FRFT与时域联合处理的欺骗干扰抑制方法

Jamming Suppression for Signal Based on FRFT and Time Domain

针对斜率抖动线性调频(SVLFM)脉冲压缩雷达受假目标欺骗信号干扰的问题,提出一种分数阶傅里叶变换(FRFT)滤波和时域联合处理的欺骗干扰抑制方法。通过分数阶傅里叶变换将欺骗干扰信号中与回波信号调频率相差较大的干扰分量进行滤波处理,对滤波后信号进行分数阶傅里叶反变换到时域后,利用相同调频率的LFM信号经加窗脉冲压缩后,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,进一步将与回波信号调频率相近的干扰分量进行区分。最后通过仿真验证了低信干比条件下,该方法能够有效滤除多分量假目标欺骗干扰信号,正确检测目标回波信号。

An interference suppression method based on fractional Fourier transform and time domain is proposed to solve the problem of false target deceptive interference for SVLFM （slope varying linear frequency modulation） radar. The interference with larger differences in chirp rate from echo signal can be eliminated based on FRFT （fractional Fourier transform）. Because of the feature that the max ampli- tude is linear with the windowing width, after pulse compression for the same LFM （linear frequency modulation） signal, but the max amplitude does not change with the windowing width if two chirp rates are different. So the interference with smaller difference from echo signal can be distinguished at time do- main. Simulation results show that the target echo can be distinguished from the false target signal effec- tively and the method is appropriate for multi-component interferences.