Coherent interference suppression via partially adaptive beamforming

The problem of adaptive beamforming in a coherent interference environment is addressed. A partially adaptive beamformer is proposed to present desired signal cancellation. The mean squared error at the beamformer output is shown to consist of a signal cancellation term associated with the presence of interferers coherent with the desired signal and an interference cancellation term. Both terms are functions of the degrees of freedom employed in the partially adaptive beamformer. Hence, the authors propose choosing the degrees of freedom to minimize the average mean squared error over a likely set of interference scenarios. An approximate solution to this optimization problem is described. Simulations are provided to illustrate the effectiveness of this approach