A Robust Adaptive Beamforming Approach

In this paper, a new adaptive weight computation algorithm for a robust array antenna is presented to improve the shortcoming of linearly constrained adaptive beamformer's sensitivity to the mismatch between the prescribed and actual direction of arrival (MPDOA). The adaptive array minimizes the mean output power under the direction constraint that the mean square deviation between the desired and actual responses satisfies a certain magnitude bound. A new efficient and accurate approximation of the continuous direction range integration is derived and an equivalent inequality constraint is given, and it is proved that the solution occurs on the inequality constraint bound, then the Lagrange multiplier method and the Newton's one are united to solve the equivalent equality constrained minimization problem. Some computer simulation results show that the superior performance of the proposed beamformer in the robustness against MPDOA and high SINR than the existing directionally constrained beamforming algorithms.