Title :
A 6.3 kb/s CELP codec suitable for half-rate system
Author :
Andreotti, F.G. ; Maiorano, V. ; Vetrano, L.
Author_Institution :
Italtel SIT, Milan, Italy
Abstract :
A codec scheme suitable for the GSM (Group Special Mobile) half-rate system is proposed. The source coding has been performed with a CELP (code-excited linear prediction) algorithm, which provides good speech quality at low bit rates. In order to fit the recommended speech of 11.4 kb/s for the traffic channel, a 6.3 kb/s CELP codec and a FIRE protecting scheme adding 5.1 kb/s of redundancy were used. The real-time implementation is based on two PC boards connected via the PC bus: this makes it easy to test the system functions. The speech quality is almost the same as that of a full-rate codec on a wide range of experiments with different speakers and different languages. Channel error effects are considered
Keywords :
cellular radio; codecs; digital radio systems; digital signal processing chips; filtering and prediction theory; speech analysis and processing; 11.4 kbit/s; 5.1 kbit/s; 6.3 kbit/s; CELP codec; FIRE protecting scheme; GSM; Group Special Mobile; PC boards; PC bus; TMS320C30; algorithm; channel error effects; code-excited linear prediction; experiments; half-rate system; languages; low bit rates; redundancy; speech quality; traffic channel; Bit rate; Fires; GSM; Prediction algorithms; Protection; Real time systems; Redundancy; Source coding; Speech codecs; Speech coding;
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.1991.150416
