Cluster-Based Resource Allocation for Interference Mitigation in LTE Heterogeneous Networks

In order to provide high data rate for indoor services, femtocells are proposed in LTE-Advanced system. Under this architecture, the main problem is how to reduce the interference between macro and femto cells and that among femtocells. In this paper, an interference graph is constructed in which the vertexes are Macro User (MUE) and femtocell. Besides, Regional Average Channel State (RACS) metric is proposed to estimate the weight of interference. Therefore, a dynamic spectrum assignment algorithm called hybrid clustering based on interference graph (HCIG) is proposed to reduce the interference, in which the optimal clustering problem is constructed as a MAX-K cut problem and a heuristic algorithm is given. Based on the cluster results, a resource allocation scheme is given to reduce the interference and improve the spectrum efficiency. System level simulation results show that compared to other three schemes, the SINR of both MUE and femto user are improved by HCIG.