A fast DOA estimation algorithm based on direct data domain least square approach

A new fast direction of arrival (DOA) estimation algorithm based on direct data domain least square ((DLS)-L-3) approach is presented. The matrix 3 equation, which is formed according to the idea of (DLS)-L-3, is solved via the conjugate gradient (CG) method to get the weight vector from different look direction. Then, the output power from each look direction and the directional spectrum is obtained. Finally, with a rough estimation by output power and a fine estimation by directional spectrum, the DOAs of incident signals are determined. As a different algorithm from conventional ones such as MUSIC, it processes very few data snapshots with no use for the formation of the sample covariance matrix and matrix inversion operation. Therefore, it may be so effective in real-time application. In addition, the proposed algorithm is also available for the DOAs estimation of coherent signals. The estimation capability is proved by simulation results.