Analysis of frequency reuse cellular systems using worst case Signal to Interference ratio

Frequency reuse schemes are an interference management techniques well suited to OFDMA-based cellular networks. In this paper, analytical expressions are derived for the worst case Signal to Interference Ratio (SIR) ratio for both Fractional Frequency Reuse (FFR), and Soft Frequency Reuse (SFR). Also, analytical expressions are derived for the best inner radius using the worst SIR in both FFR, and SFR schemes. The analysis is performed in cellular network using exponent path loss model. The results showed that FFR with reuse four has the smallest interference hence better edge spectral effiency than SFR with different power ratios. For SFR it is better to use power ratios between 2, 4 as they achieve reasonable inner radii than other power ratios. The analysis showed that there is tradeoff aspect between capacity and coverage related to SFR and FFR respectively.