A new approach to adaptive DOA estimation based upon a database retrieval technique

In this paper, a new approach to adaptive direction-of-arrival (DOA) estima tion based upon a database retrieval technique is proposed. In this method, angles and signal powers are quantized, and a set of true correlation vect ors of the array antenna input vectors for various combinations of the quan tized angles and signal powers is stored in a database. The k-d tree is the n selected as the data structure to facilitate range searching. Estimated a correlation vector, range searching is performed to retrieve several corre lation vectors close to it from the k-d tree. The DOA and the signal power are estimated Ly laking the weighted average of angles and powers associate d with the retrieved correlation vectors. Unlike the other high-resolution methods, this method requires no eigenvalue computation, thus allowing a fa st computation. It is shown through simulation results that the processing speed of the proposed method is much faster than that of the root-MUSIC tha t requires the eigenvalue decomposition.