Optimum broadband beamforming for coherent broadband signals and interferences

Abstract

The problem of optimum broadband beamforming using linear arrays is considered with a view to avoid signal cancellation that normally results when signal-correlated interferences are present in the environment. The optimum approaches proposed here are based on a harmonic model for signals and interferences on the one hand, and a convenient characterization of the signal-free interference subspace from the observed data, on the other. The characterization so obtained leads to a broadband generalization of results reported earlier in the literature for narrowband beamforming. The three beamformers proposed here completely eliminate signal cancellation without any adverse effects. Computer simulations are presented which validate the expected performance of the three beamformers proposed here in the presence of correlated and uncorrelated interferences.