Energy Efficiency of Base Station Deployment in Ultra Dense HetNets: A Stochastic Geometry Analysis

Ultra dense heterogeneous networks (HetNets), which involve densely deployed small cells underlaying traditional macro cellular networks, will be an enabling solution for extremely high data rate communications. However, the dense deployment of small cell base stations (BSs) inevitably triggers a tremendous escalation of energy consumption. In this letter, we investigate the impact of BS deployment, especially BS density on energy efficiency in ultra dense HetNets using the stochastic geometry theory. The minimum achievable data rate in terms of the traffic load in each tier is characterized, and then the minimum achievable throughput of the whole HetNets is obtained. Finally, the closed-form energy efficiency with respect to the BS deployment is derived. The simulation validates the accuracy of the theoretical analysis, and demonstrates that the energy efficiency maximization can be achieved by the optimized BS deployment.