Joint Effect Analysis of Phase Noise, Carrier Frequency Offset, Doppler Spread and Nonlinear Amplifier on the Performance of OFDM System

In this paper, we provide an exact closed-form expression of the effective signal-to-noise ratio (SNR) for orthogonal frequency division multiplexing (OFDM) performance under the combined effect of phase noise, frequency offset, and amplifier nonlinearities of the soft envelope limiter (SEL). This formula describes explicitly the various parameters with the system performance. After deriving the effective SNR, we evaluate the bit-error-rate (BER) for slowly fading Rayleigh channel for QPSK and 16QAM modulation formats. We also obtain the minimum total degradation (TD) versus phase noise rate for different values of frequency offset rate as a criterion of performance evaluation. We show that the degradation is increased as the phase noise levels and frequency offset levels are increased. Even worse results are obtained for 16QAM modulation format compared with QPSK modulation format. Key-Words: OFDM, CFO, Doppler spread, and amplifier nonlinearity.