Analytical Performance Evaluation of OFDMA-based Heterogeneous Cellular Networks Using FFR

Two-tier wireless architectures where the macro-cellular network is complemented with a deployment of femtocells are becoming an attractive solution to increase the global throughput in the context of OFDMA-based 4G/5G networks. This paper presents an analytical framework allowing the performance evaluation of fractional frequency reuse (FFR) aided OFDMA-based two-tier HetNets. A worst-case scenario in terms of inter-tier interference is evaluated in which macrocell and femtocell tiers are assumed to be uncoordinated and co-channel deployed. The proposed framework allows the evaluation of the impact produced by both inter-and co-tier interferences on either the macro-user-equipments (MUEs) or the femto-user-equipments (FUEs). Analytical performance results are used to optimise the FFR parameters as a function of, for instance, the resource block scheduling policy used at both the MBSs and the FBSs, the number of MUEs per cell, the density of FBSs per area unit or the degree of isolation provided by wall penetration losses.