The rising need for bandwidth created innumerable efforts from academic and industry group towards development of most efficient optical communication networks. In order to compete it numerous investigators have designed their own novel schemes. In this view the paper presents multiple modulation dense wavelength division multiplexed transmission designed links each with a total capacity of 640Gbps and with channel to channel to spacing of 100Ghz, employing multiple modulation schemes such as non return to zero rectangular, non return to zero raised cosine, return to zero rectangular, non return to zero raised cosine, return to zero soliton, return to zero Super Gaussian. The optical transmission performance characteristics like bit error rate, Q parameter at the output have been investigated by simulating different systems for a fixed transmission length of 260kilometers. Results show that transmission performance of DWDM system with non return to zero raised cosine scheme has been better with quality factor ranging from 16 to 23dB and bit error rate ranging from 10-11 to 10-40 for detected channels at selected transmission reach (260KM) and other schemes with good performance were RZ Super Guassian DWDM and RZ Soliton DWDM systems for the same transmission reach. The transmission parameter jitter have been also investigated for each system which depict that jitter effect is more severe for return to zero systems as compared to non return to zero DWDM systems. From the performance analysis for different optical links involving different modulation schemes it can be articulated that novel modulation scheme generally improves the transmission performance and must for modern optical communication systems operating at high bit rate and longer reach.

1. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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Design and Performance Study of MMDWDM
Systems
Devendra Kr,Tripathi, Pallavi Singh, N.K.Shukla and H.K.Dixit
Department of Electronics &Communication,
J.K.Institute of Applied Physics &Technology,
University of Allahabad
Allahabad, U.P, India
Abstract-The rising need for bandwidth created innumerable efforts from academic and industry group
towards development of most efficient optical communication networks. In order to compete it numerous
investigators have designed their own novel schemes. In this view the paper presents multiple modulation
dense wavelength division multiplexed transmission designed links each with a total capacity of 640Gbps
and with channel to channel to spacing of 100Ghz, employing multiple modulation schemes such as non
return to zero rectangular, non return to zero raised cosine, return to zero rectangular, non return to zero
raised cosine, return to zero soliton, return to zero Super Gaussian. The optical transmission performance
characteristics like bit error rate, Q parameter at the output have been investigated by simulating different
systems for a fixed transmission length of 260kilometers. Results show that transmission performance of
DWDM system with non return to zero raised cosine scheme has been better with quality factor ranging
from 16 to 23dB and bit error rate ranging from 10-11
to 10-40
for detected channels at selected
transmission reach (260KM) and other schemes with good performance were RZ Super Guassian DWDM
and RZ Soliton DWDM systems for the same transmission reach. The transmission parameter jitter have
been also investigated for each system which depict that jitter effect is more severe for return to zero
systems as compared to non return to zero DWDM systems. From the performance analysis for different
optical links involving different modulation schemes it can be articulated that novel modulation scheme
generally improves the transmission performance and must for modern optical communication systems
operating at high bit rate and longer reach.
Key words: Time division multiplexing (TDM), code division multiplexing (CDM), fiber optic
communication (FOC), orthogonal frequency division multiplexing (OFDM)
1. Introduction
Communication is the basic need of people since primordial days. People adopted numerous ways
of information sharing altogether. Together with development of human civilization from time to
time several eras of communication have been surpassed. The present era is of telecommunication
revolution and fiber-optic transmission is one of the most trustworthy schemes which have got
concentration due to development of fiber optic communication supporting devices. Now a day’s
fiber optic communication (FOC) is most customary and employed over worldwide for national,
intercontinental information and data transportation purposes. However with innovation of the
World Wide Web there is swift increase in multimedia services and the information traffic have
grown up exponentially. Thus it immediately provokes requirement for additional capacity data
networks[1].For that several capacity enhancing schemes have been devised involving
deployment of multichannel systems such as time division multiplexing(TDM), code division
multiplexing(CDM), frequency division multiplexing(FDM),sub carrier multiplexing(SCM),
orthogonal frequency division multiplexing(OFDM)and wavelength division
multiplexing(WDM).WDM is the method which employs multiple optical carriers at different
wavelengths that were modulated by means of independent electrical bit streams and after that

2. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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transmitted over the same fiber with capability of exploiting the huge bandwidth obtainable by
optical fibers.
Introduction of WDM has created revolution in light wave system designing community.WDM
devices were simpler to put into operation as all components in WDM devices were required to
function only at electronic speed. As a consequence numerous WDM devices were devised,
accessible in the marketplace since past time and at present, still in growing stage. Although
significant works were around 1980’s with narrowly spaced channels and a channel spacing of
less than 0.1nm were illustrated by 1990 with multichannel systems and throughout the decade of
1990s WDM systems grown up swiftly[1-12]. The novel designed 10Gb/s binary NRZ systems
with electronic-signal-processing show that up to 1.6bits/sec/Hz of spectral efficiency were
obtainable, an improved efficiency[13].For two channel WDM system at bit rate 10Gb/s study
exhibited that spectral characteristics were highly dependent on channel spacing and dispersion
coefficient and cross phase modulation dependent on the optical powers of the injected signals in
a very large range of system parameter [14].Study for 340Gb/s capacity link, illustrated by
transmitting seventeen channels and each channel operating at 20Gb/s over150km
successfully[15].Novel designed three WDM systems transmission performance were
investigated for dispersion values, show that system were affected by dispersion and non-linear
effects. Presently the long-haul communication systems employ multiple carrier wavelengths and
higher data rates which created higher channel capacity. As spectral efficiency is one of the most
important parameter for optical systems, have to be achieved in the investigations. Due to high
data rates the limitation imposed by dispersion and nonlinearities in the optical communication
system has been of great concern as parameters such as quality factor (Q), Jitter, BER and optical
modulation selected limits the overall efficiency of the system. The performance study with
chirped RZ and NRZ formats showed, improved transmission performance [16-17].Further study
with non-return to zero (NRZ) and RZ modulation format show that with increased data rates
RZmodulation formats present benefits over NRZ since higher robustness against distortions
[18-20].
Study in eight channel WDM at 10Gb/s with NRZ/RZ/ Duo-binary signal formats for distances
(5Km to 100Km) for Quality factor(Q) and Jitter show that NRZ is good modulation format in the
intensity modulated direct detection fiber-optical communication systems. As NRZ pulses are
with narrow optical spectrum and reduced spectrum width improves the dispersion tolerance
however inter symbol interference (ISI) is present. While a part of the bit slot is occupied with RZ
pulse and a broad spectrum as RZ pulse shape allows an enhanced robustness to fiber non linear
effects as well as to the cause of polarization mode dispersion[21-22].Later on study with non
binary encode technique such as multilevel intensity or phase modulation systems ultimate
spectral efficiency showed for various modulation formats (NRZ/RZ/RZ-SuperGaussian) at data
rates 10/15/20/25Gb/s and impact of EDFA power were investigated showed that smaller
width,3rd
to 5th
order super Gaussian pulse, full width at half maximum (FWHM) 10ps to 60ps,
with raised cosine filter, post and symmetric scheme showed better transmission performance.
With single channel 100Gb/s transmission investigation with ASK/PSK/RZ-DQPSK, exhibited
BER of 10-10
without FEC at 1920km of transmission [23-25].
Later study for three WDM systems (RZ/NRZ/CSRZ/Duo binary) of four channel and two
channel systems for the effect of different dispersion values, effect of FWM investigated showed
that CSRZ signal is far less sensitive to fiber nonlinear effects, RZ system has reduced dispersion
tolerance, NRZ system has improved dispersion tolerance and good transmission performance
although it has the effect of inter-symbol interference between the pulses this modulation format
is not suitable when high bit rates, showed that BER got improved with duo binary modulation
format and by increasing core effective area which will offer a significant performance benefit in
digital systems[26-28].Further significant performance improvement shown with CSRZ format,
in contrast to the conventional NRZ /RZ formats, over 120km with pre/ post/symmetrical

3. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
13
dispersion compensation schemes for various input signal powers. Better performance also shown
with post compensation scheme in terms of Q value, eye opening over 120km of transmission, for
32-channel DWDM system investigated the Kerr effect of nonlinearity over 120km,illustrated
that for 80GHz and above channel spacing the power loss becomes constant and does not depend
on the number of channels so for optimal BER and power penalty with 80 GHz channel spacing
have to be used.FWM effect also diminished while maintaining bandwidth efficiency with
unequal channel spacing using channel allocation method based on the optimal Golomb ruler
(Exhaust and Search algorithm)[29-31].Study with 2.5 Gbit/s HDWDM transmission system
based on the quasi-rectangular optical filter technique, illustrated that channel interval be greater
than 25 GHz and for the 10Gbit/s HDWDM system not less than 37.5 GHz. Implementation of
OADM with DWDM transmission, for the dispersion value of 1.5 ps/nm/km, EDFA power of
4dBm and lower value of attenuation factor illustrated optimum performance over three hundred
km transmission reach[32-33].
Lots of study has been performed in past but still some unearthed work has to come in front of
swiftly varying communication world and investigations on this approach were always going on
to achieve higher spectral efficiency which pertains higher data rates per channel and deployment
of high-order modulation formats in the multiplexed links. So in this view novel designed
MMDWDM (multiple modulations DWDM) links with every thirty two channel DWDM links
were designed with fixed optical modulation and each channel operates at 20Gb/s data rate, to
investigate for the selected transmission reach.
2. Theoretical Presentment
For long haul transmission, modulation is the fundamental necessitate of any communication
system and previously for the optical links different types of optical modulation schemes were
studied to fulfill the rising need for higher data rates and to cut in links cost. Since past decades
on off keying (OOK) in either RZ or NRZ were one of the alternatives for physical layer level of
optical communication [34]. Advanced optical modulation formats is one of key component to
the design of present optical communication networks having special focus on metro, core and
access networks. Thus to modulate a signal the component electrical drivers were used which
performs the simulations. It converts the logical input signal, a binary sequence of zeros and ones
into an electrical signal. Several mapping laws were available, ranging from simple ones, such as
NRZ, NRZ raised cosine and RZ rectangular shaped, RZ raised cosine, RZ Super Gaussian and
RZ soliton shaped pulses, a brief of each one is presented below.
NRZ Rectangular-With NRZ rectangular driver, an electrical output signal assumes one of the
two electrical levels depending upon the transmitted bits. For “0" and "1" fed into the driver, the
output signal is at the high level and low level during the entire bit time respectively and
switching in between the levels, can be instantaneous for field set(time slope) to zero or else the
needed time slope.
NRZ Raised Cosine-Here the NRZ raised cosine driver is simulated and switching between
the two levels is not instantaneous but it follows a raised cosine shape with a given roll-off, while
driver were joined to a linear optical modulator, can shape either the optical amplitude or the
optical power.
Return to Zero (RZ) Rectangular- This component simulates the RZ rectangular driver. It
has an output signal that can assume two electrical levels. When a "1" is transmitted, the output
signal is at the High Level for a time equal to the product of the duty cycle by the bit time. Then it
goes down to the Low Level for the remaining time. When a "0" is transmitted, the output is
constant at the low level for the entire bit time. Switching between the two levels is instantaneous

4. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
14
with resulting square edges. The parameters duty cycle is the ratio between the time at High
Level for the first part of the bit, when a "1" is transmitted, and the bit time.
Return to Zero (RZ) Raised Cosine-The return to zero raised cosine driver simulates the RZ
raised cosine driver the switching between the two levels were not instantaneous. It follows a
raised cosine shape with a selected roll-off generates raised cosine waveform. The raised cosine
waveform, when the driver is connected to a linear optical modulator, can shape either the optical
amplitude or the optical power. Let for a centered pulse peak in which relative time origin in the
center of a bit the electrical output when "1" is transmitted it is with expression shown below:
‫܄‬ = ሺ‫ۯ‬‫ ܐ‬ − ‫ۯ‬‫ܔ‬ሻ܎ሺ‫܂‬ሻ + ‫ۯ‬‫ܔ‬
For raised cosine pulse chosen in power
‫܄‬ = ሺ‫ۯ‬‫ ܐ‬ − ‫ۯ‬‫ܔ‬ሻ܎૛ሺ‫܂‬ሻ + ‫ۯ‬‫ܔ‬
Now for amplitude chosen raised cosine pulse Ah is the high level, Al is the low level and f (t) is
standard raised cosine function.
ࢌሺࢀሻ = {
૚
૛
[૚ − ‫ܖܑܛ‬ ቆ࣊
|ࢀ| − ࢀࡸ
ࢻࢀࡸ
ቇ]
fሺ‫܂‬ሻ =
‫ە‬
ۖۖ
‫۔‬
ۖۖ
‫ۓ‬ ૙ , |‫|܂‬ >
‫܂‬‫ ۺ‬ሺ૚ + હሻ
૛
૚
૛
ቈ૚ − ‫ܖܑܛ‬ ቆૈ
|‫|܂‬ − ‫܂‬‫ۺ‬
હ‫܂‬‫ۺ‬
ቇ቉ ,
‫܂‬‫ ۺ‬ሺ૚ − હሻ
૛
≤ |‫|܂‬ ≤
‫܂‬‫ ۺ‬ሺ૚ + હሻ
૛
૚, |‫|܂‬ <
‫܂‬‫ ۺ‬ሺ૚ − હሻ
૛
Where ࢀ =
ࢀ࢈
૚ାહ
the parameter α is the roll- off factor and Tb is the bit time.
Return to Zero (RZ)_Super-Gaussian-The return to zero (RZ) Super Gaussian driver and
for “0" is transmitted the output signal is at the high level and when “1” is transmitted it
generates a pulse with Super Gaussian shape during the entire bit time respectively. Now let for a
centered pulse peak in which relative time origin in the center of a bit the electrical output when
"1" is transmitted it is with expression shown below:
ࢂሺ࢚ሻ = ሺ࡭ࢎ − ࡭࢒ ሻࢋ
ି૚ሺ
࢚
ࢀ૙
ሻ૛࢓
૛ + ࡭࢒
Where m is the Super Gaussian order, Al and Ah were the low and high level amplitudes and T0
is related to the TFWHM (full width half maximum time) through this function:
‫܂‬૙ =
‫܂‬۴‫ۻ۶܅‬
√‫ܖܔ‬૛
૛‫ܕ‬
Return to Zero (RZ)Soliton-It generates a soliton shaped pulse for a "1" is transmitted when
employed with return to zero soliton driver and when a "0" is transmitted the output signal is set
to the low level for the entire bit time. Now for a peak centered pulse let us assume that a time
origin in the center of bit time, then for a transmitted bit “1” the electrical output signal have the
expression:

5. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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‫܄‬ሺ‫܂‬ሻ = ሺ‫ۯ‬‫ ܐ‬ − ‫ۯ‬‫ ܔ‬ሻ‫ܐ܋܍ܛ‬૛
൬
‫ܜ‬
‫܂‬૙
൰ + ‫ۯ‬‫ ܔ‬
Where Al and Ah were the low and high level amplitudes and T0 is related to the TFWHM (full
width half maximum time) through this function:
‫܂‬૙ =
‫܂‬۴‫ۻ۶܅‬
‫ܖܔ‬૜ + ૛√૛
3. The Simulink Design Presentment
The figure1 shows design of the proposed topology implemented for the simulation and figure 2
shows design used for each single transmitter employed with their respective modulation
schemes. Based on these transmitter designs total of six DWDM transmission links have been
proposed. Each of the proposed transmission link is having with thirty two channel DWDM
optical system, where each channel operated at 20Gb/s.The employed optical modulation of each
DWDM link were different such as NRZ rectangular, NRZ raised cosine, RZ rectangular, RZ
raised cosine, RZsuperGuassian and RZ soliton optical modulations. In each of the DWDM
transmission link transmitter consists of CW laser array, data modulators and the optical
multiplexer. The used emission frequency range is 193.79 to 195.102THz with the channel to
channel frequency spacing of 100GHz, centre frequency were 193.45 THz. After the optical
modulation thirty two channels signals were multiplexed and resulting signal is passed through
single mode fiber repeater loop along with pre and post amplification, in which semiconductor
optical amplifiers were used at 200mA,Amplifier length of 300nm and while active layer width as
2.5nm. Thereafter signal were optically demultiplexed and dmuxed optical signal passed through
their respective optical filters which were tuned to particular channels frequency (with -3dB
frequency is 25 GHz) thereafter passed through PIN diode detector. In this for all MMDWDM
links at the receiving end out of thirty two channels only randomly selected five channels
operating at frequencies 191.9Thz,192.6Thz,193.4Thz,194.2Thz,195Thz were used for the
detection. Resulting detected electrical signal is passed through Bessel electrical filter (with -3dB
frequency is 20 GHz) thereafter to a measuring instrument such as eye diagram, BER, Q value,
eye opening etc.
Figure1: General Topology used for DWDM (640Gbps) system

6. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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(a) (b) (c) (d) (e) (f)
Figure2:MMDWDM systems with (a)RZ-SuperGuassian (b)RZ_Rectangular (c)NRZ_raised cosine
(d)RZ_soliton (e)RZ_raised cosine (f) NRZ_Rectangular
4. Results and Discussion
The multiple modulation DWDM optical transmission links each with total transmission capacity
of 640Gbps have been designed and their transmission performances were successfully
investigated for transmission reach of more than 250kilometers. In each of the MMDWDM
designed system every single channel operates at 20Gbps data rate and individual systems were
designed with employed modulation formats as NRZ rectangular, NRZ cosine, RZ-recctangular,
RZ super Guassian, RZ cosine and RZ_soliton. The transmission performances were examined in
terms of quality factor (Q) which represents the signal-to-noise ratio at the receiver decision
circuit in voltage or current unit and jitter values which is an estimate of the input signal. Jitter
value is estimated as the standard deviation of the position of the maximum of the received signal
termed to the bit frame. The simulated results were illustrated for the quality factor transmission
reach and jitter vs. transmission reach in the numerous resulting plots. The figure3 depict input
optical spectrum for respective MMDWDM (32chx20Gbps) systems at transmitting end.
Figure3: Optical spectrum at input with (32chx20Gbps)MMDWDM(a)soliton (b)NRZrect
(c)NRZraisedcosine (d)RZraised cosine (e)RZ Super Guassian (f)RZ rectangular modulation DWDM
systems.

7. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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Figure4. Quality factor (Q) vs. transmission distance performance with DWDM nrz-rectangular (640Gbps)
modulation system
The simulated results as exhibited in figure4 for the quality factor (Q) vs. transmission length
with NRZ-rectangular (640Gbps) modulation DWDM system. It is noticed that quality factor,
which is the performance measuring parameter, is high (Q>6dB) for all of the randomly detected
channels but with increase in transmission distance Q factor is diminishing.
Figure5: Quality factor (Q) vs. transmission distance performance with DWDM NRZ-raisedcosine
(640Gbps) modulation system
Figure 5 shows transmission performance for the quality factor (Q) vs. transmission length
employing NRZraisedcosine (640Gbps) modulation DWDM system, it is noticed that quality
factor (Q) ranging from 16 to 23dB.It have achieved highest quality factor value in the range of
23dB for the randomly detected channels with increase in transmission distance.

8. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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Figure6: Quality factor (Q) vs. transmission distance performance with DWDM RZrectangular (640Gbps)
modulation system
Figure6 illustrates results for the quality factor (Q) vs. transmission length using RZrectangular
(640Gbps) modulation with DWDM system. It is perceived that quality factor is severely
degraded (lowest Q=6dB) the randomly detected channels with increase in transmission distance.
Figure7: Quality factor (Q) vs. transmission distance performance with DWDM RZraisedcosine (640Gbps)
modulation system
The simulation result as shown in figure7 for the quality factor (Q) vs. transmission length
employing RZraised cosine (640Gbps) modulation DWDM system. It is noticed that overall
quality factor is satisfactory (12 to 22dB) for all of the randomly detected channels with increase
in transmission distance.

9. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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Figure8: Quality factor (Q) vs. transmission distance performance with DWDM RZsoliton(640Gbps)
modulation system
The results as shown in figure8 for quality factor (Q) vs. transmission length employing
RZsoliton (640Gbps) modulation DWDM system, it is noticed that quality factor is high and
satisfactory ranging from 13 to 18dB for all of the randomly detected channels with increase in
transmission distance. Thus high quality factor has been achieved with soliton pulse modulation
system so transmission performance is excellent.
Figure9: Quality factor (Q) vs. transmission distance performance with DWDM RZSuperGuassian
(640Gbps) modulation system
Figure9 illustrates the simulated results for the quality factor (Q) vs. transmission length with
RZSuperguassian (640Gbps) modulation DWDM system. It is observed that quality factor is
good ranging from 14 to 26dB, achieved for all of the randomly detected channels with increase
in transmission distance its performance is very much satisfactory.

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Figure10: Jitter vs. transmission distance performance of DWDM RZSuperGuassian (640Gbps) modulation
Figure11: Jitter vs. transmission distance performance of DWDM RZ-soliton (640Gbps) modulation
Figure12: Jitter vs. transmission distance performance of DWDM RZraisedcosine (640Gbps) modulation
Figure13: Jitter vs. transmission distance performance of DWDM RZraisedCosine (640Gbps) modulation

11. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
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The simulated results were exhibited for the jitter vs. transmission length in the figure10 to
figure13 with numerous DWDM (640Gbps) links with different return to zero (RZ) modulation
schemes. It is noticed that jitter is growing for all the channels with raise in transmission distance
for all the received channels.
Figure14: Jitter vs. transmission distance performance of DWDM with NRZ-rectangular (640Gbps)
modulation system
Figure15: Jitter vs. transmission distance performance of DWDM with NRZ-raised cosine (640Gbps)
modulation system
Results as shown in figure14 and figure15 for jitter vs. transmission length with DWDM
(640Gbps) with non return to zero modulation schemes it is noticed that jitter is constant for all
the channels but few received channels show a high jitter value with increase in transmission
distance.

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Figure16: BER vs. received channels performance of MMDWDM (640Gbps) at 260K.M
For good optical transmission performance quality factor (Q) must be higher and bit error rate
must be low, for satisfactory transmission performance of an optical transmission link it requires
Q>6dB for the BER of 10-9
.This BER provide an upper limit for the signal because some
degradation arises on the receiving end. From the comprehensive performance analysis of
MMDWDM transmission links, it is noticed that MMDWDM link with NRZ raised cosine
pattern has shown better transmission performance in terms of quality factor, bit error rate
(figure16) which were in the range of 10-11
to 10-40
for all received channels at selected
transmission reach of 260kilometers, followed by other schemes as Rzsuperguassian and
RZSoliton transmission links. While for the same transmission reach (260km) RZrectangular
scheme has shown poor transmission performance as compared to other schemes employed. An
additional optical transmission parameter of observation is jitter, on observing jitter performance
of various transmission links it is noticed that jitter show low impact on DWDM systems with
NRZ type of modulations but it is more dominant for the DWDM transmission links with RZ
format.
5. Conclusion
The article illustrates comprehensive performance study of the multiple modulation DWDM
systems each with aggregate capacity of 640Gbps.The systems were employed with different
type of modulation schemes such as NRZrectangular, NRZraisedcosine, RZ-recctangular, RZ
Super Guassian, RZ cosine and RZ soliton schemes and each system were investigated on the
basis of optical transmission parameters such as quality factor, jitter and bit error rate. After
successful transmission the performance were compared for the fixed transmission reach of
260kilometers,it exhibited that DWDM link with non return to zero raised cosine scheme has
shown better transmission performance followed by Rz superguassian and RZ Soliton in contrast
to other schemes employed. Comparing jitter performance for all transmission links, it is
observed that jitter effect is more dominant for the DWDM systems with RZ type formats in
contrast DWDM transmission links using NRZ format. Consequently from the study it can be
inferred that a novel advanced optical modulation scheme is always must to compete with swiftly
changing spectrum need, highly efficient system were to design and for that NRZ-Raised cosine
(leading scheme), RZ superguassian and RZ Soliton pattern are the other frontier schemes, will
be an aid to design of the advanced optical communication systems.
10
-40
10
-30
10
-20
10
-10
10
0
1
2
3
4
5
BER
Channel
NRZ Rectangular
NRZ RaisedCosine
RZ RaisedCosine
RZ Rectangular
RZ SuperGuassian
RZ Soliton

13. Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
23
Acknowledgement
Thanks to J.K.Institute Allahabad (University of Allahabad) for providing the software
OptSim(R-Soft) optical communication system.
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Authors:
D. K. Tripathi received his BSc from A.U and B. Tech and M. Tech degree in
Electronics and Telecommunication engineering from the Department of Electronic &
Communication, University of Allahabad. Presently he is pursuing his Ph.D. degree in
Electronics Engineering. His area of interest includes Wireless communication
technology and fiber optics communication. He is life member of ISTE
Pallavi Singh received B.Tech and M.Tech degrees in electronics and Telecommunication
engineering from Department of Electronics & Communication University of Allahabad, in
1999 and 2002, respectively, where she is currently pursuing her Ph.D.degree in electronic
engineering. Her current research interests include wavelength converter and all
logic gates using SOA-based Mach-
.
Dr N.K. Shukla is associate Professor in J.K.Institute of Applied Physics and Technology,
University of Allahabad (India). He started teaching in the department as lecturer, having
teaching experience of more than 18 Years. His main research area is fiber optics
communication and Holography. He has supervised many PhD candidates. He has
published a lot of papers in National, International journals and in National and
International conferences. He is a member of many academic bodies of other University
and institution, and life member and fellow in organizations like ISTE, IETE etc.
Prof. (Dr) H.K. Dixit is former head of department of J.K. Institute of Applied Physics and
Technology, University of Allahabad (India). He started teaching in the department as
lecturer in March 1975 and teaching experience of more than 38 Years. His main research
area is fiber optics communication and Holography. He has supervised a number of PhD
candidates. He has published a lot of papers in National, International journals and in
National and International conferences. He is a member of a number of RDC, and academic
bodies of other University and Institution, and life member and fellow in organizations like ISTE, IETE etc.
Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
Kawal Preet Singh, Navpreet Singh et.al (March 2012)” Performance Analysis of different WDM
Systems, “JEST, vol.4, no.03, pp.1140-44.
rna et.al(2012)” Evaluate the Effect of Stimulated Raman Scattering in DWDM
Transmission System with Direct Detection Binary WSK Receiver,” IEEE/OSA/IAPR International
Conference on Infonnatics, Electronics & Vision, ICIEV 2012,pp.698-701.
n,V K Chaubey(2012)” Design and Simulation of CSRZ Modulated 40Gbps
System in Presence of Kerr Non Linearity,”IEEE-2012, 978-1-4673-1989-8/12/$31.00 ©2012 IEEE.
S Sugumaran, Neeraj Sharma et. al (Apr-May 2013)”Effect of Four-wave Mixing on WDM Sy
and its Suppression Using Optimum Algorithms,“JET, vol 5 no 2, pp.1432-1444.
. Ivanovs, V. Bobrovs, et.al (May 2010)” Realization of HDWDM transmission system,”
International Journal of the Physical Sciences Vol. 5(5), pp. 452-458.
D.K.Tripathi et.al (June 2013)”Optimization and performance study in DWDM for PON’s with
OpticalADM,” IJARECE, Volume 2, Issue 6, pp.607-610.
G. P. Agrawal,(2002)“Fiber Optic Communications Systems”, third edition, 2002, Wiley Series in
optical engineering, 2002.
received his BSc from A.U and B. Tech and M. Tech degree in
Electronics and Telecommunication engineering from the Department of Electronic &
Communication, University of Allahabad. Presently he is pursuing his Ph.D. degree in
Electronics Engineering. His area of interest includes Wireless communication
technology and fiber optics communication. He is life member of ISTE
ceived B.Tech and M.Tech degrees in electronics and Telecommunication
engineering from Department of Electronics & Communication University of Allahabad, in
1999 and 2002, respectively, where she is currently pursuing her Ph.D.degree in electronic
ing. Her current research interests include wavelength converter and all-optical
-Zehnder interferometer
Dr N.K. Shukla is associate Professor in J.K.Institute of Applied Physics and Technology,
India). He started teaching in the department as lecturer, having
teaching experience of more than 18 Years. His main research area is fiber optics
communication and Holography. He has supervised many PhD candidates. He has
ational, International journals and in National and
International conferences. He is a member of many academic bodies of other University
and institution, and life member and fellow in organizations like ISTE, IETE etc.
head of department of J.K. Institute of Applied Physics and
Technology, University of Allahabad (India). He started teaching in the department as
lecturer in March 1975 and teaching experience of more than 38 Years. His main research
communication and Holography. He has supervised a number of PhD
candidates. He has published a lot of papers in National, International journals and in
National and International conferences. He is a member of a number of RDC, and academic
University and Institution, and life member and fellow in organizations like ISTE, IETE etc.
Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 1, February 2014
24
Kawal Preet Singh, Navpreet Singh et.al (March 2012)” Performance Analysis of different WDM
rna et.al(2012)” Evaluate the Effect of Stimulated Raman Scattering in DWDM
Transmission System with Direct Detection Binary WSK Receiver,” IEEE/OSA/IAPR International
n,V K Chaubey(2012)” Design and Simulation of CSRZ Modulated 40Gbps-DWDM
8/12/$31.00 ©2012 IEEE.
wave Mixing on WDM System
. Ivanovs, V. Bobrovs, et.al (May 2010)” Realization of HDWDM transmission system,”
D.K.Tripathi et.al (June 2013)”Optimization and performance study in DWDM for PON’s with
G. P. Agrawal,(2002)“Fiber Optic Communications Systems”, third edition, 2002, Wiley Series in
International conferences. He is a member of many academic bodies of other University
head of department of J.K. Institute of Applied Physics and
Technology, University of Allahabad (India). He started teaching in the department as
lecturer in March 1975 and teaching experience of more than 38 Years. His main research
communication and Holography. He has supervised a number of PhD
candidates. He has published a lot of papers in National, International journals and in
University and Institution, and life member and fellow in organizations like ISTE, IETE etc.