scholarly journals Implementation of Dimming controlled Visible Light Communication using Raspberry Pi

2021 ◽  
Author(s):  
Sandip Das ◽  
Biswajit Jana ◽  
Soumitra Kumar Mandal
Keyword(s):  
Visible Light ◽  
Optical Communication ◽  
Incidence Angle ◽  
Low Cost ◽  
Data Communication ◽  
Visible Light Communication ◽  
Raspberry Pi ◽  
Efficient Technology ◽  
Wireless Optical Communication ◽  
Dimming Control

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.

scholarly journals Performance evaluation of optical attocells configuration in an indoor visible light communication

2019 ◽  
Vol 14 (2) ◽  
pp. 668 ◽  
Author(s):  
M.S. M. Gismalla ◽  
M.F. L. Abdullah
Keyword(s):  
Visible Light ◽  
Power Distribution ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Data Communication ◽  
Visible Light Communication ◽  
Base Stations ◽  
Configuration Model ◽  
Received Power ◽  
Small Base

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.

DATA COMMUNICATION USING VISIBLE LIGHT

2015 ◽  
Vol 3 (5) ◽  
pp. 358-362
Author(s):  
Tyran Kinny ◽  
Franklin Puthuva ◽  
Ashore Komban ◽  
Dipti Belekar
Keyword(s):  
Visible Light ◽  
Low Cost ◽  
Data Communication ◽  
Visible Spectrum ◽  
Visible Light Communication ◽  
Light Sources ◽  
Human Eye ◽  
Data Rates ◽  
Communication Devices ◽  
Normal Light

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.

A CDMA system implementation with dimming control for visible light communication

2018 ◽  
Vol 412 ◽  
pp. 172-177 ◽  
Author(s):  
Danyang Chen ◽  
Jianping Wang ◽  
Jianli Jin ◽  
Huimin Lu ◽  
Lifang Feng
Keyword(s):  
Visible Light ◽  
Visible Light Communication ◽  
Cdma System ◽  
System Implementation ◽  
Dimming Control

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
Keyword(s):  
Modulation Depth ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Data Communication ◽  
Experimental System ◽  
Digital Signal ◽  
Visible Light Communication ◽  
Cost Driver ◽  
Limiting Factors ◽  
Light Sources

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.

scholarly journals Design and Implementation of a Monitoring System using Optical Camera Communication for a Smart Factory

2019 ◽  
Vol 9 (23) ◽  
pp. 5103 ◽  
Author(s):  
Nguyen Cong Hoan ◽  
Nguyen Van Hoa ◽  
Vu Thanh Luan ◽  
Yeong Min Jang
Keyword(s):  
Visible Light ◽  
Monitoring System ◽  
Low Cost ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Light Emitting ◽  
Hospital Patients ◽  
Effects On Children ◽  
The Time Domain ◽  
Optical Camera Communication

Wireless technologies that are based on radio frequencies are currently widely used, with numerous applications around the world. However, they pose some disadvantages to human health. High frequencies can have potentially harmful effects on children, hospital patients, and even healthy people if the signal power exceeds the permitted standard. Conversely, the use of visible light for data transmission is a trend that presents new options, including optical wireless communication, optical camera communication, and visible light communication. This paper proposes a modulation scheme based on on-off keying in the time domain, which is applied to a monitoring system using optical camera communication. This scheme has various compatible supports for the global-shutter camera and rolling-shutter camera, which are popular commercially available cameras. Furthermore, this scheme facilitates a low-cost monitoring system. By using small light-emitting diodes (LEDs) and controlling the exposure time in a single camera, the camera, as a receiver, can simultaneously detect signals from up to 10 sensor devices in different positions at a maximum distance of up to 50 m, with a low error rate.

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