Coherent and incoherent interference reduction using a subband tradeoff beamformer

Signals captured by a set of microphones in a speech communication system are mixtures of desired and undesired signals. In this paper another perspective on subband beamformers in room acoustics is provided. Specifically, the observed undesired signals are divided into coherent and incoherent additive components while no assumption is being made regarding the number of coherent undesired sources. From this perspective a general tradeoff beamformer is proposed that enables a compromise between noise reduction and speech distortion on the one hand, and coherent noise versus incoherent noise reductions on the other hand. The presented performance evaluation shows how existing beamformers and the tradeoff beamformer perform in a particular scenario.