1. THE PERFORMANCE ANALYSIS OF
OPTICAL WIRELESS COMMUNICATION
USING ALAMOUTI STBC.
PRESENTED BY
SHERIN V.K.
ROYAL COLLEGE OF ENGINEERING AND TECHNOLOGY
1

2. • The performance analysis of the optical
wireless communication using alamouti STBC
by coherent detection was studied for different
channel conditions.
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THE PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION USING ALAMOUTI STBC.
OBJECTIVE
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3. INTRODUCTION
• Optical wireless communication (OWC)
– Direct detection based OWC.
• Coherent OWC systems
– Local oscillator used at the receiver.
– Excellent background noise/interference rejection.
– Enhanced transmit power efficiency.
– Improved spatial and frequency selectivity.
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THE PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION USING ALAMOUTI STBC. 27-03-2015

4. • OWC system using Alamouti coded STBC.
– Useful in RF applications.
– To reduce decoding complexity.
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5. • The new two architectures
 A 2 x1 Alamouti Coded Coherent OWC System
Using A Single Carrier Frequency.
 A 2 x1 Alamouti Coded Coherent OWC System
Using multiple Carrier Frequency.
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THE PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION USING ALAMOUTI STBC. 27-03-2015

6. THE TWO NEW ALMOUTI STBCS
• To overcome turbulence –induced fading
• To overcome phase noise from transmitter
lasers, receiver local oscillators and turbulence
channel.
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THE PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION USING ALAMOUTI STBC. 27-03-2015

7. A 2 x1 Alamouti Coded Coherent OWC System
Using A Single Carrier Frequency.
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8. A 2 x1 Alamouti Coded Coherent OWC System
Using multiple Carrier Frequency.
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9. Previous work
• “Alamouti-Type STBC for Atmospheric Optical
Communication Using Coherent Detection” by
Mingbo Niu, Julian Cheng, and Jonathan F. Holzman.
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10. The new ideas
• Implemented the two new alamouti
architectures.
• Applied it for different channel turbulence
conditions.
• The performance analyzed by considering
different parameters.
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11. Channels
1. Gamma gamma channel.
3.Rayliegh channel.
2.Log normal.
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12. Analyzing parameters
1.Bit error rate.
2.No of transmitters.
3.No of recievers.
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13. SIMULATION RESULT
alpha =1, beta =1
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14. alpha =2.0, beta =1.1
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0 5 10 15 20 25
10
-5
10
-4
10
-3
10
-2
10
-1
Eb/No, dB
BitErrorRate
BER for BPSK modulation with Alamouti STBC (gamma channel)
theory (nTx=1,nRx=1)
theory (nTx=1,nRx=2, MRC)
theory (nTx=2, nRx=1, Alamouti)
sim (nTx=2, nRx=1, Alamouti)
THE PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION USING ALAMOUTI STBC. 27-03-2015
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15. alpha =3.6, beta =3.3
15
0 5 10 15 20 25
10
-5
10
-4
10
-3
10
-2
10
-1
Eb/No, dB
BitErrorRate
BER for BPSK modulation with Alamouti STBC (gamma channel)
theory (nTx=1,nRx=1)
theory (nTx=1,nRx=2, MRC)
theory (nTx=2, nRx=1, Alamouti)
sim (nTx=2, nRx=1, Alamouti)
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16. Rayleigh channel
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17. Log normal channel
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18. CONCLUSION
• Generated the STBC code and done the
performance analysis.
• Implemented it for different turbulence
channels.
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19. REFERENCE
• X. Zhu and J. M. Kahn, B Free-space optical communication through
atmospheric turbulence channels,[ IEEE Trans. Commun., vol. 50, no. 8, pp.
1293–1300, Aug. 2002.
• M. Razavi and J. H. Shapiro, BWireless optical communications via diversity
reception and optical preamplification,[ IEEE Trans. Wireless Commun., vol.
4, no. 3, pp. 975–983, May 2005.
• J. Li, J. Q. Liu, and D. P. Taylor, BOptical communication using subcarrier
PSK intensity modulation through atmospheric turbulence channels,[ IEEE
Trans. Commun., vol. 55, no. 6, pp. 1598–1606, Jun. 2007.
• M. Niu, J. Cheng, and J. F. Holzman, Error rate analysis of M-ary coherent
free-space optical communication systems with K-distributed turbulence,[
IEEE Trans. Commun., vol. 59, no. 3, pp. 664–668, Mar. 2011.
• V. Tarokh, H. J. Jafarkhani, and A. R. Calderbank, BSpace-time block codes
from orthogonal designs,[ IEEE Trans. Inf. Theory, vol. 45, no. 5, pp. 1456–
1467, Jul. 1999.
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