Quantisation for Multiple Description Coding for voice over IP

Abstract

The transmission of voice over IP networks is heavily affected by packet losses. An increasingly popular method to increase the error resilience of these systems is the use of multiple description coding (MDC). However, the MDC techniques commonly used tend to add a significant amount of redundancies, which are not always easy to use optimally. In this paper, we propose a simple vector quantisation scheme to maximise MDC performance, and study several factors affecting its performance under various error conditions. The results show that it is possible to obtain good performance under packet loss conditions, while using only limited amounts of redundancy.