基于回波预处理和相参积累的C&I干扰抑制算法

C&I jamming suppression algorithm based on echo preprocessing and coherent integration

C&I(chopping and interleaving)干扰是一种针对线性调频(linear frequency modulation,LFM)雷达的典型干扰样式,干扰子信号调频斜率与雷达发射信号相同,利用信号处理工具分离真实回波与干扰信号难度较大。针对该问题,以LFM相参雷达抗自卫式C&I干扰为背景,提出基于回波预处理和相参积累的干扰抑制算法。根据估计的回波时延,设置距离窗截取受干扰回波段,在此基础上,通过对回波预处理,改变不同重复周期内假目标的快时间位置分布,通过相参积累实现干扰抑制。仿真试验表明,所提算法能够有效抑制强干扰背景下的C&I干扰,干扰抑制后真实目标检测概率大幅提高,虚假目标数量明显减少。

Chopping and interleaving(C&I)jamming is a typical active jamming for linear frequency modulation(LFM)radar.Since the frequency-modulation slope of jamming sub-signal is same as that of the radar transmitting signal,it is difficult to separate target echo from jamming signal using conventional signal processing tools.Aiming at this problem,taking LFM coherent radar countering self-screening C&I jamming as background,ajamming suppression algorithm based on echo preprocessing and coherent integration is proposed.According to the estimated echo delay,a range-window is set to intercept jammed echo.On this basis,fast-time position distribution of false targets in different pulse repetition period changes by echo preprocessing.And,the objective of jamming suppression is achieved through coherent integration.Simulation results show that the algorithm can effectively suppress C&I jamming in strong interference background.After jamming suppression,true target detection probability is greatly improved and false target number is significantly reduced.