Abstract
In this paper, optimal and suboptimal routing protocols are proposed for cognitive radio networks. We first investigate optimal routing protocol that consists in searching among all available paths, the one that minimises the end-to-end outage while verifying interference constraint to primary receiver. A suboptimal one-hop routing protocol is proposed where the best relay is selected in each hop. The last routing protocol consists in decomposing the network in many subnetworks composed of K hops. Then, the best route is determined in each of these subnetworks so that the K-hops outage probability is minimised. The proposed K-hops routing protocol allows a good compromise between complexity and performance. The outage probability of the different routing protocols is evaluated theoretically and through simulation results. Copyright (C) 2014 John Wiley & Sons, Ltd.