Abstract
The impact of the signal pulse width and the optical filter bandwidth on the performance of both RZ and NRZ On-Off Keying (OOK) Optical Time Division Multiplexing (OTDM)-Wavelength Division Multiplexing (WDM) systems are studied in this chapter. Using polynomial fitting, an approximated expression for the optimal signal pulse duty cycle as a function of the spectral density SD and Optical Signal to Noise Ratio (OSNR) is provided. Further, it is found that the bit rate per WDM channel does not affect the optimum signal pulse duty cycle. As the spectral density SD increases, DCopt increases, reducing the signal spectral width to compensate for the reduced the WDM channel frequency spacing ?f. For increasing OSNR, DCopt increases slightly, especially at higher SD. The authors found that ideal NRZ performs better than optimized RZ at high SD but worse at low SD.
Reference20 articles.
1. Abbou, F. M. (n.d.). RZand NRZ OOK OTDM-WDM Transmission System Optimizations. Academic Press.
2. Technique for evaluating system performance using Q in numerical simulations exhibiting intersymbol interference
3. Bergano, N. S. (2002). 640 gb/s Transmission of Sixty-four 10 gb/s wdm Channels over 7200 km with 0.33 (bits/s)/hz Spectral Efficiency. Academic Press.
4. Margin measurements in optical amplifier system
5. On the use of NRZ, RZ, and CSRZ modulation at 40 Gb/s with narrow DWDM channel spacing