Adaptive forward-backward quantizer for low bit rate high-quality speech coding

A novel variable rate linear predictive coding (LPC) parameter quantization scheme is proposed in which linear prediction is done by using either the current (forward LPC) or previously decoded (backward LPC) speech blocks. The proposed LPC quantization scheme was integrated into the FS1016 Federal Standard CELP coder. Signi cant LPC bit rate reduction is achieved without compromising the decoded speech quality. Submitted to IEEE Trans. on Speech and Audio Processing EDICS Category: SA 1.4.2 Analysis-by-Synthesis Coding Tel. (573) 882-2382 Fax. (573) 882-8318 E-mail: [email protected] This work was supported in part by NSF Award IRI 95-02074 and by NASA Applied Information Systems Research award NAG-2573 and NASA Innovative Research award NAGW-4698 managed by Glenn Mucklow.