Performance Comparison of IEEE 802.16e and IEEE 802.20 Systems under Different Frequency Reuse Schemes

IEEE 802.16e and 802.20 are emerging as two promising technologies for broadband wireless access systems. In order to improve capacity and coverage performance, both of them addressed a fractional frequency reuse (FFR) scheme to combat co-channel interference in multi-cell deployment, which is referred to as FFR₁₆ and FFR₂₀ respectively in this paper. As for the scheme of FFR₂₀, virtual area partition is proposed in this paper, and fractional frequency reuse factor (FFRF) is achieved by tuning the parameter of signal strength ratio. The optimal combination of resource allocation strategy and signal strength ratio is determined through simulation. In order to compare the performance of FFR₁₆ and FFR₂₀, three evaluation metrics are introduced, including average throughput, outage probability and spectrum efficiency. Simulation results show that outage probability is much lower under FFR₂₀ scheme, which goes beyond the acceptable range when FFRF is smaller than 2.4. The resource utilization efficiencies of both are continuously increasing with regard to FFRF within range [2.4, 3]. Besides, FFR₂₀ outperforms FFR₁₆ under given conditions, in terms of average throughput and spectrum efficiency.