基于FrFT的LFM间歇采样转发干扰对抗方法

Fractional Fourier Transform-based LFM Radars for Countering Interrupted-sampling Repeater Jamming

针对间歇采样转发干扰对线性调频雷达产生相关干扰的问题,提出基于分数阶傅里叶变换(FrFT)进行干扰抑制的方法:将混合有干扰的信号以特定的阶数作FrFT,然后通过窄带滤波抽取目标信号,抑制掉干扰信号,从而实现对目标的检测。研究了间歇采样直接转发、重复转发、循环转发干扰模型,介绍了基于FrFT的抗干扰原理并进行了仿真,结果表明,该方法算法复杂度较低、运算时间短,可实现较低信噪比或较高干信比条件下的干扰抑制。

In this paper,a novel method of LFM radars countering interrupted-sampling repeater jamming(ISRJ)is presented.The mixed signal is transformed into fractional Fourier transform(FrFT)with a specific angle,then the target signal is extracted by narrowband filtering.At the same time,the ISRJ has been suppressed,so the target signal can be detected.The models of ISRJ and FrFT-based anti-jamming method is analyzed and simulated.It has been proved by the simulation results that the proposed technique,whose algorithm complexity is low,can resist the ISRJ in low-SNR and high-JSR environment.