Throughput Optimizing for Power-Splitting Based Relaying in Wireless-Powered Cooperative Networks

To realize an efficient utilization of harvested energy and improve throughput with the help of a battery, a harvest-use-store power splitting (PS) relaying strategy with distributed beamforming is proposed for the wireless-powered multi-relay scenario in this paper. To this end, harvested energy via PS can be accumulated and stored for future usage, which affects throughput at subsequent time slots due to the battery operations including the charging and discharging. As a result, PS and battery operations are coupled with distributed beamforming, such that the throughput optimization problem is intractable looking. To address the intractability of the optimization, a layered optimization method with an ideal non-causal channel state information (CSI) assumption is proposed. As a result, the optimal joint PS and battery operation design in the proposed strategy is derived in a decoupled manner. Simulation results confirm the accuracy of the proposed method, and revealed that the proposed strategy has significant performance gains over the conventional designs.