Cooperative sensing throughput analysis over fading channels based on hard decision

Cooperative sensing is a way of improving the performance of spectrum sensing by exploring the spatial diversity in cognitive radio networks. One of the critical parameters of cooperative sensing is the estimation of optimal sensing time over probable channel noise impediments such as AWGN, Rayleigh, and Rician fading. In this paper, the optimal sensing time is evaluated for single node as well as for multinode over fading channels based on throughput analysis of the cognitive radio user with the constraints imposed by the IEEE 802.22 WRAN standard. Hard decision fusion methods are considered to make the global decision. Performance is analysed with Monte-Carlo simulations of 1500 iterations. The simulations are carried out for different prior probabilities of licensed user signal off P(H0) and signal on P(H1) status in a channel to be scanned. The results reveal that the optimal sensing time is found to be 2.7msec in case of single node sensing and it is dependent on number of users in the case of multinode sensing over considered fading channels.