Coprime L-shaped array connected by a triangular spatially-spread electromagnetic-vector-sensor for two-dimensional direction of arrival estimation

摘要

The authors propose a hybrid L-shaped array composed of two sparse scalar arrays and a single triangular spatially-spread electromagnetic-vector-sensor (SS-EMVS) for two-dimensional (2D) direction-of-arrival (DOA) estimation. These two sparse but uniform scalar arrays are placed along the x-axis and y-axis, respectively, which constitute two arms of the L-shaped array. These two arms are connected by an SS-EMVS, which consists of a spatially-spread dipole-triad plus a spatially-spread loop-triad. Further, the inter-dipole/loop spacings of SS-EMVS follow a coprime relationship with the inter-sensor spacings of the L-shaped scalar array. In proposed DOA estimation algorithm, they first perform the vector-cross-product algorithm to SS-EMVS to obtain a high-accuracy but ambiguous direction cosine estimation; they then apply the ESPRIT algorithm to the scalar array on each arm to get another high-accuracy but cyclically ambiguous direction cosine estimation; finally, they adopt the Chinese Remainder Theorem to disambiguate the ambiguous estimations. Because the authors' proposed array has 2D array aperture extension, it can achieve a high angular estimation performance. Moreover, one component of triangular SS-EMVS rather than an SS-EMVS is used as the array unit of two scalar arrays; thus, the whole array cost decreases dramatically. Simulation results validate the array configuration and the developed algorithm.