g.729e语音编码算法的研究及实现-research and implementation of g 729 e speech coding algorithm.docxVIP

摘 要语音编码是公共交换电话网，视频会议系统，数字蜂窝通信及 VOIP 系统的基础。 各种网络的发展推进了网络协议的标准化，使研究语音编码技术、标准及其在当今及 将来社会的应用具有越来越重要的意义。ITU＿T 于 1996 年 3 月公布了 G.729 建议， 它是 8kbit/s 共轭结构－代数码激励线性预测（CS－ACELP）编码方案。随着多媒体 技术的发展，对语音编码质量提出了更高的要求，ITU-T 于 1998 年 9 月制定了 G.729 的高速率扩展标准，即 G.729E：11.8kbit/s CS-ACELP 语音编码算法，此语音编码 算法特别增加了对音乐信号及带背景噪声的语音信号的处理，在多媒体通信中具有广 泛的应用前景。本文以 G.729E 编解码算法为研究对象，首先通过 Matlab 软件对算法 的关键部分进行仿真，较深入地分析了 LPC、线谱对、知觉加权、基音分析、矢量量 化等技术的原理及作用，并总结出一种基于知觉加权的基音预测算法；接着对本算法 定点 C 程序进行分析，把此算法包装成编码及解码两个工程，利用 VC++中的 MFC 制 作了具有完成编码功能及解码功能的 Windows 操作界面，在 PC 机上实现了 G.729E 编解码算法，完成语音数据的存储；最后对 G.729E 算法在 TMS320VC5416DSP 上实 时实现进行了研究。【关键词】：G.729E语音编码CS－ACELPTMS320VC5416 Abstract AbstractSpeech coding is fundamental to the operation of the public switched telephone network, video conferencing systems, digital cellular communications, and emerging voice over Internet protocol (VOIP) applications. With the developing of the network, the network protocols are standardized, the reaserch of speech coding technologies and standards are more and more important in today and in the future society. ITU-T provided the G.729 in March 1996. G.729 is a speech coding algorithm at 8k bit/s using Conjugate-Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP). With the developing of multimedia techniques, the demand of speech coding quality is higher and higher. In Sep. 1998, ITU-T provided the high level description of the higher bit rate extensions of Recommendation G.729, named G.729 Annex E(G.729E: 11.8kbit/s CS-ACELP speech coding algorithm), designed to speech with background noise and even music. G.729E will be widely used in multimedia communication. Based on the G.729E speech coding algorithm, this paper firstly simulated the keys of the algorithm principle(such as LPC, LSP, perceptual weighting，pitch analysis and VQ, etc.) by MATLAB. Thispaper also concluded a pitch detection method base on perceptual weighting; Secondly, this paper analysed the fixed-point C code and made two projects: coder and decoder on VC++6.