CIF: Small: From Fano to Shannon: Information Theory and Broadband Matching

多输入多输出（MIMO）通信的研究表明，使用多个天线可以显着提高无线信道的容量。由于无线设备的尺寸有限，使用多个天线通常需要紧密的间隔，这导致天线之间的耦合。耦合可以深刻地影响接收功率、分集和系统容量。此外，这种影响不仅取决于天线及其在空间中的排列方式，还取决于无线收发器的细节，例如将天线连接到接收器前端其余部分的阻抗匹配网络。目前的方法来设计这些网络耦合MIMO系统本质上是窄带和宽带条件下表现出较差的性能。其主要思想是，法诺的宽带匹配理论提供了物理可实现的匹配网络的表征，而香农的信息理论提供了一种方法来评估每个网络如何以最佳方式进行通信。通过结合这些理论，该项目考虑了天线，匹配网络和通信算法如何相互作用以确定整体系统性能，以及如何最好地联合优化这些组件。解决了三个主要问题：宽带单天线系统性能的新信息和决策理论界限;宽带MIMO系统的扩展;以及联合优化天线、匹配网络和通信算法的信息理论设计标准。这项工作有可能通过提供更统一的RF前端视图以及开发可能显着提高无线性能的新通信和匹配技术来显着推进科学和工程。

Research on multiple-input, multiple-output (MIMO) communications has shown that using multiple antennas can dramatically improve the capacity of wireless channels. Since wireless devices are limited in size, using multiple antennas often requires close spacing which leads to coupling among the antennas. Coupling can profoundly impact the received power, diversity and system capacity. Moreover, this impact depends not only on the antennas and how they are arranged in space; it also depends on detailed aspects of the wireless transceiver, such as the impedance matching networks that connect the antennas to the rest of the receiver front end. Current approaches to designing these networks for coupled MIMO systems are intrinsically narrowband and exhibit poor performance under broadband conditions.This project seeks to develop a unified theoretical framework for the design of broadband wireless transceivers. The main idea is that Fano's broadband matching theory provides a characterization of physically-realizable matching networks, while Shannon's information theory provides a way to evaluate how each network could be used to communicate in the best possible way. By combining these theories, this project considers how antennas, matching networks and communications algorithms interact to determine overall system performance, and how best to jointly optimize these components. Three main issues are addressed: new information- and decision-theoretic bounds on the performance of broadband single-antenna systems; extensions to broadband MIMO systems; and information-theoretic design criteria to jointly optimize the antennas, matching networks and communications algorithms. This work has the potential to significantly advance science and engineering by providing a more unified view of the RF front end and by developing new communications and matching techniques that may significantly improve wireless performance.