Energy-efficient power allocation with dual-utility in two-tier OFDMA femtocell networks

This paper investigates the downlink power allocation problem to mitigate the cross- and co-tier interference in the spectrum-sharing two-tier OFDMA femtocell network, which are comprised of macrocells underlaid with femtocells. The problem is formulated as a non-cooperative game with dual-utility. To achieve green radio access, the objective of the utility for each macro BS is to maximize its energy efficiency under power constraints in each sub-channel, and both circuit and transmit powers have been considered, while the objective of the utility for each femto BS is to maximize its own SINR for customers´ interests. Then, the existence, characteristic and uniqueness of the equilibrium for the proposed game are studied. With practical LTE parameters and three-dimensional femtocell network model, 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 the minimum QoS requirement of femtocell users.