Full-duplex wireless information and power transfer in two-way relaying networks with self-energy recycling

Abstract

In this paper, we consider full-duplex (FD) two-way relaying networks, where wireless power transfers from hybrid power access-point, H to user and wireless information transmits from user to H via relay. We propose FD-based power splitting (PS) and time-switching (TS) protocols which enables the energy harvesting (EH) and information processing at relay. These protocols overcome the limitation of spectral efficiency and in band self-interference caused by half-duplex relaying and operation of FD respectively. The energy constraint nodes such as relay and user harvest energy from H by radio-frequency signal, where relay also harvests energy by self-energy recycling. The optimal PS ratio and the optimal TS ratio are investigated and expressed in closed-form. With Rayleigh fading channel, we derive the end-to-end ergodic capacity for PS and TS protocols. Numerical results show that our proposed FD-based EH schemes outperform the benchmark schemes significantly. In particular, the PS protocol is superior to TS protocol at high transmit power of H while at low transmit power of H, TS protocol is better than the PS protocol.