基于STFRFT的LFM引信抗欺骗干扰方法

针对线性调频脉冲压缩引信易受转发式假目标欺骗干扰问题,提出了基于短时分数阶傅立叶变换(STFRFT)的抗欺骗干扰方法。首先,通过分数阶傅立叶变换将回波信号与欺骗干扰各分量信号进行分离;再利用相同调频率的LFM信号经短时分数阶傅立叶变换后最大幅值与窗函数宽度成线性关系,而不同调频率的最大幅值不随窗函数宽度变化的特点,有效分辨假目标欺骗干扰,正确检测目标回波信号;最后,通过仿真证明了方法的正确性,并验证所提方法具有良好的抗欺骗干扰效果。

Deception Jamming Suppression Method of LFM Fuze Based on STFRFT

Aiming at the deception jamming for LFM fuze, a new method based on STFRFT(short time fractional fouriertransform) was proposed to suppress the interference. The frequency modulation ratio of SVLFM(slope varying linear fre.quency modulation) fuze changed at random in every pulse period, so the target echo and the deceptive signal could be sep.arated by FRFT. Because of the characteristic that the max amplitude of STFRFT was linear with the windowing width forthe same LFM signal, but the max amplitude was not change with the windowing width if two frequency modulation ratiowas different, then the target echo could be distinguished from the false target signal effectively under low SJR. Simulationresults showed that the principle was right and the method had good ability to suppress deceptive interference.