Geometric Power Control for Time-Switching Energy-Harvesting Two-User Interference Channel

This paper studies the optimization of power control for the two-user interference channel in which the terminals are time-switched between the communication and energy-harvesting phases. The objective is to maximize the sum rate, subject to the minimum data and harvested energy constraints at the receivers, assuming a fixed time-switching coefficient. Our key contribution is a geometric approach that analyzes the feasible region governed by the constraints, which gives rise to the optimal power control solution. We assume that perfect channel state information is available at both transmitters to determine the solution.

I. Introduction

In RECENT years, green communications has been a main research theme in wireless communications, with an ever-increasing focus on energy efficiency [1]. While power saving continues to be important, many have turned their attention to studying ways to extend the lifetime of mobile terminals to realize genuine sustainability. The concept of simultaneous wireless information and power transfer (SWIPT) has thus emerged as a refreshing idea to exploit the power-bearing characteristics of wireless signals for possible remote charging [2]– [4].