Energy Efficient Power and Time Allocation in a Macrocell/Femtocell Network

he co-channel deployment of a femtocell with a macrocell is considered. We investigate the resource allocation in the downlink with co-channel interference. A novel utility function is introduced as an energy efficiency metric. Two competing objectives (energy minimization and capacity maximization) are included in the utility function in order to balance the network in possible energy savings and to maintain the quality of service of end users. Energy Efficiency = (Sum Energy consumption at the base station)/(Sum rate of the cell). In order to improve the energy efficiency of the entire network, tiers are separately addressed, so that we could avoid a centralized resource allocation scheme. The problem is then converted into a convex optimization formulation with an interference coordination scheme.