Preclipping experiment for subcarrier-multiplexed AM/64QAM optical transmission
Bit-error-rate degradation of the 64QAM signal due to clipping distortion caused by overmodulation at the laser diode is compensated for by preclipping for subcarrier-multiplexed AM/64QAM optical transmission. The worst composite distortions of CSO < –60 dBc and CTB < –65 dBc have been achieved in the 40-channel AM signal band. It has also been confirmed that preclipping is more effective than Reed-Solomon (204, 188) error correction against clipping distortion.