Two Time-Scale Resource Allocation in Hybrid Energy Powering 5G Wireless System

In this paper, the 5G wireless communication system with hybrid energy supply is considered, where the energy arrival variations and the channel fading are of different time-scales. In such a system, there exists multi-dimension randomness caused by the variations of energy harvesting, channel fading and electricity price. Faced with this challenge, we address the two time-scale cross-layer resource allocation problem to maximize the user experience while minimizing the energy cost from a long-term perspective. The formulated problem can be decoupled into three subproblems based on Lyapunov optimization, including the energy management subproblem over the large time-scale, and the rate control subproblem as well as the joint channel and power allocation subproblem over the small time- scale. Next, these subproblems are solved by combining linear programming, convex optimization, and matching theory, without the requirement of noncausal information. Finally, simulation results demonstrate that the proposed algorithm can achieve superior performance while guarantee reliable data transmission and efficient energy utilization.