Performance Analyses on OFDM-PON in Coherent Detection Schemes

Performance analyses are presented theoretically on OFDM-PON working in IQ modulationheterodyne detection scheme for downstream and in intensity modulation-homodyne detection scheme for upstream which include the characterization of non-linear distortion in IQ modulator, pilot light multiplexing for optical phase noise cancellation in ONU receiver, heterodyne detection with LO provided by sharing the seed light power to RSOA,downstream system optimization and non-linear optical phase noise cancellation in OLT receiver. Simulation and experiment show that the receiver sensitivity can reach –(21~27) dBm for downstream light at single wavelength carrying 64/16 QAM-modulated OFDM signal in 2GHz band, when LO power is higher than –10 dBm and the receiver sensitivity can reach –20 dBm for upstream light at single wavelength carrying 16 QAM-modulated OFDM signal in1.6 GHz band, when LO power is high than 0 dBm. Key-Words: OFDM-PON, IQ modulator, Coherent Detection, Self Homodyne, Heterodyne, MQAM, Nonlinear distortion, optical phase noise