Improved G723.1 Codec Speech Quality Under Burst Packet Loss Conditions

In this paper, a Packet Loss Concealment (PLC) algorithm is proposed for G723.1 CELP-type speech coders in order to improve the quality of decoded speech in VoIP under burst packet loss. The original PLC method implemented in this codec is based on the generation of excitations. The generated excitations are used as input to the LP synthesis filter based on past LP coefficients. In an easier way, it relies on the last frame, which is well received to generate a new frame that replaces the lost frame. The proposed PLC is designed as a PLC algorithm for G.723.1. The proposed method performance is compared with the PLC algorithm employed in G.723.1, through the Perceptual Evaluation of Speech Quality (PESQ). The experiments have shown that the proposed PLC algorithm provides significant enhancement of the speech quality than the PLC of G.723.1, especially in the presence of burst packet loss and voice onset conditions.