Performance of cooperative multi-hop cognitive radio networks with selective decode-and-forward relays

Multi-hop relaying is used to extend the reach of wireless communication systems whereas cooperative relaying is used to improve the performance gain by exploiting the spatial diversity. In this study, the authors combine these two techniques to improve the range as well as the performance gain of cognitive radio networks (CRNs). Selective decode-and-forward relays are considered and two relay selection schemes are used to study the performance of multi-hop CRNs over Rayleigh fading channels. The exact outage probability and throughput of the considered system are derived for both the schemes by considering the effect of both peak-power and peak-interference constraints. By using the derived outage probability, the diversity gains for both considered schemes are determined. Numerical results show that the outage probability monotonically improves, whereas the throughput has concave behaviour with respect to increasing number of relaying hops.