Energy-Aware User Association in Energy-Cooperation Enabled HetNets

This paper focuses on user association (UA) in energy- cooperation enabled heterogeneous networks (HetNets). Energy-cooperation enables energy to be transferred between base stations (BSs), which can reduce the unnecessary offloading and mitigate the signaling cost and the interference. However, some of the energy will be lost during the energy transfer process, which implies that there exists a tradeoff between offloading and energy- cooperation. Motivated by these, in this paper, UA is formulated as an optimization problem, aiming at maximizing the number of accepted users by taking advantage of energy-cooperation while minimizing the energy transfer loss between BSs. An energy efficient UA algorithm is proposed based on the primal-dual interior point method. Simulation results show that the proposed algorithm can greatly increase the energy efficiency and the number of accepted users of the whole network, which highlights the merits of energy-cooperation between BSs. Moreover, the energy efficiency gain achieved in the scenario with energy- cooperation is more significant when the number of users requiring services increases.