DCT_M model for excitation parameter in low bit rate vocoder  

作　　者：Xiaoyan DANG Kun TANG 

机构地区：[1]State Key Laboratory on Microwave and Digital Communications,Department of Electronic Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of Electrical and Electronic Engineering in China》2008年第2期204-207,共4页中国电气与电子工程前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.60272020).

摘　　要：The description precision of an excitation signal greatly influences the quality of reconstructed speech in low bit rate vocoders.To improve the reconstruction quality,the DCT_M model is proposed to express the excitation spectral parameter,which transforms the variable length vector to fixed dimension vector through DCT transformation.It then quantizes the fixed length vector using multi-stage vector quantization.Tests show that the proposed method can keep the shape of the entire spectral envelope and reduce model error thus greatly improve the description precision.Test results in the sine excitation linear prediction(SELP)vocoder show that the DCT_M model can improve the naturalness of reconstructed speech,with subjective test score of 65%.

关 键 词：VOCODER DCT_M model model error 

分 类 号：TN9[电子电信—信息与通信工程]