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Journal of Symbolic Computation - Special issue on computational algebraic complexity
Journal of VLSI Signal Processing Systems - Special issue: algorithms and parallel VSLI architecture
Using portfolio theory for better and more consistent quality
Proceedings of the 2007 international symposium on Software testing and analysis
Multiuser Power and Channel Allocation Algorithm in Cognitive Radio
ICPP '07 Proceedings of the 2007 International Conference on Parallel Processing
OS-MAC: An Efficient MAC Protocol for Spectrum-Agile Wireless Networks
IEEE Transactions on Mobile Computing
Computer Networks: The International Journal of Computer and Telecommunications Networking
A survey on MAC protocols for cognitive radio networks
Ad Hoc Networks
IEEE Transactions on Wireless Communications
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WCNC'09 Proceedings of the 2009 IEEE conference on Wireless Communications & Networking Conference
Energy-efficient power allocation in OFDM-based cognitive radio systems: A risk-return model
IEEE Transactions on Wireless Communications
Cognitive radio: brain-empowered wireless communications
IEEE Journal on Selected Areas in Communications
Decentralized cognitive MAC for opportunistic spectrum access in ad hoc networks: A POMDP framework
IEEE Journal on Selected Areas in Communications
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Guaranteeing Quality of Service (QoS) in Cognitive Radio (CR) networks is a challenging task due to the random nature of radio channel conditions and primary user traffic. In this paper we analyze the recently proposed mean-variance based QoS and resource management methods, and introduce the concept of mean-variance evaluation of QoS and resource management techniques. Inspired by financial Portfolio Selection theory, mean-variance based resource management techniques for CR networks are statistical approaches and do not require instantaneous knowledge of channel state and Primary User (PU) activity, and enable the option to tradeoff between risk (QoS variance) and reward (QoS mean). Using throughput as a measure of QoS, we present a derivation of the theoretical throughput mean-variance characteristics of a CR-OFDM system employing a mean-variance based QoS management strategy. We conduct an analysis of existing Portfolio Selection based strategies in the mean-variance domain and compare them to the theoretical performance. Finally, we present a further enhancement of the approach by explicitly considering constraints on individual channel power allocation in the mean-variance optimization problem. Simulation results illustrate the effect of our enhancements in improving the risk-reward profile of the mean-variance based QoS management strategy, by moving it closer to the theoretical characteristic.