Cognitive Interference Mitigation in Heterogeneous Femto-Macro Cell Networks

In this paper, we study the cognitive interference management (CIM) scheme in the coexistence networks of macro-cells and femtocells. A single-channel detection based spectrum allocation algorithm is proposed to enhance the performance of femtocells considering the cross-tier interference and co-tier interference. The proposed scheme converts the complex interference environment into several specific channel categories and successfully recognizes these channel patterns, while the group-channel resource allocation algorithm does not distinguish the interference channels in detail and operates on the continuous group of channels. Therefore, femtocell base stations (FBSs) can recognize the spectral environment more completely and allocate more available channels. As a result, our scheme is able to significantly improve the femtocell spectral efficiency and the signal-to-interference-and-noise ratio (SINR) performance of femtocell users (FUEs), meanwhile, it avoids the strong interference on the existing macrocell. Numerical simulations verify the conclusions.