An Experiment of Coherent Optical DFT-spread OFDM with Laser Phase Noise

We investigate the impact of laser phase noise (LPN) on the DFT-spread CO-OFDM system. The experiment shows that DFT-spread CO-OFDM is more sensitive to LPN than conventional CO-OFDM. This is because DFT-spread COOFDM suffers higher inter-carrier interference (ICI) caused by LPN. We also observed that if the number of sub-bands is increased then the ICI due to LPN is increased as well. The bit-error-ratio (BER) is improved by applying the noniterative interpolation based partial ICI compensation method to DFT-spread CO-OFDM.