G.723.1标准在TMS320VC5402上的实现

【作者】 王元；

【导师】 彭启琮；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2002， 硕士

【摘要】 在现代各种通信系统中，话音通信一直是一项重要的、必不可少的业务。随着通信网络用户数量的增加、网络业务更加综合化、多样化，系统容量、服务质量与网络带宽的矛盾也日益突出，如何在不牺牲语音通话质量的前提下尽可能降低话音信号传输的比特速率是摆在研究者面前的重要课题。同时，由于用数字化的方法进行语音信号处理是目前发展最为迅速的信息学研究领域之一，由此诞生了许多种语音压缩处理方法。ITU-T也在此基础之上提出了一系列关于低速率语音编码的解决方案，G.723.1标准就是其中之一。 本文首先从语音产生的离散数字模型出发，简要叙述了低速率语音编码的基本原理。然后文章对获得广泛应用(并且也是G.723.1标准的基础)的线性预测编码声码器的一些关键技术进行了详细的论述。 在G.723.1标准的实现过程中，我们首先建立了语音编码硬件基础，基于TI公司的TMS320C54xx系列DSP平台，对此做了比较详细的介绍。然后，从系统级的角度剖析了G.723.1标准的结构，并提出了在TMS320C 5402上实现该标准的一个解决方案。最后讨论了该方案实现过程中所遇到的一些问题及其解决方法。 最后，考虑到算法标准本身的不断改进，以及具体实现中需要重点考虑的降低算法复杂度的问题，在论文的最后一章，就如何进一步降低编解码算法的速率及复杂度等问题作了一些探索。更多还原

【Abstract】 Speech Communication is an important and indispensable service in different modern communication systems. With the increasing of network users > the integrating and diversifying of network service, the contradictions among bandwidth, system capacity and service quality are more and more obvious. How to reduce the bit-rate of speech without remarkably degrading its perceptual quality is a question placed at the front of the researchers. At the same time, the process of speech signal by digital is developed rapidly in information science. There are many ways been brought forward in voice compres^. ITU-T has also put forward a series of ones in low rate speech coder, including recommendation G.723.1.At first, from the discrete digital model of the speech generate, this paper briefly recount some basic terms and principles in low rate speech processing. Then focus on the research of the linear predictive coding, which is used widely (and is the base of G.723.1 too), and narrate in detail some key techniques in this area.During the concretely realize of the recommendation G.723.1, we set up the hardware elements of the speech coding, which is the TMS320C54xx DSP platform of TI Inc. We introduce it in this paper too., In the following we discuss the framework of the G.723.1 from the systematic view, and bring out a blue print of implementation this recommendation. Combined to my works, we even introduce the problems we met and the solutions we found.At last, considering the algorism is mended, some innovative improvement thoughts on further reducing the code-rate and decreasing the complexity of vocoders are included in this dissertation.更多还原