a type of method based on mainlobe interference parameter estimation and filter design to filter out interference. However, this method relies on the design accuracy of the filter and has high requirements for the order of the filter. At the same time, the interference parameters will be estimated incorrectly due to the low interference-to-signal ratio.

[0005] It can be seen that when the signal-to-interference ratio and signal-to-noise ratio are low, the target detection method resistant to intermittent sampling store-and-forward interference in the related art has low target detection accuracy due to interference parameter estimation errors and target energy loss during interference suppression. Summary of the Invention

[0006] In order to solve the above problems existing in the prior art, the present invention provides a method for resisting main lobe interference based on signal separation. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for resisting main lobe interference based on signal separation, comprising:

[0008] S1: De-skewing the echo signal received by the radar system to obtain the real and imaginary parts of the de-skewing signal;

[0009] S2: performing L-layer wavelet decomposition on the real part and the imaginary part of the de-skewed signal respectively to obtain M sub-modes of the de-skewed signal;

[0010] S3: Calculate the matching degree between the M sub-modes and the radar matching coefficient, and select the sub-mode corresponding to the target signal component;

[0011] S4: Take the sub-mode corresponding to the target signal component as the mode to be reconstructed, and obtain the reconstructed signal through wavelet reconstruction;

[0012] S5: Perform an inverse de-skewing operation on the reconstructed signal to obtain a reconstructed echo signal.

[0013] In one embodiment of the present invention, the S1 includes:

[0014] S11: Multiply the echo signal received by the radar system by exp(-jπμt 2 ) obtain a de-skewing signal to convert the interference and target into a single-frequency signal, where μ represents the frequency modulation coefficient of the linear frequency modulation signal and t represents time;

[0015] S12: Acquire the real part and the imaginary part of the de-skewed signal.

[0016] In one embodiment of the present invention, the S2 includes:

[0017] S21: the real part of the de-skewing signal and the imaginary part After L-layer wavelet decomposition, the real part of M sub-modes u is obtained r n,1 ,u r n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M ;

[0018] S22: According to the M submodes u of the real part r n,1 ,u r n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M , obtain the M submodes u of the de-skewed signal as a whole n,1 ,u n,2 ,…,u n,M , where the i-th submode of the de-skewing signal is represented by u n,i =u r n,i +ju i n,i ,u r n,i represents the i-th submode of the real part, u i n,i represents the i-th submode of the imaginary part.

[0019] In one embodiment of the present invention, the S3 includes:

[0020] S31: Calculate the correlation coefficients cor of the M sub-modes of the de-skewed signal and the transmitted signal = [p n,1 ,p n,2 ,…,p n,M ];

[0021] S32: Obtain the correlation coefficient cor=[p n,1 ,p n,2 ,…,pn,M ] and select the sub-mode corresponding to the maximum value as the sub-mode corresponding to the target signal component.

[0022] In one embodiment of the present invention, the S31 includes:

[0023] S311: M sub-modes u of the de-skewed signal n,1 ,u n,2 ,…,u n,M Perform wavelet reconstruction to obtain the reconstructed echo signal of each sub-mode;

[0024] S312: Based on the radar transmission signal length L n Perform sliding window interception on the reconstructed echo signal of each sub-mode, and calculate the correlation coefficient between each segment of the reconstructed echo signal and the transmitted signal after interception

[0025] S313: Get sub-modality u n,1 The maximum correlation coefficient As a submodal u n,1 The final correlation coefficient of M sub-modes is obtained by cor = [p n,1 ,p n,2 ,…,p n,M ].

[0026] In one embodiment of the present invention, the step S311 specifically includes:

[0027] Perform wavelet reconstruction on the real and imaginary parts of the i-th sub-mode respectively to obtain the real part reconstruction signal and the imaginary part to reconstruct the signal Then the reconstructed signal of the i-th sub-mode is obtained Then the reconstructed signal r i (t) multiplied by The reconstructed echo signal of the i-th sub-mode is obtained.

[0028] In one embodiment of the present invention, the S4 includes:

[0029] The sub-mode μ corresponding to the target signal component M The real and imaginary parts of are reconstructed by wavelet respectively to obtain the sub-mode μ M The real part of the reconstructed signal and the imaginary part to reconstruct the signal Then the sub-mode μ is obtained M The reconstructed signal

[0030] In one embodiment of the present invention, the S5 includes:

[0031] S51: Obtain the reconstructed signal after wavelet reconstruction

[0032]

[0033] in, Represents the initial phase of the target signal after wavelet reconstruction;

[0034] S52: reconstructing the signal Multiply by exp(jπμt 2 ), and obtain the reconstructed echo signal

[0035]

[0036] in, Represents the initial phase of the original echo target signal, S T (t) represents the target signal component.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention is based on a signal separation method to combat mainlobe interference. For situations with low signal-to-interference ratio (SIR) and low signal-to-noise ratio (SNR), the echo is divided into interference and target components according to wavelet decomposition, and the target component is retained to reconstruct the echo. This removes the interference component of the radar mainlobe, ensures the integrity of the target information as much as possible, and reduces the target's energy loss.

[0039] 2. The present invention separates the components of the echo signal based on wavelet analysis, retains the target component of the echo, and eliminates the interference component of the radar main lobe, avoiding the leakage of interference energy caused by poor filter design or masking method, which in turn affects the detection of the target.

[0040] 3. The present invention retains the target component of the echo based on wavelet decomposition and does not involve parameter estimation of interference. Therefore, the effect of interference suppression will not be affected by the estimation error of interference.

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart of a method for combating main lobe interference based on signal separation provided by an embodiment of the present invention;

[0043] Figure 2 This is a time domain diagram and spectrum diagram of the real part of the echo signal after de-skewing provided by an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of a three-layer wavelet decomposition provided by an embodiment of the present invention;

[0045] Figure 4 This is a flow chart of calculating the matching degree of M sub-modes and radar matching coefficients provided by an embodiment of the present invention;

[0046] Figure 5 1 is a schematic diagram of a sub-modal reconstructed echo sliding window interception provided by an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of intermittent sampling interference provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description of an anti-main lobe interference method based on signal separation proposed in accordance with the present invention in combination with the accompanying drawings and specific implementation methods.

[0049] The aforementioned and other technical contents, features, and effects of the present invention are clearly presented in the following detailed description of the specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a deeper and more specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose can be obtained. However, the accompanying drawings are provided for reference and illustration purposes only and are not intended to limit the technical solutions of the present invention.

[0050] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the article or device comprising the element.

[0051] See Figure 1 , Figure 1 1 is a flow chart of a method for suppressing main lobe interference based on signal separation provided by an embodiment of the present invention. The method for suppressing main lobe interference includes:

[0052] S1: De-skewing the echo signal received by the radar system to obtain the real and imaginary parts of the de-skewing signal.

[0053] This step de-skewing the echo signal received by the radar system, converting the target and interference into a single-frequency signal to facilitate subsequent processing. Specifically, step S1 includes:

[0054] S11: Multiply the echo signal received by the radar system by exp(-jπμt 2 ) obtains a de-sloped signal to convert the interference and target into a single-frequency signal, where μ represents the frequency modulation coefficient of the linear frequency modulation signal and t represents time.

[0055] The acquired echo signal is sampled and processed according to the preset sampling time interval and the preset number of sampling points. The discretized echo signal data can be expressed as x=[x1,x2,…,x l ,…x L-1 ,x L ], where L represents the preset sampling points of the echo signal, x l The echo signal data of the lth sampling unit is represented by . Afterwards, the echo signal data is de-skewed.

[0056] The echo signal can be expressed as:

[0057] S r (t) = S T (t)+S J (t)+n(t) (1)

[0058] Among them, S T (t) represents the target component, S J (t) represents the interference component, and n(t) represents the noise component.

[0059] Assume that in the echo signal, the target component can be expressed as:

[0060]

[0061] Where μ represents the frequency modulation coefficient of the linear frequency modulation signal, T p represents the pulse width of the transmitted signal, τ represents the target delay, rect(·) is the rectangular window function, and t represents time. After de-skewing the echo signal, the de-skewing signal of the target signal It can be expressed as:

[0062]

[0063] The frequency of the target signal after de-skewing can be expressed as:

[0064] f T =μτ (4)

[0065] It can be seen that the target frequency after de-skewing is related to the frequency modulation coefficient μ and the delay τ. For intermittent sampling interference, for the convenience of analysis, it is assumed that the jammer samples the starting segment of the transmitted signal and forwards it. The forwarded interference slice can be expressed as:

[0066]

[0067] Where μ represents the frequency modulation coefficient of the linear frequency modulation signal, T j Indicates the pulse width of the interference signal, τ j Indicates the delay of the interference signal forwarding. After the echo signal is de-skewed, the de-skewed interference signal It can be expressed as:

[0068]

[0069] The frequency of the interference segment after de-skewing can be expressed as:

[0070] f J =μτ j (7)

[0071] Generally speaking, since the jammer needs to store and forward the transmitted signal, the jamming delay τ j Different from the target delay τ, the target signal and the interference signal will be converted into single-frequency signals of different frequencies after de-skewing. Figure 2 As shown in FIG, after the echo signal is de-skewed, the target signal and the interference signal become single-frequency signals. The de-skew processing makes the target and the interference separable in the frequency domain.

[0072] S12: Obtain the real part and the imaginary part of the de-skewed signal.

[0073] In this embodiment, the echo signal is de-skewed to convert the target and interference into a single-frequency signal. The real part of the de-skewed signal is obtained. and the imaginary part The real and imaginary parts of the de-skewed signal contain the single-frequency components of the de-skewed target and interference.

[0074] S2: performing L-layer wavelet decomposition on the real part and the imaginary part of the de-skewed signal respectively to obtain M sub-modes of the de-skewed signal.

[0075] In this step, the de-skewed signal is subjected to wavelet decomposition. The decomposed M sub-modes correspond to cosine signals of different frequencies of the de-skewed signal. Since the frequency of the de-skewed signal is related to the time delay of the target signal and the interference signal, the interference signal and the target signal will correspond to different frequencies after de-skew, that is, they belong to different sub-modes.

[0076] In this embodiment, the real part and the imaginary part of the de-skewing signal contain three components, namely interference information, noise information and target information. S2 of this step includes:

[0077] S21: the real part of the de-skewing signal and the imaginary part After L-layer wavelet decomposition, the real part of M sub-modes u is obtained r n,1 ,ur n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M ;

[0078] S22: According to the M submodes u of the real part r n,1 ,u r n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M , obtain the M submodes u of the de-skewed signal as a whole n,1 ,u n,2 ,…,u n,M , where the i-th submode of the de-skewing signal is represented by u n,i =u r n,i +ju i n,i ,u r n,i represents the i-th submode of the real part, u i n,i represents the i-th submode of the imaginary part. The interference signal and the target signal are scattered in different submodes due to their different frequencies after de-skewing.

[0079] See Figure 3 , Figure 3 This is a schematic diagram of a three-layer wavelet decomposition provided by an embodiment of the present invention. Wavelet decomposition is a multi-level division of low-frequency signals to match the signal spectrum, thereby obtaining a decomposition of the signal. The sub-modes obtained by decomposition represent the different frequency segments of the echo signal after de-skewing. The number of sub-modes increases with the increase of the number of wavelet decomposition layers L, and the division of the frequency segments will also become more refined. When the number of decomposition layers L is designed reasonably, the target and interference components can be separated in theory.

[0080] S3: Calculate the matching degree between the M sub-modes and the radar matching coefficient, and select the sub-mode corresponding to the target signal component.

[0081] The matching degree between the M sub-modes of wavelet decomposition and the radar matching coefficient is calculated. Since the radar matching coefficient corresponds to the complete transmitted signal, the sub-mode corresponding to the target will be calculated to have a higher matching degree.

[0082] See Figure 4 , Figure 4 This is a flow chart of calculating the matching degree of M sub-modes and radar matching coefficients provided by an embodiment of the present invention. Specifically, calculating the matching degree of M sub-modes and radar matching coefficients includes the following steps:

[0083] S31: Calculate the correlation coefficients cor of the M sub-modes of the de-skewed signal and the transmitted signal = [p n,1 ,p n,2 ,…,p n,M ]; specifically includes the following steps:

[0084] S311: M sub-modes u of the de-skewed signal n,1 ,u n,2 ,…,u n,M Perform wavelet reconstruction to obtain the reconstructed echo signal of each sub-mode.

[0085] Submodes represent different frequency bands of the echo signal after deskewing. When the number of decomposition layers L is designed reasonably, a submode should contain only one of the target component and the interference component. The real and imaginary parts of the i-th submode are reconstructed by wavelet to obtain the real part reconstructed signal and the imaginary part to reconstruct the signal Then the reconstructed signal of the i-th sub-mode can be expressed as Then multiply the submodal reconstructed signal by The reconstructed echo signal of each sub-mode is obtained.

[0086] S312: Based on the radar transmission signal length L n Perform sliding window interception on the reconstructed echo signal of each sub-mode, and calculate the correlation coefficient between each segment of the reconstructed echo signal and the transmitted signal after interception

[0087] See Figure 5 , Figure 5 The embodiment of the present invention provides a schematic diagram of a sub-modal reconstructed echo sliding window interception. The radar reconstructs the echo signal of the sub-modal with a length L n Intercept and correlate the transmitted signal to obtain the correlation coefficient Then the sliding window is intercepted with a sliding step of 1, and the correlation coefficient is obtained in the same way Thus, the LL of each sub-mode is obtained n Correlation coefficient

[0088] S313: Get sub-modality u n,1 The maximum correlation coefficient As a submodal u n,1The final correlation coefficient of M sub-modes is obtained by analogy, thus obtaining the final correlation coefficient of M sub-modes cor = [p n,1 ,p n,2 ,…,p n,M ].

[0089] That is, in each sub-modal LL n The maximum value is selected from the correlation coefficients as the final correlation coefficient of each sub-mode, thus forming the final correlation coefficient set of M sub-modes cor = [p n,1 ,p n,2 ,…,p n,M ].

[0090] S32: Obtain the correlation coefficient cor=[p n,1 ,p n,2 ,…,p n,M ] and select the sub-mode corresponding to the maximum value as the sub-mode corresponding to the target signal component.

[0091] In this embodiment, the correlation coefficient p of the i-th sub-mode is n,i is the correlation coefficient vector corresponding to the sub-mode The maximum value of . Vector The LL obtained by sliding window interception of the reconstructed echo of this sub-mode is represented by n The correlation coefficient of the echo band and the radar transmission signal is assumed to be x = [x1, x2, ..., x l ,…x L-1 ,x L ], the discrete form of the transmitted signal is expressed as The length of the intercept window is L n , then a total of LL can be intercepted n echo bands, taking the first echo band as an example, the signal within the interception window can be expressed as: The signal in the last interception window is expressed as: Obtained LL n The echo signal can be expressed as Each column represents the signal segment intercepted by the sliding window. cor Each column and Calculate the correlation coefficient to get the correlation coefficient corresponding to the M sub-modes The maximum value of the correlation coefficient It reflects the matching degree between the sub-modal reconstructed echo and the transmitted signal. Figure 6 , Figure 6This is a schematic diagram of intermittent sampling interference provided by an embodiment of the present invention. Since intermittent sampling interference is obtained by forwarding a portion of the transmitted signal after sampling, the matching degree between the interference sub-modal reconstructed echo and the transmitted signal is low. n,1 ,p n,2 ,…,p n,M ) is the sub-modality corresponding to the target.

[0092] S4: Take the sub-mode corresponding to the target signal component as the mode to be reconstructed, and obtain the reconstructed signal through wavelet reconstruction.

[0093] In steps S4 and S5, the submode judged as the target can obtain a reconstructed signal through wavelet reconstruction, and the reconstructed signal can be de-skewed to obtain a reconstructed echo signal. At this time, only the target component is retained in the echo signal to achieve the effect of interference suppression.

[0094] In this embodiment, step S4 includes:

[0095] S41: Sub-mode μ corresponding to the target signal component M As a modality to be reconstructed;

[0096] S42: Perform wavelet reconstruction on the mode to be reconstructed to obtain a reconstructed signal

[0097] In this embodiment, the sub-mode μ corresponding to the target signal component M Wavelet reconstruction is to reconstruct the sub-mode μ M The real and imaginary parts of μ are reconstructed by wavelet respectively to obtain μ M Real part reconstructed signal and the imaginary part to reconstruct the signal Reconstructing the signal Submode μ M It corresponds to the frequency band of the target signal after de-skewing. M Wavelet reconstruction preserves the target information.

[0098] S5: Perform an inverse de-skewing operation on the reconstructed signal to obtain a reconstructed echo signal.

[0099] Specifically, the reconstructed signal is multiplied by exp(jπμt 2 ), and obtain the reconstructed echo signal

[0100] In this embodiment, the reconstructed signal is the signal reconstructed by wavelet. The reconstructed signal only contains the target component. It can be expressed as:

[0101]

[0102] in, Represents the initial phase of the target signal after wavelet reconstruction. The reconstructed echo signal can be expressed as:

[0103]

[0104] in, Represents the initial phase of the original echo target signal. If the target component is completely preserved during the wavelet decomposition and reconstruction process, then At this time, the reconstructed echo signal It contains complete target information and the interference information is removed.

[0105] The effect of the anti-mainlobe interference method based on signal separation of the present invention is further verified and explained through simulation experiments below.

[0106] (1) Simulation conditions:

[0107] The simulation running system of the present invention is Intel(R) Core(TM) i5-12500h CPU@2.50GHz, 64-bit Windows11 operating system, and the simulation software adopts MATLAB (R2020b).

[0108] The effectiveness of the anti-main lobe interference method based on signal separation of the present invention is verified by simulation experiments. The experimental scenario is set as follows: the radar system transmits a linear frequency modulation signal, the received SNR is [4, 6, 8, 10, 12, ..., 26] dB, and the target echo is at random distance; the jammer randomly transmits JSR = [2 0 ,…,2 12 ] interference, and the interference position is random. Wherein, JSR represents the interference signal ratio and SNR represents the signal-to-noise ratio.

[0109] (2) Simulation content and result analysis:

[0110] The detection probability of the target is calculated by using the anti-mainlobe interference target detection method provided by the present invention, and the detection probability comparison under different SNR and JSR conditions is obtained. The specific situation is shown in Table 1:

[0111] Table 1 Detection probability of targets under different JSR and SNR

[0112]

[0113]

[0114] As can be seen from Table 1, when JSR = 4 to 16 and SNR = 8 to 20 dB, the target detection probability is relatively high, basically maintained at around 95%; however, when JSR and SNR are high, the target detection probability is relatively low, indicating that the present invention has a good target detection probability in low interference-to-signal ratio and low signal-to-noise ratio environments.

[0115] In summary, in an environment with low interference-to-signal ratio and low signal-to-noise ratio, the present invention separates the components of the echo signal based on wavelet decomposition, extracts the target component for echo reconstruction, suppresses the main lobe interference by retaining the target component, and improves the performance of target detection.

[0116] The embodiment of the present invention is based on a method for resisting mainlobe interference based on signal separation. For situations of low interference-to-signal ratio and low signal-to-noise ratio, the echo is divided into interference and target components according to wavelet decomposition and the target component is retained to reconstruct the echo, thereby removing the interference component, ensuring the integrity of the target information as much as possible, and reducing the energy loss of the target. The present invention performs component separation on the echo signal based on wavelet analysis, retains the target component of the echo and removes the interference component, thereby avoiding the leakage of interference energy due to poor filter design or masking method, which in turn affects the detection of the target. The present invention retains the target component of the echo based on wavelet decomposition and does not involve parameter estimation of interference. Therefore, the effect of interference suppression will not be affected by the estimation error of the interference.

[0117] Another embodiment of the present invention provides a storage medium, wherein a computer program is stored in the storage medium, and the computer program is used to execute the steps of the anti-mainlobe interference method based on signal separation described in the above embodiment. Another aspect of the present invention provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps of the anti-mainlobe interference method based on signal separation as described in the above embodiment are implemented. Specifically, the above-mentioned integrated module implemented in the form of a software function module can be stored in a computer-readable storage medium. The above-mentioned software function module is stored in a storage medium, including several instructions for enabling an electronic device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0118] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for combating main lobe interference based on signal separation, characterized in that: include: S1: De-skewing the echo signal received by the radar system to obtain the real and imaginary parts of the de-skewing signal; S2: performing L-layer wavelet decomposition on the real part and the imaginary part of the de-skewed signal respectively to obtain M sub-modes of the de-skewed signal; S3: Calculate the matching degree between the M sub-modes and the radar matching coefficient, and select the sub-mode corresponding to the target signal component; S4: Take the sub-mode corresponding to the target signal component as the mode to be reconstructed, and obtain the reconstructed signal through wavelet reconstruction; S5: Perform an inverse de-skewing operation on the reconstructed signal to obtain a reconstructed echo signal.

2. The method for combating main lobe interference based on signal separation according to claim 1, wherein: Said S1 comprises: S11: Multiply the echo signal received by the radar system by exp(-jπμt 2 ) obtain a de-skewing signal to convert the interference and target into a single-frequency signal, where μ represents the frequency modulation coefficient of the linear frequency modulation signal and t represents time; S12: Acquire the real part and the imaginary part of the de-skewed signal.

3. The method for combating main lobe interference based on signal separation according to claim 1, wherein: The S2 includes: S21: the real part of the de-skewing signal and the imaginary part After L-layer wavelet decomposition, the real part of M sub-modes u is obtained r n,1 ,u r n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M ; S22: According to the M submodes u of the real part r n,1 ,u r n,2 ,…,u r n,M and the imaginary part of M submodes u i n,1 ,u i n,2 ,…,u i n,M , obtain the M submodes u of the de-skewed signal as a whole n,1 ,u n,2 ,…,u n,M , where the i-th submode of the de-skewing signal is represented by u n,i =u r n,i +ju i n,i ,u r n,i represents the i-th submode of the real part, u i n,i represents the i-th submode of the imaginary part.

4. The method for combating main lobe interference based on signal separation according to claim 1, wherein: The S3 includes: S31: Calculate the correlation coefficients cor of the M sub-modes of the de-skewed signal and the transmitted signal = [p n,1 ,p n,2 ,…,p n,M ]; S32: Obtain the correlation coefficient cor=[p n,1 ,p n,2 ,…,p n,M ] and select the sub-mode corresponding to the maximum value as the sub-mode corresponding to the target signal component.

5. The method for combating main lobe interference based on signal separation according to claim 4, characterized in that: The S31 includes: S311: M sub-modes u of the de-skewed signal n,1 ,u n,2 ,…,u n,M Perform wavelet reconstruction to obtain the reconstructed echo signal of each sub-mode; S312: Based on the radar transmission signal length L n Perform sliding window interception on the reconstructed echo signal of each sub-mode, and calculate the correlation coefficient between each segment of the reconstructed echo signal and the transmitted signal after interception S313: Get sub-modality u n,1 The maximum correlation coefficient As a submodal u n,1 The final correlation coefficient of M sub-modes is obtained by cor = [p n,1 ,p n,2 ,…,p n,M ].

6. The method for combating main lobe interference based on signal separation according to claim 5, characterized in that: The S311 specifically includes: Perform wavelet reconstruction on the real and imaginary parts of the i-th sub-mode respectively to obtain the real part reconstruction signal and the imaginary part to reconstruct the signal Then the reconstructed signal of the i-th sub-mode is obtained Then the reconstructed signal r i (t) multiplied by The reconstructed echo signal of the i-th sub-mode is obtained.

7. The method for combating main lobe interference based on signal separation according to claim 6, wherein: The S4 includes: The sub-mode μ corresponding to the target signal component M The real and imaginary parts of are reconstructed by wavelet respectively to obtain the sub-mode μ M The real part of the reconstructed signal and the imaginary part to reconstruct the signal Then the sub-mode μ is obtained M The reconstructed signal 8. The method for combating main lobe interference based on signal separation according to claim 7, wherein: The S5 includes: S51: Obtain the reconstructed signal after wavelet reconstruction in, Represents the initial phase of the target signal after wavelet reconstruction; S52: reconstructing the signal Multiply by exp(jπμt 2 ), and obtain the reconstructed echo signal in, Represents the initial phase of the original echo target signal, S T (t) represents the target signal component, T p represents the pulse width of the transmitted signal, and τ represents the target delay.

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