A memory-efficient algorithm for network echo cancellation in VoIP systems

In recent years, considerable interest has been focused on voice-over-IP (VoIP) systems. VoIP media gateways implement voice and packet processing for hundreds of channels. One of the limiting factors in such high channel-density voice processing applications is the memory requirement. A substantial amount of memory is used to store the coefficients of the network echo canceller. This paper describes a new algorithm that reduces the memory requirements for echo cancellation by a factor of 2 to 4. When the new memory reduction algorithm is combined with standard NLMS, it also provides faster convergence rate, and better echo path tracking than the standard NLMS algorithm.