A 1200 bits/s HSX speech coder for very-low-bit-rate communications

This paper presents a new very-low-bit-rate speech coder that was selected for an application of vocal paging in North America. The coder is based on the harmonic stochastic excitation (HSX) algorithm, a technique that was developed by Thomson-CSF in collaboration with the University of Sherbrooke. The paper gives a brief description of the HSX algorithm, presents the quantization process for its operation at 1200 bit/s, and gives the CPU and memory requirements for its implementation on a fixed-point (TI C54x) and a floating-point (TI C3x) DSP. Some evaluation results are also given.