An 8 kb/s low complexity ACELP speech codec

Author

Deyuan, Cheng

Author_Institution

Dept. of Electron. Eng, Shenzhen Univ., China

Volume

1

fYear

1996

fDate

14-18 Oct 1996

Firstpage

671

Abstract

An 8 kb/s ACELP speech codec is proposed. The encoding algorithm is based on code-excited linear prediction (CELP) with a multi-level pulse amplitude algebraic codebook (ACELP). Only integer pitch delay is searched. There are 8 non-zero pulses with fixed amplitudes, each of +1, or +0.5, or -1 or -0.5, or zero in each algebraic codevector of length of 64 samples. An efficient nonexhaustive codebook search method is developed. The codevector´s gain and LSP frequencies are scalar quantized. An adaptive pitch prefilter before LP synthesis filter and a spectral postfilter after LP synthesis filter are adopted in the speech decoder to enhance the reconstructed speech quality

Keywords

adaptive filters; algebraic codes; computational complexity; filtering theory; linear predictive coding; search problems; speech codecs; speech coding; 8 kbit/s; ACELP speech codec; LP synthesis filter; LSP frequencies; adaptive pitch prefilter; algebraic codevector; code-excited linear prediction; codevector gain; encoding algorithm; integer pitch delay; low complexity; multi-level pulse amplitude algebraic codebook; nonexhaustive codebook search method; reconstructed speech quality; scalar quantization; spectral postfilter; Decoding; Encoding; Filters; Frequency; Signal synthesis; Speech analysis; Speech codecs; Speech coding; Speech enhancement; Speech synthesis;

fLanguage

English

Publisher

ieee

Conference_Titel

Signal Processing, 1996., 3rd International Conference on

Conference_Location

Beijing

Print_ISBN

0-7803-2912-0

Type

conf

DOI

10.1109/ICSIGP.1996.567352

Filename

567352