An Efficient Cooperative Spectrum Sensing under Bandwidth Constraint with User Selection

This paper investigates double-threshold based energy detection for cooperative spectrum sensing in cognitive wireless radio networks. We first propose a hybrid double-threshold based energy detector (HDTED) to improve sensing performance at the secondary users (SUs) by exploiting both their local decisions and the global binary decisions at the fusion centre (FC). We then derive closed- form expressions for the probability of missed detection and the probability of false alarm considering a practical scenario where all channel links suffer from Rayleigh fading. The derived expressions not only show the improved performance but also enable us to develop an optimal SU selection algorithm for forwarding the local decisions to the FC. Finally, numerical results are provided to demonstrate the validity of the analytical findings.