Closed-Form Delay-Optimal Power Control for Energy Harvesting Wireless System with Finite Energy Storage

摘要

In this paper, we consider delay-optimal power control for an energyharvesting wireless system with finite energy storage. The wireless system ispowered solely by a renewable energy source with bursty data arrivals, and ischaracterized by a data queue and an energy queue. We consider a delay-optimalpower control problem and formulate an infinite horizon average cost MarkovDecision Process (MDP). To deal with the curse of dimensionality, we introducea virtual continuous time system and derive closed-form approximate priorityfunctions for the discrete time MDP at various operating regimes. Based on theapproximation, we obtain an online power control solution which is adaptive tothe channel state information as well as the data and energy queue stateinformation. The derived power control solution has a multi-level water-fillingstructure, where the water level is determined jointly by the data and energyqueue lengths. We show through simulations that the proposed scheme hassignificant performance gain compared with various baselines.