Combined adaptive beamforming techniques for noise reduction in changing environments

This paper introduces two novel adaptive beam-forming techniques for noise reduction applications. The proposed architectures derive from the generalized sidelobe canceller (GSC); the novelty relies on the use of a combined adaptive sidelobe cancelling structure which allows the system to achieve robustness in nonstationary environments. This structure is composed of a convex combination of two multiple-input singleoutput (MISO) adaptive systems with complementary capabilities which is able to preserve the best properties of each system. The difference between the two schemes lies in the way of combining the two MISO systems. The effectiveness of the proposed systems is assessed in a typical context of a hands-free teleconferencing application in a noisy environment. The experiments show that the proposed beamforming system is capable of improving performance of conventional techniques.