Towards energy efficiency with uplink cooperation in heterogeneous networks

Coordinated Multi-Point (CoMP) reception between base stations (BSs) has shown to be an efficient way to improve user performance in the uplink (UL). However, it comes with an increased network power consumption due to additional signal processing at the base station and information transfer on the backhaul. In this paper we analyze the impact of two UL CoMP schemes on the energy consumption of a heterogeneous network featuring fast BS sleep mode. We show that depending on the load and the UL CoMP scheme applied, a network with UL CoMP may be more energy efficient than without. We also propose a CoMP scheme selection algorithm so that the most energy efficient scheme is selected for a user during its activity time. Results show that the selection algorithm, evaluated in an ideal and a practical variant, leads to the lowest network power consumption for different traffic loads.