Max-Min Fairness Scheme in Wireless Powered Communication Networks with Multi-user Cooperation

In wireless powered communication networks (WPCNs), different channel states of energy harvesting and information transfer result in the large gap of throughput performance between user nodes. In this paper, the multi-user cooperation was used to improve the throughput fairness in the WPCN. We discuss one important fairness problem called the max-min throughput problem with resource allocation. The problem is modeled as a mixed-integer nonlinear programming. Although it is hard to be solved by existing methods, we use a branch and bound method based on the piece-wise linear method to obtain the lower bound. The simulation results that the proposed method achieves an average of 97% performance gain when path loss component alpha = 3 with random progress method.