Pulse width modulated optical OFDM

In this paper, the PWM encoding of an optical OFDM transmission is studied and simulated. Traditional optical OFDM schemes make use of linear drivers, but the inherent nonlinear behavior of the optical emitters produce a harmful effect on the demodulated signal. PWM allows the use of nonlinear drivers, avoiding this harmful effects and increasing the efficiency of the transmission. Furthermore, synchronization is easier and can be edge-directed, taking advantage of the pulsed nature of the PWM. As OFDM samples may be considered normally distributed, nonlinear predistortions can be used to increase the BER performance. The proposed modulation is studied in terms of spectral efficiency, energy efficiency and thoroughly simulated for different parameters.