Distributed beamforming for energy-harvesting relaying in vehicular networks

Recently, battery capacity and charging speed have been the bottlenecks of mobile communication networks. Energy harvesting (EH) relaying has become a promising solution for green 5th generation mobile communication with the advancement of wireless power transfer technology. In this paper, we investigate EH relaying in vehicular networks and adopt distributed beamforming (DB) to enhance the reliability and capacity of EH relaying. To be more specific, we propose a DB solution based on the joint optimization of power-splitting (PS) factors. For amplify-and-forward relaying, to transform the optimization problem into a quasi-convex one, we apply the semidefinite relaxation (SDR) method so that we can effectively attain the global optimal solution, while the suboptimal DB solution with distributed optimal PS factor which only requires local channel state information is also proposed. For decode-and-forward relaying, to get the optimal PS factors, we set a signal-to-noise ratio threshold at the relays, which can reduce the system error rate caused by the poor transmission link. Simulation results demonstrate the efficiency of our proposed DB-based EH relaying scheme in vehicular networks. © 2020, Posts and Telecom Press Co Ltd. All rights reserved.