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International Journal of Advent Research in Computer and Electronics (IJARCE)
Vol.1, No.6, October 2014
E-ISSN: 2348-5523
Performance Analysis of the Third Order Dispersion
using Various Compensation Technique with FBG and
EDFA in Ultra High Speed Long Haul Communication
System
Reena Rani1, Er.Gurpreet Bharti2
1
M.Tech Student E.C.E , Assistant Professor E.C.E2, Ycoe Talwandi Sabo, Punjabi University Patiala1, 2
Email:reenarani305@gmail.com1,er.gurpreetbharti@gmail.com2
Abstract- In this paper fiber-optic dispersion and its
effect on optical transmission system are analyzed.
The most commonly used dispersion compensation
fiber (DCF) with FBG technology is studied. Three
schemes (pre-compensation, post compensation, mixcompensation) with DCF and FBG are proposed.
Simulation results show that mix compensation
scheme is the best. Mix compensation having high Qfactor with Min BER. It can greatly reduce the
influences of the fiber nonlinearity and increase the
transmission distance greatly.
Index Terms- Third-order dispersion (TOD), RZ
Gaussian pulse, Dispersion Compensating Fiber
1. INTRODUCTION
In recent years, with the rapid growth internet
business needs, people urgently need more capacity
and network systems. So the demand for transmission
capacity and bandwidth are becoming more and more
challenging to the carriers and service suppliers.
Optical fiber plays important role for high data rate
and long haul communication. But Loss and
dispersion are the major factor that effect fiber-optical
communication being the high-capacity develops.
When optical signals are transmitted over optical
links, different wavelength components of the optical
signals
will
generally
experience
different
propagation times due to the fact that the transport
medium has different effective refractive indices for
different wavelengths. The EDFA is the gigantic
change happened in the fiber-optical communication
system; the loss is no longer the major factor to
restrict the fiber optical transmission. The EDFA
works in 1550 nm wave band, the average Single
Mode Fiber (SMF) dispersion value in that wave band
is very big, about 16 ps / (nm.km-1). It is easy to see
that the dispersion become the major factor that
restricts long distance fiber optical transfers [5]. In
this study, we propose three compensation schemes,
pre, post and symmetrical/mix compensation scheme.
It is found from the simulation that mixcompensation performance is the best. It can greatly
reduce the influences of the fiber nonlinearity and
increase the transmission distance greatly.
(DCF), Group Velocity Dispersion (GVD), Q-factor,
dispersion management (DM).
2. OPTICAL FIBER DISPERSION
The dispersion in the transmitted optical signal causes
distortion for both digital and analog transmission
along optical fibers. Dispersion within the fiber cause
broadening of the transmitted light pulses as they
travel along the channel. Due to broadening of pulses,
these pulses overlap with their neighboring pulses and
become indistinguishable at the receiver input which
is shown in Figure1.
Figure 1 Optical pulse broadening caused by
chromatic dispersion [5].
Dispersion in multi mode fiber also called intermodal
dispersion occurs due to different paths followed by
different rays. Single mode fiber has intramodal
dispersion which is due to group velocity associated
with the fundamental mode is frequency dependent.
The group velocity dispersion effects can be
minimized using a narrow line width laser and
operating close to the zero dispersion wavelengths.
Third- order dispersion (TOD) causes pulses to have
trailing ripples which degrades the performance of the
ultrahigh speed optical transmission systems [4].
3.
DISPERSION COMPENSATION
TECHNOLOGY
To improve overall system performance and reduced
as much as possible the transmission performance
influenced by the dispersion, several dispersion
compensation technologies were proposed [4].
Amongst the various techniques the ones that appear
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International Journal of Advent Research in Computer and Electronics (IJARCE)
Vol.1, No.6, October 2014
E-ISSN: 2348-5523
to hold immediate promise for dispersion
compensation and management could be broadly
classified as: dispersion compensating fiber (DCF),
and fiber Bragg gratings (FBG) The idea of using
dispersion compensation fiber for dispersion
compensation was proposed as early as in 1980 but,
until after the invention of optical amplifiers, DCF
began to be widespread attention and study. DCF has
become a most useful method of dispersion
compensation and has been extensively studied. There
is positive second-order and third-order dispersion
value in SMF while the DCF dispersion value is
negative. So by inserting a DCF, the average
dispersion is close to zero. And Fiber Bragg gratings
(FBG’s) are very attractive components because as
well as being passive, linear, and compact, they
possess strong dispersion in both reflection and
transmission. In reflection, the dispersion arises when
the edge of the band gap varies with axial position
along the grating such as in linearly chirped or
ramped gratings. Different wavelengths in a dispersed
pulse are reflected at different positions in the grating,
leading to different optical path lengths and thus
providing the possibility of compensating for
dispersion in long-haul fiber links [2].As the local
dispersion of higher transmission link, FWM and
XPM were ignored; only to consider the role of SPM
and dispersion.
4.
This scheme achieves dispersion compensation by
place the DCF before a certain conventional singlemode fiber, or after the optical transmitter.
.
Figure 2 Pre compensation
4.2 Post compensation
This scheme achieves dispersion compensation by
place the DCF after a certain conventional singlemode fiber, or before the optical transmitter.
SIMULATION SETUP FOR DISPERSION
COMPENSATION TECHNIQUES
The DM transmission model consists of a number of
fiber spans in between a transmitter and a receiver.
The simulation setup consist of standard single-mode
fiber (SSMF) and DCF with modulator and detector.
In the transmitter section consists of data source,
electrical driver, and laser source and amplitude
modulator. The data source generates return-to-zero
(RZ) Gaussian data format at one of the four bit rates
(40/100/160/220Gb/s) .A PRBS of length 27−1 is used
to propagate through the optical fiber. The length of
SSMF is 50 km. This fiber has an effective core area
of 80 µm2 and nonlinear index coefficient of 2.6×10-20
m2/W. The signals are transmitted through an 8 km
DCF with an effective core area of 23 µm2 and
nonlinear index coefficient of 3×10-20 m2/W.The DM
map total length is 58 km. This DM map is repeated
thirty five times to cover the total transmission length
of 2030 km. The EDFA is chosen in gain control
mode with gain of 14 dB for SSMF-DCF model and
noise figure is 4dB.Optical link consists of an optical
amplifier at the end terminal of the span and a
receiver with p-i-n photodiode at transmission end.
The simulation set up for three compensation
technique. These are Pre, Post and Mix compensation
shown in figure1.figure2.figure3.respectivly.
4.1 Pre compensation
Figure 3 Post compensation
4.3 Mix compensation
This scheme is consist of post compensation and precompensation Different location on the system will
generate different nonlinear effects.
Figure 4 Mix compensation
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International Journal of Advent Research in Computer and Electronics (IJARCE)
Vol.1, No.6, October 2014
E-ISSN: 2348-5523
5.
SIMULATION RESULTS AND ANALYSIS
Table no.1 Simulation results for pre compensation
using DCF and FBG for high data rate.
Data rate
Q-factor
Min BER
(Gb/s)
40
11.3012
4.31134e-030
100
7.14493
3.25744e-013
160
6.82153
3.61833e-012
220
5.62446
7.44487e-009
polarization mode dispersion occurred in the cannel in
long haul transmission.
From the simulation results it is found that mix
compensation is having high Q-factor and Min BER
as compared to other two techniques. . The Q-Factor
and BER pattern for various compensation techniques
are shown in figure techniques.
Table no.2 Simulation results for post compensation
using DCF and FBG for high data rate
Data rate
Q-factor
Min BER
(a)
(Gb/s)
40
12.7254
1.65311e-037
100
8.9949
9.76046e-020
160
7.26914
1.5579e-013
220
6.37621
7.55874e-011
Table no.3 Simulation results for mix compensation
using DCF and FBG for high data rate
Data rate
Q-factor
Min BER
(Gb/s)
(b)
Figure 5 (a) Show the Q-factor (b) Min BER for 40
40
14.5339
3.05282e-048
100
10.0071
5.52981e-024
160
9.27773
7.31158e-021
220
7.51129
2.49076e-014
In optical communication systems, only optical signal
to noise ratio (OSNR) could not accurately measure
the system performance, especially in WDM systems.
Typically, as a quality factor, Q is a one of the
important indicators to measure the optical
performance by which to characterize the BER.
BER is the function of system quality factor Q. The
quality factor is an electrical domain measure of ratio
of separation between digital states to the noise
associated with the state. Q -factor decides the
performance of system parameter such as
accumulated optical noise generated by optical
amplifiers, polarization dependent losses and
GB/s pre compensation
(a)
20
International Journal of Advent Research in Computer and Electronics (IJARCE)
Vol.1, No.6, October 2014
E-ISSN: 2348-5523
(b)
(a)
Figure 6 (a) Show the Q-factor (b) Min BER for 220
GB/s pre compensation
(b)
Figure 8 (a) Show the Q-factor (b) Min BER for 220
(a)
(b)
GB/s post compensation
(a)
Figure 7 (a) Show the Q-factor (b) Min BER for 40
GB/s post compensation
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International Journal of Advent Research in Computer and Electronics (IJARCE)
Vol.1, No.6, October 2014
E-ISSN: 2348-5523
thirty five times to cover the total transmission length
of 2030 km. In this paper we have visualized Q-factor
and BER Pattern Simulation results show mix
compensation is better having high value of Q factor
and Min BER. So mix compensation is useful for high
data rate and long haul communication.
(b)
Figure 9 (a) Show the Q-factor (b) Min BER for 40
GB/s mix compensation
(a)
REFERENCES
[1] Bo-ning, Hu; Wang, Wei. (2010): Analysis on
dispersion compensation with DCF based on
Optisystem. 2nd
International conference on
Industrial and Information Systems. IEEE
explorations, pp. 40-43.
[2] Christophe, Peucheret; Norbert, Hanik; Ronald,
Freund. (2000): Optimization of pre- and postdispersion compensation schemes for 10-Gbits/s
NRZ links using Standard and dispersion
compensating fibers. IEEE photonics technology
letter vol.12, no.8 pp.992-994.
[3] Divya, Dhawan; Neena, Gupta. (2011):
Optimization of the fiber based dispersion
compensation in RZ and NRZ data modulation
format. Journal of Engineering science and
technology vol. 6, no. 6, pp.651 – 663.
[4] Farzaon, Zaki; Mohammad, Faisal. (2013):
Impact of third order dispersion in ultra high
speed long haul optical fiber communication
system. 2013 IEEE exploration.
[5] P, Pavitra; P, Prkash; Ganesh. (2012): Dispersion
compensation using delay line filter (DLF) with
2X2 coupler. International conference on
electronics
and
communication
engineering.pp.73-78.
(b)
Figure 10 (a) Show the Q-factor (b) Min BER for
220GB/s mix compensation
Above simulation figures shows that the mix
compensation performance is better as compared to
Pre and post compensation .The value of Q factor is
high with minimum BER for low and high data rate.
6. CONCLUSION
In this paper compensation techniques (pre, post and
mix) is analyzed for high data (40/100/160/220) Gb/s.
And long distance. Transmission loop as an optical
link with of SMF 50 km and DCF 8km, with Fiber
Bragg Grating and EDFA. This DM map is repeated
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