Real-time 20.37 Gb/s optical OFDM receiver for PON IM/DD systems.

This paper presents the hardware architecture of an OFDM receiver suitable for optical communications. The receiver has been implemented in an FPGA device and used to demonstrate experimentally an optical OFDM transmission in a passive optical link with a directly modulated DFB laser and DAC/ADC at 5 GS/s. A bit rate of 20.37 Gb/s is achieved using an OFDM signal with subcarrier modulation format up to 512-QAM, it has been successfully transmitted over 10 km SSMF with a spectral efficiency of 8.38 bit/s/Hz.