双基地分布式阵列MIMO雷达的DOA和DOD估计方法

结合分布式阵列和双基地多输入多输出(Multiple-Input Multiple-Output, MIMO)雷达的特点, 提出了一种新的双基地分布式阵列MIMO雷达的接收角(Direction of Arrival, DOA)和发射角(Direction of Departure, DOD)估计方法.根据发射阵列和接收阵列的空域旋转不变特性, 利用旋转不变估计技术(Estimation of Signal Parameters via Rotational Invariance Techniques, ESPRIT)获取无模糊DOA粗估计和高精度周期性模糊的DOA、DOD精估计; 再利用无模糊DOA粗估计、目标的双基地距离信息以及双基地MIMO雷达的几何特点, 解除DOA、DOD精估计的周期性模糊, 得到高精度且无模糊的DOA和DOD估计.最后, 根据ESPRIT算法原理和估计误差的概率统计特性进行算法的性能分析, 给出算法基线模糊门限的近似计算方法.该算法有效地放宽了发射阵列孔径扩展程度的限制, 从而提高了阵列在大孔径下的角度估计精度, 且能够实现DOA和DOD估计的自动配对.仿真结果验证了所提算法和性能分析方法的有效性.

DOD and DOA estimation in bistatic MIMO radar with distributed subarray antennas

Combining the characteristics of distributed subarray antennas (DSA) and bistatic multiple-input multiple-output (MIMO) radar, a novel algorithm for direction of departure (DOD) and direction of arrival (DOA) estimation is proposed.First, according to spatial rotational invariance of transmitting array and receiving array, we use estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm to obtain the non-ambiguous coarse DOA estimation and the high accurate but cyclically ambiguous fine DOD and DOA estimation.Then, the high accurate and unambiguous DOD and DOA estimation can be obtained by using the non-ambiguous coarse DOA estimation, range information of targets, and the geometry of bistatic MIMO radar to disambiguate the above mentioned cyclic ambiguity.Last, the performance of the proposed algorithm is analyzed according to the ESPRIT algorithm principle and the statistic characteristics of estimation error.We also give an approximate method for calculating baseline thr-eshold.The proposed algorithm relaxes the restriction on the aperture of transmitting array, and the accuracy of angle estimation is improved under large aperture array.Moreover, the DOD and DOA estimation using our method is automatically paired.Simulation results show the good performance of proposed method and the effectiveness of performance analysis method.