Cooperative Source and Channel Coding

协作源和信道编码当前和下一代无线设备和服务与只能携带语音信号的原始蜂窝电话有很大的不同。第三代/第四代蜂窝和无线局域网被设计为支持数据服务、图像和视频通信以及语音。多媒体信号比语音信号需要更高的数据速率和更大的带宽。这需要更有效地利用已经稀缺的无线电资源。此外，考虑到无线信道不可靠并且最有效的压缩算法涉及错误传播，保证图像和视频的期望信号质量水平（以总体失真来衡量）尤其困难。为了提供鲁棒的无线多媒体通信，本研究使用协作通信技术，沿着联合优化的源压缩和信道编码策略。无线终端之间的协作是通过偷听其他终端的信号并向期望的目的地重发来实现的。这提供了信号分集，并实现了鲁棒的源到目的地路由，该路由可以适应无线环境的变化。 为了建立合作的信源和信道编码的理论和实践，研究计划包括三个相互关联的组成部分：信源信道合作的信息理论;设计合作的信源和信道编码技术的数值/仿真研究，以共同优化的参数;和这些技术的应用到无线视频传输。

Cooperative Source and Channel CodingCurrent and next generations of wireless devices and services are substantially different than the original cellular phones which could only carry voice signals. Third/fourth generation cellular and wireless local area networks are designed to support data services, image and video communications as well as voice. Multimedia signals require higher data rates and larger bandwidths than their voice counterparts. This necessitates a more efficient use of already scarce radio resources. Furthermore, guaranteeing a desired level of signal quality for image and video, measured in terms of overall distortion, is especially difficult given that the wireless channel is unreliable and most efficient compression algorithms involve error propagation.In order to provide robust wireless multimedia communications, this research uses cooperative communication techniques along with jointly optimized source compression and channel coding strategies. Cooperation of wireless terminals is achieved by overhearing other terminal's signals and retransmitting towards the desired destination. This provides signal diversity and enables robust source-to-destination routes which can adapt to changes in the wireless environment. In order to establish the theory and practice of cooperative source and channel coding, the research plan consists of three interrelated components: Information theory of source channel cooperation; design of cooperative source and channel coding techniques with numerical/simulation studies to jointly optimize the parameters; and application of these techniques to wireless video transmission.