scholarly journals A simplified approach for single carrier visible light communication transceiver using off-the-shelf components

2020 ◽  
Vol 1 (2) ◽  
pp. 64-70
Author(s):  
Augustus Ibhaze ◽  
Patience Orukpe ◽  
Frederick Edeko

Over the past decades, the demand for high-speed data transmission has grown exponentially, necessitating broadband technology integration to satisfy the emerging data-hungry society. This concern has engendered the proposition of a simplified optical wireless transceiver module using off-the-shelf electronic devices. According to the transistor to transistor logic levels, the transmitter module was made up of a single negative-positive-negative (NPN) transistor operated as a switch to drive an off-the-shelf 12V 5W light-emitting diode (LED). In contrast, the receiver was made up of a photodetector (solar) module for photons detection and back-conversion to electrical signals. The received signal was passed through a four-stage amplification process to remove the ambient noise and retrieve the data signal. The last transceiver module was demonstrated using personal computers. It was observed to perform at different optimum points consistent with exposure to fluorescent light, daytime, and night-time operations consequent upon the induced ambient light interference at data rates constrained by the communication device interface.

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Shuangshuang Li ◽  
Yang Guo

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.


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.


2014 ◽  
Vol 12 (1) ◽  
pp. 010605-10608 ◽  
Author(s):  
Nan Chi Nan Chi ◽  
Yuanquan Wang Yuanquan Wang ◽  
Yiguang Wang Yiguang Wang ◽  
Xingxing Huang Xingxing Huang ◽  
Xiaoyuan Lu Xiaoyuan Lu

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Xinyue Guo ◽  
Yang Guo ◽  
Shuangshuang Li

Light-emitting diode- (LED-) based visible light communication (VLC) has become a potential candidate for next generation high-speed indoor wireless communication. Due to the limited modulation bandwidth of the LED, orthogonal frequency division multiplexing (OFDM) modulation is particularly preferred in the VLC system to overcome the ISI, which suffers from the high peak-to-average power ratio (PAPR) and leads to severe performance loss. In this paper, we propose and experimentally demonstrate a novel Zadoff-Chu matrix (ZCM) precoding scheme, which can not only reduce the PAPR, but also provide uniform signal-to-noise ratio (SNR) profile. The theoretical analysis and simulation show that the proposed scheme achieves better PAPR performance compared with the traditional precoding schemes. The experimental demonstration further validates the bit error rate (BER) performance improvement, where the measured BERs are all below the 7% pre-forward error correction (pre-FEC) limit of 3.8 × 10−3 when the transmitted data rate is 50 Mb/s.


Author(s):  
Maad Mohsin Mijwil

Visible light communication (VLC) also known as "Li-Fi", uses standard LEDs to transmit data such as information, images, music, and videos. The first LED was developed in 1927 by Oleg Vladimírovich Lósev (1903-1942), however it was not used in the industry until the 1960s.In this paper, will describe the implementation of Modified Phase Equalization (MPH) on visible white LED lamps signal because it's has slow transition time that severely limits in the communication system data speeds with phase equalization that increases the bandwidth of the LED modulation. Employ two filters with Modified Phase Equalization: first, Complementary (C) filter to combine between all kinds moving signals and second, finite impulse response (FIR) filter to obtain all coefficients that respective. Implementation in two phases: first, frequency 150KHz with number of signals 15000 signals and second, doubling frequency 300KHz with number of signals 30000 signals of LEDs without losing their main functionality as illumination sources.


2021 ◽  
Vol 11 (24) ◽  
pp. 11582
Author(s):  
Julian Webber ◽  
Abolfazl Mehbodniya ◽  
Rui Teng ◽  
Ahmed Arafa ◽  
Ahmed Alwakeel

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yingjun Zhou ◽  
Jianyang Shi ◽  
Zhixin Wang ◽  
Junwen Zhang ◽  
Xingxing Huang ◽  
...  

We propose quasi-linear preequalization to be used for high speed visible light communication (VLC) system. Compared with zero-forcing preequalization, this kind of preequalization method is more suitable for a real VLC experimental system with peak power limitation. We carry out simulations and experiments to test the performance of quasi-linear preequalization. With this equalizer, the 3 dB bandwidth of the system can be extended from 17 MHz to 450 MHz. We implement 2.32 Gbit/s phosphorescent white light-emitting diode (LED) VLC transmission over 1 m distance with quasi-linear equalizer, bit and power loading OFDM, differential amplification positive intrinsic negative diode (PIN) receivers, and maximum ratio combining algorithm. To our knowledge, this is the highest transmission data rate based on a phosphorescent white LED VLC system.


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.


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