Proactive link handover deploying coordinated transmission for indoor visible light communications (VLC) networks

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Cong-Nam Tran ◽  
Trong-Minh Hoang ◽  
Nam-Hoang Nguyen

AbstractVisible Light Communications (VLC) is considered as an emerging technology for indoor wireless communications to achieve high-speed and secure data transmission. Instead of using radio frequency (RF) spectrum, VLC uses the visible light spectrum to perform lighting and communications functions simultaneously. Multiple access points VLC (multi-AP VLC) networks use ceiling access point (ceiling-AP) and desk access point (desk-AP) to provide both uniform and spot lighting in order to achieve full coverage and high spectral efficiency. Because mobile user equipment (UE) require seamless connectivity when moving, fast link handover between VLC access points (VLC-AP) has to be supported in the VLC networks. In this paper, we present a coordinated multi-channel transmission method (CMcT) used to improve quality of service (QoS) of cell-edge UEs and propose a novel proactive link handover scheme deploying the CMcT method for multi-AP VLC networks. Performance results obtained by computer simulation show that the proactive link handover scheme deploying the CMcT method can significantly improve user throughput and packet delay comparing with those of other link handover schemes.

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Cong-Nam Tran ◽  
Nam-Hoang Nguyen ◽  
Trong-Minh Hoang

AbstractVisible light communications (VLC) is considered as an alternative communications technology for providing indoor wireless services. VLC systems are expected to offer high data transmission rate and seamless coverage. In order to achieve these requirements, VLC systems utilizing multi-lightbeam access points (multibeam VLC-AP) for downlink transmission have been proposed recently. In this paper, we present a lightbeam configuration method and an interference elimination resource scheduling mechanism (IERS) for indoor multibeam multi-access point VLC systems. The proposed lightbeam configuration method ensures seamless connectivity between user equipment and VLC-AP. The proposed IERS mechanism consists of a beam assignment algorithm and a resource allocation algorithm for eliminating co-channel interference as well as improving system performance. Performance results obtained by computer simulation indicate that there are significant improvements in terms of downlink signal to interference plus noise ratio, user throughput and packet delay when the proposed IERS mechanism is deployed.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saad M. Hardan ◽  
Ayad A. Abdulkafi ◽  
Saadi Hamad Thalij ◽  
Sherine S. Jumaah

Abstract The continued increase in several mobile applications forces to replace existing limited spectrum indoor radio frequency wireless connections with high-speed ones. Visible light communications (VLC) technology has gained prominence in the development of high data rate transmission for fifth-generation networks. In optical wireless communications, light-emitting diode (LED) transmitters are used in applications that desire mobility as LED divergence enables larger coverage. Since each VLC access point covers a small area, handovers of mobile users are inevitable. Wavelength division multiplexing (WDM) can be used in VLC systems to tackle the above issue and to meet the increasing demand for indoor connectivity with high bit rates. In this paper, a new system architecture for WDM with coded modulated optical in orthogonal frequency division multiplexing (OFDM) VLC system in conjunction with red, green, blue, and yellow (RGBY) LEDs is proposed to reduce the impact of random receiver orientation of indoor mobile users over VLC downlink channels and improves the system’s bit-error-rate (BER) performance. Simulation results show that the proposed method is not affected by the user’s mobility and hence it performs better than other approaches, in terms of BER for all scenarios and at all positions. This study reveals that using WDM-OFDM-VLC with RGBY LEDs to construct a VLC system is very promising.


2017 ◽  
Vol 5 (35) ◽  
pp. 8916-8920 ◽  
Author(s):  
D. A. Vithanage ◽  
A. L. Kanibolotsky ◽  
S. Rajbhandari ◽  
P. P. Manousiadis ◽  
M. T. Sajjad ◽  
...  

We report the synthesis, photophysics and application of a novel semiconducting polymer as a colour converter for high speed visible light communication.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Shuangshuang Li ◽  
Yang Guo

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.


2015 ◽  
Vol 13 (8) ◽  
pp. 080605-80609 ◽  
Author(s):  
Honglei Li Honglei Li ◽  
Yini Zhang Yini Zhang ◽  
Xiongbin Chen Xiongbin Chen ◽  
Chunhui Wu Chunhui Wu ◽  
Junqing Guo Junqing Guo ◽  
...  

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2157
Author(s):  
Yousef Almadani ◽  
David Plets ◽  
Sander Bastiaens ◽  
Wout Joseph ◽  
Muhammad Ijaz ◽  
...  

Visible Light Communication (VLC) is a short-range optical wireless communication technology that has been gaining attention due to its potential to offload heavy data traffic from the congested radio wireless spectrum. At the same time, wireless communications are becoming crucial to smart manufacturing within the scope of Industry 4.0. Industry 4.0 is a developing trend of high-speed data exchange in automation for manufacturing technologies and is referred to as the fourth industrial revolution. This trend requires fast, reliable, low-latency, and cost-effective data transmissions with fast synchronizations to ensure smooth operations for various processes. VLC is capable of providing reliable, low-latency, and secure connections that do not penetrate walls and is immune to electromagnetic interference. As such, this paper aims to show the potential of VLC for industrial wireless applications by examining the latest research work in VLC systems. This work also highlights and classifies challenges that might arise with the applicability of VLC and visible light positioning (VLP) systems in these settings. Given the previous work performed in these areas, and the major ongoing experimental projects looking into the use of VLC systems for industrial applications, the use of VLC and VLP systems for industrial applications shows promising potential.


2014 ◽  
Vol 644-650 ◽  
pp. 4538-4541
Author(s):  
Qiang Li ◽  
Xin Rui Zhang

This design is based on Visible Light Communication Technology, to achieve outdoor visible light communications and image recognition etc. through traffic lights. It will play a role on promoting the utilization of traffic lights. The system uses a LED dot matrix to imitate the traffic light, loading QR Code information on the LED dot matrix and then transporting it in a very high-speed flashing. In receiving terminal, first, webcam OV7670 collects information which from the LED dot matrix, then conveys the picture to FPGA, which is the processor. FPGA will handle the picture by gray scale processing, medium filtering and binary processing at last. Thus, the picture from the LED dot matrix will change to ‘0’ and ‘1’ in binary area. Secondly, as there’s a relationship between LED dot matrix and webcam pixels, we can count how many pixels represent one LED. Finally, we can decode the QR Code based on its own style, and display the final result on the TFT screen.


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