LAUSR

Dense femtocell deployment in macrocell system is an important tendency in future cellular networks due to the increasing demand in indoor communications, where the cross-tier interference mitigation between the macrocell and femtocells is one of the most critical issues. However, the current studies mostly focus on the cross-tier interference in two-dimensional scenarios with a few works considering the tridimensional cell. In this paper, based on the traditional fractional frequency reuse (FFR) method, we propose a simple yet effective tridimensional frequency reuse strategy to mitigate the cross-tier interference in two-tier femtocell networks. We analyze the performance of the proposed strategy and present the theoretical expression of the interference and the data rate. Moreover, we compare it with the traditional FFR method and the original co-channel method. Simulation results show the huge gain achieved by our proposed strategy and demonstrate its effectiveness on interference mitigation in the tridimensional cell.