Analysis of Transmitter Phase Noise in OFDM System and its Mitigation

In reality, oscillators experience spectral broadening due to internal noise process, which becomes a potentially serious problem in OFDM transmission schemes, especially when high order signal constellations are employed. The paper analyzes the influence of the transmitter phase noise to the OFDM system in the multi-path fading channel, and shows when the transmitter contains large phase noise, the immunity of OFDM system to multipath fading is destroyed and the frequency domain model of the influence of phase noise used by some algorithms is no longer suitable. Then a feedback method to reduce the transmitter phase noise is proposed. Simulation results show that after pre- correction of transmitter phase noise, the existing algorithms that have been proposed in the receiver end can be performed to mitigate the receiver phase noise more effectively in the scenario when PHN generated at the transmitter is large compared to PHN generated at the receiver end.