Double-threshold based cooperative spectrum sensing over imperfect channels

This paper proposes a hybrid double-threshold based energy detector (HDTED) for cooperative spectrum sensing over imperfect channels in cognitive wireless radio networks (CWRNs). The proposed HDTED improves the sensing reliability in CWRNs by exploiting both local decisions at secondary users (SUs) in either binary or energy values and global binary decisions feedback from fusion centre. Particularly, we consider a practical scenario where all channel links suffer from fading and noise. By deriving closed-form expressions and bounds for the probabilities of missed detection and false alarm, we not only show the improved performance achieved with the HDTED scheme but also validate the effects of the number of the SUs and the fading channels on the overall sensing performance.