CN-116243251-B - Main lobe deception jamming inhibition method based on waveform diversity and subspace projection

CN116243251BCN 116243251 BCN116243251 BCN 116243251BCN-116243251-B

Abstract

The invention discloses a main lobe deception jamming inhibition method based on waveform diversity and subspace projection, which can effectively inhibit main lobe deception jamming in an intermittent sampling forwarding mode. Step 1, designing the waveform of a transmitting signal to be an inter-pulse agile waveform according to interference parameters, and obtaining a receiving echo after the transmitting signal is transmitted by a radar. And step 2, adopting a reconstruction submodule to reconstruct the interference signal in the received echo, and obtaining a reconstruction result of the interference signal. And 3, carrying out reconstruction processing on the target signal in the received echo after the interference cancellation reconstruction result by adopting a reconstruction sub-module to obtain a reconstruction result of the target signal. And step 4, the reconstruction result of the target signal is eliminated from the received echo, the interference signal in the updated received echo is used as the input of the step 2, the step 2-3 is circularly executed until the iteration is completed, and the main lobe deception interference in the intermittent sampling forwarding mode can be effectively inhibited after a plurality of iterations.

Inventors

REN LIXIANG
LIU ZIHAO
FAN HUAYU
GAO YUHANG
QIANG XIAOMIN
MAO ERKE

Assignees

北京理工大学

Dates

Publication Date: 20260508
Application Date: 20221213

Claims (6)

1. A main lobe deception jamming inhibition method based on waveform diversity and subspace projection is characterized by comprising the following steps: Step 1, designing the waveform of a transmitting signal to be an inter-pulse agile waveform according to interference parameters, and acquiring a receiving echo after the transmitting signal is transmitted by a radar; Step 2, adopting a reconstruction submodule to reconstruct the interference signal in the received echo to obtain a reconstruction result of the interference signal ; Step 3, adopting a reconstruction submodule to cancel Performing reconstruction processing on the target signal in the received echo to obtain a reconstruction result of the target signal ; Step 4, canceling the reconstruction result of the target signal from the received echo The updated interference signal in the received echo is used as the input of the step 2, the step 2 is returned, and the steps 2-3 are circularly executed until the set iteration times are reached or the reconstruction result of the target signal of the last iteration is reached Reconstruction result of target signal of current iteration And (3) the difference value is smaller than a set threshold value, and a target result after interference reconstruction cancellation is obtained.
2. The main lobe deception jamming inhibition method based on waveform diversity and subspace projection as claimed in claim 1, wherein the waveform of the designed transmitting signal according to the jamming parameter is an inter-pulse agile waveform, specifically: estimating interference intermittent sampling width using interference sensing technique And intermittent sampling period Wherein In order to interfere with the intermittent sampling sequence number, The number of times of intermittent sampling is the interference; Constructing an envelope of interference intermittent samples in a transmitted signal Envelope of undisturbed samples The theory of the formula of the Chinese medicine is that And Construction of the first Each transmitted signal The N pulse signals transmitted are designed in sequence to generate inter-pulse agile waveforms.
3. The main lobe spoofing interference suppressing method based on waveform diversity and subspace projection of claim 2 wherein the envelope of the interference intermittent samples In order to achieve this, the first and second, (1) Wherein the method comprises the steps of , Is a time axis; envelope of undisturbed samples in a transmitted signal Expressed as: (2) Wherein the method comprises the steps of Pulse width for the transmitted signal; Set up the transmission signal to be common Pulse by pulse, pulse by pulse modulated signal And to the first Interference intermittent sampling part of each transmitted signal modulates initial phase Partially modulated primary phase of undisturbed samples Then (1) Each transmitted signal Expressed as: (3)。
4. The main lobe deception jamming inhibition method based on waveform diversity and subspace projection as claimed in claim 3, wherein the reconstruction submodule performs the following processing steps of inter-pulse phase compensation, fast time matched filter processing, subspace projection, fast time inverse matched filter processing and recovering inter-pulse phase; Compensating the pulse-to-pulse modulation phase of each pulse for the input signal to obtain a compensated signal; The fast time matched filtering process includes setting reference signal along fast time dimension, and matching filtering the compensated signal ; The subspace projection is specifically that Pulse Doppler PD processing is carried out along a slow time dimension, doppler frequency corresponding to peak points in PD processing results is extracted, a subspace projection matrix is constructed by utilizing the Doppler frequency corresponding to the peak points, and subspace projection is carried out by utilizing the subspace projection matrix pair to obtain ; The fast time inverse matched filtering process is as follows Performing inverse matched filtering along a fast time dimension to obtain an inverse matched filtering result; the inter-pulse phase recovery is specifically to add inter-pulse modulation phases of all pulses to the inverse matched filtering processing result to obtain a reconstruction result.
5. The main lobe deception jamming inhibition method based on waveform diversity and subspace projection as claimed in claim 4, wherein the reconstruction processing is carried out on the jamming signal in the received echo by adopting a reconstruction submodule, wherein the input signal of the reconstruction submodule is the reconstruction result of subtracting the target signal of the last iteration from the received echo, and the initial value of the reconstruction result of the target signal is set to 0; the reconstruction processing process for the interference signal specifically comprises the following steps: First for receiving echo Compensating for interfering modulation phases of pulses And along the fast time dimension to interfere with the sampling portion Is a reference signal pair Matched filtering is carried out to obtain Then to PD processing is carried out along the slow time dimension, and Doppler frequency corresponding to peak point in PD processing result is extracted and recorded as , For different Doppler channel numbers where peak points are located, constructing an interference subspace projection matrix according to a formula (4) : (4) Wherein, the Represents the complex conjugate transpose of the present invention, The inverse of the matrix is represented and, Representing the kronecker product of the two, ; For a pair of Sub-space projection is performed to obtain , (5) Then to Performing inverse matched filtering along the fast time dimension, and adding interference modulation phase of each pulse Obtaining the reconstruction result of the interference 。
6. The main lobe deception jamming inhibition method based on waveform diversity and subspace projection as claimed in claim 5, wherein the reconstruction processing is carried out on the target signal in the received echo by adopting a reconstruction submodule, and the input signal of the reconstruction submodule is the reconstruction result of the received echo minus the jamming; The reconstruction processing process for the target signal specifically comprises the following steps: First from receiving echo Cancellation of reconstructed interference Then compensating for the target modulation phase of each pulse And along the fast time dimension to interfere with the non-sampled portion Is a reference signal pair Matched filtering is carried out to obtain Then PD processing is carried out along the slow time dimension, and Doppler frequency corresponding to peak point in PD result is extracted and recorded as , For different Doppler channel numbers where peak points are located, a target subspace projection matrix is constructed according to a formula (6), (6) And is opposite to Sub-space projection is performed to obtain , (7) Then to Inverse matched filtering along the fast time dimension and adding the target modulation phase of each pulse Obtaining a reconstruction result of the target 。

Description

Main lobe deception jamming inhibition method based on waveform diversity and subspace projection Technical Field The invention belongs to the technical field of anti-interference, and particularly relates to a main lobe deception jamming inhibition method based on waveform diversity and subspace projection. Background As one of the most dominant interference modes, radar main lobe deception interference generates a high-fidelity echo signal through simulation, thereby confusing an enemy radar and affecting the detection and tracking of a real target. The most commonly used radar interference devices are digital radio frequency memories (Digital Radio Frequency Memory, DRFM), and the DRFM can generate interference signals in various modes by storing samples of radar signals and copying and modulating the samples. The current most efficient main lobe spoofing jamming pattern based on DRFM is intermittent sampling forwarding jamming. The interference is repeated interception and forwarding of the radar transmitting signal, so that the interference signal and the radar transmitting signal are partially related, partial processing gain can be obtained in subsequent pulse compression and related accumulation, the requirement on transmitting power is reduced, meanwhile, due to the intermittent sampling forwarding working mode, the interference signal can form a plurality of false target groups after pulse compression, and the interference effects of suppression and deception can be achieved through the design of sampling time and forwarding times. Most of the current methods for resisting intermittent sampling forwarding interference take a linear frequency modulation (Linear Frequency Modulation, LFM) signal as a transmitting signal, a band-pass filter is constructed by extracting a target echo fragment without interference in a received echo, and the interference suppression is realized by carrying out band-pass filtering on the received echo after the declassification processing, or the target echo is directly reconstructed by carrying out sparse recovery on the target echo fragment extracted after the declassification processing. However, such methods require high signal-to-noise ratio and require target echo fragments that are not completely covered by interference, which is difficult to achieve in practical electronic warfare scenarios. Main lobe spoofing interference in the form of intermittent sampling forwarding is currently the main threat faced by modern radars, and the existing method has limitation in suppressing intermittent sampling forwarding interference, so that a method capable of effectively suppressing the main lobe spoofing interference in the form of intermittent sampling forwarding is needed. Disclosure of Invention In view of the above, the invention provides a main lobe deception jamming inhibition method based on waveform diversity and subspace projection, which can effectively inhibit main lobe deception jamming in an intermittent sampling forwarding mode. In order to achieve the above purpose, the technical scheme of the invention comprises the following steps: Step 1, designing the waveform of a transmitting signal to be an inter-pulse agile waveform according to interference parameters, and obtaining a receiving Echo after the transmitting signal is transmitted by a radar. And 2, adopting a reconstruction submodule to reconstruct the interference signal in the received echo, and obtaining a reconstruction result R J of the interference signal. And 3, carrying out reconstruction processing on the target signal in the received echo after the cancellation R J by adopting a reconstruction submodule to obtain a reconstruction result R T of the target signal. And 4, canceling a reconstruction result R T of the target signal from the received echo, updating an interference signal in the received echo, taking the updated interference signal as an input of the step 2, returning to the step 2, and circularly executing the step 2-3 until the set iteration times are reached, or the difference value between the reconstruction result R T of the target signal in the last iteration and the reconstruction result R T of the target signal in the current iteration is smaller than a set threshold value, so as to obtain a target result after interference reconstruction cancellation. Further, the waveform of the transmitting signal is designed to be an inter-pulse agile waveform according to the interference parameters, specifically, an interference sensing technology is utilized to estimate an interference intermittent sampling width T j＝[Tj1,Tj2,...,TjM and an intermittent sampling period T s＝[Ts1,Ts2,...,TsM, wherein M is an interference intermittent sampling sequence number, M is the number of interference intermittent sampling times, an envelope U J (T) of interference intermittent sampling and an envelope U T (T) which is not subjected to interference sampling in the transmitting signal are construc