Simultaneous Wireless Information and Power Transfer in a two-user OFDM Interference Channel

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.