Joint relay selection and power allocation in energy harvesting AF relay systems with ICSI

In various wireless networks, power allocation scheme promises significant benefits in energy harvesting (EH) wireless networks. However, these benefits depend on the knowledge of the channel state information (CSI), which is hardly perfect. Therefore, in this study, the authors investigate an EH two-way relaying network with channel estimation error taking into consideration. First, the system outage performance is studied and closed-form expressions for the outage probability are derived. On the basis of minimising the outage probability, an optimal power allocation (OPA) scheme is proposed and the effective ways to solve this OPA scheme are presented. In addition, a joint relay selection and the OPA scheme is provided to further improve the system performance. Finally, by comparing the OPA scheme with conventional power allocation schemes via simulations, the superiority of the OPA scheme is demonstrated. Moreover, the impact of imperfect CSI on the system performance is analysed and the simulation results show the robustness of the OPA scheme.