摘要
码激励线性预测(CELP)编码在中低速率上与传统的LPC声码器相比可以提供更加自然的语音质量。本文介绍了CELP的基本原理及激励码本的构成。然后提出了在4.8 kbit/s速率上改进话音质量的两种方法:①计算长时预测参数的半闭环搜索法;②激励码本的时变修正法。计算机模拟结果表明,采用这两种方法可使语音质量得到改善。
Code-Excited Linear Predictive (CELP) coding can provide natural speech quality at medium and low bit rates in contrast with conventional LPC vocoder. In this paper, the basic principle of CELP and the construction of excitation codebook are introduced. Two methods are proposed to improve speech quality at 4.8 kbit/s:1)partial closed-loop search of long-term predictor parameters; 2) modification of excitation codebook. The computer simulation results show improvement of speech quality with these two approaches.
出处
《通信学报》
EI
CSCD
北大核心
1990年第6期34-37,共4页
Journal on Communications
