scholarly journals A 40 Mb/s VLC System Reusing an Existing Large LED Panel in an Indoor Office Environment

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1697
Author(s):  
Xicong Li ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvánovec ◽  
Paul Anthony Haigh

With advances in solid-state lighting, visible light communication (VLC) has emerged as a promising technology to enhance existing light-emitting diode (LED)-based lighting infrastructure by adding data communication capabilities to the illumination functionality. The last decade has witnessed the evolution of the VLC concept through global standardisation and product launches. Deploying VLC systems typically requires replacing existing light sources with new luminaires that are equipped with data communication functionality. To save the investment, it is clearly desirable to make the most of the existing illumination systems. This paper investigates the feasibility of adding data communication functionality to the existing lighting infrastructure. We do this by designing an experimental system in an indoor environment based on an off-the-shelf LED panel typically used in office environments, with the dimensions of 60 × 60 cm2. With minor modifications, the VLC function is implemented, and all of the modules of the LED panel are fully reused. A data rate of 40 Mb/s is supported at a distance of up to 2 m while using the multi-band carrierless amplitude and phase (CAP) modulation. Two main limiting factors for achieving higher data rates are observed. The first factor is the limited bandwidth of the LED string inside the panel. The second is the flicker due to the residual ripple of the bias current that is generated by the panel’s driver. Flicker is introduced by the low-cost driver, which provides bias currents that fluctuate in the low frequency range (less than several kilohertz). This significantly reduces the transmitter’s modulation depth. Concurrently, the driver can also introduce an effect that is similar to baseline wander at the receiver if the flicker is not completely filtered out. We also proposed a solution based on digital signal processing (DSP) to mitigate the flicker issue at the receiver side and its effectiveness has been confirmed.

Author(s):  
Tyran Kinny ◽  
Franklin Puthuva ◽  
Ashore Komban ◽  
Dipti Belekar

Visible Light Communication (VLC) using a Light Fidelity system, as proposed by a German physicist—Harald Haas, provides transmission of data through illumination by sending data through an LED light source that varies in intensity that can be controlled and adjusted such that it appears as normal light to the naked human eye. Here the property of persistence of vision of the human eye is exploited for additional application of a free, sustainable and green source that can be used for wireless communication at very fast data rates. This paper focuses on developing a low cost Li-Fi based system and analyses its performance with respect to existing wireless technology. Wi-Fi is great for general wireless coverage within buildings, whereas Li-Fi is ideal for high density wireless data coverage in confined area and for relieving radio interference issues. Li-Fi based system provides better bandwidth, efficiency, availability and security than Wi-Fi and has already achieved higher data rates. By leveraging the low-cost nature of LEDs and lighting units there are many opportunities to exploit this medium, from public internet access through day-to-day light sources which have their primary purpose of only emitting light. This project envisions a future where data for communication devices will be transmitted through the visible spectrum thus de-clogging the currently overused RF spectrum.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Simarpreet Kaur ◽  
Mahendra Kumar ◽  
Ashu Verma

AbstractWe demonstrated a full duplex hybrid passive optical network and indoor optical wireless system employing coherent optical frequency division multiplexing. To accomplish reliable transmission in passive optical networks integrated visible-light communication (VLC), yellow light-emitting diode and infrared LED is used in downstream and upstream, respectively, for intra building network. In order to support high data rate, pulse-width reduction scheme based on dispersion compensation fiber is incorporated and system successfully covered the distance of 50 km. A data stream at the rate of 30 Gb/s is transmitted for each user out of eight users. VLC-supported users are catered with the bit rate of 1.87 Gb/s over 150 cm and in order to realize a low-cost system, visible and infrared LEDs are used in downlink and uplink, respectively.


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.


Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1382 ◽  
Author(s):  
A B M Mohaimenur Rahman ◽  
Ting Li ◽  
Yu Wang

Because of the limitations of the Global Positioning System (GPS) in indoor scenarios, various types of indoor positioning or localization technologies have been proposed and deployed. Wireless radio signals have been widely used for both communication and localization purposes due to their popular availability in indoor spaces. However, the accuracy of indoor localization based purely on radio signals is still not perfect. Recently, visible light communication (VLC) has made use of electromagnetic radiation from light sources for transmitting data. The potential for deploying visible light communication for indoor localization has been investigated in recent years. Visible-light-based localization enjoys low deployment cost, high throughput, and high security. In this article, the most recent advances in visible-light-based indoor localization systems have been reviewed. We strongly believe that visible-light-based localization will become a low-cost and feasible complementary solution for indoor localization and other smart building applications.


2020 ◽  
pp. 4-22
Author(s):  
Wout van Bommel

To avoid disappointments with LED lighting installations, detailed knowledge of the typical characteristics of the many different solid-state light sources is essential, while already long-available information on vision and colour seeing has to be combined with entirely new fundamental research on the relationship between lighting on the one hand and vision, performance, comfort, health and well-being on the other hand. Lighting has apart from visual effects also far-reaching non-visual biological effects. These effects influence the way our body “operates” and therefore, influence our health, well-being and alertness. Interior lighting installations today have to be designed so that they provide both suitable visual and non-visual biological effects, while adverse effects of lighting, like flicker, blue light hazard and disruption of the biological clock, are avoided. LEDs offer the possibility to use them not only for lighting but also for data transmission. The use of LED lighting as a means for data communication is referred to as “light beyond illumination”. Visible Light Communication (VLC), LiFi, and light itself used as sensor are part of this subject. The modern lighting professional has to get familiarised with these new technologies and applications. The author of this article published in 2019 the book “Interior Lighting, fundamentals, technology and application” with Springer [1]. It discusses in 500 pages all topics important for the up-to-date interior lighting professional. The present overview article is entirely based on this book and follows the same chapter structure. Each chapter also describes, as an example, one or two crucial aspects in more detail.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 714 ◽  
Author(s):  
Pablo Corral ◽  
Fernando Rodríguez-Mas ◽  
José Luis Alonso ◽  
Juan Carlos Ferrer ◽  
Susana Fernández de Ávila

In this article, we compare two different kinds of commercial light-emitting diodes (LEDs) in transmission and organic photodetectors based on poly(3-hexylthiophene) (P3HT) and a phenyl-C61-butyric acid methyl ester (PCBM) blend used as active layer in reception. Photovoltaic cells based on massive heterojunctions of semiconductor polymers have focused the attention of researchers due to their several potential advantages over their inorganic counterparts, such as their simplicity, low cost, and ability to process large area devices, even on flexible substrates. Furthermore, in logistics, storage management systems require the implementation of technological solutions that allow the control of merchandise in real time by means of light-emitting diode signals that send information about the product. However, the slow response time of these organic photodetectors should not be critical for this application, where the light intensity changes are very slow, which limits the speed of data transmission compared to inorganic based systems that use wireless optical communications. Finally, we show a low-cost visible light communication system based on organic photodetectors with a frame based on on-off keying with Manchester encoding to support device-to-device connections.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Teh-Lu Liao ◽  
Chih-Yung Chen ◽  
Hsin-Chieh Chen ◽  
Yung-Yi Chen ◽  
Yi-You Hou

A novel technique for transmission of information through visible light communication (VLC) is developed in this study. A light-emitting diode is used as the light source at the transmitting side to send the encrypted information. At the receiving side, a light sensor, OPT-101, is used to receive the light signals that carry the encrypted information. The Arduino Due microcontroller board is used for digital signal processing at both the transmitting and receiving sides. Furthermore, to prevent the transmitted message from being intercepted, two chaotic systems, a master and a slave, with a synchronization controller are designed to obtain the transmitted audio signals. The design enables not only a VLC system with the light transmission path as a straight line (so that data cannot be stolen) but also the encryption of the audio signals with the chaotic system (Rössler system) to enhance data transmission security. The effectiveness of this system is then experimentally verified.


2019 ◽  
pp. 22-31
Author(s):  
Eszter Udvary

Communication applying visible light technology is a novel approach. Visible Light Communication (VLC) development is motivated by the increasing demand for wireless communication technologies. It has the potential to provide highspeed data communication with good security and improved energy efficiency. The rapid evolution of VLC was sustained by the LEDs performances. The Light-Emitting-Diode (LED) luminaires are capable of switching to the different light intensity at a fast rate. This function can be used for data transmission. This article focuses on the physical layer of the VLC links. It reviews the technology, the topology of the proposed connection, and the benefits of this approach. The main research trends are identified emphasizing state of the art in this area. It shows how VLC technology evolved and what are the performances achieved at this time. Various structures of the transmitter and receiver are studied, and different modulation schemes are investigated. Finally, numerous applications of VLC technology are presented.


2021 ◽  
Author(s):  
Sandip Das ◽  
Biswajit Jana ◽  
Soumitra Kumar Mandal

Abstract Visible light communication (VLC) is a technology of wireless optical communication, which combines lighting and communication simultaneously. In indoor VLC system, both data communication and lighting quality plays an important role and must be considered. Thus, to achieve the desired levels of illumination, dimming control in VLC is an efficient technology. In this paper, the authors have designed and implemented a dimming control VLC system employing multi header-hybrid pulse position modulation (MH-HPPM) to achieve dimming functionality. MH-HPPM supports various dimming levels and also doesn’t have flicker problems. In this paper, the authors present the implementation of MH-HPPM based VLC system using Raspberry pi. The prototype is designed using low-cost commodity hardware. Comprehensive experiments are carried out to evaluate the performance of MH-HPPM based VLC under dimming levels 0.25, 0.5 and 0.75. The results demonstrate that designed prototype supports a communication distance up to 3m for dimming level 0.25 and 3.6m for dimming level 0.5 and 0.75. It is also observed that MH-HPPM based VLC system also achieves and maintains better throughput for different incidence angle.


Author(s):  
Syifaul Fuada ◽  
Angga Pratama Putra ◽  
Yulian Aska ◽  
Trio Adiono

<p class="0abstract">Visible Light Communication (VLC) as one of wireless technology must be able to offer a good capability as mobile communication system. The signal will be faded when the distance and angle of LED to photo-detector become higher at a certain distance. Other problem at VLC system is light interference noise which is caused by flicker effect from other light sources such as incandescent, fluorescent, DC-lamp (i.e. flashlight) and the sunlight. Each of lights have specific carried signal characteristics and it can influences the VLC system. In this paper we offer design of mobile VLC system based on analog domain. We use Automatic Gain Controller (AGC) circuit using commercially available IC and it will be placed at analog front-end receiver side. AGC can self-adjust its gain according to the input signal amplitude.  We also design analog filter to eliminate all interferences noise spectrum which is existed under 50 KHz. We design both circuits, analog filter and AGC in VLC receiver system with low-cost. The test data are obtained through the simulation and achieved good results in ideal condition.</p>


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