Optimal energy-harvesting design for AF and DF two-way relay beamforming in 6G

Energy consumption is an important point which is crucial for green communications in 6G era, especially for those networks with limited life span or affected by dangerous environments where batteries are inconvenient to be changed. Therefore, energy harvesting (EH) has become a very attractive research field in recent years. In this paper, a new type of two-way EH relay beamforming system with two transceivers and many single-antenna relays is designed. All the transmit power of relay nodes is not restricted by the total quota or the personal quota and can be obtained entirely by energy harvesting. We use power splitting (PS) method for EH. We first establish a two-way system model for the amplify-and-forward and decode-and-forward relaying and then analyze the sum rate, and the gradient descent algorithm is used to solve the nonlinear joint PS factor optimization problem. Finally, the results of our analysis are verified by simulation, and they show that our method can not only optimize the PS factor efficiently, but also the model can improve the performance of the system.