Design and implementation of Vector Quantizer for a 600 bps cocoder Based on MELP

This paper describes a vector quantization of a 600 bps speech coding parameters based on the Mixed Excitation Linear Prediction (MELP) model, which was accepted as a standard in communication on narrow-band HF channels. The MELP speech coders are robust in difficult background noise environments and intended mostly for military communications. To reduce the bit rate, a joint vector quantization of multi-frame is developed that takes advantage of inherent inter-frame redundancy of the MELP parameters. By grouping parameters of 4 frames into a multi-frame and using vector quantization, bit rate is decreased 4 times and output speech is still intelligible.