针对机载多输入多输出(MIMO)雷达杂波抑制问题,提出一种简化的杂波特征相消器(EC)。根据杂波在空时二维平面的先验分布离线构造杂波子空间,以此替代由协方差矩阵特征值分解(EVD)得到的杂波子空间,从而将最优权简化为一个确知投影矩阵与目标信号空时二维导向矢量的乘积,避免了传统EC方法中复杂的协方差矩阵估计和EVD运算,既消除了因协方差矩阵估计不准确而导致的性能损失又减小了运算量。仿真结果表明,在理想杂波模型条件下,简化MIMO-EC方法可获得接近最优的杂波抑制性能。
This paper proposes a simplified eigencanceler (EC) for clutter suppression in an airborne multiple input multiple autput (MIMO) radar. By using the prior knowledge of the space-time distribution of the clutter, the clutter subspace is constructed off-line to replace the clutter subspace obtained via matrix eigendecomposition, and then the weight vector is simplified to the product of a constant projection matrix and the space-time steering vector of the desired signal. This method does not require complicated covariance matrix estimation and eigenvalue decomposition (EVD), and it not only eliminates performance degradation caused by inaccurate estimation of the covariance matrix, but also reduces computational cost. Simulation results demonstrate that with an ideal clutter model, the simplified MIMO-EC method can provide near optimal clutter suppression performance.
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