Energy efficiency in MIMO large scale two-tier networks with beamforming and adaptive modulation

Abstract

In this paper, the energy efficiency in the downlink of a two-tier network consisting of macro- and femtocells using beamforming is analyzed. Orthogonal subchannel allocation is used in order to eliminate inter-tier interference. The random locations of the interferers in both tiers are modeled via a Poisson Point Process. Improvements in the energy efficiency of the system (in b/J/Hz), when several femtocells are deployed in a network, are observed under different scenarios. Finally, using realistic implementation parameters, we examine how the energy efficiency is affected by different antenna configurations, and we also obtain the optimal configurations.