VLC communication project on electronics and communication

project of vlc

1. CHANNEL CAPACITY IMPROVEMENT OF VLC SYSTEM WITH D-MIMO RELAY Under the Guidance of :- Mr . Vinay Singh Presented by :- Ajitesh Kumar (1509731009) Akshay Kumar Mishra (1509731012) Ankit Mishra (1509731019) Deepak Mishra (1509731038)

2. TABLE OF CONTENT Introduction Motivation Objective Literature Review System Model Mathematical Model Simulation Parameters Result and Discussion Conclusion References

3. INTRODUCTION Optical wireless communication (OWC) enables wireless connectivity using infrared, visible or ultraviolet bands. OWC systems operating in the visible band (390-750 nm) are commonly referred to as visible light communication (VLC ). VLC can be possibly used in a wide range of applications including wireless local area networks, wireless personal area networks and vehicular networks among others . Visible light communication (VLC) is rapidly emerging as a compelling technology for supplementing traditional radio frequency communication and enabling new wireless device use cases that are uniquely achievable with this technology. The key property of LEDs that enables VLC is their susceptibility to amplitude modulation at frequencies high enough to achieve meaningful data rates while not affecting the LED’s primary illumination function.

4. MOTIVATION According to Cisco’s Global IP Traffic Forecast, they predicted that by 2018 there will be 21 billion networked devices, up from 12 billion in 2013. With approximately half of these devices will be mobile, meaning they stay connected through wireless transmission (“Visual Networking Index”). Current systems use the radio frequency spectrum . Unfortunately, the radio frequency band is overcrowded and cannot keep up with the demand. Visible Light Communication (VLC) can be used for communication in the same room. These LEDs would be blinking much faster than the human eye can detect, making it non-intrusive and unnoticeable. In situations where privacy is key, visible light communication would act as a means of wireless transmission that is completely safe from being captured outside the room. Because of this fundamental difference in how this device works versus other forms of wireless transmission, much of the costs associated with even reserving a frequency can be dismissed and the overhead becomes much lower.

5. LITERATURE REVIEW S. No. Reference Findings Limitations 1. Jovicic, A., Li, J. and Richardson, T., 2013. Visible light communication: opportunities, challenges and the path to market. IEEE Communications Magazine, 51(12), pp.26-32. Visible light communication can supplement radio frequency communication and improve wireless network performance wherever short-range links are used The downlink use case has the potential to enhance wireless network performance, there are certain business challenges facing its widespread adoption in the consumer market. 2. Lee, S.H., Jung, S.Y. and Kwon, J.K., 2015. Modulation and coding for dimmable visible light communication. IEEE Communications Magazine, 53(2), pp.136-143. High-rate transmission over a broad visible light spectrum and dimming support are identified as the two main driving forces that motivate the creation of new enhanced specifications in VLC.   Modifications in coding and modulation are necessary to support adaptive dimming, whereas new coding schemes are essential for performance enhancement.

6. LITERATURE REVIEW (CONTD..) S. No. Reference Findings Limitations 3. Do, T.H. and Yoo, M., 2014. TDOA-based indoor positioning using visible light. Photonic Network Communications, 27(2), pp.80-88.   The simulation result shows that the system can achieve a high estimation accuracy of 3.59 cm in average. The accuracy estimation is less than most existing indoor positioning system using LED light. 4. Rajagopal, S., Roberts, R.D. and Lim, S.K., 2012. IEEE 802.15. 7 visible light communication: modulation schemes and dimming support. IEEE Communications Magazine, 50(3), pp.72-82.   This article presents mechanisms to mitigate flicker and support dimming as defined in the IEEE 802.15.7 visible light communication standard.   Channel models for VLC are not well understood. Networking of the Light source and upgrading current infrastructures to support communication

7. LITERATURE REVIEW (CONTD..) S. No. Reference Findings Limitations 5. Elgala, H., Mesleh, R. and Haas, H., 2011. Indoor optical wireless communication: potential and state-of-the-art. IEEE Communications Magazine, 49(9), pp.56-62.   This article reviews OW communication technology, overviews research activities, and states the design challenges The design challenges that still need to be overcome before being able to realize an entire OW system that can be commercially deployed.   6. Zeng, L., O'Brien, D.C., Le Minh, H., Faulkner, G.E., Lee, K., Jung, D., Oh, Y. and Won, E.T., 2009. High data rate multiple input multiple output (MIMO) optical wireless communications using white LED lighting. IEEE Journal on Selected Areas in Communications, 27(9), pp.1654-1662. In both cases data rates from several hundred Mbit/s to 1Gbit/s can be achieved. The systems analyzed in this paper to some extent represent the ’limiting cases’-that of imaging and non-imaging To what optical system creates the best optical MIMO system.                    

8. LITERATURE REVIEW (CONTD..) S. No. Reference Findings Limitations 7. Nuwanpriya, A., Ho, S.W. and Chen, C.S., 2015. Indoor MIMO visible light communications: Novel angle diversity receivers for mobile users. IEEE Journal on selected areas in communications, 33(9), pp.1780-1792. The channel capacity and BER performance under different numbers of transmitters and receivers are reported. The proposed receivers support mobile users and additionally they do not occupy much space so that they are suitable for hand-held devices. 8. Chvojka, P., Zvanovec, S., Haigh, P.A. and Ghassemlooy, Z., 2015. Channel characteristics of visible light communications within dynamic indoor environment.  Journal of Lightwave Technology, 33(9),pp.1719-1725.   Analytical and experimental results for a VLC system affected by movement of people for different indoor conditions, considering random movement of people within the room and focusing on the impacts of shadowing and blocking on mobility We showed that in the furniture office environment (people density > 0.16 people/m 2 ) the CDF of the received power differs in the worst case by up to 7%. On the other hand, the highest RMS delay spread of 6.5% in comparison to the case with no people was observed for the empty hall

9. LITERATURE REVIEW (CONTD..) S. No. Reference Findings Limitations 9. Bykhovsky, D. and Arnon, S., 2014. Multiple access resource allocation in visible light communication systems.  Journal of Lightwave Technology ,  32 (8), pp.1594-1600.   An algorithm that manages interference-constrained sub-carrier reuse between different transmitters and power re-distribution between different subcarriers in a heuristic manner. The allocation time varies between 0.15–0.5s, depending on the number of transmitters and receivers. The speed-optimized code is expected to run a few times faster. Additional speed gain may be achieved by organizing subcarriers into groups (chunks) 10. Tsiropoulou , E.E., Gialagkolidis , I., Vamvakas , P. and Papavassiliou , S., 2016, July. Resource allocation in visible light communication networks: NOMA vs OFDMA transmission techniques. In  International Conference on Ad-Hoc Networks and Wireless  (pp. 32-46). Springer, Cham.   Problem of Optical Access Point (OAP) selection and resource allocation in the uplink of VPANs under OFDMA and NOMA. Assumption that all users request the same type of service. However, considering various types of requested services, allocation problem towards achieving users’ Quality of Service (QoS) prerequisites in VLC wireless networks is of high interest.

10. OBJECTIVE To improve the channel capacity of VLC system with Distributed MIMO relay by varying the refractive index of optical concentrator.

11. System Configuration of a D-MIMO Relaying VLC System

12. SYSTEM MODEL (a) BC Configuration

13. (b) MAC Configuration SYSTEM MODEL (CONTD..)

14. SYSTEM MODEL (CONTD..) In the BC configuration, the signal received at the n - th relay terminal is given by  = γ s + Combined received signal vector r can be represented as r= γ Hs + w where, r = H = w =  

15. For the source–destination link in the BC configuration, the received signal can be expressed as = γ Ks+ In MAC channels, The M × 1 vector signal received at the destination terminal is then given by y = + + if we let , t = , G= then , y= G t + γ Ks+   SYSTEM MODEL (CONTD..)

16. From these vectors, the emission angle using vector dot product is presented as ϕ = To present the luminescence mechanism of white LED light, the Lambert radiant model was considered and can be expressed as     SYSTEM MODEL (CONTD..)

17. The DC channel gain of the direct path between the i th white LED to the j th PD can be expressed as: g( ϕji ) is the gain of the optical concentrator with internal refractive index η, which is given by g Therefore, a L ×M channel matrix H n is presented as H n =   SYSTEM MODEL (CONTD..)

18. The channel capacity of a general Gaussian relay channel is upper bounded by C } Considering only the broadcast channels, a combined vector form can be expressed as follows: C = Given t, the conditional mutual information of the corresponding BC channel is expressed as I ≤ The mutual information of the MAC channel is expressed as I ≤ -   SYSTEM MODEL (CONTD..)

19. Upper bound on the capacity of D-MIMO relaying VLC is derived C min where,   SYSTEM MODEL (CONTD..)

20. SIMULATION PARAMETERS Parameters Values   Shot Variance Thermal Variance   2.1120* 10 -16 17.5348* 10 -16 Room size (18 × 18) m 2 Height of ceiling LEDs 3 m Height of mobile terminals 0.7–1.3 m Number of LED-PD pair in Relay (L) 4 Number of LED-PD pair in Source & Destination (M) 4 P LED 10 mW PD responsivity γ 0.4 A/W Order of Lambertian emission m 1 Semi-angle at half-power emission ψ 1/2 60 ◦ FOV of the receiver ϕ c 70 ◦ Optical filter gain T s 0.5-0.8 Refractive index η 1.5 Photodetector area A 1 cm 2

21. RESULT AND DISCUSSION Capacity versus the number of LED-PD pairs of a relay (q=3m, z=3m, η =1.5) Capacity versus the number of LED-PD pairs of a relay (q=3m, z=3m, η =1.8) W e observe that on increasing the value of refractive index from 1.5 to 1.8 there is increase of 28.3% in the channel capacity of the network.

22. RESULT AND DISCUSSION (CONTD..) Capacity versus the height of relays (M=4, L=4, η =1.5) Capacity versus the height of relays (M=4, L=4, η =1.8) We observe that on increasing the value of refractive index from 1.5 to 1.8 there is increase of 22.4% in the channel capacity of the network .

23. RESULT AND DISCUSSION (CONTD..) Capacity versus the distance between relays (M=4, L=4, η =1.5) Capacity versus the distance between relays(M=4, L=4, η =1.8) We observe that on increasing the value of refractive index from 1.5 to 1.8 there is increase of 14.56% in the channel capacity of the network.

24. CONCLUSION This thesis introduced a D-MIMO-relaying VLC scheme and analysed the capacity performance for indoor environment . Considering the broadcast and multiple access channels, a tight upper bound of the channel capacity of D-MIMO relaying VLC was derived . The effect of refractive index on the channel capacity of the network is proposed. Here we examine the refractive index of optical concentrator of the relay . We have come to observe that the channel capacity increases upon increasing the number of relays as a general trend but after a particular limit there is no point in increasing the number of relays as when the relay lies at a far end from the source it tends to escape its FOV thereby it has no effect on the channel matrix . The capacity performance of D-MIMO-relaying VLC can be improved further by selecting different type of concentrator. Here we have considered Compound Parabolic Concentrator (CPC), other concentrator which can be considered is Fluorescent Concentrator (FC).

25. REFERENCES Jovicic , A., Li, J. and Richardson, T., 2013. Visible light communication: opportunities, challenges and the path to market.  IEEE Communications Magazine ,  51 (12), pp.26-32 Lee, S.H., Jung, S.Y. and Kwon, J.K., 2015. Modulation and coding for dimmable visible light communication.  IEEE Communications Magazine ,  53 (2), pp.136-143. Do, T.H. and Yoo, M., 2014. TDOA-based indoor positioning using visible light.  Photonic Network Communications ,  27 (2), pp.80-88. Rajagopal, S., Roberts, R.D. and Lim, S.K., 2012. IEEE 802.15. 7 visible light communication: modulation schemes and dimming support.  IEEE Communications Magazine ,  50 (3), pp.72-82. Mesleh, R., Elgala, H. and Haas, H., 2012. LED nonlinearity mitigation techniques in optical wireless OFDM communication systems.  Journal of Optical Communications and Networking ,  4 (11), pp.865-875.

26. REFERENCES Zeng, L., O'Brien, D.C., Le Minh, H., Faulkner, G.E., Lee, K., Jung, D., Oh, Y. and Won, E.T., 2009. High data rate multiple input multiple output (MIMO) optical wireless communications using white LED lighting.  IEEE Journal on Selected Areas in Communications ,  27 (9), pp.1654-1662. Nuwanpriya, A., Ho, S.W. and Chen, C.S., 2015. Indoor MIMO visible light communications: Novel angle diversity receivers for mobile users.  IEEE Journal on selected areas in communications ,  33 (9), pp.1780-1792. Chvojka, P., Zvanovec, S., Haigh, P.A. and Ghassemlooy, Z., 2015. Channel characteristics of visible light communications within dynamic indoor environment.  Journal of Lightwave Technology ,  33 (9), pp.1719-1725. Bykhovsky, D. and Arnon, S., 2014. Multiple access resource allocation in visible light communication systems.  Journal of Lightwave Technology ,  32 (8), pp.1594-1600. Tsiropoulou, E.E., Gialagkolidis, I., Vamvakas, P. and Papavassiliou, S., 2016, July. Resource allocation in visible light communication networks: NOMA vs OFDMA transmission techniques. In  International Conference on Ad-Hoc Networks and Wireless  (pp. 32-46). Springer, Cham.

27. Thank You