A fixed blocking matrix for robust microphone array beamforming

In this paper, we introduce a novel fixed blocking matrix into the generalized sidelobe canceller (GSC) beamformer. This new scheme increases the tolerance of the adaptive beamformer to errors in the direction of the target signal. Signal suppression is maintained even when the estimated direction of a desired signal deviates significantly from its true direction. The increased tolerance is the result of widening the central allowable region in the blocking matrix by introducing multiple s; as will be apparent, the increased tolerance is at the cost of reduced resolution in the look direction of the microphone array. Simulation results are included to illustrate the performance of noise reduction for a linear microphone array which incorporates our fixed blocking matrix.