Collaborative Research: The Role of Feedback in Two-Way Communication Networks

协作研究：反馈在双向通信网络中的作用

• 批准号: 0729119
• 负责人: Tsachy Weissman
• 金额: $ 30万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0729119&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Feedback; Two

Many common communication situations are over inherently two-way channels, such as telephone systems, digital subscriber lines (DSL), cellular networks, and the Internet. In fact, even `point-to-point' systems, where the end goal is to transfer information in one direction, often give rise to two-way communication scenarios due to the presence of feedback. In such systems, one can receive feedback from the other end of the channel, which can be used to improve the quality of communication. Although feedback is present in many communication systems, and is being used in certain primitive forms as in channel estimation and automatic repeat request, the theory behind its use is far from complete. This research investigates the role of feedback in two-way communication networks and provides architecture-level guidance for designing robust and efficient communication systems. While positive results lead to novel approaches to communication systems design, negative results prevent over-engineering and allow more confidence in simple and modular implementations. At the same time, feedback is a pivotal concept in biological and artificial control systems, learning machines, and communication networks. A deeper understanding of the role of feedback in one area (communication) will lead to a better understanding of the role of feedback in a broader multidisciplinary context.Concretely, this research focuses on and develops new approaches for tackling problems arising in the following areas: 1) feedback capacity of single-user channels with memory (new coding theorems based on directed information, causal conditioning, and Shannon strategy, as well as the development of concrete schemes for achieving the fundamental limits), 2) multiple-user channels with feedback (emphasis on multiple access channels and broadcast channels: characterization of fundamental limits as well as the construction of practical coding schemes), 3) capacity region of the two-way channel such as the Blackwell-Shannon binary multiplying channel (dynamic programming and infinite-dimensional convex optimization), 4) robust feedback coding techniques under channel uncertainty (universal decoding schemes), and 5) reliable communication with noisy feedback (new perspectives on cross-layer design of channel codes and network protocols). Massey's directed information takes the role of Shannon's mutual information in many feedback communication problems. Thus the role of directed information is investigated as a fundamental notion in general causal inference problems. Examples include gambling in horse-race markets with causal side information and its dual in source coding.

许多常见的通信情况都属于固有的双向通道，例如电话系统，数字订户线（DSL），蜂窝网络和互联网。 实际上，即使是“点对点”系统，最终目标是向一个方向传输信息，由于反馈的存在，通常会引起双向通信方案。在这样的系统中，可以从渠道的另一端接收反馈，这些反馈可用于提高通信质量。 尽管许多通信系统中都存在反馈，并且正在以某些原始形式使用，如渠道估计和自动重复请求中，但其使用背后的理论远非完整。 这项研究调查了反馈在双向通信网络中的作用，并为设计强大而有效的通信系统提供了体系结构级别的指导。尽管积极的结果导致了通信系统设计的新型方法，但负面的结果可以阻止过度工程，并使对简单和模块化的实现更加信心。 同时，反馈是生物和人工控制系统，学习机和通信网络中的关键概念。 A deeper understanding of the role of feedback in one area (communication) will lead to a better understanding of the role of feedback in a broader multidisciplinary context.Concretely, this research focuses on and develops new approaches for tackling problems arising in the following areas: 1) feedback capacity of single-user channels with memory (new coding theorems based on directed information, causal conditioning, and Shannon strategy, as well as the development of concrete schemes 2）具有反馈的多用户渠道（强调多个访问渠道和广播渠道：基本限制的表征以及实用编码方案的构建），3）双向通道的容量区域，例如Blackwell-Shannon二进制型二元频道（诸如Blackwell black-Shannon bixplying频道）的反馈技术，并在各种频道中进行了反馈技术，4不确定性（通用解码方案）和5）具有嘈杂反馈的可靠通信（有关频道代码和网络协议的跨层设计的新观点）。 Massey的定向信息在许多反馈交流问题中扮演了香农的共同信息的角色。 因此，在一般因果推断问题中，将有导信息的作用研究为一个基本概念。 例子包括在马赛市场上赌博，并具有因果关系信息以及其双重源编码。