Direction-of-Arrival Estimation for Coprime Arrays via Interpolation of Sum-Difference Co-array

In this paper, we propose a novel efficient approach for direction-of-arrival (DOA) using coprime arrays. Specifically, we derive the equivalent received signals of the sum-difference array using the received input of the conjugate augmented coprime array. Subsequently, we designed an interpolation algorithm to obtain the maximum virtual uniform linear array (ULA) using complete array information. The covariance matrix of the virtual array is restored by re-weighted atomic norm minimization (RNM). Finally, we estimate the DOAs of sources via the MUSIC spectral search algorithm. The proposed method outperforms several existing approaches, as demonstrated through numerical experiments.