Réduction du débit des LSF's par un système d'énumération en treillis
Bachir BOUDRAA, Malika BOUDRAA, Mouloud DJAMAH, Merouane BOUZID, Bernard GUERIN.

In the present study, we were interested in the reduction of the bit-rate observed in the speech coder named CELP FS1016 (federal standard developed by the US department of the defense "DoD "). More precisely, the quantization of the Line Spectrum Frequencies (LSF) parameters was concerned. In the standard CELP FS1016, these coefficients are coded with 34 bits. We propose the use of an enumeration technique in conjunction with a treillis search coding schemes that exploits the natural ordering of the LSF. The technique allows reducing the bit rate of the LSF coefficients to 30 bits without decreasing the performance of the coder.