Caching cooperation with energy harvesting based small cells in heterogeneous networks

In this paper, the caching cooperation scheme between hybrid-powered small base stations (SBSs) is studied to minimize the system transmit power in heterogeneous networks. The SBS with on-grid power is used to respond to user requests and keep itself working; the harvested energy is exploited for caching cooperation among SBSs. To stimulate the SBS with full use of harvested energy in every slot, a scheme is proposed to select the cooperating target and allocate the harvested energy. The problem of minimizing the system power consumption is formulated and a suboptimal algorithm is used to approximate its solution. According to the numerical results, the proposed scheme can save transmit power greatly compared with a no-caching cooperation scheme and performs much better than the arbitrary selection scheme.