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)). 

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 An Efficient Data Transmission with GSM-MPAPM Modulation for an Indoor VLC System

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1232 ◽  
Author(s):  
Bao ◽  
Hsu ◽  
Tu
Keyword(s):  
Visible Light ◽  
Short Distance ◽  
Pulse Width Modulation ◽  
Pulse Amplitude ◽  
Visible Light Communication ◽  
Spatial Modulation ◽  
Theoretical Scheme ◽  
Error Ratio ◽  
Bit Error Ratio ◽  
Dimming Control

As an emerging wireless communication technique, visible light communication is experiencing a boom in the global communication field, and the dream of accessing to the Internet with light is fast becoming a reality. The objective of this study was to put forward an efficient and theoretical scheme that is based on generalized spatial modulation to reduce the bit error ratio in indoor short-distance visible light communication. The scheme was implemented while using two steps in parallel: (1) The multi-pulse amplitude and the position modulation signal were generated by combining multi-pulse amplitude modulation with multi-pulse position modulation using transmitted information, and (2) certain light-emitting diodes were activated by employing the idea of generalized spatial modulation to convey the generated multi-pulse amplitude and position modulation optical signals. Furthermore, pulse width modulation was introduced to achieve dimming control in order to improve anti-interference ability to the ambient light of the system. The two steps above involved the information theory of communication. An embedded hardware system, which was based on the C8051F330 microcomputer and included a transmitter and a receiver, was designed to verify the performance of this new scheme. Subsequently, the verifiability experiment was carried out. The results of this experiment demonstrated that the proposed theoretical scheme of transmission was feasible and could lower the bit error ratio (BER) in indoor short-distance visible light communication while guaranteeing indoor light quality.

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 Li-Pos: A Light Positioning Framework Leveraging OFDM for Visible Light Communication

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4310
Author(s):  
Jianbin Wu ◽  
Sami Ahmed Haider ◽  
Muhammad Irshad ◽  
Jehangir Arshad ◽  
Sohail M. Noman ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Orthogonal Frequency Division Multiplexing ◽  
Pulse Width Modulation ◽  
Light Emitting Diode ◽  
Area Under The Curve ◽  
Visible Light Communication ◽  
Delay Spread ◽  
Entire Area ◽  
Receiver Plane

The design of solid-state lighting is vital, as numerous metrics are involved in their exact positioning, and as it is utilized in various processes, ranging from intelligent buildings to the internet of things (IoT). This work aims to determine the power and delay spread from the light source to the receiver plane. The positions of the light source and receiver were used for power estimation. We focus on analog orthogonal frequency-division multiplexing (OFDM) in visible light communication (VLC) and assess the area under the curve (AUC). The proposed system was designed using modulation techniques (i.e., quadrature amplitude modulation; QAM) for visible light communication (VLC) and pulse-width modulation (PWM) for dimming sources. For the positioning and spreading of brightness, the proof-of-concept was weighted equally over the entire area. Therefore, the receiver plane was analyzed, in order to measure the power of each light-emitting diode (LED) in a given area, using the delayed mean square error (MSE). A framework was applied for the placement of LEDs, using full-width at half-maximum (FWHM) parameters with varying distances. Then, the received power was confirmed. The results show that the AUC using DRMS values for LEDs significantly increased (by 30%) when the number of source LEDs was changed from four to three. These results confirm that our system, associated with the simple linear lateration estimator, can achieve better energy consumption.

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

FSO-Based Analysis of LTE-A MAC Protocols to Achieve Improved QoS

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Prabhjot Kaur ◽  
Hardeep Singh Saini
Keyword(s):  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Optical Signal ◽  
Transmission Efficiency ◽  
Mac Protocols ◽  
Wireless Access Networks ◽  
Free Space Optical ◽  
Medium Access ◽  
Carrier Sense ◽  
Efficient Data

AbstractFiber wireless (Fi-Wi) communication network is the amalgamation of optical and wireless access networks, which provides better bandwidth for achieving efficient data transmission. Medium access control (MAC) protocols are used in the wireless network for controlling the data flow from the transmitter to the receiver end. The delay produced by these protocols tells about the system efficiency. This paper shows a Fi-Wi system in the long-term evaluation-advanced (LTE-A) environment, which incorporates the dependency of delay generated by the specific MAC protocols during the transmission process. This paper aimed to scrutinize the effects of Carrier Sense Multiplexing Access with Collision Detection (CSMA/CD), Carrier Sense Multiplexing Access with Collision Avoidance (CSMA/CA) and Slotted ALOHA on the performance of the Fi-Wi system. Free space optical (FSO) channel is incorporated to forward the data to user end. In such system, the optical signal is multiplexed using the Orthogonal Frequency Division Multiplexing (OFDM) technique and finally the data are fetched at the receiver end and different criterions such eye-height, Q-factor and bit error rate are evaluated. Simulation results are performed using MATLAB software. The comparative analysis is also performed in terms of data transmission efficiency, delay and throughput of MAC protocols. This shows the effective results of the proposed system according to the delay produced by MAC protocols.

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