Underdetermined DOA estimation based on covariance matrix reconstruction using coprime array

In this paper, a novel covariance matrix reconstruction method was proposed to fill the holes in the difference coarry of coprime array for direction of arrival (DOA) estimation. First, the propose method extend the covariance matrix to a Toeplitz matrix by solving the trace minimization problem, thereby the available degree of freedom are increased. Then employ the reconstructed covariance matrix with root music to estimate DOAs. Compared with existing method, the proposed method can detect more signals than sensors and alleviate the effect of basis mismatch. Numerical experiment results are provided to demonstrate the effectiveness of the proposed method.