Abstract
Cognitive radio offers a means to meet the increasing demands of wireless traffic. Since the allocated spectrum is often underutilized by licensees, energy detectors are used to determine the spectral occupancy by primary users (licensees) so that underutilized bands could be used by others. But, the performance of energy detectors is adversely impacted by the fading in wireless channels. The N*Nakagami cascaded model where the signal-to-noise ratio (SNR) is treated as the product of several gamma variables, provides a very general description of fading. The performance of the energy detector in such a channel is studied in this work. Analytical expressions for the detection probability and area under the receiver operating characteristic curves (AUC) are obtained in series forms. Expression for a third quantitative measure, the partial AUC index is also derived. Results show the dependence of the average SNR, Nakagami parameter and number of cascaded elements (N) on the performance of the energy detector. The availability of closed form solutions for the detection probability and AUC provides a direct and simple means to analyze the performance of the energy detectors since the cascaded channel allows the modeling a wide range of fading conditions in wireless channels.
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Shankar, P.M. Performance of Cognitive Radio in N*Nakagami Cascaded Channels. Wireless Pers Commun 88, 657–667 (2016). https://doi.org/10.1007/s11277-016-3190-3
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DOI: https://doi.org/10.1007/s11277-016-3190-3