In this paper, an energy-efficient full-duplex (FD) unmanned aerial vehicle (UAV) relaying network is proposed, where UAV acts as a mobile relay and assists information exchange between two transceivers. Specifically, the load-carry-and-delivery scheme is applied to positively take advantage of the time-varying channel gain in delay-tolerant networks; meanwhile, the FD communication policy is used to potentially further increase the energy efficiency (EE). In particular, the self-interference channel gains follow the complex Gaussian distribution instead of being constant. The EE is first rigorously derived and then, the optimum flight speed is determined under the information causality constraint to maximize the EE. Numerical results demonstrate that the proposed scheme outperforms the half-duplex as well as static schemes in terms of the EE. In addition, the impact of the self-interference cancellation factor on the EE is also demonstrated, which provides valuable insights for the system design of UAV-assisted relaying networks.INDEX TERMS Energy efficiency (EE), delay-tolerant networks, full-duplex relaying (FDR), load-carryand-delivery (LCAD), UAV.
For an energy harvesting relay network, an optimal secure transmission scheme is proposed. In the case of limited harvesting energy and total power, destination-based jamming technique is applied to protect the confidential information from relay's jamming and eavesdropping. Moreover, the penalty function algorithm is utilised to obtain the optimal power allocation factor to maximise secure rate. The impacts of power allocation factor and energy transformation efficiency on the system secure rate are analysed. Simulation results validate the correctness and efficiency of the proposed scheme.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.