Energy-aware user association and energy cooperation for smart-grid-powered HetNet

As renewable energy is intermittent and randomly distributed, it is difficult for energy harvesting enabled networks to reliably supply the time-varying mobile traffic. We propose a brand new approach of energy sharing and load shifting to overcome this issue. In this paper, we first investigate the user association (UA) problem with energy cooperation to minimize the grid energy expenditure of heterogeneous networks (HetNets) whose base stations (BSs) are powered by both grid and renewable energy. Then we use greedy decomposition to convert this problem into two sub-problems which are energy cost aware user association and energy cooperation. For the first problem, we implement an optimal offline algorithm by using relaxing, dual decomposition. To solve the second problem, we propose a many-to-many matching algorithm. Finally, our simulation results show the effectiveness of the proposed algorithms and demonstrate that our algorithm is the most on-grid energy saving algorithm compared with existing schemes.