Orthogonal frequency division multiplexing (OFDM) in photonic communications

OFDM has emerged as a promising modulation technique in long-haul and access optical networks because of a number of advantages: Scalable spectrum partitioning, good spectral efficiency, dispersion tolerance, and a natural suitability for software-defined transmission. However, there are also issues inherent in OFDM: High peak-to-average power ratio making the system more susceptible to nonlinearity, sensitivity to frequency offset and phase noise, and the required computational complexity. With the advent of powerful digital signal processors and by exploiting all-optical signal processing, some of these obstacles can be overcome.