Opportunistic wireless information and energy transfer for sustainable cooperative relaying

Inspired by the green communication trend of next-generation wireless networks, we propose an opportunistic wireless information and energy transfer relaying scheme for sustainable cooperative relaying, in which the relay nodes are powered only by their independent harvested energy to forward the desired information to the destination. Thus there exists an inherent tradeoff between the information decoding (ID) and the energy harvesting (EH) for forwarding. We first analyze the tradeoff and formulate an optimization problem on joint EH/ID receive mode selection and transmit power control for the relay nodes. By Lagrangian optimality, we obtain the optimal solution in opportunistic relay and power control. Due to the NP-hard property of the EH/ID mode selection, we propose a low-complexity algorithm by relaxation for EH/ID mode selection. The simulation results show that the performance of the low-complexity algorithm is close to the optimal solution, and outperforms the baselines.