相关信源编码及在中继协作通信中的应用

发布时间：2018-08-03 07:29

【摘要】：随着多媒体移动通信技术的快速发展,人们对信息可靠且有效的传输需求日益增长,但是由于受到无线带宽资源和多径衰落等因素的影响,很难实现高速可靠的数据传输。要解决这一矛盾我们必须采用全新的通信理论及技术。中继协作通信技术通过中继传输获得空间分集,避免了多径衰落带来的影响。另外,它还可以降低用户发送功率,扩展网络覆盖,是一种高效的无线资源分配解决方案。在中继传输方案中,压缩-转发(Compress-and-Forward,CF)策略是一种较好的选择。中继节点通过利用和目的节点接收信号的相关性对接收信号进行压缩并转发。理论研究表明压缩-转发策略可获得许多其他策略不能获得的可达速率点,但是实际可行的CF方案却远滞后于理论。本文主要针对相关信源的编译码方法及其在CF中继协作通信方案的设计方面进行了相关研究。本文首先对相关信源编码的相关理论进行了介绍,包括信源编码、相关信源编码及其分布式编码方案,相关信源的联合信源-信道编码(Joint Source-Channel Coding,JSCC)等。JSCC将信源编码和信道编码综合考虑,使系统达到最佳的平衡点,成为现代编码领域的研究热点。然后,基于Turbo码的编译码理论,研究了两相关信源在高斯信道下的联合信源-信道编译码算法。包括相关信源的生成,信源的联合信源-信道编码,目的节点的联合信源-信道译码算法等。对不同相关系数下的系统性能进行了仿真,证明它非常接近Shannon和Slepian-Wolf理论结合的极限值。最后,针对三节点中继信道模型,对一种译码-压缩-转发(Decode-Compress-and-Forward,DCF)中继传输方案进行了研究。中继节点将接收到的源节点信息软输出解码,量化和编码,然后转发至目的节点。目的节点利用直传信号和中继接收信号的相关性,采用相关信源的联合译码算法进行译码。仿真分析了不同的权衡因子f以及中继节点的位置对系统性能的影响,并与已有的译码-放大-转发(Decode-Amplify-Forward,DAF)方案进行了比较。
[Abstract]:With the rapid development of multimedia mobile communication technology, the demand for reliable and effective transmission of information is increasing day by day. However, due to the influence of wireless bandwidth resources and multipath fading, it is difficult to achieve high-speed and reliable data transmission. In order to solve this contradiction, we must adopt new communication theory and technology. Relay cooperative communication technology acquires spatial diversity through relay transmission, which avoids the influence of multipath fading. In addition, it can reduce user transmission power and extend network coverage. It is an efficient wireless resource allocation solution. Compress-and-forward CF is a good choice in relay transmission scheme. The relay node compresses and forwards the received signal by using the correlation between the received signal and the destination node. Theoretical research shows that the compression-forwarding strategy can obtain many reachable rate points which other strategies cannot obtain, but the practical CF scheme lags far behind the theory. This paper mainly focuses on the encoding and decoding methods of related sources and the design of CF relay cooperative communication scheme. In this paper, the related theories of source coding are introduced, including source coding, source coding and its distributed coding scheme. The joint source-channel coding (JSCC) of correlated sources takes the source coding and channel coding into account, which makes the system achieve the best balance point and become the research hotspot in the field of modern coding. Then, based on the encoding and decoding theory of Turbo code, the joint source-channel encoding and decoding algorithm of two correlated sources in Gao Si channel is studied. It includes the generation of related sources, the joint source-channel coding of the source, the joint source-channel decoding algorithm of the destination node and so on. The performance of the system with different correlation coefficients is simulated and it is proved that it is very close to the limit value of the combination of Shannon and Slepian-Wolf theory. Finally, a decode-Compress-and-forward (DCF) relay transmission scheme is studied for a three-node relay channel model. The relay node decodes, quantizes and encodes the received source node information and forwards it to the destination node. Using the correlation between direct signal and relay received signal, the joint decoding algorithm of correlation source is used to decode the node. The effects of different tradeoff factors f and the location of relay nodes on the system performance are analyzed and compared with the existing Decode-Amplify-Forward-DAF schemes.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.21;TN929.5

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