1. Semester Progress Presentation on
Performance comparisons between Avalanche and PIN
photodetectors for underwater optical wireless
communication system
Under the Supervision of Presented by:
Prof. Monika Agrawal Priya Pandey
2018CRZ8653
5th Semester
4 August 2022
C.A.R.E. IIT Delhi
1
2. Contents
2
Progress till date
Introduction of Underwater Optical wireless communication
Results
Future Work
References
C.A.R.E. IIT Delhi 4 August 2022
3. Progress till
date
3
Completed comprehensive presentation.
Completed course work with the CGPA of 9.0.
Published Conference paper in MTS TechSym held at IIT Madras.
Published Conference paper in IEEE OCEANS-2020 Singapore.
Conference paper has been accepted in IEEE OCEANS-2021 San
Diego - Porto.
C.A.R.E. IIT Delhi 4 August 2022
4. Introduction
4
Underwater optical wireless communications (UOWC) have gained a considerable
interest during the last years as an alternative means for broadband inexpensive
submarine communications.
UOWC present numerous similarities compared to free space optical (FSO)
communications
By using suitable wavelengths, high data rates can be attained.
Presently, acoustic waves are predominantly used for the same.
5. Underwater Communication Methods
RF and Acoustic waves are used earlier but because of few limitations
we switched on to Optical waves.
Differentiation among them is given in the table:
5
6. Block diagram of the UOWC system model
6
Figure 1:UOWC System Model [1]
7. Constraints in UOWC System
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In UWOC, some constraints are there
First, information X is modulated as the instantaneous optical intensity, so
the optical signals are usually restricted to be a nonnegative real variable.
X≥ 0: (1)
Second, Due to the eye and skin safety regulations, the peak optical
intensity of the LED is limited, that is,
X≤A; (2)
where A is the peak optical intensity of the LED
8. Ocean water types
8
Ocean water varies both geographically, from extremely clear ocean to
coastal areas, and vertically due to the decreasing amount of light that is
received from the sun as well as less background radiation.
The various water types are divided into two groups, oceanic and
coastal, based on the down-welling irradiance of sunlight.
C.A.R.E. IIT Delhi 4 August 2022
9. Different
types of
ocean water
9
C.A.R.E. IIT Delhi 4 August 2022
Clear Ocean water, with an increased concentration of dissolved
particles that produce large amounts of scattering and play a larger
role in overall attenuation;
Coastal ocean water, in which the absorption due to phytoplankton
phytoplankton is the main limiting factor and, thus, the ideal
wavelengths tend towards green;
Turbid harbor water is characterized by a very high concentration
of suspension matters and color dissolved organic matter (CDOM)
such as fulvic and humic acids that exhibit a strong absorption at the
blue wavelengths.
10. Absorption and Scattering coefficients
10
.
Table 1:Typical values of absorption and scattering coefficients [15]
Water Type a(𝒎−𝟏
) b(𝒎−𝟏
) c(𝒎−𝟏
)
Clear ocean 0.114 0.037 0.151
Costal
ocean
0.179 0.220 0.339
Turbid
harbour
0.366 1.829 2.195
The overall attenuation in underwater can be expressed as a beam extinction
coefficient, c(λ) which is the linear combination of absorption and scattering
coefficients given [2]
c (λ) =a (λ)+ b(λ) (3)
This is combined with Beer-Lambert's law to give an expression for the irradiance
I (𝐼0 is the irradiance at the source), after a specified distance z
I=I0𝑒−𝑐𝑧 (4)
12. 4 August 2022
C.A.R.E. IIT Delhi
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Parameter Value
Extinction Coefficient for:
a) Clean Ocean
b) Coastal Ocean
c) Turbid Ocean
0.15
0.3
2.19
Operational Wavelength:
a) Blue
b) Green
c) Red
450nm
550nm
650nm
Optical Efficiency for:
a) Transmitter
b) Receiver
0.9
0.9
Transmitter power 125nm
ϴ 30 degrees
Beam divergence angle (𝜃0) 60 degrees
Receiver Width 100μm
Link Range 10m-2000m
Optical Transmitter
Power
Wavelength
Modulation
125mW
450nm, 550nm, 650nm
NRZ
Optical receiver
Photodetector
Responsivity
Dark Current
Bit Rate
Amplitude of NR pulse
Modulation Index
Cut-off frequency of filter
With shot noise and thermal noise
1 A/W
10nA
1GHz
1 a.u.
1
0.75*Bit rate
15. PIN APD
4 August 2022
C.A.R.E. IIT Delhi
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Water
type
Distance
(m)
BER SNR
(dB)
Clean 700 4.28x10−9
95
Coastal 583 2.89x10−9
100
Turbid 483 3.57x10−9
105
Water
type
Distance
(m)
BER SNR
(dB)
Clean 900 2.09x10−9
85
Coastal 780 1.37x10−9
90
Turbid 500 1.08x10−9
98
Amplitude
Modulation
16. Conclusion
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Using Avalanche photodetector at the receiver side, it enhances the communication
link distance as compared to the PIN photodetector.
In Avalanche photodetector, less SNR is required to attain 10−9
BER as compared
to PIN photodetector.
C.A.R.E. IIT Delhi 4 August 2022
17. Future Work
17
Hardware implementation of these Designs.
Using different types of light sensors at the receiver side to enhance the
performance of UWOC.
Design pre-distorter and post distorter to mitigate non-linearity of LED.
C.A.R.E. IIT Delhi 4 August 2022
18. References
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1. Hemani Kaushal1, Georges Kaddoum,” Underwater Optical Wireless
Communication “,IEEE Access ,vol 4,2016.
2. A. Sevincer, A. Bhattarai, M. Bilgi, M. Yuksel, and N. Pala, “LIGHTNETs: Smart
LIGHTing and Mobil Optical Wireless NETworks – A Survey”, IEEE Communications
Surveys & Tutorials, Vol. 15, No. 4, pp. 1620-1641, 2013.
3. S. Q. Duntley, “Light in the sea_,” J. Opt. Soc. Am., vol. 53, no. 2, pp.214–233, Feb.
1963.
4. NOAA, “How much water is in the ocean?” https://oceanservice.noaa.
gov/facts/oceanwater.html, online; accessed 10 Dec. 2017.
5. Lermusiaux, P. F. J., Chiu, C. S., Gawarkiewicz, G. G., Abbot, P., Robinson, A. R.,
Miller, R. N., Haley, P. J., Leslie, W. G., Majumdar, S. J., Pang, A., Lekien, F., (2006),
Quantifying Uncertainties in Ocean Predictions in Oceanography, special issue on
Advances in Computational Oceanography, Paluszkiewicz T., Harper S., Eds.,
19(1)1, pp. 92-105
6. S. Tang, X. Zhang, and Y. Dong, “Temporal statistics of irradiance in moving
turbulent ocean,” in MTS/IEEE OCEANS-Bergen (IEEE, 2013), pp. 1–4.
7. J. Grubor et al., “Wireless high-speed data transmission with phosphorescent white-
light LEDs,” in 2007 33rd European Conf. and Exhibition of Optical
Communication—Post-Deadline Papers (published 2008), pp. 1–2, IEEE (2007).
C.A.R.E. IIT Delhi 4 August 2022
19. References
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8. M. Hoa Le et al., “80 Mbit∕s visible light communications using pre equalized white
LED,” in 34th Eur. Conf. Optical Communication,2008 (ECOC 2008), pp. 6–9 (2008).
9. W. C. Cox Jr, Simulation, modeling, and design of underwater optical communication
systems. North Carolina State University, 2012.
10. W. Cox and J. Muth, “Simulating channel losses in an underwater optical
communication system,” JOSA A, vol. 31, no. 5, pp. 920–934, 2014.
11. C. Gabriel, M.-A. Khalighi, S. Bourennane, P. Le´on, and V. Rigaud, “Monte-
carlo-based channel characterization for underwater optical communication
systems,” Journal of Optical Communications and Net- working, vol. 5, no. 1, pp. 1–
12, 2013.
12. L. C. Andrews, R. L. Phillips, and C. Y. Hopen, Laser beam scintillation with
applications. SPIE press, 2001.
13. H. Gerc¸ekciog˘lu, “Bit error rate of focused Gaussian beams in weak oceanic
turbulence,” JOSA A, vol. 31, no. 9, pp. 1963–1968, 2014
14. H. Zhang and Y. Dong, “Impulse response modeling for general underwater wireless
optical MIMO links,” IEEE Commun. Mag., vol. 54, no. 2, pp. 56–61, 2016.
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