Energy-efficient resource allocation with interference mitigation for two-tier OFDMA femtocell networks

In order to suppress cross-tier interference (CTI) and inter-cell interference (ICI) between adjacent macrocells, this paper proposes an effective resource allocation scheme for the two-tier OFDMA femtocell networks, in which macro BSs adopt the soft frequency reuse (SFR) strategy. Consider that macrocell users (MUEs) are prior to femtocell users (FUEs), firstly the subbands are allocated to MUEs utilizing SFR for the ICI mitigation, based on which the sub-bands are efficiently allocated to femocells for CTI mitigation. The proposed scheme is optimized in terms of energy efficiency, while guarantees that both MUEs and FUEs attain at least a given data rate, especially for cell-edge MUEs. With a three dimensional two-tier femtocell network model and practical LTE parameters, simulation results show that the proposed scheme rivals other two prominent related schemes on the CTI and ICI suppression, while outperforms them on energy efficiency for wireless overlay networks.