Robust adaptive beamforming using beamspace steering vector estimation

To solve the problem of performance degradation owing to imprecise knowledge of the array steering vector and inaccurate estimation of the sample covariance matrix, a novel algorithm based on beam-space steering vector estimation for robust adaptive beamforming is presented. By using the complementary set of the spatial sector in which the actual steering vector lies, a beam-space transformation matrix can be constructed to remove the signal of interest from the sampling covariance matrix. The beam-space steering vector is estimated by solving a non-convex quadratically constrained quadratic optimisation problem. The effectiveness and robustness of the proposed algorithm is verified by the simulations.