【作者】 柴斌；

【导师】 单承赣；

【作者基本信息】 合肥工业大学 ， 信号与信息处理， 2004， 硕士

【摘要】 在过去50年中，通信领域是在一个假设上发展起来的，即通信中的两个基本问题可以分别独立处理，而性能不会收到影响。这个假设被称为独立原则，简单说就是信源编码和信道编码能够独立实现。这样，就把一个单独复杂的问题分成两个简单的问题。这个“独立原则”指导了通信的发展近50年。在技术上的发展实例包括CDROM、快速解调、无线通信系统和互连网。独立原则很有效同时也有限制。随着现代通信的发展，独立原则在很多实际场合中，例如资源有限，多用户系统中或网络时变的情况等，都不适用。于是出现了信源信道独立编码向信源信道联合编码过渡的趋势。本论文在这方面做了一些有益的探索。 首先，本文对信源信道联合编码做了综述，介绍了它的理论背景，应用情况和研究概况以及发展趋势。作者在对算术编码做了深入研究的基础上，运用汉明距离对其加以改进，使算术编码具有了较好的纠错能力，克服了算术编码易受传输错误的影响，使其适用于信道干扰较大的场合。本文着重研究了信源信道联合编码中的分层编码方法，设计了一个基于SPIHT算法的分层编码的编解码方案，并做了仿真，实验证明这个方案适用于信道情况未知的场合中。最后，作者就今后工作的发展方向提出了一些个人的观点和看法。更多还原

【Abstract】 For the past 50 years,the field of communications has developed under the assumption that the two basic components of the communications problem can be performed independently with no performance degradations relative to joint design. Briefly,this idea,known as the "separation principle",states that "source coding" and "channel coding" can and should be performed independently. By dividing a single difficult problem into two simpler problems,the separation principle has led to 50 years of enormous advances in communications theory and technology. Examples of technologies made possible by communications advances include CD ROMs,fast modems,wireless communications systems,and the Internet. The separation principle is both extremely powerful and extremely limiting to the advancement of communications technology. With the development of modern communication,some systems will lead to the violation of the separation principle,such as resource constraints,multiuser system or time-varying networks. For such systems,performance improvements may be achieved by moving from separate design and operation of source and channel codes to "joint source and channel code" design and operation.In this thesis,we review the joint source and channel coding firstly,introducing fundamental theories,design methodologies,and practical applications. Secondly,an approach is presented for improving arithmetic coding by embedding hamming distance. The approach prevents error propagation of the arithmetic coding. Thirdly,a scheme of layered coding is proposed,which can be applied for rate-varying systems. Finally,the areas for further research are pointed out.更多还原