Energy Efficient User Association and Power Control for Dense Heterogeneous Networks

Dense heterogeneous network (HetNet) is a promising solution to satisfy the unprecedented demand for higher data rate and energy efficiency in the next generation mobile networks. In dense HetNets, one of the main challenge is how to dynamically assign the limited resources, such as frequency band and transmit power. In order to efficiently address the challenge and strive towards high network energy efficiency, efficient user association and power control schemes should be designed carefully. However, the conventional user association policy is unsuitable for dense HetNets, since the transmit power disparity of macro and small base stations (BSs) will lead to the association of most of the users with the macro BSs, hence potentially resulting in inefficient small cell deployment. To address this issue, a heuristic user association scheme is proposed in this paper. Then in order to improve the average energy efficiency of all the users, an uplink power control algorithm is also proposed. Numerical results demonstrate that the proposed heuristic user association scheme and power control algorithm can improve the average energy efficiency of all the users dramatically.