Energy Efficiency Evaluation of Uplink Transmissions with Maximum Power Constraint

Energy efficiency of uplink users is critical for evaluating the energy consumption of heterogeneous cellular networks (HCNs) with heavy loading. The energy efficiency of user equipments (UEs) in HCNs depends heavily on power control scheme as well as maximum power constraint. This paper investigate the energy efficiency of uplink UEs in HCNs taking into account the flexible power control policy along with maximum transmission power limitation. We show that there exists a transfer path loss in the uplink energy efficiency which depends on the density of BS A, threshold of receiver po and power control coefficient e. The energy efficiency of users, which have small path loss to the BS, highly depends on the values of path loss and power control coefficient. On the other hand, the energy efficiency of users with large path loss is impacted by path loss and power control coefficient independently. We investigate the bound of transfer path loss and simulation results show the uplink energy efficiency affected by system parameters, such as the density of BS and power control coefficient.