Joint Elevation and Azimuth Direction Finding Using L-Shaped Array

For two-dimensional (2-D) directions-of-arrival (DOA) estimation problem, the L-shaped array seems to have higher accuracy than other structured arrays [see ¿An L-shaped array for estimating 2-D directions of wave arrival¿ by Hua for details], and has received much attention. To estimate elevation and azimuth angles, two correctly matched electric angles (functions of elevation and azimuth angles) are estimated in advance, so that elevation and azimuth angles are obtained from the two correctly matched electric angles. However, the failure in pairing will cause severe performance degradation. In this communication, a novel algorithm, which doesn't require match procedure, is proposed to estimate 2-D DOA in the L-shaped array geometry. The key points of this communication are: i) by introducing a novel electric angle, the steering vector is separated into two parts; ii) the two parts can be obtained in turn by generalized ESPRIT approach and eigenvalue decomposition (EVD) of one particular matrix, respectively; iii) elevation and azimuth angles can be obtained from the recovered steering vector. The resultant algorithm avoids match operation, and requires one-dimensional search once. Simulation results are presented to validate the performance of the proposed method.