Distributed cooperative spectrum sensing based on consensus among reliable secondary users

Cooperative spectrum sensing (CSS) is a key technology to improve the sensing performance. Fully distributed CSS has been applied in cognitive radio ad hoc networks with good detection performance. However, when the number of secondary users (SUs) is large and the range of cognitive radio network is wide, sensing overheads (e.g., time and energy consumption) will increase correspondingly. Meanwhile, the reliability of SUs will potentially influence the detection performance. In this paper, a fully decentralized cooperative spectrum sensing scheme based on consensus theory among reliable SUs is proposed. Firstly, belief vector is used for distinguishing the reliable SUs from the unreliables. Secondly, the sub network with most reliable SUs is chose as reliable region, in which sensing information of reliable SUs can be exchanged among their one-hop neighbors with finite iterations based on consensus theory. Lastly, SUs in consensus network will get a consensus sensing outcome which will be shared with SUs outside of consensus network. The proposed scheme does not need the prior knowledge of primary user in the entire process. Simulation results show that the proposed scheme has better detection performance than traditional methods.