非合作无源探测中的参考信号提纯新方法

A novel algorithm for reference signal purification in non-cooperative passive detection

非合作无源探测系统通过直达波提纯来获取参考信号,参考信号的纯净程度对系统探测性能具有重要影响。针对非合作无源探测中的参考信号提纯问题,提出了一种基于稀疏特性的参考信号提纯新方法。首先将参考通道接收的混合信号变换到对时延敏感的分数阶傅里叶变换域上,并对直达波信号和多径干扰信号在分数阶傅里叶变换域上的稀疏特性进行了分析;然后利用分数阶傅里叶变换域的尖峰推导出直达波信号的参数,恢复直达波信号,实现参考信号提纯。仿真结果表明了本文提出新方法的有效性,与时域自适应滤波方法相比,该方法提纯的参考信号失真更小。

The non-cooperative passive detection system obtains the reference signal by purifying the direct-path signal,and the purity of the reference signal will make a difference to the performance of target detection.A novel algorithm for reference signal purification is proposed based on sparse characteristics.First,the mixed signal received by the reference channel is transformed to the fractional Fourier domain.The sparse characteristics of direct-path signal and multipath signals are analyzed in the fractional Fourier domain.Then,the estimation of parameters from derivation of peaks in the fractional Fourier domain will be used to reconstruct the direct-path signal.Finally,simulation results demonstrate that the proposed algorithm is effective and outperforms the temporal adaptive filter as well as the purified reference signal is distortionless.