有源干扰条件下机载MIMO雷达STAP协方差矩阵秩的分析

摘要

The covariance matrix structure of clutter plus jamming is analyzed for side-look airborne MIMO radar, and the upper bound on its rank is derived to equal the summation of clutter and jamming rank subtracting the jammer number. According to this, a certain range of jammer number is attained. If the number of jammers is in this range, the clutter plus jamming covariance matrix is full rank for SIMO radar, whereas rank deficiency for MIMO radar. As a result, the performance of SIMO radar deteriorates severely under this condition, however, the performance of MIMO radar is much better, due to sufficient degrees of freedom to suppress clutter and jamming for MIMO radar. The simulations validate the above conclusion.%该文分析了正侧阵机载MIMO雷达杂波加有源干扰协方差矩阵的结构,得到杂波加有源干扰协方差矩阵秩的上界为杂波的秩与有源干扰的秩之和减去有源干扰个数.并由此得到MIMO雷达杂波加有源干扰协方差矩阵非满秩而SIMO雷达杂波加有源干扰协方差矩阵满秩时有源干扰个数的范围.当有源干扰的数目在此范围时,SIMO雷达的理论性能严重下降,而MIMO雷达在理论上仍然有足够的自由度来抑制杂波和有源干扰,从而保证有较好的性能.通过仿真实验验证了上述结论.