Area Power Consumption in a Single Cell Assisted by Relays

Green radio attracts a lot of attention due to global climate change. Compared with the traditional cellular systems in which the area spectral efficiency is the system performance metric, the green cellular systems should take both system energy consumption and system spectral efficiency as the system performance metric. The area power consumption is considered as the system energy consumption metric in this paper and the area power consumption given a target area spectral efficiency is analyzed in a single cell assisted by circularly located relays. We introduce a novel power model of the relay assisted systems at first. And then, the power consumption in the single cell assisted by relays is discussed. The direct transmission and two-hop transmission schemes are introduced at first and then an energy efficient mode switching scheme based on the different user´s location is proposed. The area power consumption of the three schemes is derived. Finally, the effect of different system parameters such as cell radius, relay position, relay number and area spectral efficiency to the area power consumption is discussed.