机载MIMO雷达可联合利用时间自由度、发射和接收空间自由度抑制杂波,但只能利用接收空间自由度抑制有源干扰。基于此特点,该文提出一种机载MIMO雷达的两级空时自适应处理方法抑制杂波和干扰。第1级处理中只利用部分空间接收自由度进行干扰抑制,同时实现降维处理;第2级通过匹配滤波获得发射空间自由度,并联合剩余接收空间自由度和时域自由度,进行空时联合自适应处理抑制杂波。该方法通过分级处理既有效利用了MIMO雷达的发射自由度进行杂波抑制,又同时大大减低了计算量和样本需求。理论分析表明存在强干扰时,两级处理的理论性能可以逼近全维处理的最优性能。仿真实验表明了该算法的有效性。
Airborne MIMO radar uses its temporal freedom and receiving transmitting spatial freedom to suppress clutter,while it nulls jammers by only receiving spatial freedom.Based on these characteristic,a novel two-stage method is presented in this paper,which separates suppression of clutter and jammers into two sequential stages.First,jammers are nulled with partial receiving freedom,and dimension reduction is also implemented.Second,matched-filtering is applied to the output data after jammer suppression,followed by clutter suppression using temporal and spatial freedom.Through the two-stage processing,transmitting spatial freedom can be fully utilized in clutter suppression together with reducing the computational load and sample requirement effectively.Both theoretic analysis and simulation experiments present that,in the presence of strong jammers,performance of the proposal can approach to that of the full dimension space-time adaptive processing for MIMO radar.