Abstract:

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 6 coherent 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 2D sub-arrays by using appropriate selection matrix are extracted. Finally, these 2D sub-arrays with spatial-smoothing are processed. After the above processes, the 2D DOA 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 2D DOA 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 decorrelate coherent sources.