Complete interference solution with MWSC consideration for OFDMA macro/femtocell hierarchical networks

OFDMA femtocells are generally accepted as a very promising solution for indoor coverage with high data rate. However, the lack of systematic schemes to effectively mitigate macro/femtocell hierarchical interference, fully utilize radio resources, provide quality-of-service (QoS) and fairness guarantee among users suffocate the performance realization of femtocells. In this paper, an Adapted Soft Frequency Reuse (ASFR) approach is raised to combat traditional inter-cell interference (ICI)¹ by inheriting the conventional soft frequency reuse (SFR) functionality and to mitigate inter-tier interference (ITI) of macro/femtocells by applying an orthogonal spectrum reuse between macro/femtocells. Moreover, a powerful inter-femtocell interference (IFI) coordination mechanism is provided to complete the interference solution for the three types of interference in the macro/femtocell hierarchical networks. While the interference handling propositions are targeted at optimized spectrum partition for base stations (macro/femtocells included), to further increase spectrum efficiency, a Maximum Weighted Sum Capacity (MWSC) based scheduling design is adopted, to optimize spectrum allocation for users, with restraints to QoS and fairness guarantees. In this way, spectrum efficiency is enhanced at both the BS and UE sides. Simulation results show that the proposed solutions provide fairly good performance in comparison with conventional co-channel macro/femtocell utilizing Proportional Fair (PF) scheduling method.