
452 Optical Fiber Communication Systems with MATLAB
®
and Simulink
®
Models
If a multilevel scheme can be incorporated with the MSK format, the transmission baud
r
ate
w
ould
b
e
r
educed
i
n
a
ddition
t
o
t
he
s
pectral
e
fciency.
T
his
e
ffectively
m
itigates
t
he
ber
i
mpairments
f
or
o
ptically
a
mplied
l
ong-haul
a
nd
u
ltra
l
ong-haul
t
ransmission
s
ystems
a
s
w
ell
a
s
r
elaxes
t
he
r
equirement
f
or
h
igh-speed
p
rocessing
e
lectronics.
T
he
a
foresaid
d
emand
i
s
t
he
p
rincipal
m
otivation
f
or
e
xploring
t
he
d
ual-level
M
SK
m
odu-
lation
scheme in ber-optic communications, which utilizes two binary bits for each
m
odulated
s
ymbol.
T
he
t
ransmission
s
ymbol ...