Title :
A long-term predictive ADPCM coder with short-term prediction and vector quantization
Author :
Aarskog, Alv ; Nilsen, Arild ; Berg, Ole ; Guren, Hans C.
Author_Institution :
EB Technol., Billingstadsletta, Norway
Abstract :
A speech coder structure based on the long-term predictive ADPCM (adaptive differential pulse-code modulation) coder with vector quantization of pitch coefficients, the LPC (linear predictive coding) coefficients, and the residual signal is presented. In order to improve the robustness against variations in the average spectral envelope a backward adaptive microphone and speaker adaptation filter is used for preprocessing the speech. With this coder, a good delay/quality tradeoff can be obtained. Simulations of a 8.133 kb/s coder with an algorithmic delay of only 7.5 ms show that a very good speech quality is produced
Keywords :
data compression; encoding; filtering and prediction theory; pulse-code modulation; speech analysis and processing; 7.5 msec; 8.133 kbit/s; LPC coefficients; adaptive differential pulse-code modulation; algorithmic delay; average spectral envelope; backward adaptive microphone filter; delay/quality tradeoff; linear predictive coding; long-term predictive ADPCM coder; pitch coefficients; residual signal; short-term prediction; speaker adaptation filter; speech preprocessing; speech quality; vector quantization; Books; Delay; Distortion measurement; Filters; Linear predictive coding; Microphones; Noise shaping; Robustness; Speech analysis; Vector quantization;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1991. ICASSP-91., 1991 International Conference on
Conference_Location :
Toronto, Ont.
Print_ISBN :
0-7803-0003-3
DOI :
10.1109/ICASSP.1991.150272
