Channel-Aware Scheduling in FFR-Aided OFDMA-Based Heterogeneous Cellular Networks

In the context of OFDMA-based 4G/5G heterogeneous cellular networks, the deployment of femtocells is a solution to increase the capacity and coverage of indoor areas. This paper presents an analytical framework allowing the downlink performance evaluation of fractional frequency reuse (FFR)-aided OFDMA-based two-tier HetNets where scheduling of both macro and femto users takes into account user fairness and channel state information. The femtocell tier is assumed to be uncoordinated and co-channel deployed over the macrocells. Due to the use of interference coordination schemes in combination with channel-aware scheduling policies, a high spectral efficiency is preserved over the whole coverage area. The proposed framework allows the performance evaluation of the resource block scheduling policy on both the macro-and femto-tier taking into account the impact produced by the inter-and co-tier interferences. The average throughput results are given as a function of, for instance, the distance threshold that separates the macrocell-centre from the edge, the average number of user equipments per cell, the density of FBSs per area unit and the degree of isolation provided by wall penetration losses.