Resource allocation analysis in OFDMA femtocells using Fractional Frequency Reuse

Femtocells are being deployed for coverage extension and higher data rates. However, interference problem between macrocell and femtocells should be solved before massive deployment. In this paper, we analyze the possible cases of frequency resource allocation in the OFDMA femtocell systems using Fractional Frequency Reuse (FFR) in order to minimize the interference between both cells. Under the assumed pre-allocation of macrocell users with the FFR, the allocable cases of sub-bands for the femtocells are investigated. Efficient and practical guidelines for femtocell's resource allocation are suggested with the consideration of macrocell users having a priority over femtocell users and of enhancing overall throughputs. Simulation results show the enhanced throughputs of both macrocell users and combined total users through practical interference-avoidance guidelines.