Abdul Rahman El Falou, PhD, Optics Department, defended his thesis May 27, 2011 at Orange Labs (Lannion)

Abstract: Since 2000, the deployment of WDM systems at 10 Gb / s has revealed limitations in some physical phenomena such as CD, PMD and nonlinear effects. Electronic equalization techniques, such as FFE / DFE and MLSE have emerged as low-cost flexible solutions to fight against these phenomena, particularly PMD. The latter, whose nature is uncertain, leads to continuous variations in the optical characteristics of the channel over time. Ground measurements on the France Telecom transport network showed very rapid variations of SOPs. In this thesis, we have developed a method to quantify and reproduce the observed variation of SOP. We then evaluated the various electronic equalizers and compared their performance in the presence of CD and PMD in dynamic mode. We have shown that fast polarization scrambling introduces a performance degradation of electronic equalizers. We also studied the interaction between the equalizer and the FEC card for both RS and EFEC codes. We have shown that the effectiveness of FEC can be changed in dynamic conditions and in the presence of SOPMD. Finally, we have proposed a compensation technique for multichannel PMD scrambling deterministic bias.

Keywords: optical transmission, PMD, EQ, chromatic dispersion