Downlink Energy Efficiency Modeling and Optimization for Ultra Cellular HetNet

Abstract

The cellular heterogeneous network (HetNet) with ultra dense small cells is called ultra cellular HetNet. The energy efficiency for this network is very important for future green wireless communications. In this paper, the data rates and power consumptions for three parts (i.e., macro cells, small cells, and mixed backhaul links) in ultra cellular HetNet are jointly formulated to model downlink energy efficiency. Then, energy efficiency optimization algorithm using the fractional programming and Lagrangian multiplier with constraints for density of ultra dense small cells and fraction of mixed backhaul links is presented. The numerical simulations demonstrate the better effect on maximizing energy efficiency in this network.