On the Accuracy of the Gaussian Approximation for Performance Estimation in Optical DPSK Systems with In-Band Crosstalk

The Gaussian approximation is known to be quite accurate for estimating the system performance of an optically pre–amplified on-off keying (OOK) system in the presence of multiple in–band interferers. This paper assesses if similar accuracy can be also achieved in an optically pre–amplified differential phase–shift keying (DPSK) system. The probability density function of the decision variable at the receiver is computed as a function of the number of interferers, and it is observed that this variable statistic is clearly non-Gaussian even for a large number of interferers. It is also shown that, for a 1 dB power penalty and a 16 interferer scenario, the Gaussian approximation over–estimates the real value of the total crosstalk level by as much as 3.7 dB for DPSK signals, while for OOK signals this gap shrinks by approximately 2 dB.

• Type: Conference
• Year: 2007
• Where: ICC
• Authors: Luís G. C. Cancela, João J. O. Pires
• Keywords: Communications, DB Power Penalty, Gaussian Approximation, ICC 2007, On-off Keying