This paper deals with adaptive antenna array beamforming under spatial information uncertainties including steering angle mismatch, random perturbations in array sensor positions, and mutual coupling between antenna array sensors. To make antenna array beamformers robust against the spatial information uncertainties, we present an iterative method to obtain an appropriate estimate of the actual direction vector for each of the desired signals. The proposed method uses only the a posteriori information of the received array data. It invokes an appropriate objective function for estimation and solves the minimization of the objective function by using a gradient based algorithm. The convergence property of the proposed method is investigated. Simulation results are provided for showing the effectiveness of the proposed method.
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