Efficient spectrum leasing in cognitive radio networks: Disjoint secondary user selection and protocol selective relaying

Abstract

In this paper, we propose an efficient spectrum leasing scheme for cognitive radio networks in which the leasing process is carried out by employing two generally non‐identical secondary users. The first secondary user is selected for cooperating with the primary network, and the second one is offered the released spectrum to perform the secondary transmission. The two mentioned secondary users are selected independently. Both the decode‐and‐forward and the amplify‐and‐forward relaying protocols are considered in this paper. Moreover, a protocol selective relaying scheme named decode‐ or amplify‐and‐forward (DAF), which smartly switches between the two protocols, is applied. We show that the disjoint secondary user selection and the protocol selective relaying result in an enhanced outage performance for both the primary and secondary networks as well as an increased achievable transmission rate for the secondary network. Numerical and simulation results are presented to evaluate the performance improvement of the proposed scheme. Using the simulation results, we also investigate the effect of disjoint secondary user selection on fairness considerations of the secondary network. Copyright © 2016 John Wiley & Sons, Ltd.