Model-based packet loss concealment for AMR coders

A general packet loss correction/concealment signal recovery framework is proposed for parametric speech coders. Both redundancy-based forward error correction (FEC) and receiver only (RO) techniques are considered in conjunction with the adaptive multi-rate (AMR) coder. The robust, low bit rate, high communications speech quality Manchester pitch synchronous (MPS) coder is employed in the proposed systems as a secondary coding process. Thus the performance of AMR/MPS-FEC/RO packetised speech transmission systems is considered. Subjective and objective computer simulation results clearly indicate the superiority of the proposed schemes over conventional AMR based systems, particularly at relatively high (>5%) packet loss rates.