Acoustic echo cancellation in the presence of microphone arrays

Hands-free communication can be applied to many practical applications such as teleconferencing, video conferencing, voice over Internet Protocol (VoIP) conferencing, and mobile telephony to make communicating more convenient and safer. In order to make sure that a high quality conversation exists between parties the hands-free system requires a microphone array beamformer, to reduce background noise, as well as an acoustic echo canceller to prevent the far-end signal from being transmitted back to the far-end. This thesis proposes a new structure for combining acoustic echo cancellation and microphone array beamforming that outperforms current structures under changing conditions within the hands-free environment. Simulations have shown that by taking into consideration the dynamic behaviour of the hands-free environment, the proposed structure outperforms current combined structures by up to approximately 2dB on average during changing acoustical environment conditions.