Reseach On Radar Anti Active Deception Jamming Tecnology

Active deception jamming, with its good coherence and strong deceptiveness, has become one of the major means to jam the radar, and has seriously threaten the normal work of the radar. Therefore, it has great significance to study the anti-active-deception-jamming technology. It is an important direction to research the suppression algorithm of active deception jamming from the signal processing field.Based on the current situation of anti-active-deception-jamming, this master thesis analyzes the basic principles and characteristics of forward DRFM(Digital Radio Frequency Memory) deception jamming, and focuses on the suppression algorithms of three major kinds of active deception jamming.(1)suppression algorithm of distance deception jamming : According to the correlated characteristic of SV-LFM(Slope-varying Linear Frequency Modulation) signal and phase perturbation theory, this algorithm uses pulse compression on anti-jamming directly. In order to improve the signal to interference ratio, the improvement of three-step matching filter algorithm is further proposed.(2)suppression algorithm of speed deception jamming: This algorithm uses wavelet transform and EMD(Empirical Mode Decomposition) time-frequency analysis methods to analyze the jammed target Doppler echo signals. In this process, the jamming Doppler frequency component is removed, and then the echo signal is reconstructed to suppress jamming.(3)suppression algorithm of distance- speed synchronous deception jamming: First, make a dechirp on the jammed radar signal and change it to a mono signal. Second, filter out the jamming Doppler frequency component by the use of wavelet transform and EMD time-frequency analysis methods. Last, reconstruct the signal and obtain the target echo signal by dechirp inverse transforming. Further the wavelet transform time-frequency analysis algorithm based on EMD is proposed to improve anti-jamming effect.