scholarly journals Color-Independent Visible Light Communications Based on Color Space: State of the Art and Potentials

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 190 ◽  
Author(s):  
Tae-Ho Kwon ◽  
Jai-Eun Kim ◽  
Youn-Hee Kim ◽  
Ki-Doo Kim
Keyword(s):  
Visible Light ◽  
Mimo System ◽  
Color Space ◽  
Past Research ◽  
Visible Light Communication ◽  
Color Variation ◽  
Target Color ◽  
Visible Light Communications ◽  
Potential Applicability ◽  
Dimming Control

Color independency is an important factor in visible light communication (VLC) systems. This paper aims to review and summarize recent achievements in color-independent visible light communication based on color space, with the main focus being on color-space-based modulation (CSBM), termed as generalized color modulation (GCM), which allows VLC to adapt to any target color. The main advantages of GCM are its color independency, reasonable bit error rate (BER) performance during color variation, and dimming control. We also address our past research works that aimed to achieve a color-independent visual MIMO system by incorporating the advantages of GCM, which can lead to higher data rates over longer distances and improved performance, using image processing in addition to color independency. Finally, two case studies are introduced to demonstrate the potential applicability of a color-independent visual-MIMO system using color-space-based modulation techniques.

scholarly journals Modeling and Analysis of DIPPM: A New Modulation Scheme for Visible Light Communications

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sana Ullah Jan ◽  
Young-Doo Lee ◽  
Insoo Koo
Keyword(s):  
Visible Light ◽  
Direct Detection ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Light Sources ◽  
Visible Light Communications ◽  
Error Performance ◽  
Communication Performance ◽  
Modeling And Analysis ◽  
Dimming Control

Visible Light Communication (VLC) uses an Intensity-Modulation and Direct-Detection (IM/DD) scheme to transmit data. However, the light source used in VLC systems is continuously switched on and off quickly, resulting in flickering. In addition, recent illumination systems include dimming support to allow users to dim the light sources to the desired level. Therefore, the modulation scheme for data transmission in VLC system must include flicker mitigation and dimming control capabilities. In this paper, the authors propose a Double Inverse Pulse Position Modulation (DIPPM) scheme that minimizes flickering and supports a high level of dimming for the illumination sources in VLC systems. To form DIPPM, some changes are made in the symbol structure of the IPPM scheme, and a detailed explanation and mathematical model of DIPPM are given in this paper. Furthermore, both analytical and simulation results for the error performance of 2-DIPPM are compared with the performance of VPPM. Also, the communication performance of DIPPM is analyzed in terms of the normalized required power.

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 Switching MIMO System with Adaptive OFDM Modulation for Indoor Visible Light Communication

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Keer Zhang ◽  
Xufa Huang
Keyword(s):  
Visible Light ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Mimo System ◽  
Transmit Diversity ◽  
Visible Light Communication ◽  
Spatial Multiplexing ◽  
Visible Light Communications ◽  
Ofdm Modulation ◽  
Adaptive Ofdm

In this paper, we propose and experimentally demonstrate a switching multiple input and multiple output (MIMO) system combining with adaptive orthogonal frequency division multiplexing (OFDM) modulation for high-speed indoor visible light communications. The adaptive OFDM modulation, which is realized by power and bit allocation on OFDM subchannels, is utilized to achieve the maximum channel capacity under a given target bit error rate (BER). Meanwhile, the MIMO mode switches between spatial multiplexing and transmit diversity adapting to the channel correlation, where the modulation order solved by adaptive OFDM modulation is chosen as the switching criterion. Experimental results validate data rates improvement over the pure spatial multiplexing and the pure transmit diversity system, where BERs are all below the 7% preforward error correction (pre-FEC) threshold of 3.8 × 10−3 in experiments.

A CDMA system implementation with dimming control for visible light communication

2018 ◽  
Vol 412 ◽  
pp. 172-177 ◽  
Author(s):  
Danyang Chen ◽  
Jianping Wang ◽  
Jianli Jin ◽  
Huimin Lu ◽  
Lifang Feng
Keyword(s):  
Visible Light ◽  
Visible Light Communication ◽  
Cdma System ◽  
System Implementation ◽  
Dimming Control

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.

Dimming control scheme based on hybrid LACO-SCFDM for visible light communications

2021 ◽  
Vol 19 (4) ◽  
pp. 040601
Author(s):  
Siqiao Li ◽  
Tiantian Zhang ◽  
Yaojun Qiao ◽  
Ji Zhou
Keyword(s):  
Visible Light ◽  
Visible Light Communications ◽  
Control Scheme ◽  
Dimming Control

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.

Constellation design for color space-based modulation in visible light communications

2018 ◽  
Vol 31 ◽  
pp. 154-159
Author(s):  
D.U. Campos-Delgado ◽  
J.M. Luna-Rivera ◽  
R. Perez-Jimenez ◽  
C.A. Gutierrez ◽  
V. Guerra ◽  
...  
Keyword(s):  
Visible Light ◽  
Color Space ◽  
Visible Light Communications ◽  
Constellation Design
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