CELP base-band coder for high quality speech coding at 9.6 to 2.4 kbps

Author

Kondoz, A.M. ; Evans, B.G.

Author_Institution

Dept. of Electron. & Electr. Eng., Surrey Univ., Guildford, UK

fYear

1988

fDate

11-14 Apr 1988

Firstpage

159

Abstract

A baseband coder is discussed and its subjective quality compared with code-excited linear prediction (CELP) and vector-quantized transform coding at various bit rates from 9.6 to 4.8 kb/s. It is also with that CELP-BB coding is capable of producing natural, intelligible and smooth speech at 2.4 kb/s. The code-book search in CELP-BB requires no convolution. The pitch filter memory is subtracted from the original baseband signal to form the reference signal, which is directly matched by the code-book sequences. Because most of the computation is performed on the baseband, which is decimated, and during code-book search only the pitch filter response is considered, the complexity of CELP-BB is very much less than that of CELP and its speech quality is not affected by LPC quantization error to such an extent as in CELP

Keywords

encoding; filtering and prediction theory; filters; speech analysis and processing; 2.4 to 9.6 kbits/s; LPC quantisation error; baseband coder; baseband signal; code-book search; code-excited linear prediction; pitch filter memory; reference signal; speech coding; speech quality; vector quantised transform coding; Decoding; Filters; Linear predictive coding; Noise shaping; Signal analysis; Signal synthesis; Speech coding; Speech enhancement; Speech synthesis; Vector quantization;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on

Conference_Location

New York, NY

ISSN

1520-6149

Type

conf

DOI

10.1109/ICASSP.1988.196537

Filename

196537