Opportunity detection for OFDMA-based cognitive radio systems with timing misalignment

Authors:
Mustafa E. Sahin;Ismail Guvenc;Hüseyin Arslan
Affiliations:
Electrical Engineering Department, University of South Florida, Tampa, FL;DOCOMO Communications Laboratories USA, Inc., Palo Alto, CA;Electrical Engineering Department, University of South Florida, Tampa, FL
Venue:
IEEE Transactions on Wireless Communications
Year:
2009

Citing 9
Cited 3

Statistics of macrocell-synchronous femtocell-asynchronous users' delays for improved femtocell uplink receiver design

IEEE Communications Letters
Initial ranging for WiMAX (802.16e) OFDMA

MILCOM'06 Proceedings of the 2006 IEEE conference on Military communications
Cooperative Spectrum Sensing in Cognitive Radio, Part I: Two User Networks

IEEE Transactions on Wireless Communications
Cooperative Spectrum Sensing in Cognitive Radio, Part II: Multiuser Networks

IEEE Transactions on Wireless Communications
Sensing-Throughput Tradeoff for Cognitive Radio Networks

IEEE Transactions on Wireless Communications
Femtocell networks: a survey

IEEE Communications Magazine
A time and frequency synchronization scheme for multiuser OFDM

IEEE Journal on Selected Areas in Communications
Cognitive radio: brain-empowered wireless communications

IEEE Journal on Selected Areas in Communications
Multichannel random access in OFDMA wireless networks

IEEE Journal on Selected Areas in Communications

ICI-minimizing blind uplink time synchronization for OFDMA-based cognitive radio systems

GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
Evolutionary algorithms for orthogonal frequency division multiplexing-based dynamic spectrum access systems

Computer Networks: The International Journal of Computer and Telecommunications Networking
A Framework to Optimize the OFDM-Based Multiuser Dynamic Spectrum Access Networks with Frequency Reuse

Wireless Personal Communications: An International Journal

Quantified Score

Hi-index	0.01

Visualization

Abstract

Accurate detection of spectrum opportunities within the frequency band of an orthogonal frequency division multiple access (OFDMA) system carries critical importance for OFDMA-based cognitive radios. In this paper, we analyze the opportunity detection performances of energy detection and ESPRIT (estimation of signal parameters by rotational invariance techniques) algorithms in the presence of timing misalignments in uplink (UL) OFDMA. For the energy detector, the statistics of subcarrier power are derived considering timing misalignments, and they are verified through computer simulations. Using these statistics, which take inter-carrier-interference (ICI) effects into account, receiver operating characteristics (ROCs) of the energy detector receiver are obtained. It is shown that energy detection has a considerably better performance than ESPRIT, especially when the subcarrier assignment changes frequently. Moreover, a closed form expression is derived for the UL-OFDMA synchronization point that minimizes the ICI. Finally, it is shown that employing resource allocation blocks with larger sizes in the primary network yields better opportunities for the cognitive radio.