New Fractional Frequency Reuse Patterns for Multi-Cell Systems in Time-Varying Channels

Fractional frequency reuse (FFR) and exploitation of the channel state information at the transmitter (CSIT) are effective approaches to improving the spectrum efficiency of the outer coverage region. When channels vary within a physical transmission frame, the above improvement is substantially suppressed. To remedy this, this letter develops new FFR patterns for multi-cell OFDMA systems with frequency or time division duplexing (FDD/TDD) in time-varying channels. Simulation results show notable performance gains of the proposed schemes over the existing ones.