Combined time frequency distribution and compression sensing radar frequency smeared spectrum interference method

Abstract

The invention discloses a combined time frequency distribution and compression sensing radar frequency smeared spectrum interference method. The method includes obtaining radar echo signals and conducting down conversion processing to obtain the radar echo baseband signal s, conducting u domain frequency sweep filtering and frequency demodulation to obtain radar eco baseband signal x after frequency demodulation, setting the discrete time sequence x(n) of x, sequentially calculating the vector form Xi<^> of the non-overlapping slide window short time Fourier Transform time frequency distribution of the Xi<^> and Xi<^> of x (n), establishing the linear relation between the Xi<^> and x, setting the time-frequency point screening threshold, screening the time-frequency points contained in the Xi<^> to sequentially obtain the time-frequency points retained in the Xi<^> and a time-frequency point screening matrix Psi<^> of the Xi<^>, setting the vector form of Xi<^> after time-frequency points screening as Xi<^> bar and obtaining the linear relation among the Xi<^> bar, Psi<^> bar and Xi<^>, setting the x frequency spectrum as X, further establishing the linear relation between the Xi<^> bar and X, conducting reconstruction and inverse Fourier transform for X to obtain a reconstructed frequency demodulation target signal X<^>, and conducting inverse frequency demodulation for the X<^> to obtain the target signal after inverse frequency demodulation.

Description

technical field [0001] The invention belongs to the field of radar technology, and in particular relates to a method for combating radar spectrum scatter interference by combining time-frequency distribution and compressed sensing, which is suitable for suppressing radar spectrum smear (Smeared Spectrum, SMSP) interference. Background technique [0002] The spectrum dispersive (Smeared Spectrum, SMSP) jamming based on Digital Radio Frequency Memory (DRFM) technology is a kind of active spoofing jamming specifically against linear frequency modulated (Linear Frequency Modulated, LFM) pulse radar, and active spoofing jamming is serious Reduce the detection performance of the radar to the target. The spectrum dispersion (SMSP) jamming modulates the intercepted radar chirp signal by the jammer according to a specific modulation method to generate a spectrum dispersion (SMSP) jamming signal, which is forwarded to the radar by the jammer. Spectrum Dispersion (SMSP) jamming signals...

AI Technical Summary

Problems solved by technology

[0004] When the radar detects that the radar echo signal contains a spectrum dispersion (SMSP) interference signal, the existing method uses Fractional Fourier Transform (Fractional Fourier Transform, FRFT) to sweep and filter the radar echo signal in the u domain, and then Realize the suppression of the spectrum dispersion (SMSP) interference signal, but this method cannot completely filter out the spectrum dispersion (SMSP) interference signal, and the requirements for the bandwidth of the sweep filter are relatively high; when the bandwidth of the sweep filter is small, it will cause Part of the information of the target signal is lost, which makes the reconstructed target signal seriously distorted; when the bandwidth of the sweep filter is large, more spectrum dispersion (SMSP) interference signal energy enters the sweep filter, resulting in the radar echo signal After performing pulse pressure, a few false target side lobes will be generated near the main lobe of the real target, which will affect the radar's acquisition of the real target

Images