Time Allocation and Load Balancing in Multi-Cell Wireless Powered Communication Networks

This paper jointly optimizes intra-cell time allocation and inter-cell load balancing to maximize the network sum-throughput in multi-cell wireless powered communication networks. Since the considered problem is a mixed integer programming problem, it is difficult to attain its global optimality. In this paper, we relax the zero-one integer user association variables into continuous ones. Then, the problem turns out to be a convex problem, which can be efficiently solved. After that, the optimal relaxed solution is rounded to integers. Analysis shows that the optimal solution to the relaxed problem has a highly sparse structure, which guarantees the effectiveness of the proposed approach. Simulation results indicate that the achieved sum-throughput is quite close to the upper bound resulted from the optimal relaxed solution and the proposed strategy significantly outperforms the pure intra-cell resource allocation without load balancing.