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.

Dimming controlled multi header pulse position modulation (MH-PPM) for visible light communication system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sandip Das ◽  
Soumitra Kumar Mandal
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Input Data ◽  
Visible Light Communication ◽  
Experimental Results ◽  
Pulse Position Modulation ◽  
Light Sources ◽  
Error Performance ◽  
Control Scheme ◽  
Dimming Control

Abstract Visible light communication (VLC) has recently drawn more attention due to the existing light sources having a bandwidth that can deliver data transmission at higher bit rates. To maintain desired brightness levels along with reliable data transmission, VLC requires to control dimming levels. In this paper, a dimming control scheme based on pulse position modulation (PPM) is proposed, which constructs a dimming encoded frame per symbol of input data. The scheme utilizes multiple headers, which is selected depending on the dimming levels and the number of bits in a symbol of input data. The proposed scheme for the VLC system supports various dimming levels. The multi header PPM frame generation for input data K = 4 $K=4$ and dimming values α = 0.25, 0.375, and 0.5 is simulated using NI Labview. The proposed dimming scheme has an excellent short-run length property which is well under the maximum flickering time period and is thus capable of flicker mitigation. The slot error performance of the proposed dimming control scheme in a VLC system for varying dimming levels is simulated in Matlab. Simulation results show that the proposed scheme has excellent error performance for a low dimming value of α = 0.25. The experimental results are also carried out in the optisystem considering the practical measured parameters of the indoor environment for free space channel and simulating the VLC system for the proposed scheme. The simulation is carried for different data rates over varying link ranges and the experimental results show that the proposed scheme performs best when dimming value α = 0.25 and data rate 2 Gbps.

scholarly journals A Novel Coding Based Dimming Scheme with Constant Transmission Efficiency in VLC Systems

2019 ◽  
Vol 9 (4) ◽  
pp. 803 ◽  
Author(s):  
Yu Zuo ◽  
Jian Zhang
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Visible Light Communication ◽  
Transmission Efficiency ◽  
Reliable Data ◽  
Error Performance ◽  
Block Coding ◽  
Dimming Control ◽  
Transmitted Signal ◽  
Simulation Results

Visible light communication (VLC) has attracted tremendous attention due to two functions: communication and illumination. Both reliable data transmission and lighting quality need to be considered when the transmitted signal is designed. To achieve the desired levels of illumination, dimming control is an essential technology applied in VLC systems. In this paper, we propose a block coding-based dimming scheme to construct the codeword set, where dimming control can be achieved by changing the ratio of two levels (ON and OFF) based on on-off keying (OOK) modulation. Simulation results show that the proposed scheme can maintain good error performance with constant transmission efficiency under various dimming levels.

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 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 Joint Error-Dimming Control Using Constant Weight Coding in Visible Light Communication Systems

2018 ◽  
Vol 173 ◽  
pp. 02019
Author(s):  
Yu Zuo ◽  
Jian Zhang
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Communication Systems ◽  
Hamming Distance ◽  
Visible Light Communication ◽  
Reliable Data ◽  
Error Performance ◽  
Constant Weight ◽  
Constant Weight Code ◽  
Dimming Control

To enhance commercial implementation, visible light communication (VLC) should facilitate dimming control and reliable data transmission simultaneously, where users can adjust the brightness levels arbitrarily. Constant weight code (CWC) based dimming method can achieve higher spectral efficiency, but the codewords need further selection to exponentially map the massage. In this paper, based on CWC, we proposed a method to achieve dimming control as well as improve error performance via optimizing the average Hamming distance of the codeword set. Simulation results show that the optimal codeword set can achieve better error performance.

scholarly journals Power Distribution and BER in Indoor VLC with PPM Based Modulation Schemes: A Comparative Study

2018 ◽  
Author(s):  
Suzan M. El-Garhy ◽  
Heba Fayed ◽  
Moustafa Aly
Keyword(s):  
Light Source ◽  
Power Distribution ◽  
Direct Detection ◽  
Optical Power ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Pulse Position Modulation ◽  
Bit Rate ◽  
Error Performance ◽  
Power Requirement

Visible Light Communication (VLC) uses an intensity-modulation and direct-detection (IM/DD) scheme to transmit data. The light source utilized in VLC structures is constantly switched on and off rapidly, resulting in flickering. Furthermore, most of illumination systems exclude dimming support to permit customers to dim the light source to the desired stage. Therefore, the modulation scheme for information transmission in VLC should consist of flicker mitigation and dimming manage abilities. Double inverse pulse position modulation (DIPPM), sub-carrier pulse position modulation (SC-L-PPM), and M-ary variable pulse position modulation (M-VPPM) are recommended for minimizing the flicker issues and supporting an excessive degree of dimming for VLC systems. In this paper, a comparison is introduced between DIPPM, SC-L-PPM, and M-VPPM according to error performance and bit rate. In addition, a simulation is carried out to measure the optical power distribution for a LED lamp in an indoor room topology for each modulation technique. The obtained results indicated that SC-L-PPM is the best choice regarding the bit error rate (BER) and optical power distribution compared to the other two schemes. A 10-6 BER is achieved with a very low power requirement at L=8, while a remarkable power distribution of 1.5 to 6.5 dBm is observed from 3×5×5 m3 room corners to the center, respectively. According to the bit rate, it is noticed that, M-VPPM is the most efficient one compared to the two other schemes. It achieves 2.3×107 bps at signal to noise ratio (SNR) of 22 dB and M=8.

Hybrid Radio and Visible Light Communications in Inter-Vehicle Communication

2014 ◽  
Vol 548-549 ◽  
pp. 1166-1172
Author(s):  
Xiao An Huang ◽  
Chika Sugimoto ◽  
Ryuji Kohno
Keyword(s):  
Visible Light ◽  
Spread Spectrum ◽  
Power Efficiency ◽  
Average Power ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Intelligent Transport System ◽  
Visible Light Communications ◽  
Radio Communications ◽  
Vehicle Communication

We firstly propose a hybrid-Radio-and-Visible-Light-Communication (HR-VLC) system in Inter-Vehicle Communication (IVC) employing Spread-Spectrum (SS) for better ranging and larger capacity. IVC, a key in Intelligent Transport System (ITS), is intended to improve the better safety and more convenient user experience. In the IVC, Radio communications system may not guarantee the precise ranging and large capacity. Thanks to the VLC with a good directionality and ubiquitous LEDs, a HR-VLC will support a reliable and better ranging system for IVC. Furthermore, the utilization of SS helps reduce the interference of ambient light proportionally to the processing gain. In the HR-VLC in IVC system, PPM is used as a modulation scheme due to high average power efficiency. It is verified that the proposed system achieves better BER performance and more precise ranging.

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

An approach to ensure joint illumination & communication performance of a forward error corrected indoor visible light communication (VLC) system in presence of ambient light interference

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sourish Chatterjee ◽  
Biswanath Roy
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Ambient Light ◽  
Ambient Illumination ◽  
Communication Performance ◽  
Light Interference ◽  
Forward Error

AbstractIn recent time of looming radio frequency (RF) spectrum crisis, visible light communication using lighting infrastructure emerged as a potential alternative at an indoor environment. This paper addresses the setback associated with ambient light interference in an indoor Visible Light Communication (VLC) system to ensure joint communication and illumination performance inside an office room. A novel VLC architecture with suitable white light emitting diode (WLED) luminaire arrangement is presented to minimize the dispersion of signal to interference plus noise ratio (SINR) across the room. Luminaires are categorized in two groups viz. data transmitting illuminants and illuminants for lighting purpose. The first group is dedicated to transmit data as well as serves the purpose of illumination. The other set creates only ambient illumination to achieve quality lighting attributes. The proposed forward error corrected receiver configuration discards the ambient light noise originated by the illuminants that serve the ambient illumination. Tail biting convolutional encoder and viterbi decoder are used at the encoding section of the transmitter and decoding section of the receiver respectively to improve bit error rate. Results obtained through MATLAB simulation shows better average bit error rate (BER) in the order of 10−8 measured at uniformly distributed 25 grid points over the working plane. At the same time achieved average horizontal illuminance with good uniformity comply with ISO recommendation.

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