Title :
Backward adaptation for low delay vector excitation coding of speech at 16 kbit/s
Author :
Cuperman, Vladimir ; Gersho, Allen ; Pettigrew, Robert ; Shynk, John J. ; Yao, Jey-Hsin
Author_Institution :
Dept. of Eng. Sci., Simon Fraser Univ., Burnaby, BC, Canada
Abstract :
To attain a very-low-delay speech coder at 16 kb/s while maintaining a quality acceptable for the public switched telephone network, low delay vector excitation coding (LD-VXC) is introduced. Backward adaptation is used to track the spectral characteristics of the signal without requiring any buffering of the input speech, thereby allowing a very low delay to be achieved in an analysis-by-synthesis structure. The algorithm differs markedly from conventional VXC or CELP (code-excited linear prediction) coders due to the use of backward adaptive linear prediction for modeling the time-varying short- and long-term correlation of speech. The LD-VXC coder provides very good speech quality at 16 kb/s, moderate complexity, a delay of under 2 ms, and a gentle degradation of quality with transmission errors. The algorithm was submitted to the CCITT as a candidate for a future 16-kb/s speech coding standard
Keywords :
correlation methods; encoding; filtering and prediction theory; speech analysis and processing; speech synthesis; standards; telephone networks; analysis-by-synthesis structure; backward adaptive linear prediction; good speech quality; low delay vector excitation coding; public switched telephone network; spectral characteristics; speech coding standard; time-varying long-term correlation; time-varying short-term correlation; transmission errors; Decoding; Delay; Distortion measurement; Information filtering; Information filters; Signal analysis; Signal synthesis; Speech analysis; Speech coding; Speech synthesis;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64153