A Hole-free Shifted Coprime Array for DOA Estimation

Coprime arrays have recently become a popular trend in estimating the direction of arrival in array signal processing, as they increase the degree of freedom (DOF). Coprime arrays utilize a couple of uniform linear subarrays to create a difference co-array with specific preferable features. In this paper, three proposed structures are considered that depend on the shifting of one of the two uniform linear arrays. The proposed configurations reveal a sequence of lags obtained by filling the holes of the co-array, which span the aperture array. The displacement value depends on the value of the pair of data in the array. The resulting virtual array achieved by means of the proposed methods may generate DOFs MN + 1, MN + N + 1, and MN + 2N - 2, respectively. The performance of the proposed configurations is evaluated by experimental simulations aiming to demonstrate the effectiveness of the array's design.