1 Überschrift 1 e ISSN 2582 5208 International Research Journal of Modernization in Engineering Technology and Science Volume 03/Issue 05/May 2021 Impact Factor 5 354 www irjmets com www irjmets com @[.]
Trang 1DATA TRANSMISSION MODEL USING LIGHT LEDS COMBINATION
OF PLC AND VLC
Tung -Phuong Dao*1
*1Department Of Technology, Dong Nai Technology University,Bien Hoa, Vietnam
ABSTRACT
In this paper, we propose a system for wireless data transmission using white light of LEDs Our Approaches research are focused on exploiting LEDs for both purposes lighting and communication applications for a particular office In this system, each device can access data from the LED light source via PLC modem Experimental results demonstrated that the data transfer rate of the proposed system can achieve 115 Kbps with the transmission distance is 80cm
Symbol
H(f) Transfer function of the PLC channel
LL dB attenuation coefficient
D cm Distance between the LED and the surface where the receiver is located
Abbreviation
I INTRODUCTION
Currently, the amount of electricity used in lighting in Vietnam accounts for over 25% and will increase even more in the coming years While the traditional energy supplies are increasingly rare and exhausted To overcome this problem, in the world today, the US and countries such as Japan, Australia, Korea and China have used LED lights to replace traditional lights With this replacement, coupled with an efficient management policy, the result can be achieved with a 50% reduction in electricity used for lighting Because of that, using LED lights is increasingly popular in the world and promises many future applications in Vietnam LED lighting
is expected to replace traditional lighting sources such as incandescent and fluorescent lamps because they have many advantages such as: high durability, no fear of hair breakage or balloon breakage, power consumption Less due to the very high luminous efficiency of the LED, aesthetics, flexibility in use because the LED is small in size, so it is easy to combine into a lamp or light array in any configuration In addition, LEDs are semiconductor devices capable of switching on and off at super high speeds By using white light to transmit information, we can solve many outstanding problems of RF technology and extend the bandwidth down to the end devices As such, LED is not only used as a smart lighting device but also as an ultra-wide band communication device Currently in the world, there are many scientific research projects on VLC that have been implemented In Japan visible light communication technology was first proposed by Toshihiki Komine in
PLC Power Line Communication VLC Visible Light Communications
PD LOS
Photodiode line-of-sight
Trang 22004 [1], the Nakagawa laboratory of Keio University has researched and published numerous articles on specific VLC for basic analysis of VLC [2], improving data transmission speed and distance [3-4] In Korea, many studies have also been published, such as measurement results for bandwidth modulation of LEDs [5], studies
of transmission channel characteristics [6-7] Research by Oxford University on modulation methods [8] and bandwidth modulation problems of LEDs applied to VLC have also been published [9] However, the results of the above studies are facing a common problem to solve that is the limited communication distance, communication reliability is not high because the transmitter and receiver have to transmit line of sight (Line-of-sight) In addition, another problem is that when deploying a VLC system it is very difficult for existing buildings and structures such as ships or vehicles to install communication cables on ceilings or floors In this study, we propose a solution that combines PLC and VLC power line communication into a complete system, in this way the system can be used anywhere with power lines installed in one the house [10-11] The results obtained from the initial experimental model show that the system operates stably, data transmission speed can reach 115Kbps with distance is 80cm
II SYSTEM MODEL
1.1 Structure of the system combining PLC and VLC
The structure of the proposed system based on the combination of PLC and VLC into a complete system is shown in Figure 1 The system consists of PLC1 modems used to convert Ethernet signals into electrical signals for transmission on the line Power and vice versa, the PLC2 modem converts electrical signals into Ethernet signals so the system can be used anywhere there are power lines, the VLC block consists of LEDs for data transmission and a PD (photodiode) located in the collection By controlling the ON / OFF continuously change
of the LED, we can transmit data, if it is switched on for a very short time (several tens of nanoseconds), the VLC system can both convert data at the same time height, just ensure lighting
PLC
Modem1
Ethernet
PLC to VLC
VLC Device [1] VLC Device [2]
Power
Fig.1: PLC-VLC combination structure
To perform full-duplex communication, the system uses infrared LEDs for the uplink block and white LED for the downlink Uplink block using infrared LED has been widely used, so in this study we only focus on analyzing downlink block, downlink block diagram is shown in Figure 2
Server
PLC modem 1 Biến đổi Eternet sang PLC
PLC modem 2 Biến đổi PLC sang Eternet Power line
Khối điều khiển LED LED
PD Khuếch
đại
xử lý
220V
Fig.2: Downlink block diagram 1.2 Transmission channel model of PLC-VLC system
PLC transmission channel model
According to [8], the model of PLC transmission channel can be described as shown in figure 3
Trang 3Fig.3: PLC multipath channel model
Each signal transmitted from the transmitter will consist of N different paths to the receiver, where the ith line is determined by two parameters, latency i and the attenuation coefficient Ci The PLC transmission channel is represented as a time-discrete impulse response h (t) The impulse response h (t) can be written as:
j f
From there the transfer function of the PLC channel can be rewritten as:
1
, i
N
j f
i
(2) Where, gi is the weights generated from the reflection and the transmission coefficients along the transmission line, A (f, li) represents the loss coefficient due to the characteristics of the PLC transmission cable [12] Noise patterns have also been added as shown in Figure 3
III MODEL OF VLC TRANSMISSION CHANNEL
In this section, we will analyze the theory of the indoor line-of-sight (line-of-sight) channel model (Figure 4) Parameters such as the received line attenuation and optical power are derived based on the metering parameters This is an important quantity for choosing the appropriate characteristics of LEDs to be used in future real tests The relationship between receive power and transmit power for the VLC transmission channel
is expressed in the following formula:
P P L (3)
In which: LL attenuation coefficient on the transmission line, is determined by [12]
2
1 cos cos
2
m r
L
L
D
Where Ar is the photodiode surface physical area, D is the transceiver distance, ϕ is the radiation angle at the generator, Ψ is the angle to the receiver side, m is the order of the LED Lumberton, 1/2 is the semi-angle at half the output power, and it determines the width of the LED's light beam
Fig.4: VLC system parameters
In the case of multiple LOS channels, the received power is equal to the sum of the received powers of each LOS line The distribution of the electrical energy at the receiver depends on the luminance distribution of the light
Trang 4source Illuminance represents the luminosity on an illuminated surface The intensity of luminance at angle ϕ
is calculated using (5) based on Lambert's Cosine's law [12]
0 cosm
I I (5)
In fact, most commercial LEDs are made according to Lambert's Cosine's laws The luminous intensity decreases as the incident angle ϕ increases Where I (0) is the central luminous intensity of the LED, ϕ is the radiation angle and m is the order of Lumberton emission Ehor horizontal illuminance at point A (x, y) is given
by [12]
2
0 cosm cos
hor
I E
D
(6) Where D is the distance between the LED and the surface where the receiver is located
1.3 Proposed channel model
3.1.1 PLC and VLC transmitter
Figure 5 depicts the structure of a data transmission circuit combining PLC and VLC
Channel
PLC Modem1
Data Ethernet
Wall Socket
Amplifier LED Data
USB To TTL
Data
Amplifier 101011
LED Channel
a) Cấu trúc PLC receiver và VLC transmitter
b) Cấu trúc VLC transmitter tương đương
PLC Modem2
Fig.5: Structure of data transmission circuit
combination between PLC and VLC
First, Ethernet data from the Server will be converted by PLC1 modem into electrical signals transmitted on power lines and connected to indoor power lines, PLC2 modem through a power outlet will convert electrical signals into original Ethernet data This data is then amplified to drive the LED to transmit data In this study for simplicity in the experimental process, we propose to replace the PLC unit in Figure 5a with a computer to transmit data as shown in Figure 5b The transmitter module input data are 0V-3.3V electrical signal pulses from the USB to TTL converter representing the data bit stream The signal entering the transmitter module is amplified by Transistor H1061 and forms the control signal LED 10W Luxeon turns on and off The transmitter module output is the optical signal of the LED on and off according to the input pulse
3.1.2 VLC receiver
TTL To USB
Khuếch đại Decision PD
Nguồn
Optical
Fig.6: The structure of the VLC receiver circuit
The receiver input data is the optical signal received from the transmitter through the photoelectric converter (PD S6968) the signal then passes through an amplifier and comparator (LM 393) decides to give the signal
Trang 5form desired electrical signal Finally, the output signal of the receiver circuit will pass through the TTL to USB converter to enter the computer as shown in Figure 6
IV EXPERIMENTAL MODEL AND RESULTS
1.4 Experimental model
After designing the actual circuit construction, the VLC data transceiver model
is shown in figure 7, figure 8 is the LabVIEW NI myDAQ used as an oscilloscope
to analyze the reception and transmit signals
Fig.7: The transmitter and receiver are placed in the horizontal plane
Figure 7 shows LED and PD placed on the same plane The receiver and transmitter are connected to two separate USB ports of the same computer Thus, we can see this PC modeling two separate virtual PCs The data
is a series of data bits and images that are transmitted in real time between these two PCs
Fig.8: LabVIEW NI myDAQ module used to analyze transceiver signal 1.5 Analysis of results
The following are the various tests that have been performed to evaluate the communication capabilities of the system
Experiment 1: Transferring data bit sequences with different transmission rates using the real channel VLC
model as shown in Figure 7, the results are presented in Figures 9 and 10
Case 1: Bit rate set 9.6 Kbps, transmission distance is 70 cm results shown in Figure 9
Fig.9: Data transmission results 9.6Kbps, 70cm
Trang 6The results from Figure 9 show that with the transmitter and receiver distance of 70 cm, the transmission speed is 9.6 Kbps, the system works well
Case 2: increase the bit rate to 115.2 Kbps, the transmission distance remains 70 cm, the results shown in Figure 10
Fig.10: Data transmission results 115.2Kbps, 70cm
The results from Figure 10 show that with the transmitter and receiver distance of 70 cm, the transmission rate increased to 115.2 Kbps the system still works well even though some noise started to appear in the received signal
Experiment 2: Lena image transfer has a capacity of 31.6 kB Resolution 200 x 200 Pixels transmission distance
is 70 cm The image transfer result from the transmitter to the receiver is shown through the software interface
on the PC as shown in Figure 11
Fig.11: Result of image transfer interface on PC
Experiment 3: The transmission bit rate is set to 115.2 Kbps, but increases the transmission distance between
the transmitter and receiver to 80 cm Results shown in Figure 12
Fig.12: Data transmission results 115.2Kbps, 80cm
The results obtained from Figure 12 show that when the transmission distance increased to 80cm, in this case there was a lot of noise in the received signal, connection error occurred
Experiment 4: In order to increase the transmission distance, the transmitter uses additional LENS for LEDs to
focus light on a smaller cubic angle to increase luminescence efficiency Set the transmission speed and distance
as in experiment 3 Results are shown in Figure 13
Trang 7Fig.13: Data transmission results 9.6Kbps and 115.2Kbps, 80cm use more LEN for LEDs
The results obtained from Figure 13 show that the signal obtained at the receiver is significantly improved by the light concentrator
V CONCLUSION
In the future, VLC can become a new generation of communication / lighting technology and will be applied in practice soon In this study, we have proposed the architecture of a basic PLC-VLC system, constructing the real model of the indoor environmental transmission channel of VLC The results obtained from the initial experimental model show that the system operates stably, the data transmission speed can reach 115.2 Kbps with the distance of 80cm Hopefully, this result will serve as a foundation for further studies in improving and improving the applicability of the VLC system
VI REFERENCES
[1] Y Tanaka, T Komine, S Haruyama and M Nakagawa, “Indoor Visible Light Data Transmission System
Utilizing White LED Lights,” IEICE Trans Communication, vol E86-B, pp.2440-2454, 2003
[2] T Komine, M Nakagawa, “Fundamental analysis for visible light communication system using LED
lights”, IEEE Trans on Consumer Elec 50 (2004) 100–107
[3] T Komine, Y Tanaka, “Basic study on visible-light communication using light emitting diode
illumination”, Proceedings of 8th International Symposium on Microwave and Optical Technology,
2001, pp.45–48
[4] Haruyama, S “Visible light communication” IEEE Trans on IEICE J86-A (2003) 1284–1291
[5] Lee.C.G, Park.C.S, Kim.J.-H, Kim, D.H, “Experimental verification of optical wireless communication link
using high-brightness illumination light-emitting diodes, Optical Engineering”, Vol 46, No 12, 2007 [6] X Zhang and K Cui, “Experimental Characterization of Indoor Visible Light Communication Channels”
IEEE International Symposium on Communications Systems, 2011
[7] R Mesleh, H Elgala and H Hass, “Optical Spatial Modulation,” Journal of Optical Communications and
Networking, Vol 3, No 3, 2011
[8] J M Kahn and J R Barry, “Wireless Infrared Communications,” in proc of IEEE, vol 85 pp 265-298,
February 1997
[9] R Cheng, X Yan, “Indoor multi-source channel characteristic for visible light communication”, The
Jounal of China University of Posts and Telecommunications, 2013
[10] Halid Hrasnica, Ralf Lehnert, “Broadband Power line Communications Networks network design”, John
Wiley & Sons Ltd, Books Inc, ISBN 0-470-85741-2, West Sussex PO19 8SQ, England, 2004
[11] S.E.Alavi, S.M.Idrus, “New Integrated System of Visible Free Space Optic with PLC”, 3th workshop on
power line communications, Italy, october 2009,
[12] Z Ghassemlooy, W Popoola, S Rajbhandari “Optical Wireless Communication: System and Channel
Modelling with Matlab” CRC Press, 2012