Visible Light Communication Research Papers (original) (raw)

- by and +1
- •
- Electromagnetic metamaterials, Metamaterials, Optimization techniques, Visible Light Communication

—Indoor localization is very important to enable Internet-of-things (IoT) applications. Visible light communication (VLC)-based indoor localization approaches embrace many advantages, such as utilization of existing ubiquitous lighting infrastructure, high location and orientation accuracy, and no interruption to RF-based devices. However, existing VLC-based localization methods lack a real-time backward channel from the device to landmarks and necessitate computation at the device, which make them unsuitable for real-time tracking of small IoT devices. In this paper, we propose and prototype a retroreflector-based visible light localization system RETRO, that establishes an almost zero-delay backward channel using a retroreflector to reflect light back to its source. RETRO locates passive IoT devices without requiring computation and heavy sensing (e.g. camera) at the devices. Multiple photodiodes (i.e. landmarks) are mounted on any single unmodified light source to sense the retroreflected optical signal (i.e. location signature). We theoretically derive a closed-form expression for the reflected optical power related to the location and orientation of the retroreflector, and validate the theory by experiments. The characterization of received optical power is applied to a received signal strength indicator (RSSI) and trilateration based localization algorithm. Extensive experiments demonstrate centimeter-level location accuracy and single-digit angular error.

- by Sihua Shao and +1
- •
- Visible Light Communication, Indoor Localization, Internet of Things (IoT), Retroreflection

Light Fidelity (LiFi) is a Visible Light Communication (VLC) based technology that making a light as a media of communication replacing the cable wire communication. LiFi is based on Visual Light Communication (VLC) that using light emitting diodes (LEDs) to fully networked wireless system. Li-Fi is a derivative of optical wireless communications (OWC) technology, which uses light from light-emitting diodes (LEDs) as a medium to deliver network,mobile, high-speed communication in a similar manner to Wi-Fi. It is wireless and uses visible light communication or infra-red and near ultraviolet (instead of radio frequency waves) spectrum, part of Optical wireless communications technology, which carries much more information and has beenproposed as a solution to the RF-bandwidth limitations. A complete solution includes an industry led standardization process.

To meet the growing demands of the data communication infrastructure in the Internet-of-Things era, alternative methods are needed to complement the current technology, one of which employs optics-based communication. In this paper, we develop optical wireless communication (OWC) infrastructure focuses on digital signal processing (DSP) part. We design System-on-Chip (SoC) architecture based on the Orthogonal Frequency-Division Multiplexing (OFDM) technique with reconfigurable hardware resources. The system developed combines ARM microprocessors with FPGAs. For accelerating the digital processing, several essential parts such as Viterbi decoder, FFT, and time synchronizer are applied to the hardware IP (H/W SoC). While the scheduling is carried out on the software (S/W SoC). With this system, the data communication with other devices can be practiced easily, using various peripherals, i.e., Ethernet, UART, and serial-based connection. Afterward, we exploit the system performance in terms of the hardware resources utilization both for DSP Transmitter and DSP Receiver, also the system latency.

By using Visible Light Communication (VLC), in contrast to radio waves, the secure connection can be established more efficiently since the visible light could not radiate through most solid objects. VLC has been applied for many use cases, one of them is Light-Fidelity (Li-Fi). With Li- Fi, internet access is no longer using conventional RF spectrum as employed in Wi-Fi technology but apply visible light. In this paper, we present the design and implementation of a Li-Fi on a System on Chip (SoC) with a low-cost discrete analog front end (AFE). We used ZYBO Zynq-7000 as a digital signal processing, 8 Watt yellow-colored high-brightness LED (HBLED) for downlink transmitter, and 3 Watts infrared LED (IR LED) for uplink transmitter. Our system is developed compliant with the IEEE 802.15.7 standard, i.e. PHY II.1. According to the result, our Li-Fi system makes the PC/Laptop connected to any internet sources with a maximum speed up to 500 kb/s, and the maximum optical channel distance (range between the light source and the light receptors) is about 110 cm with two lenses.

A comprehensive study of outdoor visible light communication (VLC) under snow and rain effects has been conducted in this paper. This paper analyzes the expected rain attenuation of Marshal, Carbonneau, and Japan models at different precipitation levels. Snow attenuation is measured in wet and dry situations at various precipitation levels as well. Therefore, a full comparison is carried out for different attenuation effects on certain outdoor VLC design characteristics such as the maximum signal-to-noise ratio (SNR), optical power received, bit error rate (BER), and maximum coverage area. VLC with various modulation techniques is considered. The ON-OFF Keying (OOK), L-Pulse Position Modulation (L-PPM), Inverse L-Pulse Position Modulation (I-L-PPM), and Subcarrier Binary Phase-Shift Keying (SC-BPSK) are investigated. The simulation results show a considerable difference in the information received under different weather conditions depending on the type of modulation scheme used. The simulation has been done on a two-lane road, and a green traffic light-emitting diode (LED) with a wavelength of 505 nm is used as a transmitter. A non-imaging concentrator coupled with a photodetector is considered to be a cost-effective receiver.

An emerging technology Li-Fi, or light fidelity is a bidirectional and fully networked wireless communications medium which uses light from light-emitting diodes (LEDs) and provides transmission of data through illumination by sending data through a LED light bulb that varies in intensity faster than the human eye can follow. It can provide connectivity within a very large area with more security and with higher data rates and high speed than data that can be transmitted through Wi-Fi. It uses visible light communication or infra-red and near ultraviolet spectrum which works by switching bulbs on and off within nanoseconds. By using Li-Fi technology highly reliable vehicle to vehicle communication is possible by transmitting and receiving data through LED headlights and tail-lights. In this paper we propose a system that uses Li-Fi enabled LED headlight , tail-light and traffic signal light that can be used for traffic management and road safety by using vehicle to vehicle data tran...

- by Israt Mouri
- •
- Communication, Microcontrollers, Arduino, Light emitting devices and Solar cells

Circuit and system of the Auto Gain Control (AGC) is a very important to be used in Visible Light Communication (VLC) transceiver receives the range of receivers and overcoming the near-far effect of the signal link. This paper discusses circuit design of AGC by using IC LM13700, a Trans-conductance amplifier. This IC is available in the electronic market and very low-cost. AGC is able to offer limited VLC mobility (movable) access at a certain distance and angle. We have performed an AGC circuit test that implemented in the optical link, the result shows (AVOL vs frequency) that AGC is effective to amplify the weak signal of VLC system (can be changed distance orientation up to 45 cm and angle of the receiver against The LED up to> 45 degrees.

VLC is an emerging optical wireless communication technology that can be added as a complementary feature into existing lighting infrastructures for alleviating pressure on the rapidly dwindling radio frequency spectrum. Although LEDs have been traditionally used as transmitters in VLC, the growing urgency for higher data rates in the gigabit class range has deviated focus toward the consideration of LDs as potential sources for VLC due to their unique features of high modulation bandwidth, efficiency, and beam convergence. This article focuses on the principles of LD-based VLC systems, highlighting the operational characteristics and link configurations. The unique features of LDs compared to LEDs are discussed alongside the communication and illumination aspects of different classifications of LD-VLC. The challenges in terms of practical implementation and the potential applications that might arise from this communication technology are also discussed.

- by Fahad Zafar and +1
- •
- Solid-State Lighting, Optical wireless Communications, Visible Light Communication, Laser Diodes

Abstact-Light Fidelity (Li-Fi) refers to the 5G Visible Light Communication systems using light-emitting diodes as a medium for high-speed communication in a similar manner as Wi-Fi. [5] As now a days where internet has become a major demand, people are in a search for Wi-Fi hotspots for their activities. Li-Fi is a better alternative to Wi-Fi in wireless communication as it is [1] bidirectional, high speed and fully networked wireless communications similar to Wi-Fi. It is a subset of visible light communication(VLC) and can be a complement to RF communication , or a replacement in contexts of data broadcasting. This paper proposes a survey on Li-Fi Technology. Li-Fi has more capacity in terms of bandwidth in visible region therefore it does not interfere in other communications which uses radio frequency range, without taking its frequency bands. It has thousand times greater speed than Wi-Fi.Such technology has brought not only greener but safer and cheaper future of communication.

- by Sachin Verma
- •
- Optical Fiber Communications, Wireless Communications, Optical Communication, Wi-Fi

Visible Light Communication (VLC) is promising new technology to be applied in the lighting system infrastructure. This communication function should not interfere with the existing lighting system. In order to prevent from this interference, the utilized modulation scheme should have a limited dynamic range to avoid flickering and dimming effect. We propose Pulse Position Modulation (PPM) technique in our VLC system due to its very minimum dynamic range feature. This paper describes the design and analysis of VLC physical layer using PPM scheme to obtain a stable illumination. The design of physical layer consists of analog front end (AFE) circuit and the data processing which is implemented in microcontroller and FPGA. Based on the test results of our VLC system using low cost photo detector, the system is able to provide stable illumination while reaching the maximum data transfer rate of 20 kbps.

- by Nur Ahmadi and +1
- •
- Visible Light Communication

As a new generation green lighting source, the light emitting diode (LED) is rapidly replacing traditional incandescent and fluorescent light sources. Apart from providing energy savings, the use of LED lighting technology creates scope for an innovative optical wireless communication technology known as visible light communication (VLC), which takes advantage of the superior modulation capability of LEDs to transmit data through a wireless channel. VLC is capable of concurrently providing communication as well as illumination. For making commercial implementation of VLC feasible, it is necessary to incorporate it with dimming schemes that will provide energy savings, moods, and increase the aesthetic value of the place using this technology. However, general dimming techniques have an adverse effect on communication since they limit the achievable data rate of a VLC link. This drives the necessity of formulating efficient dimming techniques, which will create a balance between the two most basic functions of VLC: illumination and communication. This paper focuses on dimming mechanisms that can be implemented in VLC systems to save energy and provide precise illumination control. The motivation behind this control mechanism, current challenges in practical implementation, driver circuitry, recent progress, and future prospects are also concisely presented.

- by R. Parthiban and +1
- •
- Visible Light Communication

Demand for bandwidth hungry applications and mobile services is pushing an unquenchable need for wireless capacity. Existing radio frequency networks are characterized by shared medium, inadequate spectrum, and restricted user capacity. Solid state lighting is modernizing indoor as well as outdoor illumination. The capability of quick switching of light emitting diode makes them superior to other lighting sources enabling simultaneous use as a communication and illumination device. Visible light communication (VLC) using light emitting diodes is an attractive approach for many networking scenarios and is considered as a complementary technology for future heterogeneous wireless networks. This article presents an architectural perspective on the applications and data rate improvement strategies. A wide range of VLC applications have been investigated, comparison has been drawn with radio frequency, and generalized network architecture is also proposed. Numerous applications of VLC are data rate intensive, so data rate improvement approaches have also been studied. At the end, a lucid conclusion is drawn about the applicability, acceptability, and utilization of VLC and co-VLC–based systems.

- by Muhammad Saadi
- •
- Wireless Communications, The Internet of Things, Localization, Green Technology

The design and implementation of medium access control (MAC) layer for network-enabled visible light communication (VLC) system is presented in this paper. The point-to-point link was chosen because of its simple in configuration as well as implementation. Whereas the FPGA Zybo Zynq-7000 is employed for prototyping the hardware of VLC system because of it serve a Linux operating system (OS), i.e. Xillinux. Our MAC layer has been realized in Python programming and running above the Zynq-7000 processor. The designed MAC Layer is adapted from IEEE 802.15.7 standard, specifically for delivering and receiving the MAC frames from the coordinator to the device or vice versa, wrapping the IP packets and unwrapping the MAC Frames with MAC headers and trailers, and performing the error detection in which the cyclic redundant check 16 (CRC-16) was selected. According to the functionality test, our proposed VLC system can perform to send the multimedia contents (video and image) as well as data packet for internet accessing purpose like a wireless fidelity (Wi-Fi) connectivity. Thus, it can be concluded that the implemented MAC layer has met the functionality specifications referred to the IEEE 802.15.7 standard. We also provide the Pseudo-code of designed MAC layer and its Python script (source-code) implementation that can be found in the Appendix section.

- by Rosmianto Aji Saputro and +1
- •
- Linux, Optical Communication, Optical wireless Communications, Linux Open Source System

Visible Light Communication (VLC) is an emerging field in Optical Wireless Communication (OWC) which utilizes the superior modulation bandwidth of Light Emitting Diodes (LEDs) to transmit data. In modern day communication systems, the most popular frequency band is Radio Frequency (RF) mainly due to little interference and good coverage. However, the rapidly dwindling RF spectrum along with increasing wireless network traffic has substantiated the need for greater bandwidth and spectral relief. By combining illumination and communication, VLC provides ubiquitous communication while addressing the shortfalls and limitations of RF communication. This paper provides a comprehensive survey on VLC with an emphasis on challenges faced in indoor applications over the period 1979-2014. VLC is compared with infrared (IR) and RF systems and the necessity for using this beneficial technology in communication systems is justified. The advantages of LEDs compared to traditional lighting technologies are discussed and comparison is done between different types of LEDs currently available. Modulation schemes and dimming techniques for indoor VLC are discussed in detail. Methods needed to improve VLC system performance such as filtering, equalization, compensation, and beamforming are also presented. The recent progress made by various research groups in this field is discussed along with the possible applications of this technology. Finally, the limitations of VLC as well as the probable future directions are presented.

- by Dilukshan Karunatilaka and +3
- •
- Visible Light Communication

Trans-impedance amplifier (TIA) are widely used for optical sensing applications (precision instrumentation) and optical communication, such as: fiber optic, IR communication and also Visible Light Communication (VLC). TIA convert the current (I) into voltage (V). Application TIA design depend of objectives requirement system, for high speed as well as highband, low noise, low power and others. This paper explains the empirical experiment of TIA for high-band VLC with over 1- MHz Gain Bandwidth Product (GPWP) estimated. We implement general topology mode: as photovoltaic. The selection of the best resistor feedback (Rf) and compensator (Cf) are presented, we compare simulation approach against real implementation. The OP-AMP chosen from Texas Instruments® product, OPA 656. The TINATM SPICE® simulator used as simulation’s tool. This research contribution lies in applied of engineering design methodology with detailed step to develop major VLC system, we focus on photodiode amplifier only. By depth analysis, can be known next research addresses and obtain the best results without trial and error methods.

- by Syifaul Fuada
- •
- Visible Light Communication, Vlc Research, Transimpedance Amplifier

Visible light communication technology similar to wireless routers will enter our lives and complement the existing RF technology applications. This paper expounds the background of the development of visible light communication technology which uses light emitting diodes as a transmitting module and the development status at home and abroad analysis its system advantages, limitations, key technologies, characteristics and existing problems, looks forward to future research trends, and introduces visible light communication for high speed data transmission, intelligent transportation for vehicle to vehicle communication and visible light communication for underwater communication. Such traditional network communication cannot cover the innovative applications and prospects of the field. Also introduces visible light communication directions, future and challenging issues.

Vehicle to vehicle data transmission, we present initial designs and results of a small-scale prototype using light fidelity (Li-Fi) technology, a new technology that was developed in the last few years, which still needs more systematic inquiry on its sustainability for outdoor vehicular networks. Vehicle to vehicle communication is the most effective solution we have used in order to reduce vehicle's accidents. The propose use of Li-Fi technology comprises mainly light-emitting diode (LED) bulbs as means of connectivity by sending data through light spectrum as an optical wireless medium for signal propagation. In fact, the usage of light emitting diode (LED) eliminates the need of complex wireless networks and protocols. The design system is aim to ensure a highly-reliable communication between a commercial LED-based transaction light and a receiver mount on a vehicle.

Li-fi Technology is one of the exploring fields that enhances the power of data communication and inter-networks. Li-Fi technology, proposed by the German physicist—Harald Haas, researched that transmission of data through illumination by sending data through an LED light bulb. As LED light varies in intensity faster than the human eye can feel ,it also have higher frequency than Radio wave which results in much higher speed than Wi-Fi. LED increases the efficiency, durability and Data rate, thus empowering the growth of Li-Fi systems and Visible Light Communication (VLC) system. The Speed of nearly 10 Gbps can be achieved by using LED Bulbs instead of using all traditional incandescent bulbs or compact fluorescent devices. The scope of the author is to use a LED Bulbs as sources of data transmission and communication in Local area network like Home, office, Organization and etc.

- by Mona Hella and +2
- •
- Software Defined Radio, Visible Light Communication

An unprecedented demand for connecting physical objects with the internet expedites the realization of internet of things, thus creating new challenges to explore new spectrums which are suitable for communication. Visible light communication (VLC) is one promising candidate not only to remove the spectrum crunch issues but also to offer virtually unlimited, unregulated spectrum. This paper discusses how VLC can help solving spectrum crunch, non-availability issues of radio frequency spectrum and how readily available spectrum of VLC can be utilized to cope up with the bandwidth requirements of next-generation networks. Furthermore, this paper also lists the technological innovations in the area of VLC from early days till present and its possible applications in various domains.

- by Muhammad Saadi
- •
- Indoor Positioning, LED Lighting, Visible Light Communication, Indoor Localization

—To date, the photodiode still the first choice component is used in optical communication, especially for visible light communication (VLC) system. It has advantages of speed, energy consumption, and sensitivity, compared to other devices (e.g. image sensor). There are many practical implementations of high-speed VLC which uses photodiode. Commercially available photodiode typically have specific characteristics, so that it needs some consideration to be used as optimal receiver devices in VLC system. In this paper, analysis of received power characteristics of the photodiode in indoor line-of-sight (LoS) channel of VLC system is discussed. MATLAB® simulation is used as approach model (student version). The experiments are done by changing several parameters such as the semi-angle half power of the transmitter, distance from the transmitter to receiver, room size, field-of-view (FOV), lens index and optical filter gain. From the results, it can be known that distance, room size, FOV and LED power factor to have linear characteristic against the received power of commercial photodiode. Also in LoS channel model, the gain of optical filter and lens index plays an important role in defining the characteristics of received power.

The new vehicle execution has been persistently improved and the examination results identifying with the wellbeing of vehicle driving have additionally been consistently announced and illustrated, it is attempting to discover an equalization point between the advancement of vehicle speed limit and the assurance of driver's security. Li-Fi is a VLC, visible light communication innovation that manages move of information through enlightenment by removing fibre from optics by sending information through a LED light that fluctuates in the force quicker than a human eye can pursue. In this undertaking we attempt to build up a framework to give the before mishap data to the vehicle control unit with the goal that it empowers the vehicle to anticipate the occurrence of mishap. Vehicle to vehicle correspondence is the best arrangement that has been utilized so as to decrease vehicles' mishaps. The proposed utilization of Li-Fi innovation in this task involves the light emitting diode (LED) bulbs as methods for network by sending information through light range as an optical remote vehicle for signal engendering. Truth be told, the use of LED dispenses with the need of complex remote systems and conventions.

- by Hany Elgala
- •
- Channel Coding, Broadcasting, OFDM, Visible Light Communication

5G networks have to offer extremely high capacity for novel streaming applications. One of the most promising approaches is to embed large numbers of co-operating small cells into the macro-cell coverage area. Alternatively, optical wireless based technologies can be adopted as an alternative physical layer offering higher data rates. Visible light communications (VLC) is an emerging technology for future high capacity communication links (it has been accepted to 5GPP) in the visible range of the electromagnetic spectrum (~370–780 nm) utilizing light-emitting diodes (LEDs) simultaneously provide data transmission and room illumination. A major challenge in VLC is the LED modulation bandwidths, which are limited to a few MHz. However, myriad gigabit speed transmission links have already been demonstrated. Non line-of-sight (NLOS) optical wireless is resistant to blocking by people and obstacles and is capable of adapting its’ throughput according to the current channel state information. Concurrently, organic polymer LEDs (PLEDs) have become the focus of enormous attention for solid-state lighting applications due to their advantages over conventional white LEDs such as ultra-low costs, low heating temperature, mechanical flexibility and large photoactive areas when produced with wet processing methods. This paper discusses development of such VLC links with a view to implementing ubiquitous broadcasting networks featuring advanced modulation formats such as orthogonal frequency division multiplexing (OFDM) or carrier-less amplitude and phase modulation (CAP) in conjunction with equalization techniques. Finally, this paper will also summarize the results of the European project ICT COST IC1101 OPTICWISE (Optical Wireless Communications - An Emerging Technology) dealing VLC and OLEDs towards 5G networks.

- by Paul Anthony Haigh and +1
- •
- Orthogonal Frequency Division Multiplexing (OFDM), Visible Light Communication, 5G

Internet today will be highly integrated with many aspects of our daily needs making it a corner stone in modern life. This dependency increased the demand on having internet services with higher Bandwidth, higher Bit Rates and lower Congestion problems. As a result, more and more applications will be widely realized for Internet based in the future, either in custom or dedicated fashion. As a result, the Light Fidelity (Li-Fi) technology-that is considered in this paper-refers to the technology that can transfer data in a faster reliable way; utilizing Light Emitted Diode (LED) bulb which is the source of illumination. The method of communication is through transfer data pulses instead of radio frequencies signals, thus providing an economic advantage by eliminating the need for complex wireless networks.

This paper presents the implementation of an IEEE standard-based Visible Light Communication (VLC) system using software defined radio (SDR) approach. Based on widely used SDR platform Universal Software Radio Peripheral (USRP) and visual programming language LabVIEW, we present a fully standard compliant implementation of all PHY I modes of the IEEE 802.15.7 standard. Rest of the equipments used in the experimental set-up are low cost and commercial off-the-shelf devices. We successfully demonstrate audio streaming through our software defined VLC system, which can transmit and receive data successfully up to 2 meters. We also present bit error rate results of all PHY I modes of IEEE 802.15.7 running on our VLC system, which operates at a distance of 1 meter.

The paper proclaims a summary of Li-Fi technology. It is an efficient data communication mechanism involving visible light as a medium of transmission. This monograph introduces the concept of Li-Fi and its working model. Furthermore, it discusses its benefits, shortcomings and examines ways to mitigate the drawbacks. Additionally, it analyzes its present applications and explores its future scope in the competitive wireless market.

- by Mihir Chauhan
- •
- Wireless Communications, LED Lighting, Visible Light Communication, Photo Diode

This paper presents a mathematical model for car-to-car (C2C) visible light communications (VLC) that aims to predict the system performance under different communication geometries. A market-weighted headlamp beam pattern model is employed. We consider both the line-of-sight (LOS) and non-line-of-sight (NLOS) links, and outline the relationship between the communication distance, the system bit error rate (BER) performance and the BER distribution on a vertical plane. Results show that by placing a photodetector (PD) at a height of 0.2-0.4 m above road surface in the car, the communications coverage range can be extended up to 20 m at a data rate of 2Mbps.

- by Pengfei Luo
- •
- Visible Light Communication
- by Monica Figueiredo
- •
- Visible Light Communication

This paper studies the feasibility of using low-power wireless technologies such as Bluetooth, IEEE 802.15.4 and ZigBee in high-speed railway scenarios that involve bidirectional land-to-train communication. The presented results have been obtained through experimental tests conducted at the high-speed railway line connecting Madrid to Barcelona. A multiplatform communication system has been installed in a high-speed train, circulating at velocities up to 300 km/h, whereas autonomous devices have been disseminated along of the railway path to communicate with the onboard devices. The conclusions drawn from this work will be used as guidelines for the future implementation of autonomous communication platforms for high-speed rail connectivity.

Now-a-days, wireless networks are deployed everywhere. The increase of Wi-Fi hotspots to the rising number of cell phones, PDAs and laptops equipped with Wi-Fi radios, that’s why, for many organizations wireless security is an ever increasing issue. So, it is important to have a basic security level of encryption protocols. This paper focuses on the penetration testing attack that break encrypted password of a wireless device with a file that contains an alphanumeric dictionary with the use of Kali Linux, that has a collection of forensics tools. This paper shows the penetration test on WEP and WPA/WPA2 protocols, how this protocol is breach with simple attacks using Kali Linux. This paper also classifies the most vulnerable access point to help network administrator, how they protect their networks for such a type of attacks and which type of the countermeasures they have to take.

- by Sumit meshram
- •
- Visible Light Communication

Visible light communications (VLC) is a new emerging technology, which provides both data transmission and illumination by utilizing the visible range (370 – 780 nm) of the electromagnetic spectrum. In order to maximize the available data rate and enhance the user’s mobility within an indoor environment, it is essential to characterize the communication channel. In this paper we present both analytical and experimental results for a VLC system affected by movement of people for different indoor conditions (i.e. furnished office room, empty hall and corridor). VLC systems utilize multiple light-emitting diodes mounted in the ceiling and the configuration is based on the non-directed line of sight. We consider random movement of people within the room, focusing on the impacts of shadowing and blocking on mobility and link system performance by investigating changes in the channel characteristics using the cumulative distribution function of the received power distribution and the delay profile. We demonstrate the behaviour of communication channels for different scenarios from corridor, the most robust against people movement induced fading, to the office rooms and halls, the most vulnerable to the received power fluctuation.

VLC technology is a modern, emerging
technology which is recently very popular in both
academia and industry due to rapid advances in
production of LED lamps and high potential of these
lamps in creating lighting and sending data
simultaneously. In this paper, classification of the current
types of building energy management systems is
mentioned, then, VLC is introduced .Advantages and
Disadvantages of using this system in BMS is discussed
and finally, combining this network with currently used
networks, a dynamic, reliable and easy to install
management system is proposed.

– Visible light communication (VLC) is vulnerable to the optical interference noise and become a big problem in the optical channel because it can degrade the VLC systems performance. In this paper, we present a characterization through measurement of the modern artificial light (incandescent, fluorescent without ballast, and LED lamp) that exist in the global market nowadays. It is essential to understand the significant noise frequency that is induced by the artificial light. Therefore, the designers can be designing the receiver circuit for VLC systems which robust from optical interference noise. Based on our investigation, both fluorescent and incandescent produce the ambient light and emit 100 – 150 Hz of noise frequency. Whereas LED lamp only emits the DC component. We also propose a received signal models of the trans-impedance amplifier in analog front-end VLC receiver.

- by Gayathri Ece
- •
- Visible Light Communication, LED, Location-Based Service, Image Sensor

—The paper proposes a 720 Mbps visible light communication (VLC) system using 64-QAM-OFDM signals. Transmission of signals is achieved by modulating red, green and blue (RGB) light emitting diodes (LEDs) and transmitting all three wavelengths over free space optical (FSO) channel after subcarrier multiplexing (SCM) of 64-QAM-OFDM signals on two RF carriers. The performance of the proposed scheme is evaluated for a free space distance under the effect of weak as well as strong scintillations. Data transmission with bit error rates under pre-FEC limit (3.8x10-3) is achieved up to 1.2 meters through the proposed VLC system.

- by rakesh krishna
- •
- Visible Light Communication

Visible Light Communication (VLC) is a blooming research area which uses visible light spectrum as the communication channel. Exponential growth of Light Emitting Diodes (LEDs) deployment as a light source is encouraged to use for communication purposes as well. With the introduction of VLC, LED can be used for communication while providing the primary function of illumination. Since location-based network access protocols have not been implemented for Wi-Fi devices, this research has been conducted with the intention of using VLC to perform location-based authentication. In our location authentication protocol, VLC technology is used for authentication purpose and Wi-Fi is used for data transfer once the device has been authenticated. The proposed protocol provides location-based connectivity to Wi-Fi devices with minimum changes to Remote Authentication Dial-In User Service (RADIUS) and Wi-Fi Protected Access 2 (WPA2) protocol by using VLC.

Phosphor-free InGaN/AlGaN core-shell nanowire light-emitting diodes (LEDs) grown by molecular beam epitaxy have been developed and their application in visible light communication (VLC) has been investigated. The electroluminescence spectra of these nanowire LEDs show a very broad spectral linewidth and fully covers the entire visible spectrum. High-brightness phosphor-free LEDs with highly stable white-light emission and high color-rendering index (CRI) of >98 were obtained by controlling the Indium composition in the device active region. Moreover, the phosphor-free nanowire white-LEDs exhibit relatively high 3-dB frequency bandwidth of ~ 1.4 MHz which is higher compared to that of phosphor-based white LEDs at the same measurement condition. Such high-performance phosphor-free nanowire LEDs are being further improved and are ideally suited for future smart lighting applications and communications.

- by Moab Rajan Philip
- •
- III-V Semiconductors, Optoelectronics, Nanowires, Visible Light Communication
- by Paul Anthony Haigh and +1
- •
- Distributed Computing, Optical Communication, Organic light emitting diodes, Modulation

— Free-standing nonpolar GaN substrates provide an excellent platform for the fabrication of high-speed blue and green light-emitting diodes (LEDs), which are attractive for visible-light communication, plastic optical fiber communication, and short-range under water optical communication. Nonpolar LEDs on free-standing GaN exhibit a large electron-hole wave function overlap, low extended defect density, and favorable thermal properties. Here, we demonstrate high-speed nonpolar InGaN/GaN LEDs with a peak emission wavelength between 455 and 465 nm on free-standing nonpolar GaN substrates. A large frequency modulation bandwidth of 524 MHz is demonstrated at a current density of 10 kA/cm 2 .

- by Morteza Monavarian
- •
- Electrical Engineering, Physics, Electronics, Semiconductor Devices

Perkembangan teknologi menciptakan banyak inovasi, salah satunya adalah lampu rumah berbasis LED yang nantinya tidak hanya digunakan sebagai penerangan saja tetapi juga untuk media komunikasi.Cahaya LED digunakan untuk pemanfaatan Visible Light Communication sebagai pengiriman berbasis teks.
Sistem visible light communication dapat memungkinkan untuk pengiriman data berbasis teks. Pada blok Transmiter terdiri atas pengirim informasi atau client 1 , USB-to-TTL , software pengirim teks yaitu Hyper terminal Communication, serta sumber radiasi berupa LED. Pada blok bagian Receiver terdiri atas photodioda , software penerima teks, USB-to-TTL dan penerima informasi atau Client 2. Hasil dari proyek akhir ini adalah dapat mengirim data berupa teks melalui komputer 1 ke
komputer 2 menggunakan sistem VLC. Parameter uji keberhasilan adalah jarak pengiriman dapat mencapai 2 meter, karakter yang dikirim adalah huruf a sampai z serta angka.

- by Hareeshma Balan
- •
- Wireless Communications, Visible Light Communication, Vlc, Optical Wireless