scholarly journals Design of Ethernet-VLC Data Conversion System Based on FPGA

2020 ◽  
Vol 12 (3) ◽  
pp. 69-73
Author(s):  
Guiling Sun ◽  
◽  
Weijian Zhao ◽  
Ruobin Wang ◽  
Xuanjie Li
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Visible Light Communication ◽  
Data Conversion ◽  
Visible Light Communications ◽  
Data Buffer ◽  
Wide Range ◽  
Conversion System ◽  
Buffer Control ◽  
Ethernet Interface

Visible light communication (VLC) has attracted people's attention due to its wide range of spectrum resources and good privacy in recent year. But research on visible light communication is mostly focused on LED materials, transfer protocol, transmission rates, etc. Lack of research that connect the visible light communications with existing communications methods. In this paper, we propose an Ethernet-visible data conversion system based on FPGA, including Ethernet interface logic, bit-width conversion logic, data buffer logic, and visible light communication transceiver logic. The proposed system achieves Ethernet and visible light access, and realizes 1000Mbps Ethernet data and 625Mbps visible light data conversion. Through buffer control, Ethernet data can be completely and reliably transmitted from high speed to low speed. By defining the structure of visible light communication frame and adding data self-recovery mechanism, data transmission has higher stability on the path of visible light. The feasibility of the system is proved by actual measurements.

scholarly journals Li-Fi the Next Generation of Wireless Communication through Visible Light Communication (VLC) Technology

2019 ◽  
pp. 30-37 ◽  
Author(s):  
Imran Siddique ◽  
Muhammad Zubair Awan ◽  
Muhammad Yousaf Khan ◽  
Azhar Mazhar
Keyword(s):  
Wireless Communication ◽  
Visible Light ◽  
Communication System ◽  
High Speed ◽  
Wave Spectrum ◽  
Visible Light Communication ◽  
Visible Light Communications ◽  
Light Emitting ◽  
Wide Range ◽  
Advance Research

Li-Fi stands for Light-Fidelity. This technology is very new and was proposed by the German physicist Harald Haas in 2011. Light based communication system is the backbone of the future of the communication system. Li-Fi is a wireless technology that uses light emitting diodes (LEDs) for transmission of data. The development of the wireless communication leads to advance research in LiFi technology. The term Li-Fi states to visible light communication (VLC) technology that uses as medium to deliver high-speed communication in a fashion similar to Wi-Fi. Li-Fi comprises a wide range of frequencies and wavelengths, from the Infrared through visible and down to the Ultraviolet spectrum. The immense use of Li-Fi may solve some bottleneck of data transmission in Wi-Fi technology. With the innovation in technology and the number of users, the existing radio-wave spectrum fails to accommodate this need. To resolve the issues of scalability, availability and security, we have come up with the concept of transmitting data wirelessly through light using visible light communication (VLC) technology. This paper objective is to study and describe the LiFi technology. The improvement of the wireless communication leads to advance research in LiFi technology through Visible Light Communications (VLC) Technology.

scholarly journals Polymer colour converter with very high modulation bandwidth for visible light communications

2017 ◽  
Vol 5 (35) ◽  
pp. 8916-8920 ◽  
Author(s):  
D. A. Vithanage ◽  
A. L. Kanibolotsky ◽  
S. Rajbhandari ◽  
P. P. Manousiadis ◽  
M. T. Sajjad ◽  
...  
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Visible Light Communication ◽  
Modulation Bandwidth ◽  
Visible Light Communications ◽  
Semiconducting Polymer ◽  
High Modulation ◽  
Very High

We report the synthesis, photophysics and application of a novel semiconducting polymer as a colour converter for high speed visible light communication.

scholarly journals Experimental Demonstration of Special-Shaped 32-Quadrature Amplitude Modulation Constellations for Visible Light Communications

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Shuangshuang Li ◽  
Yang Guo
Keyword(s):  
Visible Light ◽  
Amplitude Modulation ◽  
High Speed ◽  
Light Emitting Diode ◽  
Rapid Development ◽  
Average Power ◽  
Visible Light Communication ◽  
Quadrature Amplitude Modulation ◽  
Visible Light Communications ◽  
Transmission Distance

With the rapid development of light-emitting diode, visible light communication (VLC) has become a candidate technology for the next generation of high-speed indoor wireless communication. In this paper, we investigate the performance of the 32-quadrature amplitude modulation (32-QAM) constellation shaping schemes for the first time, where two special circular constellations, named Circular (4, 11, 17) and Circular (1, 5, 11, 15), and a triangular constellation are proposed based on the Shannon’s criterion. Theoretical analysis indicates that the triangular constellation scheme has the largest minimum Euclidian distance while the Circular (4, 11, 17) scheme achieves the lowest peak-to-average power ratio (PAPR). Experimental results show that the bit error rate performance is finally decided by the value of PAPR in the VLC system due to the serious nonlinearity of the LED, where the Circular (4, 11, 17) scheme always performs best under the 7% preforward error correction threshold of 3.8 × 10−3 with 62.5Mb/s transmission data rate and 1-meter transmission distance.

Researching the Information of Transmission Technology Based on Traffic Lights

2014 ◽  
Vol 644-650 ◽  
pp. 4538-4541
Author(s):  
Qiang Li ◽  
Xin Rui Zhang
Keyword(s):  
Visible Light ◽  
Image Recognition ◽  
Communication Technology ◽  
High Speed ◽  
Visible Light Communication ◽  
Qr Code ◽  
Visible Light Communications ◽  
Traffic Light ◽  
Traffic Lights ◽  
Very High

This design is based on Visible Light Communication Technology, to achieve outdoor visible light communications and image recognition etc. through traffic lights. It will play a role on promoting the utilization of traffic lights. The system uses a LED dot matrix to imitate the traffic light, loading QR Code information on the LED dot matrix and then transporting it in a very high-speed flashing. In receiving terminal, first, webcam OV7670 collects information which from the LED dot matrix, then conveys the picture to FPGA, which is the processor. FPGA will handle the picture by gray scale processing, medium filtering and binary processing at last. Thus, the picture from the LED dot matrix will change to ‘0’ and ‘1’ in binary area. Secondly, as there’s a relationship between LED dot matrix and webcam pixels, we can count how many pixels represent one LED. Finally, we can decode the QR Code based on its own style, and display the final result on the TFT screen.

scholarly journals About Digital Communication Methods for Visible Light Communication

2021 ◽  
Vol 13 (03) ◽  
pp. 01-13
Author(s):  
Wataru Uemura ◽  
Yasuhiro Fukumori ◽  
Takato Hayama
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Pulse Wave ◽  
Low Voltage ◽  
Threshold Value ◽  
Visible Light Communication ◽  
Wave Modulation ◽  
Wide Range ◽  
Pulse Wave Modulation ◽  
Communication Methods

The visible light communication (VLC) by LED is one of the important communication methods because LED can work as high speed and VLC sends the information by high flushing LED. We use the pulse wave modulation for the VLC with LED because LED can be controlled easily by the microcontroller, which has the digital output pins. At the pulse wave modulation, deciding the high and low voltage by the middle voltage when the receiving signal level is amplified is equal to deciding it by the threshold voltage without amplification. In this paper, we proposed two methods that adjust the threshold value using counting the slot number and measuring the signal level. The number of signal slots is constant per one symbol when we use Pulse Position Modulation (PPM). If the number of received signal slots per one symbol time is less than the theoretical value, that means the threshold value is higher than the optimal value. If it is more than the theoretical value, that means the threshold value is lower. So, we can adjust the threshold value using the number of received signal slots. At the second proposed method, the average received signal level is not equal to the signal level because there is a ratio between the number of high slots and low slots. So, we can calculate the threshold value from the average received signal level and the slot ratio. Unfortunately, the first proposed method adjusts the threshold value after receiving the data, once the distance between the sender and the receiver is changed, then the performance becomes worse. And after adjusting the threshold, the performance becomes better. Therefore, this method should be used in stable environments. The second proposed method can change the threshold value during the signal is received. That means this method can work very quickly. So, this method can show good performance for the wide range. We show these performances as real experiments.

scholarly journals Carrierless amplitude and phase modulation in wireless visible light communication systems

2020 ◽  
Vol 378 (2169) ◽  
pp. 20190181 ◽  
Author(s):  
N. Bamiedakis ◽  
R. V. Penty ◽  
I. H. White
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
High Speed ◽  
Low Cost ◽  
Visible Light Communication ◽  
Practical Implementation ◽  
Visible Light Communications ◽  
Modulation Formats ◽  
Spectrally Efficient ◽  
Basic Features

Visible light communications (VLCs) have attracted considerable interest in recent years owing to the potential to simultaneously achieve data transmission and illumination using low-cost light-emitting diodes (LEDs). However, the high-speed capability of such links is typically limited by the low bandwidth of LEDs. As a result, spectrally efficient advanced modulation formats have been considered for use in VLC links in order to mitigate this issue and enable higher data rates. Carrierless amplitude and phase (CAP) modulation is one such spectrally efficient scheme that has attracted significant interest in recent years owing to its good potential and practical implementation. In this paper, we introduce the basic features of CAP modulation and review its use in the context of indoor VLC systems. We describe some of its attributes and inherent limitations, present related advances aiming to improve its performance and potential and report on recent experimental demonstrations of LED-based VLC links employing CAP modulation. This article is part of the theme issue ‘Optical wireless communication’.

scholarly journals Hardware Architectures of Visible Light Communication Transmitter and Receiver for Beacon-based Indoor Positioning Systems

2019 ◽  
Author(s):  
Phuc Duc Nguyen
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Large Scale ◽  
Response Times ◽  
Vlsi Architecture ◽  
Visible Light Communication ◽  
Visible Light Communications ◽  
Soft Decision ◽  
Soft Decoding ◽  
Positioning Systems

High-speed applications of Visible Light Communications have been presented recently in which response times of photodiode-based VLC receivers are critical points. Typical VLC receiver routines, such as soft-decoding of run-length limited (RLL) codes and FEC codes was purely processed on embedded firmware, and potentially cause bottleneck at the receiver. To speed up the performance of receivers, ASIC-based VLC receiver could be the solution. Unfortunately, recent works on soft-decoding of RLL and FEC have shown that they are bulky and time-consuming computations. This causes hardware implementation of VLC receivers becomes heavy and unrealistic. In this paper, we introduce a compact Polar-code-based VLC receivers. in which flicker mitigation of the system can be guaranteed even without RLL codes. In particular, we utilized the centralized bit-probability distribution of a pre-scrambler and a Polar encoder to create a non-RLL flicker mitigation solution. At the receiver, a 3-bit soft-decision filter was implemented to analyze signals received from the VLC channel to extract log-likelihood ratio (LLR) values and feed them to the Polar decoder. Therefore, the proposed receiver could exploit the soft-decoding of the Polar decoder to improve the error-correction performance of the system. Due to the non-RLL characteristic, the receiver has a preeminent code-rate and a reduced complexity compared with RLL-based receivers. We present the proposed VLC receiver along with a novel very-large-scale integration (VLSI) architecture, and a synthesis of our design using FPGA/ASIC synthesis tools.

scholarly journals Multiuser Transmit Precoding Design for Dimming Compatible Visible Light Communications

2019 ◽  
Vol 9 (6) ◽  
pp. 1147
Author(s):  
Baolong Li ◽  
Xiaomei Xue ◽  
Qiong Wu ◽  
Yang Liu ◽  
Guilu Wu ◽  
...  
Keyword(s):  
Visible Light ◽  
Optical Power ◽  
Pulse Amplitude ◽  
Visible Light Communication ◽  
Visible Light Communications ◽  
Zero Forcing ◽  
Multiuser Interference ◽  
Wide Range ◽  
Dimming Control ◽  
Transmit Precoding

In multiuser visible light communication (VLC) systems, many transmit precoding (TPC) techniques have been investigated to suppress multiuser interference. However, these conventional works restrict their modulation to the special case of zero mean, which inherently limits their application to some popular modulations associated with the non-zero mean in VLC, such as pulse position modulation (PPM). Since the modulation with non-zero mean leads to more intricate optical power constraints and design objective functions than the case of zero mean, the TPC design that can support a general modulation is still an open problem. In the paper, we conceive of a general solution of the TPC scheme combined with dimming control for multiuser VLC systems, which is capable of mitigating multiuser interference, while at the same time, achieving the desired dimming level. The proposed scheme is applicable to a wide range of modulations in VLC, such as pulse amplitude modulation (PAM), PPM, and so on. Simulation results demonstrate that the proposed scheme outperforms the traditional pseudo-inverse-based zero-forcing TPC in terms of bit error rate (BER).

scholarly journals Finger-Gesture Recognition for Visible Light Communication Systems Using Machine Learning

2021 ◽  
Vol 11 (24) ◽  
pp. 11582
Author(s):  
Julian Webber ◽  
Abolfazl Mehbodniya ◽  
Rui Teng ◽  
Ahmed Arafa ◽  
Ahmed Alwakeel
Keyword(s):  
Visible Light ◽  
Gesture Recognition ◽  
Video Processing ◽  
Communication Systems ◽  
High Speed ◽  
Short Term Memory ◽  
Light Transmission ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Visible Light Communications

Gesture recognition (GR) has many applications for human-computer interaction (HCI) in the healthcare, home, and business arenas. However, the common techniques to realize gesture recognition using video processing are computationally intensive and expensive. In this work, we propose to task existing visible light communications (VLC) systems with gesture recognition. Different finger movements are identified by training on the light transitions between fingers using the long short-term memory (LSTM) neural network. This paper describes the design and implementation of the gesture recognition technique for a practical VLC system operating over a distance of 48 cm. The platform uses a single low-cost light-emitting diode (LED) and photo-diode sensor at the receiver side. The system recognizes gestures from interruptions in the direct light transmission, and is therefore suitable for high-speed communication. Gesture recognition accuracies were conducted for five gestures, and results demonstrate that the proposed system is able to accurately identify the gestures in up to 88% of cases.

scholarly journals Visible Light Communication System Technology Review: Devices, Architectures, and Applications

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1098
Author(s):  
Tai-Cheng Yu ◽  
Wei-Ta Huang ◽  
Wei-Bin Lee ◽  
Chi-Wai Chow ◽  
Shu-Wei Chang ◽  
...  
Keyword(s):  
Visible Light ◽  
Secure Communication ◽  
High Speed ◽  
Stark Effect ◽  
Visible Light Communication ◽  
Optimal Choice ◽  
Light Sources ◽  
Modulation Bandwidth ◽  
High Data ◽  
Wide Range

Visible light communication (VLC) is an advanced, highly developed optical wireless communication (OWC) technology that can simultaneously provide lighting and high-speed wireless data transmission. A VLC system has several key advantages: ultra-high data rate, secure communication channels, and a lack of interference from electromagnetic (EM) waves, which enable a wide range of applications. Light-emitting diodes (LEDs) have been considered the optimal choice for VLC systems since they can provide excellent illumination performance. However, the quantum confinement Stark effect (QCSE), crystal orientation, carrier lifetime, and recombination factor will influence the modulation bandwidth, and the transmission performance is severely limited. To solve the insufficient modulation bandwidth, micro-LEDs (μ-LEDs) and laser diodes (LDs) are considered as new ideal light sources. Additionally, the development of modulation technology has dramatically increased the transmission capacity of the system. The performance of the VLC system is briefly discussed in this review article, as well as some of its prospective applications in the realms of the industrial Internet of Things (IoT), vehicle communications, and underwater wireless network applications.

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