itut g.729a协议的研究及其实现研究-research and implementation of itu g 729 a protocol.docx

中文摘要
摘要
随着计算机、宽带网络技术和集成电路技术日新月异的发展,以多媒体通信为主题的信息网络已成为世界关注的热点。尤其是因特网的巨大成功,己使IP成为末来信息网络的支柱技术。IP网络电话的成功丌发和应用预示了以IP为基础的新一代信息网络的出现。
IP网络电话是一项涉及计算机网络、信令协议、数字信号处理等多个领域的综合性技术,而数字信号处理更多的是rP语音处理,也即语音信号的编译码。对于 IP电话的语音编译码方案国际电信联盟标准组织ITU—、、 、(、。
本论文着重研究了其中的标准之一,(以下简称为G,729A)。论文首先对语音编码的各种方案进行了比较,并对(。然后对语音信号的特征及其分析方法、语音信号的形成机理的数学模型以及各种编码方案进行了比较深入、系统的分析。结合语音信号的特点及其相应的数字模型,对(。并通过对比两者的不同,。在对陔协议进行了深刻探讨的基础上, 运用丌发工具VC++ C语言仿真软件做了进一步的分析、研究,着重研究了其中的功能函数和相应的算法。并在综合了国内外芙于语音编码的改进方案之后,提出了对语音编译码的改进建议:即从提高重建语音信号的质量和减小算法时延两个方面进行。:码本搜索的顺序根据目标矢量和滤波后的自适应码本矢量间的
加权均方误差重新排序,码本搜索直至达到预定的门限。
关键词:语音压缩编码,(,,码本
茎茎塑至
ABSTRACT
With the rapid development work and IC technology,the
work mainly basing on munication es the world’S ,the great ess of makes IP e the backbone technology of the futln'e the essful development and application of IP telephony foreshow the appearance of the new work
basing on IP.
This thesis mainly studied the mendation and its annex A(G729A)
among the above mendations.
The characteristics of G729 were contrasted with the most speech signal coding
mendations at first,and then analyzed the characteristics,analysis methods, digital models and different speech signal coding it,the algorithms of G729 and G729A were also contrasted in order to show how the
CS—ACELP algorithms are simplified in the following chapteg the fixed point ANSC C simulation programs G729A using VC++ Was analyzed and studied, and great emphasis Was put on the functions and the end ofthe thesis,the research actuality of the improving schemes of the coding of speech signal inside and outside the country were summarized,and brought forward the suggestion that it Can
improve the coding algorithm of the speech signal by improving the quality of speech signal and sh