Title :
A unified framework for ACELP codebook search based on low-complexity multi-rate lattice vector quantization
Author :
Zhou, Cheng ; Hu, Ruimin ; Zhang, Yong
Author_Institution :
Wuhan Univ., Wuhan
Abstract :
Speech codec with ACELP structure are widely used due to their high performance for the bit rates between 4 kbps and 16 kbps. In ACELP codec, searching for the best codevector from a huge codebook is the crucial pan in both performance and complexity. In some cases, the effect of codebook search does not fit our expectation. Furthermore, there is no unified method for ACELP codebook search; rather different method is developed for each ACELP codec. In this paper, a unified framework for fixed codebook search based on Low-complexity multi-rate lattice vector quantization is proposed, and is applied to a standard ACELP codec AMR-WB+. It is confirmed that the proposed method enhances the performance especially at lower bit rates.
Keywords :
speech codecs; vector quantisation; ACELP codebook search; AMR-WB+; multirate lattice vector quantization; speech codec; Adaptive filters; Decoding; Distortion; Frequency; Information filtering; Information filters; Information technology; Lattices; Nearest neighbor searches; Vector quantization; ACELP; AMR−WB+; fixed codebook search; lattice vector quantization;
Conference_Titel :
Communications and Information Technologies, 2007. ISCIT '07. International Symposium on
Conference_Location :
Sydney,. NSW
Print_ISBN :
978-1-4244-0976-1
Electronic_ISBN :
978-1-4244-0977-8
DOI :
10.1109/ISCIT.2007.4392266
