A hybrid inter-cell interference mitigation scheme for OFDMA system

In OFDMA cellular system, the inter-cell interference is the main interference of the system, which greatly degrades the system performance. In order to enhance cell average throughput and the cell-edge user−s peak bit rate, a hybrid inter-cell interference mitigation scheme is proposed. The hybrid scheme combines the fractional frequency reuse scheme and the frequency hopping scheme, in which cell-edge user transmits data through frequency hopping method in a restricted subcarrier group and inner-cell user is scheduled by frequency-selective scheduler in the left subcarriers. The hybrid scheme can improve the peak bit rate of cell-edge user while getting high cell average throughput. According to the different hopping pattern, the hybrid scheme has two manners: mirroring frequency hopping with fractional frequency reuse and multi-cell joint frequency hopping. The simulation result demonstrates that the cell-edge peak bit rate increases 7% with the proposed hybrid method.