High-Performance DOA Estimation for Coprime Arrays with Unknown Number of Sources

Pal et al. proposed a method to extend a coprime array to a larger virtual uniform linear array (ULA), thus subspace-based direction of arrival (DOA) estimation algorithms can be used to detect more sources than the number of array elements. However, since the subspace-based DOA estimation methods are applied, the DOA estimation accuracy depends on the number of sources estimation performance. By employing a set of Toeplitz matrices, we propose a DOA estimation method for coprime array, which does not need to know the number of sources prior to computing the spatial spectrum. Computer simulations are provided to demonstrate effectiveness of the proposed approach.