EFFECT OF INTERFERENCE OF IMPULSE NOISE-INDUCED BY CLIPPING ON BER OFM-QAM SIGNAL IN ANALOG DIGITAL HYBRID OPTICAL-TRANSMISSION SYSTEMS/

The bit error rate (BER) of the M-QAM signal in analog/digital hybrid optical transmission (hybrid transmission) shows a floor-like feature due to impulse noise induced by clipping the subcarrier multiplexed si gnal at the laser threshold. This paper proposes a new BER analysis mo del, which is modified from our previous one based on Middleton's clas s A impulse noise model, and compares analytical results with experime ntal data. The analytical results agree particularly well with the exp erimental data for small optical modulation indexes (OMI) of the M-QAM signal; consequently, these results can be applied to estimating the bit error rate of the digital channel in hybrid transmission. There is also a tendency for the analysis results to diverge more greatly from the experimental data as the OMIs of the M-QAM signal increase. We al so discuss the reasons for this divergence. (C) 1998 Scripta Technica.