基于分离式电磁矢量传感器阵列的相干信号波达方向估计

Coherent sources DOA estimation with spatially spread electromagnetic vector sensor array

目前,分离式电磁矢量传感器相干源估计问题研究处于起步阶段,现有方法最多只能解6个相干信号源。研究空间平滑算法在分离式电磁矢量传感器阵列中的应用,以解决该问题。首先对平面阵列进行两维子阵划分,然后通过选择矩阵对该划分子阵进行抽取,最后对各抽取子阵进行空间平滑处理。完成两维空间平滑后,利用子空间旋转不变技术和矢量叉积算法完成目标的两维波达方向估计。所提方法在解决共点式电磁矢量传感器互耦严重、硬件设计困难的同时,采用稀疏阵列提高了波达方向测量精度,且该方法不受制于6个相干入射信号源。计算机仿真结果证明了所提空间平滑方法在均匀分离式电磁矢量传感器平面阵中解相干的有效性。

The aspect of direction-of-arrival（DOA）estimation of coherent sources with the spatially spread electromagnetic vector sensor（SS-EMVS）is in the early stages of development.The existing methods can only resolve 6coherent sources.The application of the spatial-smoothing method to improve resolvable coherent sources in SS-EMVS is studied.Firstly the rectangular SS-EMVS array is divided into two-dimensional（2D）sub-arrays.Then the 2Dsubarrays by using appropriate selection matrix are extracted.Finally,these 2Dsub-arrays with spatial-smoothing are processed.After the above processes,the 2DDOA estimation can be obtained by using the estimation of signal parameters via rotational invariance techniques（ESPRIT）and the vector-cross product estimator.The proposed method solves the problems of serious mutual coupling and difficult hardware design.It improves 2DDOA estimation accuracy greatly,and shows that the resolvable number of coherent sources is not limit to 6.Simulation results verify the effectiveness of the proposed spatial-smoothing method in uniform rectangular SS-EMVS array to de-correlate coherent sources.