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Tricolor visible-light laser diodes based visible light communication operated at 40.665 Gbit/s and 2 m free-space transmission
(2019-09-02)
Wei, Liang-Yu
;
Chow, Chi-Wai
;
Chen, Guan-Hong
;
Liu, Yang
;
Yeh, Chien-Hung
Visible light communication (VLC) can provide a dedicated, secure, and high data rate wireless transmission link. It has gained considerable attentions recently, and is considered as one of the promising technologies for beyond 5G mobile and wireless communications. In this work, we demonstrate a VLC system with a recorded data rate of 40.665 Gbit/s using tricolor red, green and blue (RGB) laser diodes (LDs) and polarization multiplexing. 2 m free-space transmission distance is achieved. The implementation of bit-loading, power-loading, and polarization multiplexing are discussed. Experimental bit-errorratio (BER) results show that each of the 6 polarization and wavelength de-multiplexed channels can achieve the forward-error-correction (FEC) requirement. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Visible Light Communication Using Advertisement-Light-Board and Rolling-Shutter-Effect based CMOS Mobile-Phone Camera
(2018-01-01)
Shiu, Ruei-Jie
;
Liu, Yen-Chun
;
Chow, Chi-Wai
;
Wei, Liang-Yu
;
Hsu, Yung
We demonstrate a visible-light-communication (VLC) system using advertisement-light-board and CMOS-camera. Experiments at wireless transmission distances of 50cm, 100cm and 150cm are performed, and at data-rate of 720bit s, satisfying the forward-error-correction (FEC) threshold.
100-m Long Distance RGB Visible Light Camera Communication
(2018-01-01)
Liu, Yen-Chun
;
Shiu, Ruei-Jie
;
Wei, Liang-Yu
;
Hsu, Chin-Wei
;
Chow, Chi-Wai
We demonstrate and analyze using different ISO values to achieve a 100-m long distance visible light camera communication using red/green/blue (RGB) light-emitting-diodes (LEDs).
Demonstration of high precision 3D indoor positioning system based on two-layer ANN machine learning technique
(2019-01-01)
He, Jiale
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Hsu, Chin-Wei
;
Zhou, Qi
;
Tang, Ming
;
Fu, Songnian
We experimentally demonstrate a high precision 3D indoor visible light positioning system utilizing two-layer machine learning technique. The measured average positioning resolution of <1cm in an unit volume of 0.9 x 1 x 0.4 m(3).
40-Gbit/s Visible Light Communication using Polarization-Multiplexed R/G/B Laser Diodes with 2-m Free-Space Transmission
(2019-01-01)
Wei, Liang-Yu
;
Hsu, Chin-Wei
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
光電工程學系
We demonstrate a recorded 40.665-Gbit/s visible-light-communication (VLC) system using polarization multiplexed red/green/blue (R/G/B) laser-diodes (LDs) with 2-m free-space transmission. Bit-and-power-loading orthogonal-frequency-division-multiplexed (OFDM) signal is employed.
Visible light communication and positioning using positioning cells and machine learning algorithms
(2019-05-27)
Chuang, Yu-Cheng
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Li, Zhi-Qing
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Hsu, Chin-Wei
;
Liu, Yang
;
Chow, Chi-Wai
We propose and experimentally demonstrate a practical visible light position (VLP) system using repeated unit cells and machine learning (ML) algorithms. ML is employed to increase the positioning accuracy. Algorithms of the 2nd-order regression ML model and the polynomial trilateral ML model are discussed. More than 80% of the measurement data have position error within 4 cm when using the 2nd-order regression ML model, while the position error is within 5 cm when using the polynomial trilateral ML model. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Visible Light Communication Using Receivers of Camera Image Sensor and Solar Cell
(2016-02-01)
Liu, Yang
;
Chen, Hung-Yu
;
Liang, Kevin
;
Hsu, Chin-Wei
;
Chow, Chi-Wai
We propose an electronic label and sensor system using visible light communication (VLC). The downlink signal is transmitted by a white-light light-emitting diode (LED) lamp that can provide lighting, VLC, and energy harvesting for mobile devices. The downlink is received by a solar cell. The uplink can be captured by a surveillance camera image sensor. However, using the camera image sensor as a VLC receiver (Rx) is challenging since the data rate is limited by the frame rate and due to uneven light exposure. The rolling shutter effect of the image sensor can be used to increase the data rate. In this paper, we propose and demonstrate how to demodulate the obtained rolling shutter pattern using a second-order polynomial (SOP) extinction ratio (ER) enhancement scheme, together with iterative and modified quick adaptive thresholding schemes. The ER enhancement scheme can significantly reduce the large ER fluctuation. Experimental results show that by using the proposed SOP ER enhancement scheme, the bit error rate (BER) improvement can be up to two orders of magnitude. We also believe that the proposed electronic label and sensor system may be applicable to Internet-of-Things sensing networks for connecting a number of mobile devices.
Visible-light communication multiple-input multiple-output technology for indoor lighting, communication, and positioning
(2015-12-01)
Liu, Yang
;
Hsu, Chin-Wei
;
Chen, Hung-Yu
;
Liang, Kevin
;
Chow, Chi-Wai
Visible-light communication (VLC) is license free and electromagnetic-interference free; it thus can be deployed in radio-frequency forbidden areas. The light-emitting diode (LED) system providing simultaneously lighting, VLC, and positioning is highly desirable for providing real-time tracking, monitoring, and navigating with very little extra cost. We propose and demonstrate a multiple-input multiple-output (MIMO) VLC-positioning system using white-light LEDs. Our scheme is based on MIMO to provide both position and VLC. Experimental results show that the proposed MIMO VLC system can achieve a bit-error rate of 10(-10), while the positioning errors are within 1 cm. Numerical analyses are also performed, showing the positioning error can be measured within 1 cm. Further analysis of tilting angle of the receiver is also presented. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)
Comparison of thresholding schemes for visible light communication using mobile-phone image sensor
(2016-02-08)
Liu, Yang
;
Chow, Chi-Wai
;
Liang, Kevin
;
Chen, Hung-Yu
;
Hsu, Chin-Wei
Based on the rolling shutter effect of the complementary metal-oxide-semiconductor (CMOS) image sensor, bright and dark fringes can be observed in each received frame. By demodulating the bright and dark fringes, the visible light communication (VLC) data logic can be retrieved. However, demodulating the bright and dark fringes is challenging as there is a high data fluctuation and large extinction ratio (ER) variation in each frame due. Hence proper thresholding scheme is needed. In this work, we propose and compare experimentally three thresholding schemes; including third-order polynomial curve fitting, iterative scheme and quick adaptive scheme. The evaluation of these three thresholding schemes is performed. (C) 2016 Optical Society of America
Light Encryption Scheme Using Light-Emitting Diode and Camera Image Sensor
(2016-02-01)
Liu, Yang
;
Liang, Kevin
;
Chen, Hung-Yu
;
Wei, Liang-Yu
;
Hsu, Chin-Wei
Visible light communication (VLC) is regarded as relatively secure communication when compared with other wireless communications using radio frequency (RF). However, due to the visual nature, the VLC signals are still subject to eavesdropping when they are emitted by the light source. Here, we propose a light encryption scheme using devices having light-emitting diode (LED) and a camera image sensor, such as a mobile phone. The original visible signal sending from the lamp can be first received by the proposed light encrypter. The information can be encrypted and then emitted. The light encrypter acts as an encryption gateway for signals in optical domain. The rolling shutter effect of the complementary metal-oxide semiconductor (CMOS) camera in the mobile phone can be used. By demodulating the rolling shutter pattern, the data information can be obtained. We also propose and demonstrate using the Otsu thresholding scheme to define the data logic in the rolling shutter pattern. We show that the Otsu scheme is effective for estimating the bit error rate (BER). The optimum number of intervals (segmentations) and the process time of the Otsu method are also studied.

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