ON THE SIMULATION OF DIGITAL OPTICAL LINKS WITH EDFAS - AN ACCURATE METHOD FOR ESTIMATING BER THROUGH GAUSSIAN APPROXIMATION

A new method for the semi-analytical estimation of the bit-error rate (BER) of digital optical systems is presented, It is based on system s imulation and accurately considers the performance degradation caused by waveform distortion, The method profits from the simplicity of Gaus sian approximation for noise statistics, though explicitly accounting for intersymbol interference (ISI) effects in noise during the BER est imation, Optically preamplified and avalanche photodiodes (APD) receiv ers are considered, for which signal-dependent noise components are do minant, The system parameters influence on receiver sensitivity is stu died, A digital optical transmission link with a single in-line erbium -doped fiber amplifier (EDFA) and with an EDFA chain is then analyzed, The influence of the EDFA chain characteristics on system performance is investigated: amplifier gain, noise figure and spacing are conside red, The tradeoffs between EDFA parameters and system optimization are addressed.