基于二次虚拟孔径扩展的双基地MIMO雷达相干分布式目标中心角度估计

摘要

A new central angle estimation method of the coherently distributed sources for bistatic MIMO radar is proposed based on second virtual array aperture extension. Firstly, the bistatic MIMO radar data model for the coherently distributed sources with the identical deterministic angular distribution function and distribution parameter is built based on nonuniform array. The second virtual array aperture extension is also realized by the colocated difference arrays of the minimum redundancy arrays. Furthermore, the new correlation matrix is obtained via transformal, eliminating redundant and changeable dimensional matrix. Finally, the central angles of DODs and DOAs are estimated without pairing algorithm by the idea of ESPRIT. Because of the second virtual array aperture extension, the proposed method provides much more parameter identifiability and better parameter estimation performance than the conventional bistatic MIMO radar. The effectiveness of the proposed method is verified with the computer simulation.%该文提出了基于二次虚拟孔径扩展的双基地MIMO雷达相干分布式目标中心角度估计算法。首先构造了基于非均匀阵列的具有相同确定性角信号分布函数和分布参数的相干分布式目标的双基地MIMO雷达信号模型，再利用基于最小冗余的差分共置阵列思想，实现了阵元二次虚拟扩展；然后通过构造置换、去冗余和换维矩阵，得到了新的协方差矩阵；最后利用 ESPRIT 算法思想，估计出相干分布式目标的发射、接收中心角，并且实现了角度参数的自动配对。由于该文算法实现了阵元二次虚拟扩展，因此相比于传统MIMO雷达能识别更多的目标，具有更高的估计精度。实验仿真结果证明了该文算法的有效性。