Closed-Form Expressions for BER Performance in OFDM Systems with Phase Noise

OFDM system suffers from significant performance degradation due to phase noise. Many phase noise analysis methods have been proposed in the literature showing its effect as a loss in the ratio of the signal power to the statistical average of the intercarrier interference (ICI). It would be more desirable, however, to predict phase noise effect on bit error rate (BER) directly. In this paper, by investigating the phase noise properties and the impacts caused by phase noise on an OFDM system, we derive approximate closed-form expressions for BER performance in AWGN channels with BPSK and QPSK modulations. In general, it is impossible to get such expression for multipath Rayleigh fading channels. Hence we establish upper and lower bounds for the degradation caused by phase noise, which give insightful view of the system performance. Simulation results show that the proposed simple analytical forms are quite accurate for different phase noise levels, which lead to the conclusion that a phase noise mitigation mechanism is needed to obtain acceptable performance in OFDM systems.