A Fast Blind Scheme With Full Rendezvous Diversity for Heterogeneous Cognitive Radio Networks

In cognitive radio networks (CRNs), unlicensed secondary users (SUs) need first meet with each other on a commonly available channel before communication, which is referred to as rendezvous. It is preferable for the distributed environments without an infrastructure that using blind rendezvous scheme to achieve rendezvous. In this paper, we propose a fast blind rendezvous scheme named modified enhanced heterogeneous radio rendezvous (MEHRR) scheme for the SUs in distributed heterogeneous CRNs. Compared with our published paper, we consider rendezvous diversity when designing the MEHRR scheme. SUs can achieve full rendezvous diversity (i.e., rendezvous on all commonly available channels) by the MEHRR scheme, which can increase the success probability of rendezvous while reducing the impact of blocking primary users (PUs) for a long time. The upper bounds on the time to rendezvous (TTR) with full rendezvous diversity are derived by theoretical analysis for the MEHRR scheme. Besides, we also theoretically analyze the channel loading, and the optimal allocation of multiple radios that can achieve the shortest maximum TTR (MTTR) with full rendezvous diversity for the SUs using the MEHRR scheme. Simulation results verify the theorems derived by the theoretical analysis. Moreover, the superiority of the MEHRR scheme compared with other state-of-the-art blind rendezvous schemes for the multiple radios-based SUs in terms of MTTR with full rendezvous diversity is also shown by the simulation results.