Title: Echo cancellation in VoIP with improved least square lattice method

Authors: Supachai Tangwongsan, Ittipon Rassameeroj

Addresses: Department of Computer Science, Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok 10400, Thailand. ' Department of Computer Science, Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok 10400, Thailand

Abstract: In this work, an approach to echo cancellation in VoIP network based on the packet-based echo cancellation model was employed. In addition, a comparative validation was performed and then analysed specifically in the state of echo canceller as adaptive filtering was done by using three algorithms: normalised least mean square (NLMS), recursive least square (RLS) and least square lattice (LSL). Communication environments with three different echo strength levels: 20%, 50% and 70% of far-end speech were simulated. The result shows that in terms of time computation, NLMS is the best, followed by LSL and RLS as the last. However, NLMS suffers from the measure of ERLE, as it falls to the third place, followed by LSL and RLS as the first. Then, taking them all into consideration, it could be concluded that LSL is the best among all for echo cancellation as verified in the experimental simulation.

Keywords: voice over internet protocol; VoIP networks; echo cancellation; adaptive filtering; least square lattice; LSL; voice over IP; simulation.

DOI: 10.1504/WRSTSD.2010.032350

World Review of Science, Technology and Sustainable Development, 2010 Vol.7 No.1/2, pp.141 - 160

Published online: 31 Mar 2010 *

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