Design of 600 bps Speech Coding Algorithm Based on MELPE
This paper describes a new 600 bps speech coding algorithm based on the enhanced mixed excitation linear prediction model (MELPe), which is the new NATO standard STANAG 4591. The MELPe speech coders are robust in difficult background noise environments and intended mostly for military communications. Multi-frame joint vector quantification algorithm is used, which takes advantage of inherent inter-frame redundancy. The predicted multi-stage vector quantization algorithm is designed to quantize the line spectrum frequency (LSF) parameters. To handle channel errors and without requiring extra overhead, simulated annealing (SA) algorithm is used to perform a judicious assignment of binary codes to index the vectors in the vector quantification codebook. Simulation results have proven that the proposed coder is found better than that of LPClOe and approximately near the 2.4 kbps MELP standard.