Performance of Adaptive Optical Transmission by Orthogonal Frequency-Shift Keying

We evaluate a flexible, low-complexity adaptive data modulation method achieved by encoding bits on the subcarrier positions in coherent optical orthogonal frequency-division multiplexing (OFDM) transmission systems. The proposed orthogonal frequency-shift-keying transmission method shows comparable or better receiver sensitivity as well as improved nonlinearity tolerance compared to polarization switching or partial subcarrier filling OFDM methods at equal data rates.