Optimal Subcarrier Allocation for Maximizing Energy Efficiency in AF Relay Systems

In this paper, we propose a new energy efficiency maximization algorithm for AF relay OFDM-SWIPT system. Specifically, we divide the transmission time into two parts. In the first part, the base station transmits information to the user and the relay node. The relay node uses different subcarriers to implement SWIPT. Then in the second part, the relay node forwards information to the user. We formulate the above process, and then through some complex calculations to get the maximum energy efficiency.