Simultaneous Wireless Information and Power Transfer in a Two-User OFDM Interference Channel

TL;DR

This paper investigates SWIPT in a two-user OFDM interference channel, proposing a single-subcarrier energy transmission strategy and a cooperative method to enhance the rate-energy trade-off.

Contribution

It introduces a one-subcarrier selection approach for energy transmission and a cooperative scheme to improve the rate-energy region in SWIPT systems.

Findings

Optimal high SNR transmission uses a single subcarrier for energy

Proposed method enlarges the achievable rate-energy region

Cooperation via message exchange improves system performance

Abstract

In this paper, we study the Simultaneous Wireless Information and Power Transfer (SWIPT) in a Single-Input Single-Output (SISO) two-user Orthogonal Frequency Division Multiplexing (OFDM) Interference Channel (IFC). We assume that the transmitters are non-cooperative and have perfect knowledge of the local Channel State Information (CSI). We show that the necessary condition for the optimal transmission strategy at high SNR is for the energy transmitter to transmit its signal by allocating its transmit power on a single subcarrier. Accordingly, we propose a one-subcarrier selection method for the energy transmitter and identify the achievable rate-energy region. In addition, we further enlarge the achievable rate-energy region by enabling a basic form of transmitter cooperation where messages are exchanged to inform the energy transmitter about the subcarriers unutilized by the information transmitter.