Browsing by Author "Wu, Fang-Ming"

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1.1-Gb/s White-LED-Based Visible Light Communication Employing Carrier-Less Amplitude and Phase Modulation
(2012-10-01)
Wu, Fang-Ming
;
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Chen, Cheng-Wei
;
Huang, Hou-Tzu
We demonstrate 1.1-Gb/s visible light communication (VLC) employing carrier-less amplitude and phase modulation (CAP) and a commercially available phosphorescent white light emitting diode (LED). Optical blue filtering, pre-compensation, and decision feedback equalization are used to compensate the frequency response of the phosphor-based white LED. Various modulation orders of CAP signals are investigated to maximize the capacity of the VLC system. The record data rate of 1.1 Gb/s with the bit error rate performance below the FEC limit of 10(-3) is successfully achieved >23-cm air-transmission via a 220-MBaud 32-CAP signal.
3.22-Gb/s WDM Visible Light Communication of a Single RGB LED Employing Carrier-Less Amplitude and Phase Modulation
(2013)
Wu, Fang-Ming
;
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Chen, Cheng-Wei
;
Chen, Zhen-Yu
We experimentally demonstrate WDM-VLC employing CAP modulation and commercially available RGB-type LED. The record aggregate data rate of 3.22 Gb/s with the BER of less than 10(-3) is successfully achieved over >25-cm air-transmission.
Electrically and Continuously Tunable Optical Delay Line Based on a Semiconductor Laser
(2010)
Wu, Fang-Ming
;
Peng, Peng-Chun
;
Chen, Jason (Jyehong)
;
Lin, Chun-Ting
;
Lin, Gong-Ru
This investigation experimentally demonstrates the feasibility of the electrically and continuously tunable optical delay line using a semiconductor laser. The time delays for a 10 Gbps data signal are electrically delayed by adjusting the bias current of laser, and the maximum delay is approximately 41 ps. We also measure the bit error rate against the receiver power by various bias currents and wavelength detuning (Delta lambda). Measurements are made to verify the feasibility to use in optical communication systems. (C) 2010 The Japan Society of Applied Physics
Indoor VLC System With Multiple LEDs of Different Path Lengths Employing Space-Time Block-Coded DMT/CAP Modulation
(2015-03-01)
Wei, Chia-Chien
;
Wu, Fang-Ming
;
Chen, Zhen-Yu
;
Lin, Chun-Ting
;
Huang, Yu-Syuan
We experimentally demonstrate a practical visible light communication (VLC) system of 3.2-m transmission using spectrally efficient discrete multitone (DMT) or carrierless amplitude phase (CAP) modulation. The transmitters consist of two light emitting diodes (LEDs) spaced 2 m apart, the arrangement of which corresponds to a common case for full-range illumination in indoor environments, and this work also investigates the influence of the difference in transmission path lengths from the LEDs to a single receiver. In the overlapped illumination area, the delay interference between the LEDs could result in up to about 40% capacity reduction using quaternary CAP or bit-loaded DMT signals, when two LEDs simply transmit the same signal. To mitigate the impact of the delay interference, Alamouti space-time block coding (STBC) is employed for both DMT and CAP signals, and the combination of CAP and STBC is proposed for the first time to the authors\' best knowledge. Employing STBC, we successfully demonstrate interference-tolerant VLC over 3.2-m air transmission, and the maximum data rates for DMT and CAP signals are 220 and 150 Mbps, respectively.
LED-based Visible Light Communication in a Practical Indoor Interfered Environment Employing DMT and STBC
(2014-01-01)
Wei, Chia-Chien
;
Wu, Fang-Ming
;
Chen, Zhen-Yu
;
Lin, Chun-Ting
;
Chen, Yung-Jui
We demonstrate practical indoor VLC of 3.2-m transmission, and investigate multipath interference between LEDs. Employing repetition coding, 161 similar to 266-Mbps DMT-signals are achieved depending on interference severity. Employing STBC, about fixed 220-Mbps data rate could be achieved.
Polarization Characteristics of Quantum-Dot Vertical-Cavity Surface-Emitting Laser With Light Injection
(2010-02-01)
Peng, Peng-Chun
;
Lan, Ruei-Long
;
Wu, Fang-Ming
;
Lin, Gray
;
Lin, Chun-Ting
This investigation explores experimentally the optical characteristics of long-wavelength quantum-dot vertical-cavity surface-emitting lasers (QD VCSELs). The InAs QD VCSEL, fabricated on a GaAs substrate, is grown by molecular beam epitaxy with fully doped distributed Bragg reflectors. The optical characteristics of QD VCSEL without and with light injection are studied in detail. The QD VCSEL has the potential to be used in all-optical signal processing systems.
RF phase shifter using a distributed feedback laser in microwave transport systems
(2009-04-27)
Peng, Peng-Chun
;
Wu, Fang-Ming
;
Jiang, Wen-Jr
;
Lan, Ruei-Long
;
Lin, Chun-Ting
This work experimentally demonstrates the efficacy of a radio-frequency phase shifter using a distributed feedback laser in a microwave transport system. Phase shifts of about 101 are obtained at 8.75GHz. The proposed phase shifter can amplify microwave signals and thereby improve transmission performance. Additionally, a similar single sideband modulation can be generated by the phase shifter. Experimental results indicate that the proposed phase shifter can be used in future long-distance microwave transport systems and all optical inverters. (C) 2009 Optical Society of America
Simple 2x2 MIMO 60-GHz OFDM RoF System with Single-Electrode MZMs Employing Beating Interference Mitigation and IQ Imbalance Compensation
(2013)
Huang, Hou-Tzu
;
Chiang, Ya-Tang
;
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Ho, Chun-Hung
We propose simple 2x2 MIMO 60-GHz RoF systems using single-electrode MZMs. Employing signal-signal beating interference mitigation, IQ imbalance compensation, and bit-loading technique, >40-Gbps OFDM signals over 12-km fiber and 3.5-m wireless transmission are achieved.
Study of Wireless Channel Characteristics of 2x2 60-GHz MIMO OFDM RoF System Employing Lattice Reduction-aided Detection
(2013)
Huang, Hou-Tzu
;
Ho, Chun-Hung
;
Lu, Tsung-Hung
;
Wang, Chih-Yun
;
Lin, Chun-Ting
We experimentally investigate the wireless channel characteristics of 2x2 60-GHz MIMO OFDM RoF system with 3.5-m wireless distance. With lattice-reduction-aided detection, the achievable data rate can be improved from 0.58Gbps to 12.61Gbps for the worst case.
Transmission improvement in fiber radio links using semiconductor laser
(2008-01-01)
Peng, Peng-Chun
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Lin, Chun-Ting
;
Jiang, Wen-, Jr.
;
Chen, Jason (Yehong)
;
Shih, Po Tsung
This investigation experimentally demonstrates the performance improvement in fiber-radio links by using a semiconductor laser. This technique improves receiver sensitivity over 4.5 dB by increasing the optical modulation depth. (C)2008 Optical Society of America.
Tunable Photonic Microwave Filter using Slow Light in Vertical Cavity Surface Emitting Laser
(2009-01-01)
Peng, Peng-Chun
;
Yeh, Shin-Kai
;
Wu, Fang-Ming
;
Chen, Jason (Jyehong)
;
Lin, Chun-Ting
A tunable photonic microwave filter using slow light in a VCSEL is proposed and experimentally demonstrated for the first time. Tunable microwave notch filter at 20 GHz can be achieved by adjusting the bias current of VCSEL. (C) 2009 Optical Society of America
Tunable Slow Light in Semiconductor Optical Amplifier without External Pump Laser
(2008-01-01)
Peng, Peng-Chun
;
Kao, Wei-Che
;
Chen, Jason (Jyehong)
;
Wu, Fang-Ming
;
Lin, Chun-Ting
This investigation experimentally demonstrates tunable slow light in a semiconductor optical amplifier (SOA) without an external pump laser. Tunable time delays are achieved by adjusting the feedback signal from the SOA.