A Side Information Based Packet Loss Recovery Algorithm in VoIP

In VoIP (Voice over Internet Protocol) applications, packet loss affects the received speech quality greatly. PCM (Pulse Code Modulation) coders are often used for VoIP and also face such problems. In this paper a side information based packet loss recovery algorithm is proposed, which introduces a small part of corrective information to provide an enhanced reconstruction of the lost packets. A virtual reconstruction is implemented for every original packet with side information and the redundancy is obtained with MMSE criterion at the sender endpoint. When packet loss happens, the lost packets will be recovered with side information and redundancy at the receiver endpoint.  The simulation results show that the speech quality over IP network is obviously improved at the price of only a low bandwidth consumption with the proposed method.