Codage efficace à bas débit des paramètres spectraux LSF.
Merouane BOUZID, Amar DJERADI, Bachir BOUDRAA.

Speech coders operating at low bit rates necessitate efficient encoding of the linear predictive coding (LPC) coefficients. Line spectral Frequencies (LSF) parameters are currently one of the most efficient choices of transmission parameters for the LPC coefficients. In this paper, an optimized trellis coded vector quantization (TCVQ) scheme for encoding the LSF parameters is developed. When the selection of a proper distortion measure is the most important issue in the design and operation of the encoder, an appropriate weighted distance measure has been used during the TCVQ construction process. Using this distance, we will show that our LSF TCVQ encoder performs better than the encoder conceived with the unweighted distance.