Browsing by Author "Chang, Gee-Kung"

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A novel 10 Gb/s TDM-PON using embedded clocks in centralized optical signals and conventional CW receivers for instantaneous burst-mode data and clock recovery
(2008-01-01)
Chien, Hung-Chang
;
Huang, Ming-Fang
;
Chowdhury, Arshad
;
Yu, Jianjun
;
Chang, Gee-Kung
A novel 10Gb/s TDM-PON architecture with embedded clocks in centralized optical signals is proposed. Using this scheme, 10Gb/s burst-mode data and clock recovery through low-cost, conventional CW receivers have been designed and demonstrated. (C) 2008 Optical Society of America.
A novel dispersion-free interleaver for bidirectional DWDM transmission systems
(2007-11-01)
Huang, Ming-Fang
;
Chen, Jason Jyehong
;
Yu, Jianjun
;
Chi, Sien
;
Chang, Gee-Kung
We propose a novel dispersion-free interleaver using optical delay lines by accurately locating the zeros in the transfer function. It has been implemented with the design of interleaver pairs with the same amplitude responses but opposite phase responses for bidirectional dense wavelength-division multiplexed (DWDM) transmission systems. The measured results are consistent with device simulation. We have further modified the original three-port design using unidirectional amplification, and a four-port interleaver has been built and demonstrated to achieve bidirectional DWDM transmission. In this paper, we fully studied and verified the applications of our four-port interleavers in bidirectional transmission. We demonstrated a bidirectional strain-line system over 210 km and a recirculating loop transmission over a 500-km standard single-mode fiber using 10-Gb/s ON-OFF keying signals. Furthermore, we also demonstrated return-to-zero differential phase-shift keying (DPSK) and nonreturn-to-zero DPSK modulation formats for more than 230 km of transmission. For comparison, the different amplification functions, such as the erbium-doped fiber amplifier and the semiconductor optical amplifier, have also been probed in this paper. The experimental results have clearly illustrated the desirable functions of this novel bidirectional amplifier in this dispersion-free interleaver.
A novel hybrid 10G/1G coexisted TDM-PON using central office controlled reflective transmitters for low-cost upstream 10G services
(2007)
Chien, Hung-Chang
;
Huang, Ming-Fang
;
Chowdhury, Arshad
;
Chen, Jyehong
;
Chi, Sien
A novel hybrid 10G/1G coexisted TDM-PON based on reflective ONUs is proposed and experimentally demonstrated. 10-Gb/s upstream is successfully achieved by 4 piped 2.5-Gb/s sub-units in the ONU with negligible power penalty less than 0.2dB.
Accurate Indoor Visible Light Positioning System utilizing Machine Learning Technique with Height Tolerance
(2018-01-01)
Hsu, Chin-Wei
;
Liu, Siming
;
Lu, Feng
;
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.
Cost-Effective Mobile Backhaul Network Using Existing ODN of PONs for the 5G Wireless Systems
(2015-12-01)
Sung, Jiun-Yu
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Liu, Yang
;
Chang, Gee-Kung
An optical distribution network (ODN) sharing scheme to integrate mobile backhaul networks with the existing passive optical network (PON) systems is proposed and demonstrated. With the ODN sharing scheme, the expense of building new fibers for the next-generation fifth-generation (5G) mobile backhaul networks can be reduced. As many wavelengths are allocated to the already deployed PON systems, there remain limited wavelengths for the mobile backhaul systems. Hence, to efficiently increase the serving cell sites of the 5G systems, spectral-efficient orthogonal frequency-division multiplexing (OFDM) is adopted in the mobile backhaul systems. In order to reduce the latency of the system, adaptive adjustment of the OFDM signals for different transmission distances is averted. The OFDM signals are transmitted only using specific available bandwidth. The available bandwidth for each wavelength is studied according to the power fading relationship between the transmission distances and the chirp induced from signal modulation. A proof-of-concept demonstration experiment has been performed. In our results, 20.17 Gb/s with a bit error rate (BER) lower than 3.8 x 10(-3) was realized with a split ratio of 256 and a 40-km transmission distance of the PON ODN. Hence, each wavelength can support about 20, six, and two nodes for the IMT-advanced, current Long-Term Evolution-Advanced (LTE-A) systems, and the expected 5G systems, respectively.
Demonstration of high precision 3D indoor positioning system based on two-layer ANN machine learning technique
(2019-01-01)
He, Jiale
;
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).
Polarization-Insensitive Remote Access Unit for Radio-Over-Fiber Mobile Fronthaul System by Reusing Polarization Orthogonal Light Waves
(2016-02-01)
Wu, Beilei
;
Sung, Jiun-Yu
;
Yan, Jhih-Heng
;
Xu, Mu
;
Wang, Jing
To reduce the complexity and cost of remote access units (RAUs), colorless transport architecture is preferred in a wavelength-division multiplexing (WDM) system. The wavelength-reuse technique is commonly adopted to realize colorless RAUs. However, in traditional approaches, RAUs employ crystal-based Mach-Zehnder modulators (MZMs) to modulate the distributed carriers. Hence, polarization tracking systems are necessary to align the polarization state of the distributed carriers with the MZM principal axis. This increases the cost of the RAUs. In this paper, a full-duplex millimeter-wave (MMW) radio-over-fiber (RoF) access architecture employing polarization-insensitive RAUs is proposed. In our proposed RAUs, the upstream signals are generated using polarization-orthogonal lights, and the performance of the upstream signals is independent of the polarization state of the MZM input lights. The proposed system is mathematically formulated and experimentally demonstrated. The 1.2-Gb/s quadrature phase-shift keying (QPSK) orthogonal frequency-division multiplexing (OFDM) downstream signal at the 60-GHz band and 5-Gb/s on-off keying (OOK) polarization-insensitive upstream signal over a 15-km standard single-mode fiber (SSMF) are demonstrated. In our results, a polarization insensitive RAU is successfully obtained. The power penalty resulting from the interference of downstream signal is about 0.4 and 0.6 dB with a bit error rate (BER) of 10(-9) in back-to-back and 15-km fiber transmission, respectively.
Reliable tree-type passive optical networks with self-restorable apparatus
(2008-03-31)
Yeh, Chien Hung
;
Shih, Fu-Yuan
;
Chang, Gee-Kung
;
Chi, Sien
;
光電工程學系
We propose and investigate a simply self-restored tree-type time-division-multiplexed passive optical network (TDM-PON) with duplex fiber system against the fiber failure. The new proposed optical line terminal (OLT), optical network unit (ONU), and remote node (RN) can be used to prevent and protect the occurrence of fiber failure in the self-protected tree-type PON. The protection and restoration time of the access network can be archived within 7 ms in this experiment. In addition, the performances of data traffic for the fiber access network are also analyzed and discussed. (C) 2007 Optical Society of America.
Simple WDM-PON architecture to simultaneously provide triple-play services by using one single modulator
(2008-01-01)
Huang, Ming-Fang
;
Yu, Jianjun
;
Chien, Hung-Chang
;
Chowdhury, Arshad
;
Chen, Jason (Jyehong)
Simple WDM-PON testbed with centralized-lightwave using single-arm IM to provide 10Gb/s data and 2.5Gb/s digital video downstream and 2.5Gb/s upstream data has been demonstrated. After 20km SSMF, power-penalty for all channels is less than 0.5dB. (C) 2006 Optical Society of America.
Two-level modulation scheme to reduce latency for optical mobile fronthaul networks
(2016-10-31)
Sung, Jiun-Yu
;
Chow, Chi-Wai
;
Yeh, Chien-Hung
;
Chang, Gee-Kung
;
光電工程學系
A system using optical two-level orthogonal-frequency-division-multiplexing (OFDM) -amplitude-shift-keying (ASK) modulation is proposed and demonstrated to reduce the processing latency for the optical mobile fronthaul networks. At the proposed remote-radio- head (RRH), the high data rate OFDM signal does not need to be processed, but is directly launched into a high speed photodiode (HSPD) and subsequently emitted by an antenna. Only a low bandwidth PD is needed to recover the low data rate ASK control signal. Hence, it is simple and provides low-latency. Furthermore, transporting the proposed system over the already deployed optical-distribution-networks (ODNs) of passive-optical-networks (PONs) is also demonstrated with 256 ODN split-ratios. (C) 2016 Optical Society of America