Coprime array adaptive beamforming with enhanced degrees-of-freedom capability

In this paper, we propose a novel coprime array adaptive beamforming algorithm based on virtual array spatial spectrum estimation to enhance the degrees-of-freedom (DOFs) capability. Specifically, the coprime array received signals are derived to virtual domain, where the spectrum estimation is performed on an equivalent virtual uniform linear array. Since the virtual array contains more virtual sensors than physical sensors, the DOFs capability is effectively enhanced. Meanwhile, the large array aperture offered by coprime array provides a higher resolution than uniform linear array. With the estimated sources' directions and interferences' power, the coprime array adaptive beamformer is designed by reconstructing the interference-plus-noise covariance matrix and desired signal steering vector. Simulation results demonstrate the effectiveness of the proposed adaptive beamforming algorithm.