On the effect of proportional fairness in energy transfer for wireless powered communication networks

Abstract

Wireless powered communication network (WPCN) is an emerging area of research where energy is transferred from the access point to the mobile terminals in the downlink and information is transferred in the uplink. In the context of WPCN, we study the effects of applying different downlink/uplink scheduling schemes on the system performance in terms of achieved system throughput and fairness. In contrast to conventional wireless networks, where data scheduling determines the system sum rate and fairness behaviour, downlink energy scheduling contributes equally in WPCNs. We propose fairness based downlink energy transfer and compare different combinations of downlink and uplink scheduling schemes. Furthermore, we propose a new metric for downlink energy transfer for the special case of finite energy buffer and evaluate its effect on the achieved system throughput and fairness. Our numerical results show that a complete throughput fairness cannot be achieved as long as fairness is not employed in energy transfer in downlink regardless of the uplink scheduling scheme. 2015 IEEE.