摘要
近年来，随着数字通信技术的发展及商业应用需求的增加，语音压缩技术得到了迅猛的发展；本文所介绍的G．729协议正是众多语音压缩技术中的一种。G．729是国际电信联盟(ITU-T)于1996年公布的使用共轭结构代数码激励线性预测(CS-ACELP)的8kbit／s语音编码标准。
本文在第一章首先对语音压缩编码技术的发展及现状作了简明的分析，并由此引出了本文的主题：ITU-T G．729语音压缩编码协议。
第二章着重讨论了G．729语音压缩协议中所涉及到的语音编码基础理论。主要包括语音信号产生的数字模型、语音信号的线性预测分析、矢量量化及其LBG算法和感知加权滤波器。这些基础理论对于更好地理解G．729协议有着很大的帮助。
第三章介绍了G．729协议的编码解码器的原理。
第四章介绍了DSP芯片的发展及现状，在此基础上选择了TI公司的TMS320C54x系列DSP芯片来实现编码，并对该系列DSP芯片作了详细介绍。
第五章详细地分析了G．729算法的流程、C程序实现、汇编实现及其优化，并对实现的结果作了分析和说明。
第六章对本文以及作者进行的工作进行了总结，并给出了下一步可以进行的改进。
With the rapid progress of digital communication technology and the increasing requirement in commercial application, speech compression technology has advanced rapidly in recent years. And G.729 protocol is one of the many technologies. The full name of G.729 is "coding of speech signal at 8 kbit/s using Conjugate-Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP)". It's publicized by ITU-T in 1996.
In section one, we give a brief introduction of the history of speech coding, and then educe the topic of this thesis: ITU-T G.729 protocol.
In section two, we introduce some of the main coding theories that was in the G.729, including the digital model of the production of speech signal, the Linear Prediction Coding, Vector Quantization, LBG arithmetic and Perceptual Weighted Filtering. These theories give great help to the understanding of G.729 protocol.
In section three, we introduce the coding and decoding principle of G.729.
In section four, we give a brief introduction of the history of digital signal processor. And then choose the TMS320C54x series DSP to realize the coding and decoding of G.729.
In section five, we focus on the flow of the algorithm, the realization with C language and Mnemonic Instruction, and the optimizing of them.
In section six, we give the summarization of this thesis, and the possible improvement as well.
引文
[1] ITU-T Recommendation G.729, coding of speech at 8 kbit/s using Conjugate-Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP) [R], 1996.3.
[2] TMS320C54x C Source Debugger. User's Guide [R]. Texas Instruments, 1998.
[3] TMS320C54x DSP CPU and Peripherals, Reference Set [R]. Texas Instruments, 1999,1.
[4] TMS320C54x DSP Mnemonic Instruction Set, Reference Set [R]. Texas Instruments, 1996,2.
[5] TMS320C54x Optimizing C Compiler User's Guide [R]. Texas Instruments, 1999,12.
[6] TMS320C54x DSP/BIOS User's Guide [R]. Texas Instruments, 2000,3.
[7] Code Composer Studio User's Guide [R]. Texas Instruments, 2000,2.
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[10] ITU- T G. 729Annex A, Reduced complexity 8kb/s CS- ACELP codec for digital simultaneous voice and data [S], 1998.
[11] ITU- T G. 729Annex B, A silence compression scheme for use with G.729 optimized for V.70 digital simultaneous voice and data application [S], 1998.
[12] ITU- T G. 729 Annex D, Proposed draft new annex D to recommendation G.729-6.4 kbit/s CS-ACELP speech coding algorithm [S], 1998.
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