Document Type : Research Paper


1 University of technology-Iraq

2 University of Technology, Baghdad, Iraq, Department of Communication Engineering


Linear and non-linear impairments are the major problems that 
affected the dense wavelength division multiplexing (DWDM) system 
performance. In this simulation designs, two different compensation techniques 
have been proposed to eliminate signal impairments. The repeater technique 
was proposed to reduce non-linear effects like four-wave mixing (FWM) which 
cause transfer power from DWDM channels to another new channels. The 
dispersion compensation fiber (DCF) technique was used to reduce dispersion 
effects which cause signal pulse broadening over long transmission distances. 
Also, three different modulation formats and four frequency separations were 
used to determine which modulation scheme is more compatible with the 
compensation techniques. The results is calculated in term of quality factor 
against power and noetic that the carrier suppressed return to zero (CSRZ) 
format offers the best performance with the DCF technique with 32.1804 Q￾factor at 15dBm threshold power then, the differential phase shift keying 
(DPSK) format is compatible with the repeater technique with 27.7959 quality 
factor and 14dBm threshold power


Main Subjects