Fractional frequency reuse-based resource sharing strategy in two-tier femtocell networks

In this paper, we propose a downlink resource sharing strategy in two-tier networks with the co-channel femtocell deployment. The proposed resource sharing strategy adopts the fractional frequency reuse (FFR) framework to maximize the spectral efficiency and overcome the femto-to-macro interference (FMI) problem at the same time. In the proposed strategy, resource units in each frequency partition (FP) are divided into a macro-privileged group and a femto-dedicated group. To protect the macrocell from the FMI, the resource usage of the femtocells is controlled according to the FP assignments of the nearby macrocell users. In addition, the per-FP resource division is determined to maximize the spectral efficiency while balancing macrocell/femtocell user throughputs. Simulation results show that the proposed resource sharing strategy can achieve high spectral efficiency while suppressing the FMI effectively.