Joint Resource Allocation and Cooperative Transmission in Distributed Wireless Powered Communication Networks

In this paper, a distributed wireless powered communication network (WPCN) which consists of a center processor(CP), multiple hybrid remote radio heads (RRHs) and multiple terminal nodes is studied. Firstly, all terminal nodes harvest the wireless energy broadcast by RRHs and send their information bits to the associated RRHs by time-division-multiple-access (TDMA). Then, each RRH sends information bits received from terminal nodes to CP via wireless fronthaul links. We jointly optimize the terminal-RRH associations and the transmit power and transmission time of RRHs and terminals to minimize the transmission completion time. The original problem is a mixed-integer nonlinear programming and we solve it by Generalized Benders Decomposition (GBD) which can get the optimal solution by generating a series upper bounds and lower bounds. When terminal-RRH associations are fixed, we speed up the resource allocation algorithm by Alternating Direction Multiplier Method (ADMM) in which the solutions to small local subproblem are coordinated to find a solution of the global problem. Simulation results reveal the influence of the average power and the number of RRHs on the spectral efficiency.