基于STFrFT的间歇采样转发干扰抑制

Interrupted-sampling repeater jamming suppression based on STFrFT

干扰机对雷达脉冲快速切片、转发形成间歇采样转发干扰,若从雷达主瓣进入,将对雷达目标检测形成严重威胁。从波形设计和时频分析的角度出发,提出一种基于短时分数阶傅里叶变换(short-time fractional Fourier transform,STFrFT)的主瓣间歇采样转发干扰抑制方法。首先设计脉内捷变频信号,提升干扰与目标信号的差异;接着采用STFrFT进行时频分析,相比传统短时傅里叶变换大大提升了时频分辨率,相比分数阶傅里叶变换类方法没有对信号参数的限制;最后结合图像学方法对干扰进行剔除,对从主瓣进入的高干信比干扰也可形成有效抑制。仿真结果表明,所提方法可在多种环境下有效对抗间歇采样转发干扰。

Jammers can rapidly slice and forward radar pulse to form interrupted-sampling repeater jamming.If it enters from the main lobe of radar,it will pose a serious threat to radar target detection.Starting from waveform design and time-frequency analysis,a main lobe interrupted-sampling repeater jamming suppression method is proposed based on short-time fractional Fourier transform(STFrFT).Firstly,an intra-pulse frequency agility signal is harnessed to improve the distinguishability between jamming and target signal.Moreover,the STFrFT is applied to time-frequency analysis,which significantly improves the time-frequency analysis accuracy compared with traditional short-time Fourier transform methods and removes the restrictions on signal parameters compared with fractional Fourier transform methods.Finally,through eliminating jamming by using image processing methods,the interference of high jamming-to-signal ratio from the main lobe of radar is suppressed effectively.The simulation results indicate that the proposed method can effectively suppress interrupted-sampling repeater jamming in various environments.