基于子空间估计的MIMO阵列降维STAP方法

当对多输入多输出(multiple input multiple output, MIMO)阵列进行空时自适应处理时，由于MIMO阵列虚拟孔径增大，相对常规相控阵列能够更好地抑制杂波和干扰，但其所需样本数据量大且计算复杂度高，工程实际中难以应用。提出基于子空间估计的MIMO阵列降维空间自适应处理（space time adaptive processing, STAP）方法，该方法结合扁长椭球波函数的时限带限特性近似构造出降维的杂波子空间，并利用与发射波形正交的辅助匹配滤波通道估计出干扰加噪声协方差矩阵，通过“逼零”方法求得MIMO阵列系统的空时权矢 量。仿真结果表明，当存在非理想因素影响时，该方法能够有效抑制杂波和干扰且降维运算量更低。

Reduced-rank STAP method for MIMO array based on estimation of subspace

As the result of the extended virtual array aperture for multiple input multiple output(MIMO) array,the MIMO array can further suppress the clutter and jammer compared with the conventional phased-array.In practice it is difficult to use because of needing more sample support and higher computational complexity.A reduced-rank MIMO space time adaptive processing(STAP) method is proposed based on jammer estimated subspace.The method utilizes the characteristics of the time-limited and band-limited of prolate spheroidal wave function(PSWF) to approximate the clutter subspace.The MIMO system space-time weight is obtained by the "zero-forcing" method,and the covariance matrix containing jammer and noise is acquired through the matched filter orthogonal to all transmitted independent signal waveforms.The simulation results demonstrate that the proposed method can effectively suppress the clutter and jammer and has lower computational complexity.