M-QAM OFDM System Performance in the Presence of Nonlinear and Frequency Offset Effects

Inhalt:
OFDM signals are subject to nonlinear distortions caused mainly by power amplifiers at transmitters because of large envelope fluctuations. Another significant problem of the multicarrier transmission is a degradation of the error probability performance due to intercarrier interference (ICI) caused by frequency offsets. An analytical expression for the bit error rate in the system with both nonlinear and frequency offset effects is derived. We show also that applications of some techniques for the mitigation of the ICI caused by frequency offsets (e.g. ICI self-cancellation scheme and the correlative coding technique) affect the statistical distribution of the peak-to-average power ratio (PAPR) and thus the above techniques should be combined with PAPR reduction methods. We show that such combinations are effective.