Energy and Spectrum Efficient Resource Allocation in Two-Tier Networks: A Multiobjective Approach

In this paper we investigate the joint power and channel allocation problem in two-tier OFDMA femtocell networks using a multiobjective approach with focus on energy efficiency. Three main objectives are considered in our problem formulations namely, energy efficiency, spectral efficiency, and power consumption. To solve the muliobjective problems, we have utilized a non-dominated sorting genetic algorithm (NSGA-II) and an algorithm have been proposed to perform the resource allocation procedures. In this investigation, to preserve the quality service of users, we have applied a minimum data rate threshold for all users. Furthermore, we impose an interference threshold limit on each subchannel to protect the macrocell user quality of service. Finally, the simulation results figure out that we can achieve 30% better energy efficiency by trading the throughput by about 20%.