CIF: Small: The Role of Feedback in Reliable Communication

现代通信系统由具有记忆的、时变的、通常建模不良并包含反馈的信道组成。此外，在许多这样的网络中，节点的功率是有限的，只有适度的计算资源。因此，迫切需要新的单用户和多用户通信技术来处理具有记忆和反馈的信道。这包括确定这些更复杂的信道的容量，以及设计在产生适度计算成本的同时性能良好的纠错码。反馈是现代通信系统的一个非常重要的特征，尽管人们对它知之甚少。反馈有很多好处，包括：(1)反馈可以增加信道的容量；(2)反馈可以增加误差指数，从而减少延迟；(3)反馈往往可以导致更简单的编码方案；(4)反馈可以适应未知或时变的通道；(5)反馈可以在多用户设置中进行协调。这项研究涉及开发一种全面利用这些不同好处的可靠通信反馈的一般理论。本研究的四个主要目标是：(1)确定基本限制和权衡。该项目的这一方面考虑了反馈质量和由此产生的香农信道容量之间的基本限制和权衡。(2)开发计算能力的计算工具。这项研究将包括软件开发。(3)算法和纠错码开发。这项研究支持开发利用反馈的高效代码。(4)教育发展。

Modern communication systems consist of channels which have memory, are time-varying, are often poorly modeled, and incorporate feedback. Furthermore, in many of these networks, the nodes are power limited and only have modest computational resources. Thus there is a pressing need for new single-user and multi-user communication techniques that treat channels with memory and feedback. This involves determining the capacity of these more complicated channels as well as designing error-correcting codes that perform well while incurring modest computational cost.Feedback is a very important, though poorly understood, feature of modern communication systems. Feedback has many benefits including: (1) feedback can increase the capacity of a channel; (2) feedback can increase the error exponent and hence decrease latency; (3) feedback can often lead to simpler coding schemes; (4) feedback can allow for adaptation to unknown or time-varying channels; and (5) feedback can allow for coordination in multi-user settings. This research involves developing a general theory of feedback for reliable communication that fully exploits these different benefits. The four main objectives of this research are: (1) Determining fundamental limits and tradeoffs. This aspect of the project considers the fundamental limits and tradeoffs between the quality of the feedback and the resulting Shannon capacity of the channel. (2) Development of computational tools for computing capacity. This research will include software development. (3) Algorithm and error-correcting code development. This research supports the development of efficient codes that take advantage of feedback. (4) Educational development.