Interference coordination based on access control in macro-femto networks

Macro-femto networks, which comprise a macrocell underlaid with multiple femto cells, have attracted much research attention due to its benefits for capacity increase and coverage extension. However, the mass deployment of femtocells with universal frequency reuse may cause severe interferences, and thus greatly deteriorate system performance. In this kind of systems, access control is an effective mechanism for interference management. In this paper, we investigate the case where the macro users may suffer severe interferences from femto base stations (FBS), and propose an access control based interference coordination scheme. By introducing auction model, FBSs decide the asking price for reserving their resources for macro users. Macro base station (MBS) bids for the access permission of macro users and selects a candidate FBS with the maximum access utility as the access point for a macro user. If an agreement for the transaction price of a macro user is reached, this user can change access point and thus the suffered interferences can be reduced. We conduct extensive simulations to validate the effectiveness of our scheme. Numerical results show that the proposed interference coordination approach operated in hybrid access mode can effectively mitigate interferences and improve system performance compared with the closed access mode.