Optimal Fairness-Aware Time and Power Allocation in Wireless Powered Communication Networks

TL;DR

This paper addresses optimal time and power allocation in wireless powered communication networks to maximize a fairness-aware utility, transforming the problem into a convex form and analyzing tradeoffs between sum rate and fairness.

Contribution

It introduces a convex reformulation of the sum alpha-fair utility maximization problem in WPCNs and explores fairness tradeoffs through adjustable alpha values.

Findings

Optimal time and power allocation strategies derived.

Convex reformulation enables efficient optimization.

Tradeoffs between sum rate and fairness demonstrated through simulations.

Abstract

In this paper, we consider the sum $\alpha$-fair utility maximization problem for joint downlink (DL) and uplink (UL) transmissions of a wireless powered communication network (WPCN) via time and power allocation. In the DL, the users with energy harvesting receiver architecture decode information and harvest energy based on simultaneous wireless information and power transfer. While in the UL, the users utilize the harvested energy for information transmission, and harvest energy when other users transmit UL information. We show that the general sum $\alpha$-fair utility maximization problem can be transformed into an equivalent convex one. Tradeoffs between sum rate and user fairness can be balanced via adjusting the value of $\alpha$. In particular, for zero fairness, i.e., $\alpha=0$, the optimal allocated time for both DL and UL is proportional to the overall available transmission power. Tradeoffs between sum rate and user fairness are presented through simulations.