Generalized Array Architecture with Multiple Sub-Arrays and Hole-Repair Algorithm for DOA Estimation

Arranging multiple identical sub-arrays in a special way can enhance degrees of freedom (DOFs) and obtain a hole-free difference co-array (DCA). In this paper, by adjusting the interval of adjacent sub-arrays, a kind of generalized array architecture with larger aperture is proposed. Although some holes may exist in the DCA of the proposed array, they are distributed uniformly. Utilizing the partial continuity of the DCA, an extended covariance matrix can be constructed. Singular value decomposition (SVD) is used to obtain an extended signal sub-space, by which the direction-of-arrival (DOA) estimation algorithm for quasi-stationary signals is given. In order to eliminating angle ambiguity caused by the holes of DCA, the estimation of signal parameters via rotational invariance techniques (ESPRIT) is used to construct a matrix that includes all angle information. Utilizing this matrix, a secondary extended signal sub-space can be obtained. This signal sub-space is corresponding to a hole-free DCA. Then, dealing with the further extended signal sub-space by multiple signal classification (MUSIC) algorithm, the unambiguous DOAs of all incident signals can be estimated. Some simulation results are shown to prove the improved performance of proposed generalized array architecture in DOA estimation and the effectiveness of corresponding hole-repair algorithm in eliminating angle ambiguity.