CAREER: Exploring the Design and Fundamental Limits of Wireless Spatial Networks

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Wireless networks now constitute a critical component of the national communications infrastructure, and information theory has served as the guiding light for the growth of wireless. However, the critical role that space, i.e., the physical locations of devices, plays in wireless networks has been largely downplayed in wireless research. Indeed, the wireless revolution would not have been possible without spatial reuse (i.e., reuse of spectrum at physically separated locations). If a link or system is studied while ignoring reuse, design conclusions can be vastly different than when reuse is considered. As wireless usage continues to grow, it is becoming increasingly important that a fundamental understanding of the limits and optimal design of networks be developed. This research introduces a framework for modeling spatial interactions in wireless networks and develops methodologies for analyzing such networks. Spectrum sharing is perhaps the most basic wireless network: transmit-receive pairs wish to communicate with each other but not with other pairs, but are forced into a shared environment because they must use common spectrum. A canonical model that explicitly models node locations, dubbed the spatial interference channel, is introduced. Different communication techniques are analyzed and fundamental bounds on information flow are derived. Ad hoc networks are a more sophisticated type of network in which nodes potentially work together to aid communication. The role of space has been acknowledged in this setting, but many theoretical questions remain unanswered. Generalized scaling laws that capture the interplay between network size, throughput, power, and bandwidth are studied, and spatial models are used to quantify the benefit of techniques such as relaying, network coding, and power control.