一种改进的4．8kb／s码激励线性预测语音编码

An Improved CELP Speech Coding at 4.8kb/s

本文介绍了码激励线性预测（ＣＥＬＰ）语音编码的基本原理，研究了一种制约随机激励的线性预测编码方案。它将随机激励码字进入合成滤波器的数量与自适应码本的性能指标联系起来，有效地减少了激励噪声对合成语音的影响．计算机模拟结果表明，这种方法在主观上改善了语音质量。

The basic CELP structure is introduced in this paper.A constrained-stochastic excitation linear predictive coding scheme is suggested.It links the amount of stochastic excitation codewords injected into the synthetic filter to a performance index of adaptive codebcok. The noisy effects of the excitation on synthetic speech are efficiently reduced. The computer simulation results show the subjective improvement of speech quality with this approach.