Throughput Maximization for Two-Way Buffer-Aided and Energy-Harvesting Enabled Multi-Relay Networks

For years, relay communications have been witnessed to extend the network coverage and improve the throughput and reliability of wireless systems. In this paper, we focus on throughput maximization for the two-way buffer-aided relay network with finite data buffers and limited energy battery, wherein relays have no fixed power supply and they replenish energy from the Radio Frequency (RF) signal radiated by source nodes. Specifically, by jointing the time switching and energy splitting for RF energy harvesting, we introduce a three time-subslot transmission model to balance the energy storage and the energy consumption for communication. On top of this transmission model, we formulate an optimization problem for throughput maximization of relay network. We purposely convert the non-convex optimization problem into a convex one by carefully decoupling and relaxing. Further, we theoretically derive the maximum throughput and apply an iterative algorithm to achieve the suboptimal solution based on relay selection and power allocation. In addition to solving the no-delay limited throughput maximization problem, we put forward the solution of the delay limited transmission in the two-way buffer-aided multi-relay networks. Extensive simulations have been conducted to demonstrate that our proposed strategy is able to significantly improve the sum-throughput under transmission energy and delay constraints.