Optimal Threshold Design for FFR Schemes in Multi-Cell OFDMA Networks

Fractional frequency reuse (FFR) is an efficient method to suppress inter-cell interference (ICI) in multi-cell OFDMA networks. In this paper, the optimal threshold is designed for FFR schemes to identify cell central and edge users. We first derive throughput of the FFR scheme considering small-scale fading channels and different scheduling strategies. Then we conclude from the analysis and simulation results that the throughput of maximum normalized SINR (MNSINR) scheduling is larger than that of round robin scheduling, and the optimal thresholds for both scheduling strategies decrease with the increase of cell user number. Simulation results also show that the performance of FFR scheme with the optimal threshold outperforms that with the conventional predefined threshold.