Dual-Utility based Green Power Game in Two-Tier OFDMA Femtocell Networks with Firefly Algorithm

This paper presents a game-theoretic approach of power allocation in two-tier OFDMA femtocell networks. A dual-utility based non-cooperative game with pricing is formulated for effectively allocating power on each sub-channel, targeting at maximizing energy efficiency for each macro BS and protecting the SINR for each femto BS for customers' interests, under power constraints in each sub-channel. The existence of a unique equilibrium for the proposed game is studied, and the impact of tunable coefficients of the proposed utility function on the equilibrium is investigated theoretically. An effective distributed power allocation algorithm with firefly algorithm (FA) theory is proposed to achieve the equilibrium. Furthermore, how to set the proper parameters of FA for the utility function is studied through numerical analysis. Simulation results show that the proposed scheme can improve energy efficiency of macrocell networks and mitigate the cross-and co-tier interference significantly while guaranteeing target QoS of femtocell users.