DMCA
Breaking Spectrum Gridlock with Cognitive Radios: An Information Theoretic Perspective (2008)
Cached
Download Links
| Citations: | 265 - 4 self |
BibTeX
@MISC{Goldsmith08breakingspectrum,
author = {Andrea Goldsmith and Syed Ali Jafar and Ivana Marić and Sudhir Srinivasa},
title = { Breaking Spectrum Gridlock with Cognitive Radios: An Information Theoretic Perspective },
year = {2008}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Cognitive radios hold tremendous promise for increasing spectral efficiency in wireless systems. This paper surveys the fundamental capacity limits and associated transmission techniques for different wireless network design paradigms based on this promising technology. These paradigms are unified by the definition of a cognitive radio as an intelligent wireless communication device that exploits side information about its environment to improve spectrum utilization. This side information typically comprises knowledge about the activity, channels, codebooks and/or messages of other nodes with which the cognitive node shares the spectrum. Based on the nature of the available side information as well as a priori rules about spectrum usage, cognitive radio systems seek to underlay, overlay or interweave the cognitive radios ’ signals with the transmissions of noncognitive nodes. We provide a comprehensive summary of the known capacity characterizations in terms of upper and lower bounds for each of these three approaches. The increase in system degrees of freedom obtained through cognitive radios is also illuminated. This information theoretic survey provides guidelines for the spectral efficiency gains possible through cognitive radios, as well as practical design ideas to mitigate the coexistence challenges in today’s crowded spectrum.
Keyphrases
cognitive radio spectrum gridlock information theoretic perspective side information system degree spectrum usage promising technology cognitive radio signal practical design idea wireless system intelligent wireless communication device noncognitive node comprehensive summary information theoretic survey available side information different wireless network design paradigm priori rule spectral efficiency gain cognitive node share transmission technique spectral efficiency capacity characterization cognitive radio system tremendous promise fundamental capacity limit spectrum utilization
