I. Introduction
Consider a linear array of uniformly spaced sensors. The goal of blind beamforming is to provide an estimate of an unknown desired signal incident on the array, without using any pilot signal. An ideal beamformer is characterized by a beam pattern that has zero attenuation in the direction of arrival (DOA) of the desired signal and infinite attenuation in the DOA of the interference signal(s), and in addition, it also filters out the measurement noise.