Channel codes that exploit the residual correlation in CELP-encoded speech

This paper describes methods by which the residual correlation in CELP-encoded speech can be exploited by an appropriately designed channel decoder. Specifically, the line spectrum pair (LSP) redundancy in Federal Standard 1016 CELP is quantified and used to effect near-MAP decoding of Reed-Solomon and convolutional codes. Coding gains of up to 3.6 dB are obtained over conventional ML algorithms.