Simple adaptive beamforming with only real weights based on covariance differencing

A simple adaptive beamformer is suggested that uses real weights only without phase shifting. The proposed beamformer finds the orthogonal complement of a subspace that contains the interference subspace which can be readily obtained using only the imaginary part of the covariance matrix of received signals. Simulation results show the beamformer converges as quickly as a complex eigenspace-based one