Downlink Spectrum Allocation for Macro-Femto Networks

In this paper, a new spectrum allocation method is proposed to address the downlink interference problem in heterogeneous macro-femto networks, where distributed femtocells coexist with macrocells. In practical heterogeneous macro-femto networks, normally there is no direct link between a macro base station and a femto base station, and any communication between the two has to be via the backhaul and hence delay-tolerant. Meanwhile, due to wide deployment of distributed femtocells, the signaling overhead via the backhaul should be kept as low as possible. To this end, this paper comes up with a dynamic fractional frequency reuse and dynamic resource allocation scheme to tackle the interference problem, taking into consideration the delay- tolerance and low overhead requirements. Performance evaluation results have demonstrated the benefits of the proposed scheme.