Novel Joint Subcarrier and Power Allocation Method in SWIPT for WSNs Employing OFDM System

In recent research trends, simultaneous wireless information and power transfer (SWIPT) has proved to be an innovative technique to deal with limited energy problems in energy harvesting (EH) technologies for wireless sensor networks (WSNs). In this paper, a method of subcarrier and power allocation for both EH and information decoding (ID) operations is proposed under orthogonal frequency division multiplexing (OFDM) systems, with an improved the quality of service (QoS) parameters. This proposed method assigns one group of subcarriers for ID and remaining group of subcarriers is assigned for EH, despite of applying any splitting schemes. We achieved maximum EH under the ID and power constraints with an effective algorithm for the first time incorporating the dual decomposition technique which deals with power and subcarrier allocation problem jointly. The obtained simulation outcomes in relation to power allocation ratio, subcarrier allocation ratio and energy harvested (EH) at the destination node proved better when compared to the schemes that contain water filling, time switching (TS) or power splitting (PS) approaches under different target transmission rates and transmitter and receiver distances.