Energy Efficient Resource Allocation for Cognitive Radios: A Generalized Sensing Analysis

• Published in: IEEE transactions on wireless communications Vol. 14; no. 5; pp. 2455 - 2469
• Main Authors: Alabbasi, Abdulrahman, Rezki, Zouheir, Shihada, Basem
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive systems; Benchmark testing; Cognitive radio; Detection; energy efficiency; Energy management; Interference; Linear programming; Mathematical analysis; Mathematical models; Measurement; Optimization; Resource allocation; Resource management; Sensors; spectrum sensing; Spectrum sharing; resource allocation; Spectrum sharing; energy efficiency; spectrum sensing
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2014.2387161

In this paper, two resource allocation schemes for energy efficient cognitive radio systems are proposed. Our design considers resource allocation approaches that adopt spectrum sharing combined with soft-sensing information, adaptive sensing thresholds, and adaptive power to achieve an energy efficient system. An energy per good-bit metric is considered as an energy efficient objective function. A multi-carrier system, such as, orthogonal frequency division multiplexing, is considered in the framework. The proposed resource allocation schemes, using different approaches, are designated as sub-optimal and optimal. The sub-optimal approach is attained by optimizing over a channel inversion power policy. The optimal approach utilizes the calculus of variation theory to optimize a problem of instantaneous objective function subject to average and instantaneous constraints with respect to functional optimization variables. In addition to the analytical results, selected numerical results are provided to quantify the impact of soft-sensing information and the optimal adaptive sensing threshold on the system performance.