12.00 Dang The Ngoc Free Space Optical Communication Systems
12.00 Dang The Ngoc Free Space Optical Communication Systems
12.00 Dang The Ngoc Free Space Optical Communication Systems
Content
1. Free-space Optical Communications
Introduction
Model of FSO systems
2. Atmospheric Channel
Atmospheric Attenuation
Atmospheric Turbulence
Misalignment Fading
3. Performance Evaluation
4. Performance Improvement Methods
5. Conclusion and Future Research
2
Advantages
High speed
License-free
Quick deployment
Cost-effectiveness
Applications
Metro network extensions
Last-mile access
Wireless backhaul
Source: http://www.surajinformatics.com/fso-freespace-optics.htm
hl exp l d
al is the attenuation coefficient: at clear air is 0.43 dB/km; at haze is 4.3
(1)
Effect
It causes rapid fluctuations in the intensity and phase of received signal
(scintillation)
Strength
Is described by the refractive index structure constant,
C n2
ha:
(.):
K-(.):
R:
exp
2
1.23
2
R
76
C n2 d 11 6
0.49
(2)
2
R
1 1.11 12 5
R
2
0
.
51
R
exp
5
1 0.69 12
R
76
56
Effect
Optical intensity fluctuation (or fading) at the receiver
Model
f h hp
p
2
2
A0
2 1
hp
0 h p A0
(3)
h hl ha h p
(4)
h: channel state
hl: path loss (deterministic)
ha: atmospheric turbulence (random)
hp: pointing error (random)
f h h
10
A0 hl
1
2
2 1
h A0 hl
K 2 ha dha
(5)
3. Performance Evaluation
FSO system using on-off keying modulation (OOK)
Photo current at the output of the photo-detector
(6)
Signal-to-noise ratio
(7)
Background noise
Thermal noise
(8)
11
14
15
16
References (1)
18
1.
D.J. Heatley, D.R. Wisely, I. Neild, and P. Cochrane, Optical wireless: The story so far, IEEE Commun. Mag., vol. 36, no. 12,
pp. 7282, Dec. 1998.
2.
Q. Liu, C. Qiao, G. Mitchell, and S. Stanton, Optical wireless communication networks for first- and last-mile broadband access
[Invited], J. Opt. Netw., vol. 4, no. 12, 807828, Dec. 2005.
3.
4.
5.
D. Kedar and S. Arnon, Urban optical wireless communications networks: The main challenges and possible solutions, IEEE
Commun. Mag., vol. 42, no. 5, pp. S2S7, Feb. 2004.
6.
M.A. Naboulsi, H. Sizum,, and F. de Fornel, Fog attenuation prediction for optical and infrared waves, Opt. Eng., vol. 43, no. 2,
pp. 319329, 2004.
7.
X. Zhu and J. M. Khan, Free-space optical communication through atmospheric turbulence channels, IEEE Trans. Commun.,
vol. 50, pp. 1293-1300, Aug. 2002.
8.
I.I. Kim , B. McArthur and E.J. Korevaar, Comparison of laser beam propagation at 785 nm and 1550 nm in fog and haze for
optical wireless communications, Proc. SPIE, vol. 4214, pp.2637, Feb. 2001.
9.
M. Ijaz , Z. Ghassemlooy , J. Pesek , O. Fiser , H. L. Minh, and E. Bentley, Modeling of fog and smoke attenuation in free space
optical communications link under controlled laboratory conditions, J. Lightw. Technol., vol. 31, no. 11, pp. 17201726, Nov.
2013.
10.
M. Akiba, K. Ogawa, K. Walkamori, K. Kodate, S. Ito, Measurement and simulation of the effect of snow fall on free space optical
propagation, Applied Optics, vol. 47, no. 31, pp. 57365743, 2008.
11.
M.A. Al-Habash, L.C. Andrews, and R.L. Phillips, Mathematical model for the irradiance probability density function of a laser
beam propagating through turbulent media, Opt. Eng., vol. 40, no. 8, pp. 15541562, Aug. 2001.
12.
C.C. Davis and I. Smolyaninov, The effect of atmospheric turbulence on bit-error-rate in an on-off keyed optical wireless system,
Proc. SPIE Free-Space Laser Commun. Laser Imaging, vol. 4489, pp. 126-137, Mar. 1997
13.
A.A. Farid and S. Hranilovic, Outage capacity optimization for freespace optical links with pointing errors, IEEE J. Lightw.
Technol., vol. 25, no. 7, July 2007.
14.
W. Gappmair, S. Hranilovic, and E. Leitgeb, Performance of PPM on terrestrial FSO links with turbulence and pointing errors,
IEEE Commun. Lett., vol. 14, no. 5, pp. 468470, May. 2010.
References (2)
19
15.
K. Kiasaleh, Performance of APD-Based, PPM Free-Space Optical Communication Systems in Atmospheric Turbulence, IEEE
Trans. Commun., vol. 53, no. 9, pp. 14551461, Sept. 2005.
16.
B.T. Vu, N.T. Dang, T.C. Thang and A.T. Pham, Bit-error rate analysis of rectangular QAM/FSO systems using APD receiver over
atmospheric turbulence channels, IEEE/OSA J. Optical Commun. and Netw., vol. 5. iss. 5, pp. 437446, May 2013.
17.
A.T. Pham, T.A. Luu, and N.T. Dang, Performance Bounds for Turbo-coded 2-D FSO/CDMA Systems over Atmospheric
Turbulence Channels, IEICE Trans. on Fundamentals, vol. E93-A, no. 12, pp. 26962699, Dec. 2010.
18.
X. Zhu and J. Kahn, Performance bounds for coded free-space optical communications through atmospheric turbulence
channels, IEEE Trans. Commun., vol. 51, pp. 12331239, Aug. 2003.
19.
I. Djordjevic, B. Vasic, and M. Neifeld, Power efficient LDPC-coded modulation for free-space optical communication over the
atmospheric turbulence channel, Proc. of Conference on Optical Fiber Communication and the National Fiber Optic Engineers
Conference (OFC/NFOEC), pp. 13, March 2007.
20.
S.G. Wilson, M. Brandt-Pearce, Q. Cao, and J.H. Leveque, Free-Space Optical MIMO Transmission With Q-ary PPM, IEEE
Trans. Commun., vol. 53, no. 8, pp. 14021412, Aug. 2005.
21.
S.M. Navidpour, M. Uysal, and M. Kavehrad, BER Performance of Free-Space Optical Transmission with Spatial Diversity, IEEE
Trans. Wireless Comm., vol. 6, no. 8, pp. 28132819, Aug. 2007.
22.
J. Akella, M. Yuksel, and S. Kalyanaraman Error Analysis of Multi-Hop Free-Space Optical Communication, Proc. of IEEE
International Conference on Commun., pp. 1777-1781, 2005.
23.
M. Safari and M. Uysal, Relay-assisted free-space optical communication, IEEE Trans. Wireless Comm., vol. 7, no. 12, Dec.
2008.
24.
C.K. Datsikas, K.P. Peppas, N.C. Sagias, and G.S. Tombras, Serial free-space optical relaying communications over GammaGamma atmospheric turbulence channels, J. Opt. Commun. Netw., vol. 2, no. 8, Agust 2010.
25.
M. Feng, J. B.Wang, M. Sheng, L. L. Cao, X. X. Xie, M. Chen, Outage performance for parallel relay-assisred free-space optical
communications in strong turbulence with pointing errors, Proc. of International Conference on Wireless Commun. and Signal
Processing (WCSP), pp.15, 2011.
26.
27.
Ricklin, J.C. and Davidson, F.M.: Atmospheric turbulence effects on a partially coherent Gaussian beam: Implications for free
space laser communication, J. Opt. Soc. Amer. A, Opt. Image Sci., vol. 19, no. 9, pp. 17941802, 2002.
28.
N.T. Dang and A.T. Pham, Performance Improvement of FSO/CDMA Systems over Dispersive Turbulence Channel using Multiwavelength PPM Signaling, OSA Optics Express, vol. 20, issue 24, pp. 26786- 26797, Nov. 2012.