Title :
A comparison of US Government standard voice coders
Author :
Welch, Vanoy C. ; Tremain, Thomas E. ; Campbell, Joseph P., Jr.
Author_Institution :
US Dept. of Defense, Ft. Meade, MD, USA
Abstract :
The new US Government standard 4800-b/s code-excited linear predictive (CELP) coder is compared with the 2400-b/s linear prediction (LPC-10e) and 16000-b/s continuously variable slope delta modulation (CVSD) Federal Standard voice coders. This comparison includes speech quality and intelligibility in quiet and noisy environments/channels, speaker recognition, analog and digital implementation requirements, tandem coding, and coding delay. CELP is shown to offer dramatic improvements in speech quality relative to LPC-10e and CVSD. Although CELP requires significantly more computation than CVSD or LPC-10e, a version can be implemented on a single, new-generation, digital-signal-processing (DSP) chip. CELP provides interoperability among various computationally complex implementations, and CELP´s robust performance tolerates a wide range of speaker variation, background noise conditions, analog impairments (i.e. nonflat microphones and channels), tandems, and errors. These features make CELP ideal for many speech applications
Keywords :
digital signal processing chips; vocoders; 16000 bit/s; 2400 bit/s; 48000 bit/s; CELP; CVSD; DSP; LPC; US Government standard voice coders; analog; chip; code-excited linear predictive; coding delay; continuously variable slope delta modulation; digital; digital-signal-processing; intelligibility; speaker recognition; speech quality; tandem coding; vocoders; Analog computers; Code standards; Delay; Delta modulation; Digital signal processing chips; Noise robustness; Speaker recognition; Speech coding; US Government; Working environment noise;
Conference_Titel :
Military Communications Conference, 1989. MILCOM '89. Conference Record. Bridging the Gap. Interoperability, Survivability, Security., 1989 IEEE
Conference_Location :
Boston, MA
DOI :
10.1109/MILCOM.1989.103937
