scholarly journals Energy-Efficient Optimization Design for the Multi-Color LED Based Visible Light Communication Systems under Illumination Constraints

2018 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Yu Zuo ◽  
Jian Zhang
Keyword(s):  
Energy Consumption ◽  
Visible Light ◽  
Power Allocation ◽  
Communication Systems ◽  
Optimization Design ◽  
Optical Power ◽  
Visible Light Communication ◽  
Visible Light Communications ◽  
Allocation Scheme ◽  
High Modulation

Visible light communications (VLCs) utilizing multi-color light-emitting diodes (LEDs) can achieve a high modulation bandwidth and high-quality illumination compared with phosphor-converted LEDs, which have attracted much attention. However, the spectrum overlapping of different colors may cause the crosstalk problem, which should be considered in the practical multi-color LED-based VLC systems. Due to the ever-increasing energy consumption, the interest in an energy-saving communication technique has further increased. In this paper, in order to maximize energy efficiency, an optimization problem of the optical power allocation scheme is formulated for the multi-color LED-based VLC systems under the necessary communication requirements and illumination constraints with luminance, chromaticity, and signal to interference plus noise ratio (SINR) constraints. Simulation results indicate that the proposed optimal power allocation scheme can reduce energy consumption while satisfying the illumination and communication requirements.

scholarly journals An ANN-Based Adaptive Predistorter for LED Nonlinearity in Indoor Visible Light Communications

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 948
Author(s):  
Jenn-Kaie Lain ◽  
Yan-He Chen
Keyword(s):  
Visible Light ◽  
Light Emitting Diode ◽  
Optical Power ◽  
Visible Light Communication ◽  
Universal Function ◽  
Visible Light Communications ◽  
Least Mean Square ◽  
Training Sequences ◽  
Led Nonlinearity ◽  
Electrical Source

By modulating the optical power of the light-emitting diode (LED) in accordance with the electrical source and using a photodetector to convert the corresponding optical variation back into electrical signals, visible light communication (VLC) has been developed to achieve lighting and communications simultaneously, and is now considered one of the promising technologies for handling the continuing increases in data demands, especially indoors, for next generation wireless broadband systems. During the process of electrical-to-optical conversion using LEDs in VLC, however, signal distortion occurs due to LED nonlinearity, resulting in VLC system performance degradation. Artificial neural networks (ANNs) are thought to be capable of achieving universal function approximation, which was the motivation for introducing ANN predistortion to compensate for LED nonlinearity in this paper. Without using additional training sequences, the related parameters in the proposed ANN predistorter can be adaptively updated, using a feedback replica of the original electrical source, to track the LED time-variant characteristics due to temperature variation and aging. Computer simulations and experimental implementation were carried out to evaluate and validate the performance of the proposed ANN predistorter against existing adaptive predistorter schemes, such as the normalized least mean square predistorter and the Chebyshev polynomial predistorter.

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 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 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 Adaptive Power Allocation Scheme for Mobile NOMA Visible Light Communication System

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 381 ◽  
Author(s):  
Zanyang Dong ◽  
Tao Shang ◽  
Qian Li ◽  
Tang Tang
Keyword(s):  
Visible Light ◽  
Power Allocation ◽  
Visible Light Communication ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Optimal Power ◽  
Adaptive Power ◽  
Achievable Data Rate ◽  
Fitting Model ◽  
Allocation Factor

Recently, due to its higher spectral efficiency and enhanced user experience, non-orthogonal multiple access (NOMA) has been widely studied in visible light communication (VLC) systems. As a main concern in NOMA-VLC systems, the power allocation scheme greatly affects the tradeoff between the total achievable data rate and user fairness. In this context, our main aim in this work was to find a more balanced power allocation scheme. To this end, an adaptive power allocation scheme based on multi-attribute decision making (MADM), which flexibly chooses between conventional power allocation or inverse power allocation (IPA) and the optimal power allocation factor, has been proposed. The concept of IPA is put forward for the first time and proves to be beneficial to achieving a higher total achievable data rate at the cost of user fairness. Moreover, considering users’ mobility along certain trajectories, we derived a fitting model of the optimal power allocation factor. The feasibility of the proposed adaptive scheme was verified through simulation and the fitting model was approximated to be the sum of three Gaussian functions.

Research of LED Emission Cross-Section on Light Communication Systems

2014 ◽  
Vol 602-605 ◽  
pp. 3039-3042
Author(s):  
Wei Min Qi ◽  
Jie Xiao
Keyword(s):  
Visible Light ◽  
Cross Section ◽  
Power Distribution ◽  
Communication Systems ◽  
Emission Cross Section ◽  
Optical Power ◽  
Visible Light Communication ◽  
Communication Performance ◽  
Light Emitting ◽  
Communication Source

Visible light communication (VLC) is an optical wireless communication technology that uses visible light emitting diodes (LEDs) as a communication source. Since the LEDs are also used for illumination, the cross-section emission effects of the LEDs need to be analyzed as they apply to indoor VLC channels. In order to evaluate the illumination and communication performance according to the emission cross-section pattern, a simple LED model with a quasi-elliptic emission cross-section is proposed and compared to a circular LED model. The LEDs with a quasi-elliptic emission cross-section provide less fluctuation in the illumination and optical power distribution at the receiving plane. The four-transmitter VLC system is found to support at least at 30 and 33 Mb/s for circular and quasi-elliptic emission cross-section LEDs for the entire receiving plane, respectively.

scholarly journals Performance of Outdoor Lamp Implementation for Visible Light Communication under Ambient Environment

2018 ◽  
Author(s):  
Ronaldo Soritua Sitanggang ◽  
Denny Darlis ◽  
Karina Wahyu Noviyanti
Keyword(s):  
Light Intensity ◽  
Visible Light ◽  
Communication Systems ◽  
Optical Power ◽  
Visible Light Communication ◽  
Digital Data ◽  
Maximum Distance ◽  
Optimal Distance ◽  
Types Of Information ◽  
Incandescent Lamps

This article is preprint for ASAIS 2018 - Visible Light Communication is the name given to wireless communication systems that convey information by modulating visible light by the human eye. Interest in the field of VLC has grown rapidly along with the development of LEDs as a source of lighting. The motivation is clear: If the room is lit by an LED, why not use it further for the communication provider, along with the lighting facilities at the same time? At the sending side, VLC technology uses LED lighting lamps which are currently very popular to replace incandescent lamps and TL (Fluorescent Lamp) lamps. Visible light communication has many advantages, including security, speed, and convenience to be applied to users to send various types of information including digital data such as text and images. Several studies have been conducted previously regarding the application of information delivery systems using VLC such as sending voice, digital data, images, and video. However, it has not been clearly stated the influence of various lighting lamps used on the system mentioned above such as electrical and optical power used, the angle of transmission and optimal distance with the influence of environmental conditions that cause information transmission losses. Data that can be sent well use yard lighting with a maximum distance of 130 cm with 15 lx light intensity, street lighting with a maximum distance of 400 cm with 6 lx light intensity, and vehicle lights with a maximum distance of 270 cm with 12 lx light intensity.

scholarly journals Cell Traffic Prediction Based on Convolutional Neural Network for Software-Defined Ultra-Dense Visible Light Communication Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shanjun Zhan ◽  
Lisu Yu ◽  
Zhen Wang ◽  
Yichen Du ◽  
Yan Yu ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Energy Consumption ◽  
Visible Light ◽  
Visible Light Communication ◽  
High Energy ◽  
Training Dataset ◽  
Allocation Scheme ◽  
Control Plane ◽  
Data Plane ◽  
Resource Allocation Scheme

With the explosive growth of ubiquitous mobile services and the advent of the 5G era, ultra-dense wireless network (UDN) architectures have entered daily production and life. However, the massive access capacity provided by 5G networks and the dense deployment of micro base stations also bring challenges such as high energy consumption, high maintenance costs, and inflexibility. Fiber-based visible light communication (FVLC) has the advantages of large bandwidth and high speed, which provides an efficient connection option for UDN. Thus, in order to make up for the poor flexibility of UDN, we propose a new FVLC-UDN architecture based on software-defined networks (SDNs). Specifically, SDN decouples the data plane and the control plane of the device and centralizes the control of the LED in the cell through a unified control plane, which can not only improve the resource allocation ability of the network but also transmit the data only as the data plane, reducing the manufacturing and implementation costs of the LED. In order to get a better resource allocation scheme, this paper proposes a model for predicting cell traffic based on convolutional neural networks. By predicting the traffic of each cell in the control domain, the traffic trend and cells’ status in the future period of time in the control domain can be obtained, so that a much more efficient resource allocation scheme can be formulated proactively to reduce energy consumption and balance communication loads. The experimental results show that on the real cell traffic dataset, this method is better than the existing prediction methods when the size of training dataset is limited.

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