Optimal power control for wireless power transfer system: A deterministic approach

This paper proposes an optimal power control in wireless power transfer systems with a large number of energy harvesting (EH) devices. Based on the rectenna circuit, we consider a practical non-linear energy harvesting model and derive the practical radio frequency to direct current conversion efficiency. Based on the conversion efficiency, we also analyze the harvesting power and power efficiency with respect to the transmission power. Then we derive the optimal harvesting power and power efficiency by utilizing the characteristics of a large number of EH devices. Simulation results show that the results of deterministic approaches perform close to the Monte Carlo results and the maximum power efficiency can be asymptotically achieved.