Robust Beamforming Method for Coprime Array with Accurate Covariance Matrix Reconstruction

In comparison to the Uniform Linear Array (ULA) with the same quantity of physical array elements, the coprime array has augmented array aperture and effectively reduces the mutual coupling effect among array elements. There are many potential advantages in resolution performance and interference rejection ability. Based on coprime array, this paper presents a robust adaptive beamforming (RAB) method. As a result of deducing the continuous elements in the differential optimization array of the coprime array, we obtain a virtual ULA that is significantly longer than a real linear array and the Toeplitz matrix of the virtual array is constructed to estimate the accurate interference direction, interference power and noise power to rebuild the interference plus noise covariance matrix (INCM). By correcting the estimated signal steering vectors (SVs), the proposed method has improved performance when the signal look direction error and array element position error exist. This method is robust and effective, as demonstrated by results from computer simulation.