DRM无源雷达多径杂波的分载波空域抑制

鉴于数字调幅广播（DRM）无源雷达面临严重的多径杂波问题,建立了该无源雷达阵列信号模型,提出了一种基于分载波空域处理的多径杂波抑制方法.该方法先将DRM无源雷达阵列接收的时域信号经去保护间隔和傅里叶变换（FFT）之后,通过对各载波信号分别求取干扰协方差矩阵和空间自适应系数以滤除直达波和多径杂波.分载波空域处理方法综合利用了多通道空域信息及同一载波下直达波和多径杂波的时域相关性,降低了杂波抑制的空域自由度要求,提高了杂波抑制能力,克服了常规空域处理方法自由度不足或杂波噪声比低导致的杂波零陷深度不够等缺点.理论分析和仿真结果表明了该算法的优越性.

Multipath clutter suppression by spatial filtering on each carrier in DRM-based passive radar

Due to the problem of severe multipath clutter pollution in DRM-based passive radar,the signal model was introduced and a spatial filtering method done on each carrier was presented.Firstly,the guard interval was cut and fast Fourier transform(FFT) was performed on the received temporal data to separate the carriers.Then the interference covariance matrix and spatial adaptive coefficient were computed for each carrier to filter the direct-path signal and multipath clutter.This method used both the multi-channel spatial information and the time-correlation of direct-path signal and multipath clutter at the same frequency,which reduced the requirement of the clutter DoF(degree of freedom),improving the clutter-suppressing capability and overcoming the disadvantage of the dissatisfactory clutter null depth due to the inadequate clutter DoF or low clutter-to-noise ratio when using the traditional spatial filtering method.Both the theoretical analysis and simulation results verified the method′s advantages.