Direction of arrival estimation using combined coprime and nested array

A combined coprime and nested array geometry is designed and a corresponding direction of arrival (DOA) method is proposed. The proposed array has three subarrays, where two are prototype coprime subarrays, and both of them are nested to the third one. Then the vectorisations of two covariance matrices yield two virtual coprime subarrays, which show a much larger aperture compared to the physical ones. Thereafter, through Toeplitz matrix reconstruction and root multiple signal classification, two coprime estimations are obtained and they are combined to obtain the final unique DOA estimation. Multiple analysis and simulations verify that the proposed method achieves larger aperture, better DOA estimation accuracy and higher angular resolution compared to other coprime array-based methods.