Using an Oblique Projection Operator for Highly Correlated Signal Direction-of-Arrival Estimations

In this paper, a high-resolution direction-of-arrival (DOA) estimation algorithm is proposed for highly correlated signals. This algorithm is divided into two stages. In Stage 1, a high-resolution method of DOA estimation using an oblique projection operator was applied to estimate the DOA of highly correlated signals. In Stage 2, because estimations obtained in highly correlated signal environments are prone to bias, a beamspace was built near the estimated angles from Stage 1 to reduce DOA bias. Next, the oblique projection operator was used on the beamspace to determine the characteristics of the signal source DOAs on a spatial spectrum for scanning and estimating the angle of arrival of signals. High-resolution estimations of DOA were thus obtained. Finally, computer simulations were performed to assess the performance and procedural accuracy of the proposed method.