基于正负频偏脉冲压缩相参积累的移频干扰鉴别方法

Frequency-shift Jamming Identification Methods Based on Positive and Negative Frequency Shift Pulse Compression Coherent Integration

基于数字射频存储器产生的移频干扰是一种针对线性调频信号(LFM)脉冲雷达的欺骗干扰,所产生的导前或滞后假目标由于诸多特性与真实目标相似因而难以鉴别。为有效对抗移频干扰,该文通过研究移频干扰信号的脉冲压缩过程,得出存在频率差的两信号进行时域卷积后输出能量与频率差呈负相关的结论。该文利用这一结论设计带有正、负频率偏移的失配滤波器,滤波器在与雷达回波信号进行时域卷积、相参积累后将出现真实目标和干扰信号的峰值差异,进而鉴别移频干扰。该文提出的移频干扰鉴别方法工程实用性强,是在以自卫式干扰条件下常规LFM脉冲多普勒雷达对抗移频干扰的有效方法。通过仿真试验验证了所提方法的有效性。

Frequency-shift jamming is a kind of spoofing jamming for Linear Frequency Modulation(LFM)pulse radar based on digital radio frequency memory.In order to resist the frequency shifting interference,by studying the pulse compression process of frequency shifting interference signals,the conclusion that the output energy of two signals with a frequency difference is negatively correlated with the frequency difference after time domain convolution is concluded.Based on this characteristic,a method for identification of frequency shifting interference based on phase-coherent accumulation of positive and negative carrier frequency pulse pressure is proposed,which can effectively counter frequency shifting interference with conventional LFM pulse Doppler radar under the condition of self-defense interference.After pulse compression and phase-coherent accumulation with matched filters with positive and negative carrier frequencies respectively,the output results of real target and interference signal after processing have peak difference,and then frequency shift interference is identifed.Simulation results demonstrate the effectiveness of the proposed method.