A novel echo canceller using silence detection and echo path minimisation

This paper describes an improved technique for the cancellation of echoes in digital telephony. The proposed technique provides for multiple gains both in terms of computational complexity and performance. It is based on two components: the silence characteristics of telephony conversations and the impulse response of the line termination. The exploitation of these characteristics allows for a reduction in costs, which is a major prohibitive factor in the deployment of echo cancellers. In addition this provides for an improvement in the quality of echo cancellation when compared to the existing classical methods. It is shown that such an optimized method provides for approximately a 90% cut in processing complexity in a typical telephony environment. In addition it is shown that the results obtained using this improved method provide better quality than those possible with the classical Normalised Least Mean Square (NLMS) algorithms.