Robust adaptive beamforming method based on interference-plus-noise covariance matrix

In order to improve the performance of adaptive beamforming, this paper proposes a robust adaptive beamforming algorithm. In this algorithm, first the signal-free interference-plus-noise covariance matrix is reconstructed using MUSIC spatial spectrum as the power density distribution, then the optimization problem of estimating the desired signal steering vector is formulated by maximizing the array output power and adopting spherical set constraint, next the Lagrange multiplier method is employed to yield the computing formula of the optimal steering vector of desired signal. Simulation results demonstrate that the performance of proposed adaptive beamformer is almost always close to optimal in a very large range of signal-to-noise ratio(SNR), outperforming existing adaptive beamformers.