Energy Efficiency Optimization Based SWIPT in Multiuser OFDM Systems

The research on wireless communication has been mainly focused on improving the system rate. However, while achieving the higher rate, it also consumes a lot of power, which leads to a reduction in energy efficiency. Therefore, in this paper, we propose a new algorithm to maximize energy efficiency in multiuser OFDM systems. More specifically, users can transfer information and collect energy simultaneously by using SWIPT technology, and the energy efficiency is maximized by optimizing the subcarrier allocation under some constraints. We formulate the proposed algorithm at first, and the initial optimization problem is non-convex, so we cannot get the optimal resource allocation directly. Later, by transforming the original objective function, the optimal solution is obtained. Finally, we validate the proposed algorithm with simulation results. The results show that the proposed algorithm can indeed improve energy efficiency. We also find that some variables have a huge impact on system energy efficiency.