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 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 Constant Transmission Efficiency Dimming Control Scheme for VLC Systems

Photonics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Jia-Ning Guo ◽  
Jian Zhang ◽  
Gang Xin ◽  
Lin Li
Keyword(s):  
Visible Light Communication ◽  
Transmission Efficiency ◽  
Error Performance ◽  
Constant Weight ◽  
Block Coding ◽  
Control Scheme ◽  
Control Schemes ◽  
Indoor Wireless ◽  
Communication Function ◽  
Dimming Control

As a novel mode of indoor wireless communication, visible light communication (VLC) should consider the illumination functions besides the primary communication function. Dimming control is one of the most crucial illumination functions for VLC systems. However, the transmission efficiency of most proposed dimming control schemes changes as the dimming factor changes. A block coding-based dimming control scheme has been proposed for constant transmission efficiency VLC systems, but there is still room for improvement in dimming range and error performance. In this paper, we propose a dimming control scheme based on extensional constant weight codeword sets to achieve constant transmission efficiency. Meanwhile, we also provide a low implementation complexity decoding algorithm for the scheme. Finally, comparisons show that the proposed scheme can provide a wider dimming range and better error performance.

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 Hybrid modulation schemes for data transmission improvement of indoor visible light communication system

2018 ◽  
Vol 7 (4) ◽  
pp. 2822 ◽  
Author(s):  
Abdelhalim Zekry ◽  
Christena Ghandour ◽  
Nazmi A. Mohammed ◽  
S El-Rabaie
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Pulse Width Modulation ◽  
Mathematical Formulation ◽  
Visible Light Communication ◽  
Pulse Position Modulation ◽  
Dimming Control ◽  
Efficient Data ◽  
Modulation Schemes

This work enhances the bit rate characteristics, receiver sensitivity and power requirements of multicarrier modulation schemes (MCM) for visible light communication (VLC) dimming control system at bit error rate (BER) less than 10-3. This study develops the mathematical formulation for merging pulse position modulation (PPM) and overlapping pulse position modulation (OPPM) with M-ary quadrature amplitude modulation DC-Biased optical orthogonal frequency division multiplexing (M-QAM DCO OFDM), which can achieve efficient data transmission while maintaining communication quality. These schemes are then compared with the conventional merging (i.e M-QAM DCO OFDM with pulse width modulation (PWM)). Relating to the recent advances in the field, the additional comparative study is established with the latest merging platform (i.e. M-QAM DCO OFDM with multiple pulse position modulation (MPPM)). 

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 A Simulation Analysis for LED Spatial Distribution for Indoor Visible Light Communication

2021 ◽  
Author(s):  
Ala Khalifeh ◽  
Karthikeyan Alakappan ◽  
Barath kumar ◽  
Jayanth Prabakaran ◽  
Prabagarane Nagaradjane
Keyword(s):  
Light Intensity ◽  
Visible Light ◽  
Data Transmission ◽  
Video Transmission ◽  
Performance Metrics ◽  
Simulation Analysis ◽  
Video Quality ◽  
Visible Light Communication ◽  
Transmission Efficiency ◽  
High Rate

Abstract Visible light communication (VLC) is a promising technology that can jointly be used to accomplish the typical lighting functionalities of the light-emitting diodes (LEDs) and data transmission, where light intensity can be modulated on a high rate that cannot be noticed by the human eye. In this paper, a VLC simulation framework to study the effect of LEDs’ distributions on different room dimensions is proposed by considering the performance metrics such as light intensity quality in accordance with the International Organization for Standardization (ISO) recommendation, and data transmission efficiency measured in terms of bit error rate (BER). To achieve the abovementioned performance metrics, a VLC communication system is designed that modulates the data, transmits it over the room utilizing the communication channel that is modeled using an accurate ray-tracing algorithm, and receives it by exploiting different receivers that are uniformly distributed in the room. Our work is different from the other published works which either studied the data transmission efficiency or lighting quality but not both. Consequently, this study can be used as a methodological foundation to design an efficient VLC that satisfies the ISO lighting requirement, application-specific BER and quality. Furthermore, a video transmission use case has been demonstrated which shows how the video quality can be significantly improved when increasing the number of transmitters, thus justifying the need for increasing the number of transmitters in scenarios that involves video transmission in an indoor VLC environment.

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
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