Abstract:
In this report, a SIMULINK model has been proposed for the optically amplified
DWDM optical transmission system. Given that the demands of ultra-wideband
transmission over the Internet, transmission techniques are now considered to be
very important. The choice of modulation format used is very important to
minimize the fiber dispersion and impairments due to nonlinear effects.
Either by deployment of new advanced fibers with ultra-high bit rate or upgrading
RZ- 10 Gb/s DWDM optical systems to 40 Gb/s channels, the transmission
capacity can be extended to Terabit/s. Modulation formats are considered to be
the most efficient technique to respond to current demands and moderately
simple to implement in the photonic domain and offer 3-6 dB power gain as well
as much more tolerable to linear and nonlinear dispersion impairments. This
research work presents DQPSK transmission technique of single light wave
channel over optical fiber communication systems. It is capable of doubling the
bit-rate compared to conventional OOK (On-Off Keying) signaling techniques.
Corning SMF (Single Mode Fiber)-28 has been modeled along with its
impairments and dispersions.
The versatile nature of this SIMULINK model demonstrates the effects of
mismatched dispersion management; hence dispersion penalty in fiber
transmission links. DCF (Dispersion Compensating Fiber) model has been
proposed to compensate all the impairments and to retrieve the data as it was
originally sent. Photonic components integrated in the model can be userdefined, enhanced or removed as desired. Essential theoretical background of
the design of the optical DQPSK system is given. Detailed operation and purpose
of each component model and its representation in SIMULINK block sets are
described. Stages required for future extension of this simulator to support
DWDM operations to allow Tb/s transmission are also outlined.
