网格失配下MIMO-STAP稀疏字典构造方法

MIMO STAP Sparse Dictionary Construction Method under Off-grid Condition

针对机载多输入多输出(MIMO)雷达空时自适应处理(STAP)技术使用稀疏方法求解杂波谱时存在的网格失配问题,提出了一种字典构造方法。该方法首先使用先验知识得到准确的杂波脊线,然后沿杂波脊线方向及其垂直方向形成网格,最后将各网格节点对应的空时导向矢量取出并将空间频率和多普勒频率超出最大取值范围的原子去除以得到能克服网格失配的字典。仿真实验表明,使用该字典可有效克服网格失配问题,网格失配条件下稀疏算法使用该字典的输出SINR性能要远优于传统字典。

A dictionary construction method was proposed for space-time adaptive processing(STAP)of multiple-input multiple-output(MIMO)radar to solve the off-grid problem.In this method,the accurate clutter ridge was firstly obtained by using priori knowledge,and then grids were formed along the direction and the vertical direction of the clutter ridge.Finally,the space-time steering vector corresponding to each grid node was taken out and the atoms whose spatial frequency and doppler frequency exceeded the maximum range were removed to obtain the dictionary which could solve the off-grid problem.The simulation results showed that using this dictionary could effectively solve the off-grid problem,and the output SINR performance of the sparse algorithm using this dictionary was far better than that of the traditional dictionary under the off-grid condition.