Femtocell‐enhanced multi‐target spectrum allocation strategy in LTE‐A HetNets

Due to prominent advantages in local coverage enhancement and indoor cellular capacity improvement, femtocell (FC) is considered as a vital component in long‐term evolution advanced (LTE‐A) heterogeneous networks (HetNets). A two‐tier LTE‐A HetNet with conventional macro base stations in the first tier and femto base stations in the second tier is considered. Under this architecture, a new downlink interference evaluation scheme is proposed, based on which a FC enhanced multi‐target resource allocation algorithm is developed to maximise user equipment (UE) throughput in a dense FC deployment scenario meanwhile providing every UE a minimum signal to interference plus noise rate (SINR) guarantee. The optimal resource allocation problem is formulated as a MAX‐K cut problem based on the graph theory approach. System‐level simulations reveal that intra‐cell interference is greatly reduced and the spectral efficiency is significantly improved by using the proposed resource allocation scheme. Femtocell throughput is elevated significantly without causing much degradation on the macrocell throughput.