Browsing by Author "Hsu, Chin-Wei"

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100-m Long Distance RGB Visible Light Camera Communication
(2018-01-01)
Liu, Yen-Chun
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Shiu, Ruei-Jie
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Wei, Liang-Yu
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Hsu, Chin-Wei
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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).
2.6 Tbit/s On-Chip Optical Interconnect Supporting Mode-Division-Multiplexing and PAM-4 Signal
(2018-06-01)
Hsu, Yung
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Chuang, Chun-Yen
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Wu, Xinru
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Chen, Guan-Hong
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Hsu, Chin-Wei
In this letter, we combine the use of dense-wavelength-division-multiplexing and mode-division-multiplexing (MDM) with advanced-modulation formats for on-chip optical interconnects. A three-mode MDM multiplexer (MUX) and de-multiplexer (DEMUX) was designed and used. Each wavelength carrier had an aggregate data rate of 192-Gbit/s using 4-level pulse-amplitude-modulation. The mode crosstalk of the MDM MUX/DEMUX was measured to he below -20 dB in the 40-nm wavelength band from 1520 to 1560 nm. Fourteen wavelength channels are multiplexed and successfully transmitted with an aggregate transmission capacity of 2.6 Tbit/s (14 wavelengths x 3 modes x 64 Gbit/s) with all channels satisfying the hard-decision forward-error-correction threshold. Numerical analysis of the mode crosstalk is also performed.
20 Gbit/s Tricolor R/G/B Laser Diode based Bi-directional Signal Remodulation Visible Light Communication System
(2018-01-01)
Wei, Liang-Yu
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Hsu, Chin-Wei
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Hsu, Yung
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Chow, Chi-Wai
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Yeh, Chien-Hung
We demonstrate a bi-directional signal-remodulated visible-light-communication (VLC) system using tricolor R/G/B laser diodes to produce a 20.231-Gbit/s orthogonal-frequency-division-multiplexed (OFDM) downstream signal and 2-Mbit/s remodulated on-off-keying (OOK) upstream signal.
20.231 Gbit/s tricolor red/green/blue laser diode based bidirectional signal remodulation visible-light communication system
(2018-05-01)
Wei, Liang-Yu
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Hsu, Chin-Wei
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Chow, Chi-Wai
;
Yeh, Chien-Hung
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交大名義發表
We propose and experimentally demonstrate a recorded 1-m bidirectional 20.231-Gbit/s tricolor R/G/B laser diode (LD) based visible-light communication (VLC) system supporting signal remodulation. In the signal remodulation system, an LD source is not needed at the client side. The client reuses the downstream signal sent from the central office (CO) and remodulates it to produce the upstream signal. As the LD sources are located at the CO, the laser wavelength and temperature managements at the cost-sensitive client side are not needed. This is the first demonstration, to our knowledge, of a > 20 Gbit/s data rate tricolor R/G/B VLC signal transmission supporting upstream remodulation. (c) 2018 Chinese Laser Press
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.
A secure WDM ring access network employing silicon micro-ring based remote node
(2014-08-01)
Sung, Jiun-Yu
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Chow, Chi-Wai
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Yeh, Chien-Hung
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Xu, Ke
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Hsu, Chin-Wei
A secure and scalable wavelength-division-multiplexing (WDM) ring-based access network is proposed and demonstrated using proof-of-concept experiments. In the remote node (RN), wavelength hopping for specific optical networking unit (ONU) is deployed by using silicon micro-ring resonators (SMR). Using silicon-based devices could be cost-effective for the cost-sensitive access network. Hence the optical physical layer security is introduced. The issues of denial of service (DOS) attacks, eavesdropping and masquerading can be made more difficult in the proposed WDM ring-based access network. Besides, the SMRs with different dropped wavelengths can be cascaded, such that the signals pass through the preceding SMRs can be dropped by a succeeding SMR. This can increase the scalability of the RN for supporting more ONUs for future upgrade. Here, error-free 10 Gb/s downlink and 1.25 Gb/s uplink transmission are demonstrated to show the feasibility of the proposed network. (C) 2014 Elsevier Inc. All rights reserved.
Accurate Indoor Visible Light Positioning System utilizing Machine Learning Technique with Height Tolerance
(2018-01-01)
Hsu, Chin-Wei
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Liu, Siming
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Lu, Feng
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Chow, Chi-Wai
;
Yeh, Chien-Hung
An accurate, low-cost indoor visible light positioning system utilizing machine learning technique is proposed and experimentally demonstrated. The average position resolution of the system can achieve 3.65 cm with height tolerance range of 15 cm.
Adaptive filtering for white-light LED visible light communication
(2017-01)
Hsu, Chin-Wei
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Chen, Guan-Hong
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Wei, Liang-Yu
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Chow, Chi-Wai
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Lu, I-Cheng
White-light phosphor-based light-emitting diode (LED) can be used to provide lighting and visible light communication (VLC) simultaneously. However, the long relaxation time of phosphor can reduce the modulation bandwidth and limit the VLC data rate. Recent VLC works focus on improving the LED modulation bandwidths. Here, we propose and demonstrate the use of adaptive Volterra filtering (AVF) to increase the data rate of a white-light LED VLC system. The detailed algorithm and implementation of the AVF for the VLC system have been discussed. Using our proposed electrical frontend circuit and the proposed AVF, a significant data rate enhancement to 700.68 Mbit/s is achieved after 1-m free-space transmission using a single white-light phosphor-based LED. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Adaptive filtering for white-light LED visible light communication
(2017-01-01)
Hsu, Chin-Wei
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Chen, Guan-Hong
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Wei, Liang-Yu
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Chow, Chi-Wai
;
Lu, I-Cheng
White-light phosphor-based light-emitting diode (LED) can be used to provide lighting and visible light communication (VLC) simultaneously. However, the long relaxation time of phosphor can reduce the modulation bandwidth and limit the VLC data rate. Recent VLC works focus on improving the LED modulation bandwidths. Here, we propose and demonstrate the use of adaptive Volterra filtering (AVF) to increase the data rate of a white-light LED VLC system. The detailed algorithm and implementation of the AVF for the VLC system have been discussed. Using our proposed electrical frontend circuit and the proposed AVF, a significant data rate enhancement to 700.68 Mbit/s is achieved after 1-m free-space transmission using a single white-light phosphor-based LED. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Bi-directional Visible Light Communication Using a Single 682-nm Visible Vertical-Cavity Surface-Emitting Laser (VCSEL) and Signal Remodulation
(2017-01-01)
Wei, Liang-Yu
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Hsu, Chin-Wei
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Hsu, Yung
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Yeh, Chien-Hung
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Chow, Chi-Wai
We demonstrate a bi-directional signal-remodulated visible light communication (VLC), using 8.148-Gbit/s orthogonal-frequency-division-multiplexed (OFDM) downstream and signal remodulated 2-Mbit/s on-off-keying (OOK) upstream, with 3-m free-space transmission distance.
Bidirectional Visible Light Communication System Using a Single VCSEL With Predistortion to Enhance the Upstream Remodulation
(2018-06-01)
Wei, Liang-Yu
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Chow, Chi-Wai
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Hsu, Chin-Wei
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Yeh, Chien-Hung
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光電工程學系
The demand of higher data rates has made it attractive to consider a low-cost laser diode (LD), such as vertical-cavity-surface-emitting laser (VCSEL) for use in visible light communication (VLC) transmitters (Tx) due to their higher electrical-to-optical modulation bandwidth, beam convergence, and energy efficiency. Many reported LD-based VLC systems only had a solitary downstream transmission. We demonstrate a 3-m bidirectional signal remodulated VCSEL-based VLC system using visible-light modulator to produce the upstream signal. The visible-light external modulator usually has limited modulation bandwidth. By using the predistortion, the upstream remodulated data rate is enhanced by similar to 2.8 times. Hence, the VCSEL-based VLC system with 10.64-Gb/s downstream signal and 5-Mb/s upstream remodulated signal can be achieved. We also analyze via numerical simulations how the predistorted signal can enhance the transmission data rate by mitigating the intersymbol interference introduced by the bandwidth limitation of the upstream modulator.
Comparison of thresholding schemes for visible light communication using mobile-phone image sensor
(2016-02-08)
Liu, Yang
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Chow, Chi-Wai
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Liang, Kevin
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Chen, Hung-Yu
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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
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
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Zhou, Qi
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Tang, Ming
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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).
Demonstration of High Speed Imaging 3x3 MIMO-OFDM Visible Light Communication System
(2016-01-01)
Hsu, Chin-Wei
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Lu, I-Cheng
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Liu, Yen-Liang
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Yeh, Chien-Hung
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Chow, Chi-Wai
We experimentally demonstrate the 3x3 imaging multiple-input multiple-output (MIMO) visible light communication (VLC) system, using orthogonal frequency division multiplexing (OFDM) modulation and bit-loading, a total data rate > 800-Mbit/s over 1-m transmission is achieved without using blue-filter.
High Speed Imaging 3 x 3 MIMO Phosphor White-Light LED Based Visible Light Communication System
(2016-12-01)
Hsu, Chin-Wei
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Chow, Chi-Wai
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Lu, I-Cheng
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Liu, Yen-Liang
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Yeh, Chien-Hung
The phosphor light-emitting diode (LED) has been widely used not only for indoor illumination but for the optical transmitter (Tx) as well in visible light communication (VLC). However, the transmission data rate is significantly limited by the modulation bandwidth of LED because of the low-speed response of phosphor. In order to enhance the data rate of the VLC system, we demonstrate a 3 x 3 imaging multiple-input multiple-output (MIMO) VLC system. Besides, the pre-equalizer circuit is used to extend the bandwidth of the LED Tx. Orthogonal frequency division multiplexing (OFDM) with bit-loading algorithm is used. By using the proposed scheme, the original 1 MHz bandwidth commercially available phosphor white light LED can achieve 1 Gbps data rate over 1-m free-space transmission distance.
Light Encryption Scheme Using Light-Emitting Diode and Camera Image Sensor
(2016-02-01)
Liu, Yang
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Liang, Kevin
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Chen, Hung-Yu
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Wei, Liang-Yu
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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.
Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator
(2016-02)
Liu, Yang
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Hsu, Yung
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Hsu, Chin-Wei
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Yang, Ling-Gang
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Chow, Chi-Wai
In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single side-band (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.
Network Architecture of Bidirectional Visible Light Communication and Passive Optical Network
(2016-06-01)
Chow, Chi-Wai
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Yeh, Chien-Hung
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Liu, Yang
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Hsu, Chin-Wei
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Sung, Jiun-Yu
Network architectures to combine the fiber network outside the building and the visible light communication (VLC) access network inside the building are important for effectively distributing the high-capacity data to different users. In this paper, we propose a bidirectional network combining the VLC access network and the time-wavelength-division-multiplexed passive optical network (TWDM-PON). Orthogonal frequency division multiplexed modulation is used since it offers high spectral efficiency for both the TWDM-PON and the VLC access network. Low-cost phosphor-based white-light light-emitting diodes are (LEDs) used; hence, the VLC access network can combine with the lighting systems.
Performance enhancement technique of visible light communications using passive photovoltaic cell
(2017-06-01)
Wu, Jhao-Ting
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Chow, Chi-Wai
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Liu, Yang
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Hsu, Chin-Wei
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Yeh, Chien-Hung
The light emitting diode (LED) based visible light communication (VLC) system can provide lighting and communication simultaneously. It has attracted much attenuation recently. As the photovoltaic cell (also known as solar cell) is physically flexible, low cost, and easily available, it could be a good choice for the VLC receiver (Rx). Furthermore, besides acting as the VLC Rx, the solar cell can convert VLC signal into electricity for charging up the Rx devices. Hence, it could be a promising candidate for the future internet-of-thing (IoT) networks. However, using solar cell as VLC Rx is challenging, since the response of the solar cell is highly limited and it will limit the VLC data rate. In this work, we propose and demonstrate for the first time using pre-distortion Manchester coding (MC) signal to enhance the signal performance of solar cell Rx based VLC. The proposed scheme can significantly mitigate the slow response, as well as the direct-current (DC) wandering effect of the solar cell; hence 50 times increase in data rate can be experimentally achieved.
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
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Chow, Chi-Wai
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Chen, Guan-Hong
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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