Voice-excited LPC coders for 9.6 kbps speech transmission

This paper considers the use of voice-excited linear predictive (LPC) coders for speech transmission at a bit-rate of 9.6 kbps. In our on-going work, we study in detail the various aspects of this class of speech coders, with the goal of maximizing the speech quality at the above rate. Important among these aspects are: baseband residual versus baseband speech transmission, coding of the baseband signal, and high-frequency regeneration from the baseband. We provide a discussion of these and other issues, and indicate a number of variables that have been included in our speech-quality optimization study. Experimental results obtained to date are summarized in the paper. More complete results and conclusions will be presented at the conference.