Optimal macrocell partitioning for redistributed fractional frequency reuse in heterogeneous networks

Fractional Frequency Reuse (FFR) has been adopted in current two-tier Heterogeneous Networks (HetNet) with femtocells deployed in the presence of an overlaid macrocell. This technology would effectively reduce the inter-cell interference (ICI), from both co-tier and cross-tier, and thus achieve higher system throughput. Cell partitioning is an important parameter in FFR scheme. In this article, a Redistributed FFR (RFFR) scheme is proposed for HetNet and the system throughput is analyzed from the point of macrocell partitioning. We apply a Fluid Model to approximate the Signal to Interference Ratio and convert the capacity maximum problem into a convex optimization. The optimal cell partitioning percentage is calculated. Simulation results show that the optimal reuse partitioning of proposed RFFR for the HetNet is 0.79. The solution has reference value for the other frequency reuse based networks.