UDK 004.772 Doi: 10.31772/2587-6066-2020-21-1-15-20
DEVELOPMENT OF METHOD FOR INCREASING SENSITIVITY IN WIRELESS OPTICAL DATA TRANSMISSION CHANNELS IN VISIBLE WAVELENGTH RANGE
Lvova A. P.
North-Caucasus Federal University, 2, Kulakova Av., Stavropol, 355029, Russian Federation. E-mail: lvova.ap@gmail.com
The original method for encoding binary data streams based on QPSK quadrature phase shift keying in a wireless optical communication channel in the visible range is suggested. The algorithm for analyzing signals in the receiving tract is presented. It allows to analyze the presence of two or three pulses of different colors at the input, which will signal the presence of interference or the occurrence of "illumination". In addition, the algorithm provides a possibility of dynamic compensation of external "illumination" by changing the gain of the photodetectors and adjusting the brightness of emitting LEDs. The functional scheme of the device for realization of the offered coding method in the wireless channel on the basis of optical radiation has been developed. Given that most photodiodes are sufficiently wide-band in the visible range of light waves, to increase sensitivity of each color channel and selectivity of the receiving tract it is necessary to apply optical filters for each color channel. The most effective are interference filters made of optically transparent materials with different physical characteristics. The approach for calculating optical filters has been presented.
Keywords: wireless data transmission, optical data transmission channel in the visible wavelength range, encoding based on quadrature phase shift keying, color channel, Li-Fi.
References

1. Nikiforov S. D. [Physical Aspects of Semiconductor Light Perception by the Human Eye]. Komponenty i
tekhnologii
. 2008, No. 89, P. 84–94. (In Russ.).
2. Zaocheng Wang, Qi Wang, Wei Huang, Zhengyang. Visible Light Communications: Modulation and Signal Processing. 2017, Wiley-IEEE Press, 368 p.
3. Elgala H., Mesleh R., Haas H., Pricope B. OFDM visible light wireless communication based on white
LEDs.
In IEEE 65th Vehicular Technology Conference. Dublin, Ireland, 22–25 April 2007, VTC2007-Spring,
P. 2185–2189.
4. Korn G. Korn T.
Spravochnik po matematike. [Handbook of mathematics]. 1974, Moscow, Nauka Pub.,
831 p.
5. Zhao S., Xu J., Trescases O. A dimmable LED driver for visible light communication (VLC) based on
LLC resonant dc-dc converter operating in burst mode. IEEE Applied Power Electronics Conference (APEC),
Long Beach, USA, March 2013, P. 2144–2150.
6. Aliaberi A., Sofotasios P., Muhaidat S. Modulation Schemes for Visible Light Communications. COMMNET
1–10, 2019.
7. Dmitrov S., Haas H. Principles of LED Light Communications: Towards Networked Li-Fi. 2015,
United Kingdom, Cambridge: Cambridge University Press, 207 p.
8. Malsugenov O., Chipiga A., Lvova A. Improving the Efficiency of Wireless Optical Transmission Channel
in the Visible Wavelength Range.
Proceedings of the 7th Scientific Conference on Information Technologies for
Intelligent decision making Support (ITIDS 2019)
advances in Intelligent Systems Research. 2019, Vol. 166,
P. 246–250.
9. Jamieson I. Visible Light Communication (VLC) Systems. July 14, 2010. Available at: http://www.bemri.org/
component/content/article/3-home/18-visible-lightcommunication-vlc-systems.html (accessed 20.12.2019).
10. O'Brien, D., Kang, T.-G., and Matsumura, T. Visible Light Communication: Tutorial. 2010. Available
at: http://www.ieee802.org/802_tutorials/2008-03/15-08-0114-02-0000-LC_Tutorial_MCSamsung-VLCC-Oxford_
2008-03-17.pdf. In IEEE 802.15-<08/0114-02> (accessed 20.12.2019).
11. Gauer J.
Opticheskie sistemy svyazi [Optical communication systems]. 1989, Moscow, Radio i svyaz Publ.,
504 p.
12. Sklyar B.
Cifrovaya svyaz. Teoreticheskie osnovy i prakticheskoe primenenie [Digital communication. Theoretical foundations and practical application]. 2007,
Moscow, Williams Publ., 1104 p.
13. Sultanov A. H., Usmanov R. G., Sharifgaleev I. A.,
Vinogradova I. L.
Volokonno-opticheskie sistemy peredachi: voprosy ocenki rabotosposobnosti [Fiber-optic
transmission systems: performance assessment issues].
2005, Moscow, Radio i svyaz Publ., 373 p.
14. Varjel S. V.
Volokonnye breggovskie reshetki [Fiber Bragg gratings]. 2015, St. Petersburg, Universitet
ITMO Publ., 65 p.
15. Nureev I. I. [Modeling of spectral characteristics of phased fiber Bragg gratings as sensors of sensor systems].
Sovremennye problemy nauki i obrazovaniya. 2015, No. 1-1, P. 350–350 (In Russ.).  


Lvova Anna Pavlovna – PhD student, assistant lecturer, department of information security of automated systems,
North-Caucasus Federal University, Institute of information technologies and telecommunications. E-mail:
lvova.ap@gmail.com.
  


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