单基地MIMO雷达中基于改进传播算子的二维DOA估计算法

单基地多输入多输出（Multiple input multiple output，MIMO）雷达中，针对传播算子算法在低信噪比和小快拍数环境下进行二维波达方向（Direction of arrival，DOA）估计性能下降的实际问题，提出了一种基于改进传播算子（Propagator method, PM）的二维DOA估计算法。该方法将数据共轭重构的思想应用到传播算子的估计中，借助传播算子的线性变换得到方向矩阵，由方向矩阵还原出二维波达角信息，利用矩阵变换与结构特点实现了仰角和方位角的自动配对。复杂度分析和仿真结果表明，该算法具有较低复杂度的同时，改善了传播算子算法在快拍数有限、低信噪比条件下的估计性能，实现二维DOA的自动配对。 

A two-dimensional DOA estimation algorithm based on improved propagator for monostatic MIMO radar

In multiple input multiple output（MIMO）radar,Due to the practical degradation performance of propagator algorithm in the low signal to noise ratio and a small number of snapshots environment for 2-D direction of arrival estimation for targets,An improved propagator is proposed in 2-D DOA estimation.In the proposed algorithm,conjugate data reconstruction thought is applied to estimate the propagation operator and the rotation invariance of the propagator is used in direction matrix estimation,and then we get the 2-D angles information by the direction matrix,According to the matrix change and structure feature,we realize the automatic matching of elevation and azimuth angles.Complexity analysis and simulation results show that the algorithm have low complexity,and the PM algorithm performance is improved when snapshot number is limited and in low SNR,and we realize the automatic matching of 2-D direction of arrival at the same time.