scholarly journals Optimized Analog Multi-Band Carrierless Amplitude and Phase Modulation for Visible Light Communication-Based Internet of Things Systems

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2537
Author(s):  
Luis Rodrigues ◽  
Mónica Figueiredo ◽  
Luis Nero Alves
Keyword(s):  
Internet Of Things ◽  
Visible Light ◽  
Pulse Shaping ◽  
Matched Filter ◽  
Low Cost ◽  
Visible Light Communication ◽  
Analog Filters ◽  
Shaping Filter ◽  
Butterworth Filters ◽  
Multi Band

This paper presents a multi-user Visible Light Communication (VLC)-based Internet of Things (IoT) system using multi band-Carrierless Amplitude and Phase (m-CAP) modulation for IoT applications. The proposed system uses a digital m-CAP modulator embedded in a ceiling LED light fixture and analog receivers, aiming at low-cost, low-power, and small-sized IoT devices. The performance was evaluated in terms of the filtering stage design and the usage of guard bands. Different pairs of emitter and receiver filters were considered. While Bessel and Butterworth analog filters were tested in the analog receiver, the digital m-CAP modulator pulse shaping filter considered raised cosine filters, as well as digital matched filters for the analog Bessel and Butterworth filters. Regarding the guard bands, two approaches were considered: either by using the raised cosine roll-off factor (bandwidth compression) or by suppressing the even bands. The Bit Error Rate (BER) performance was obtained by simulation. The usage of the Bessel filter in the receiver, along with a digital matched filter, proved to be the best solution, achieving a BER lower than 10−3 for an Eb/No of 6 dB, using a third-order filter. Furthermore, guard bands should be used in order to mitigate inter-band interference in order to have improved performance when multiple users intend to simultaneously communicate.

Multi-band transmission color filters for multi-color white LEDs based visible light communication

2017 ◽  
Vol 403 ◽  
pp. 330-334 ◽  
Author(s):  
Qixia Wang ◽  
Zhendong Zhu ◽  
Huarong Gu ◽  
Mengzhu Chen ◽  
Qiaofeng Tan
Keyword(s):  
Visible Light ◽  
Visible Light Communication ◽  
White Leds ◽  
Color Filters ◽  
Multi Band

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.

An Integrated High-Speed Full Duplex Coherent OFDM-PON and Visible-Light Communication System

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Simarpreet Kaur ◽  
Mahendra Kumar ◽  
Ashu Verma
Keyword(s):  
Visible Light ◽  
Optical Networks ◽  
High Speed ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Dispersion Compensation ◽  
Optical Network ◽  
Visible Light Communication ◽  
Passive Optical Network ◽  
Full Duplex

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.

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.

scholarly journals Towards Federated Learning-Enabled Visible Light Communication in 6G Systems

2021 ◽  
Author(s):  
Shimaa Naser ◽  
Lina Bariah ◽  
sami muhaidat ◽  
Mahmoud Al-Qutayri ◽  
Ernesto Damiani ◽  
...  
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
High Speed ◽  
Large Scale ◽  
Low Cost ◽  
Visible Light Communication ◽  
Future Research ◽  
Communication Overhead ◽  
Green Communications ◽  
Raw Data

<div>Visible light communication is envisaged as a promising enabling technology for sixth generation (6G) and beyond networks. It was introduced as a key enabler for reliable massive-scale connectivity, mainly thanks to its simple and low-cost implementation which require minor variations to the existing indoor lighting systems. The key features of VLC allow offloading data traffic from the current congested radio frequency (RF) spectrum in order to achieve effective short-range, high speed, and green communications. However, several challenges prevent the realization of the full potentials of VLC, namely the limited modulation bandwidth of light emitting diodes, the interference resulted from ambient light, the effects of optical diffuse reflection, the non-linearity of devices, and the random receiver orientation. Meanwhile, centralized machine learning (ML) techniques have exhibited great potentials in handling different challenges in communication systems. Specifically, it has been recently shown that ML algorithms exhibit superior capabilities in handling complicated network tasks, such as channel equalization, estimation and modeling, resources allocation, opportunistic spectrum access control, non-linearity compensation, performance monitoring, detection, decoding/encoding, and network optimization. Nevertheless, concerns relating to privacy and communication overhead when sharing raw data of the involved clients with a server constitute major bottlenecks in large-scale implementation of centralized ML techniques. This has motivated the emergence of a new distributed ML paradigm, namely federated learning (FL). This method can reduce the cost associated with transferring the raw data, and preserve clients privacy by training ML model locally and collaboratively at the clients side. Thus, the integration of FL in VLC networks can provide ubiquitous and reliable implementation of VLC systems. Based on this, for the first time in the open literature, we provide an overview about VLC technology and FL. Then, we introduce FL and its integration in VLC networks and provide an overview on the main design aspects. Finally, we highlight some interesting future research directions of FL that are envisioned to boost the performance of VLC systems. </div>

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