Scaling Laws of Energy Efficiency Related Metrics for Varying Cell Radii in Downlink Cellular Systems

Energy efficiency in wireless communication systems has recently attracted great interest. Small-sized cell topology is a key idea for energy saving. In this letter, we characterize the scaling laws of energy efficiency related metrics such as base station (BS) transmit power, capacity per user, and energy efficiency per user for varying cell radii in downlink cellular networks by investigating the asymptotic behaviors. The scaling laws of the BS transmit power per user, capacity per user, and energy efficiency per user follow R
^γ-2
, R
^-2
, and R
^-γ
, respectively, where R is the cell radius and γ denotes the path loss exponent.