Content Caching in Energy Harvesting Powered Small Cell Network

The rapidly growing mobile traffic calls for higher quality of service (QoS) and lower on-grid energy cost. Integrating energy harvesting (EH) to small cell network (SCN) with caching has been regarded as a promising solution. However, considering the limited resource of the small cell base stations (SBSs), how to cache contents and serve the mobile users (MUs) is a crucial problem. In this paper, we design a green content caching mechanism in the SCN, where the number of MUs' content requests handled by the SBSs is maximized. First, the content caching problem is formulated, which is NP-hard. To decrease the complexity of the problem, we divide it into two subproblems: MU-BS association and content placement. When the number of SBSs is large, the two subproblems can't be efficiently solved by conventional centralized approaches. Thus we adopt the exact potential game (EPG) to model the subproblems. Finally, we propose a two-dimensional iteration algorithm (TDIA) to solve the proposed problem. The simulation results show that the proposed algorithm can achieve significant performance.