Resource allocation and reuse for inter-cell interference mitigation in OFDMA based communication networks

Inter-cell interference (ICI) mitigation is always a big challenge issue in cellular systems. In this work we propose an Enhanced Fractional Frequency Reuse (EFFR) scheme with an interference-aware reuse mechanism to achieve not only ICI limitation at cell edge but also enhancement of overall cell capacity in orthogonal frequency division multiple access (OFDMA) based communication networks. The EFFR scheme divides the whole available bandwidth into a Primary Segment and a Secondary Segment. The exclusive reuse-3 subchannels in the Primary Segment will be preferentially used by cell-edge users with higher transmission power, whereas the remaining subchannels are all reuse-1 subchannels allowing to be used with lower power. In addition, the resources in the Secondary Segment will be occupied by means of signal-to-interference-ratio (SINR) estimation. We implement the proposed EFFR scheme in a system-level simulator OpenWNS and compare its performance with the well-known Incremental Frequency Reuse (IFR) scheme, the classical reuse-1 and reuse-3 schemes. In order to reach a reliable evaluation, schemes are simulated with individual power masks, and using a scenario with surrounding cells up to 2nd-tier. The simulation results show that with the usage of the EFFR scheme substantial improvements in both, the overall cell capacity as well as the cell-edge user performance can be gained.