scholarly journals Analysis of Visible Light Communication Link’s Performance in Fire Smoke Environment

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yu-Feng Yang ◽  
Kang-Kang Chang ◽  
Ying Ci

This paper mainly studies the communication performance of visible light communication link in fire smoke environment. Compared with the previous studies, this study no longer only considers a single wavelength and considers the influence of smoke and background light noise. Firstly, the variation of background light noise caused by sunlight during a day was analyzed, then signal-to-noise ratio (SNR) and bit error rate (BER) of the visible light communication link in fire smoke environment with different visibility were calculated, and finally, the variation of received power with the angle β between the LED optical axis and the communication link (from LED to receiver) was analyzed. The results show that, during a day from 07:00 to 18:30, background light noise first increases and then decreases, BER changes in the same trend and reaches the maximum at about 13:00, while SNR changes in the opposite trend and reaches the minimum at about 13:00. When visibility is 100 m, the maximum difference of SNR between 7:00 and 13:00 is about 19 dB, and the maximum difference of BER is about 5.3E-10. At 7:00, the maximum difference of SNR is about 13 dB between the visibility of 1 m and the visibility of 100 m, and the maximum difference of BER is about 1.44E − 11, and received power decreases with the increase of β. In addition, SNR increases with visibility of fire smoke environment, and BER changes in the opposite trend. Lastly, in order to enhance the performance of visible light communication in fire smoke environment, this paper gives the transmitting power scheme.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Thai-Chien Bui ◽  
Suwit Kiravittaya ◽  
Keattisak Sripimanwat ◽  
Nam-Hoang Nguyen

Design of an efficient indoor visible light communication (VLC) system requires careful considerations on both illumination and communication aspects. Besides fundamental factors such as received power and signal-to-noise ratio (SNR) level, studies on mobility scenarios and link switching process must be done in order to achieve good communication link quality in such systems. In this paper, a comprehensive lighting configuration for efficient indoor VLC systems for supporting mobility and link switching with constraint on illumination, received power, and SNR is proposed. Full connectivity in mobility scenarios is required to make the system more practical. However, different from other literatures, our work highlights the significance of recognizing the main influences of field of view angle on the connectivity performance in the practical indoor scenarios. A flexible link switching initiation algorithm based on the consideration of relative received power with adaptive hysteresis margin is demonstrated. In this regard, we investigate the effect of the overlap area between two light sources with respect to the point view of the receiver on the link switching performance. The simulation results show that an indoor VLC system with sufficient illumination level and high communication link quality as well as full mobility and support link switching can be achieved using our approach.


Author(s):  
M.S. M. Gismalla ◽  
M.F. L. Abdullah

Visible light communication VLC is deemed as futuristic technology applied for both illumination and data communication due to the low-cost energy consumption, long life expectancy, huge bandwidth, and high security compared to radio frequency RF. Uncovered area, minimum signal-to-noise ratio (SNR) and received power results from the non-uniform distribution of small base stations (i.e. Optical attocells) in the room. In this paper, the researchers propose a new LEDs distribution of five optical attocells configuration model in order to optimize the received power distribution and SNR at the center of the room for indoor VLC system. The optical attocells configuration in terms of received power to fill the uncovered area at the center of the room has been investigated. The simulation results showed that the proposed attocells configuration saved 24.9% of the transmitted power. Besides that, the whole room was covered uniformly.  As a result, the received power and SNR are improved.


2021 ◽  
Author(s):  
Hugo Sanchez Quispe ◽  
Pablo Palacios Játiva ◽  
Freddy Ajila Zaquinaula ◽  
Santiago Logroño Naranjo ◽  
Hilter Figueroa Saavedra ◽  
...  

Abstract Currently, agriculture based on agronomic greenhouses is replacing traditional agriculture. This technique reduces dependence on rain on crops. It also generates a controlled internal environment making optimal use of land and water resources. However, this environment needs more care and attention compared to traditional agriculture. To overcome this limitation, various radio frequency (RF)-based technologies can be used. Nevertheless, studies show that the use of communications in RF bands degrades crops' growth and quality. Therefore, an efficient solution is to use the visible light spectrum for communication, the main technology of which is called visible light communication (VLC). Despite numerous studies for the application of VLC in indoor environments, specific VLC systems for agronomic greenhouse environments or their channel models are not yet investigated in depth. To collaborate on state of art on this topic, we present in this paper a novel channel model that incorporates specific factors that affect the quality of VLC systems in agronomic greenhouse environments. Factors such as the random position and orientation of the transmitters and external environmental agents such as atmospheric and different noise types are considered. These components are integrated into an analytical framework by developing the mathematical model of the VLC channel. Furthermore, the analytical expressions of the received power, the signal-to-noise-ratio (SNR), and the bit error rate (BER) are obtained. A VLC system applied to an agronomic greenhouse scenario is developed through computer simulations to validate the mathematical analysis. The results show that illuminance is adequate for the efficient operation of the greenhouse. Besides, the influence of atmospheric factors and noises on the magnitude and temporal dispersion of the channel impulse response is verified. Finally, the results show the system's performance in terms of SNR and BER, observing their differences compared to a traditional indoor VLC system.


2015 ◽  
Vol 23 (26) ◽  
pp. 33656 ◽  
Author(s):  
José Ramón Durán Retamal ◽  
Hassan Makine Oubei ◽  
Bilal Janjua ◽  
Yu-Chieh Chi ◽  
Huai-Yung Wang ◽  
...  

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1713
Author(s):  
Hyunwoo Jung ◽  
Sung-Man Kim

We experimentally demonstrated full-duplex light-emitting diode (LED)-to-LED visible light communication (VLC) using LEDs as the transmitter and receiver. Firstly, we investigated the performance dependency on the wavelengths of the LED transmitter and receiver by measuring the rise time and signal-to-noise ratio (SNR). Through the investigation, we were able to choose the optimal LED color set for LED-to-LED VLC using Shannon’s channel capacity law. The bit error rate (BER) results of full-duplex and half-duplex LED-to-LED VLC systems with the optimal LED sets are shown to compare the performance. Furthermore, we discuss major distortions and signal losses in the full-duplex LED-to-LED VLC system.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5661
Author(s):  
Jorik De Bruycker ◽  
Willem Raes ◽  
Stanislav Zvánovec ◽  
Nobby Stevens

Visible Light Communication (VLC) has received substantial research attention in the last decade. The vast majority of VLC focuses on the modulation of the transmitted light intensity. In this work, however, the intensity is kept constant while the polarization direction is deployed as a carrier of information. Demodulation is realized by using a differential receiver pair equipped with mutually orthogonal polarizers. An analytical expression to evaluate the Signal-to-Noise Ratio (SNR) as a function of the rotation angle of the receiver is derived. It is demonstrated that the signal quality can deteriorate heavily with receiver orientation when using a single differential receiver pair. A way to overcome this drawback using two receiver pairs is described. The analytical expression is experimentally verified through measurements with two different receiver setups. This work demonstrates the potential of polarization-based modulation in the field of VLC, where receiver rotation robustness has been achieved by means of a dedicated quadrant photodiode receiver.


2014 ◽  
Vol 685 ◽  
pp. 306-309
Author(s):  
Hao Wang ◽  
Ze Yu Han

Visible light communication technology is a emerging wireless and optical communication technology developed after invention and application of white LED.In this paper, we have a research based on indoor visible light communication system of lighting white LED,discuss of the visible light communication channel characteristics,detailedly analysis of the indoor visible light communication link. This paper focuses on the modulation and demodulation method applied to visible light communication. In the past visible light communication is mainly used off keying modulation,however, the data transfer speed is limited due to the influence of ISI .This paper presents a solution based on OFDM modulation and demodulation, to reduce the impact brought from inter-symbol string under high data transfer speed.Based on data analysis and computer simulation,the program presented in this paper can be used as indoor lighting and high-speed data transmission.Finally, give scheme to achieve visible light communication modulation and demodulation,provide a theoretical basis for further experiments.


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