基于频域干扰剔除的 OTHR 射频干扰抑制算法

摘要

目前，天波超视距雷达（over-the-horizon radar，OTHR）大多是在空域或匹配滤波后的时频域抑制射频干扰，往往会同时抑制掉射频干扰附近的目标。考虑到在匹配滤波后，射频干扰与目标信号都是近似单频信号难以区分；而在匹配滤波前，目标信号是宽带的线性调频信号，而射频干扰是近似单频的窄带信号，射频干扰与目标信号显著不同，易于分离。基于该特点，提出了一种基于匹配滤波前的频域干扰置零的射频干扰抑制算法。该算法在频域中检测射频干扰的频点位置并将该频点的信号成分置零，最后变换到时域实现射频干扰抑制。与传统方法相比，本文所提算法在抑制射频干扰时基本不损害目标信号。实测数据的处理结果验证了所提方法的优越性。%In over-the-horizon radar (OTHR),the traditional methods suppress the radio frequency inter-ference (RFI)in space or time domain after matched filtering,and they tend to suppress the target around the RFI at the same time.We notice that RFI and the target signal are the similar narrowband signal after matched filtering,so it is difficult to distinguish them in the time domain or frequency domain;while before matched fil-tering,the target signal is a wideband signal,and the RFI is a narrowband signal.Based on these features,a RFI suppression algorithm based on interference elimination in the frequency domain is proposed.The algorithm firstly suppresses the sea clutter in the Doppler domain and transforms the signal into the frequency domain,de-tects the frequency position of RFI in the frequency domain,and then sets the frequency position to zero in the frequency domain of the original signal,finally transforms the signal to the time domain.Compared with the traditional methods,the proposed algorithm can effectively suppress the RFI and protect the target signal.Ex-perimental results verify the superiority of the proposed algorithm.