Title :
CELP coding at 4.0 kb/sec and below: improvements to FS-1016
Author :
Zinser, Richard L. ; Koch, Steven R.
Author_Institution :
GE Corp. Res. & Dev., Schenectady, NY, USA
Abstract :
While code excited linear prediction (CELP) speech coders can produce high levels of output speech quality at rates near 4 kb/s, they may not be suitable for toll quality communications. The authors propose several modifications to improve the quality of the standard CELP algorithm while simultaneously reducing its transmission rate. The modifications include a multimode excitation that increases the convergence rate of the adaptive (pitch) codebook. A low-complexity spectral vector quantization algorithm is also developed that reduces the coding rate and decreases the spectral distortion. SNR improvements of 2 dB and a significant reduction in perceptual artifacts have been observed
Keywords :
linear predictive coding; speech coding; telecommunication standards; 4 kbit/s; CELP algorithm; CELP coding; FS-1016; SNR; adaptive codebook; code excited linear prediction; coding rate; convergence rate; multimode excitation; output speech quality; perceptual artifacts; pitch; spectral distortion; spectral vector quantization algorithm; speech coders; standard; toll quality communications; transmission rate; Bit rate; Code standards; Convergence; Encoding; Iterative algorithms; Loudspeakers; Research and development; Speech coding; Stochastic processes; Vector quantization;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1992. ICASSP-92., 1992 IEEE International Conference on
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-0532-9
DOI :
10.1109/ICASSP.1992.225909
