Downlink power control in two-tier OFDMA femtocell networks with Firefly Algorithm

To alleviate the cross-tier interference in two-tier Orthogonal Frequency Division Multiple Access (OFDMA) femtocell networks, this article put forward a distributed utility-based downlink power control algorithm. We firstly modeled the objective of power control with utility functions for macrocell and femtocell based on the factor of Area Spectral Efficiency (ASE). Then we developed a power control algorithm with Firefly Algorithm (FA) to find the optimal power settings in iteration procedure which can maximize the value of utility function. The simulation results show that the proposed algorithm can improve the total throughput and the throughput of femto users with minor impact on macro users.