A Decentralized Interference Coordination Method for OFDMA Femtocell Networks

Femtocell is an emerging technology that promises increased network capacity and enhanced indoor coverage at a low capital and operational cost. As femtocells are customer-deployed without proper network planning, their interference environment tends to be much more complicated than traditional cellular networks. In this paper, we design a decentralized asynchronous inter-cell coordination method to deal with inter-macrocell interference and inter-femtocell interference. Based on this method, we propose a hierarchical scheme to solve the cross-tier interference problems in macro/femtocell heterogeneous networks. The simulation results show that this scheme can stably allocate subcarriers among cells in a distributed manner, and that it is adaptive to traffic loads and on-offs of femtocell base stations. The target of interference coordination is achieved, and a good spatial multiplexing efficiency can be attained.