User Association for Energy-Load Tradeoffs in HetNets With Renewable Energy Supply

A user association algorithm is proposed for energy consumption and traffic load balancing tradeoffs among heterogeneous base stations in heterogeneous networks with renewable energy supply. The concept of topology potential is introduced to represent the attraction between base stations and users, which takes the traffic load of users and the available renewable energy of base stations into consideration for energy-load tradeoffs. Then the user association optimization problem is formulated for base station utility proportional fairness. The proposed algorithm is proved to converge to the global optimum of the formulated optimization problem. Simulation results demonstrate the effectiveness of the proposed algorithm in achieving load balancing as well as in making the best use of renewable energy harvested by base stations.