In this paper the different modulation techniques
used in fiber optic technology are compared to check which one
has the better bit error rate (BER). There are a number of
different modulation techniques used in WDN-PON systems but
here the comparison is made among carrier-suppressed
return-to-zero (CSRZ), duobinary return-to-zero (DRZ) and
modified duobinary return-to-zero (MDRZ) modulation. The
comparison to determine which is better is made my performing
simulations in OptiSystem version 17 software. OptiSystem 17 is
the current version of the software at the time the simulations were
being carried out. In the OptiSystem software an optical fiber
system is simulated from transmitter all the way to receiver. In the
experiment when checking the performance of the different
modulation formats, the optical fiber and the receiver are left
unchanged and only the transmitter part is changed according to
the modulation format being simulated at that particular instance.
The modulation in the transmitter is done by using proper
components from the OptiSystem library which when organized in
the right order will give out a signal modulated in a certain format
by the time it is fed into the optical fiber. Knowing the
performance of modulation can help in WDM PON where the
network gets to use passive components as it goes to user. Since no
active amplification or correction equipment is used in
WDM-PON, therefore using the format with the best performance
can help with performance of overall system.
Study The Performance Evaluation of Radio over Optical Fiber System with Optical OFDM using Different Modulation Techniques