Stochastic geometry analysis of energy efficiency in HetNets with combined CoMP and BS sleeping

Base station (BS) sleeping has been proved to be an effective technique for saving energy consumption in cellular networks. However, BSs in sleeping mode might cause coverage holes, which have a negative impact on the connectivity of the network. In order to overcome this problem, we propose a combined coordinated multi-point (CoMP) transmission and BS sleeping scheme under the heterogeneous networks (HetNets) scenario. The proposed scheme aims at improving energy efficiency as well as increasing coverage probability. In this paper, stochastic geometry analysis is adopted for evaluating the performance of the proposed scheme, instead of the conventional hexagonal grid based approach. Impact of CoMP on energy efficiency in HetNets with a random on/off strategy applied at macro base stations (MBSs) is examined thoroughly. We derived two performance indicators which are coverage probability and energy efficiency in a two-tier HetNets scenario. Numerical results confirm that the combined CoMP and BS sleeping can improve the energy efficiency as well as increase the coverage probability compared with implementing BS sleeping only. The impact of the density ratio of MBSs to Pico BSs (PBSs) on energy efficiency and coverage probability is also quantified.