A Novel Direction-of-Arrival Estimation Algorithm Without Knowing the Source Number

As the eigenvalue ranking problem is analyzed, a direction-of-arrival (DOA) estimation method without knowing the number of sources is proposed. The proposed method is utilized through ranking the eigenvalue of specific covariance matrix to get the smallest eigenvalue and construct a new spatial spectrum. By deducing the novel algorithm, the mapping between the eigenvalues and power of signals is presented. Using the mapping, the minimum detection threshold for this algorithm is derived. Besides, the reason for the formation of pseudo-peaks is interpreted, and an approach to parameter selection is provided. The validity of the related theory of the algorithm is further investigated by simulations.