G.K. Chang - Academia.edu (original) (raw)
Papers by G.K. Chang
2012 IEEE Photonics Society Summer Topical Meeting Series, 2012
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2011 XXXth URSI General Assembly and Scientific Symposium, 2011
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Journal of Lightwave Technology, 2019
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Journal of Lightwave Technology
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The paper presents the architecture and experimentation of a 10-Gb/s QoS-enabled almost-all-optic... more The paper presents the architecture and experimentation of a 10-Gb/s QoS-enabled almost-all-optical packet switching system (QOPS) for metro WDM networks. By applying cluster-based wavelength sharing and downsized single-staged optical buffers, QOPS is featured ...
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Small-cell systems based on cloud radio access network (cloud-RAN) architecture have been propose... more Small-cell systems based on cloud radio access network (cloud-RAN) architecture have been proposed as promising solutions to meet the ever-increasing capacity demand of the next-generation wireless access networks. By centralizing the processing power to reduce the complexity of conventional cell sites, the cloud-RAN architecture is ideal for large-scale small-cell system at reduced capital and operational expenses. However, high-speed, flexible, and scalable backhaul links between the centralized baseband processing unit (BBU) and the remote antenna units (RAUs) are required to support the high throughput of the small-cell cloud-RANs, and the conventional approaches are based on digital baseband signal transmission in the backhaul links. In this paper, we propose a novel multi-service small-cell wireless access architecture based on radio-over-fiber (RoF) technologies. By utilizing analog radio frequency (RF) signal transmission in the optical backhaul links, the design of RAUs can...
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We have experimentally compared the performances of optical millimeter-wave generation or up-conv... more We have experimentally compared the performances of optical millimeter-wave generation or up-conversion using external modulators based on different modulation schemes. The generated or up-converted optical millimeter wave using the optical carrier suppression (OCS) modulation scheme shows the highest receiver sensitivity, highest spectral efficiency, and smallest power penalty over long-distance delivery. Moreover, the OCS modulation scheme has a simple configuration and low-frequency bandwidth requirement for both electrical and optical components. Employing an OCS modulation scheme, 16-channel dense wavelength-division multiplexing signals at 2.5-Gb/s per channel have been up-converted to a 40-GHz carrier simultaneously.
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This paper introduces two radio-over-fiber (RoF) architectures for the future broadband optical-w... more This paper introduces two radio-over-fiber (RoF) architectures for the future broadband optical-wireless access network-all-band RoF and band-mapped 60-GHz RoF that can be integrated in ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON). Legacy wireless services and multi-gigabit millimeter-wave (mm-wave) applications are integrated and delivered simultaneously under one shared infrastructure. With centralized system control and signal processing, the proposed systems provide cost-effective and protocol-transparent solutions for the next-generation multi-service bundle in heterogeneous networks (HetNets). In the all-band RoF network where wireless services are kept at their original carrier frequencies, Wi-Fi, WiMAX, and 60-GHz high-speed mm-wave services are transmitted based on subcarrier multiplexing (SCM) and dual-wavelength heterodyne beating techniques in avoidance of optical filters and large-bandwidth optoelectronic components. In the indoor env...
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Journal of Lightwave Technology
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Journal of Lightwave Technology
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Optics express, Jan 3, 2016
We propose a simple and reconfigured dispersion-tolerant single sideband (SSB) orthogonal frequen... more We propose a simple and reconfigured dispersion-tolerant single sideband (SSB) orthogonal frequency division multiplexing (OFDM) radio over fiber (RoF) system enabled by digital signal processing (DSP), one in-phase/quadrature (I/Q) modulator and direct-detection. The generated radio frequency (RF) is based on DSP and the frequency can be flexibly adjusted, which can be employed in the future software-defined radio access network (RAN). Based on our proposed system, we have experimentally demonstrated 16-ary quadrature amplitude modulation (16QAM) 21.87-Gb/s 21-GHz and 38-GHz SSB-OFDM RoF signal generation and transmission over 80-km single-mode fiber (SMF), respectively.
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We demonstrate a novel frequency-doubled wireless over fiber system to offer multiband services i... more We demonstrate a novel frequency-doubled wireless over fiber system to offer multiband services including baseband, 60-GHz millimeter-wave and 15-GHz microwave without carrier suppression. Multiband wireless signals are successfully transmitted through both fiber and air channels.
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Photonics Packaging and Integration VI, 2006
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Optical Fiber Communication Conference, 2016
We propose and demonstrate a novel sub-Nyquist sampling technique for bandwidth-efficient and har... more We propose and demonstrate a novel sub-Nyquist sampling technique for bandwidth-efficient and hardware-efficient mobile fronthaul supporting massive MIMO, simultaneously achieving 32-fold reduction in sampling rate and 1.5-dB improvement in performance in a 128×128 MIMO experiment.
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OFC/NFOEC 2007 - 2007 Conference on Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007
ABSTRACT
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56th Electronic Components and Technology Conference 2006, 2006
We have developed a parallel process for the cost effective fabrication of active lightwave circu... more We have developed a parallel process for the cost effective fabrication of active lightwave circuits and optical transceivers. In this novel process no out-of-plane beam turning components (mirrors or lenses) are used and light never leaves the waveguide except at the photodetector
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2006 Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference, 2006
There is a strong interest in providing both broadband wireless and wired access services in the ... more There is a strong interest in providing both broadband wireless and wired access services in the emerging optical-wireless networks [1-8]. We proposed a novel ROF architecture which provides not only wireless based access at carried band in high frequency, but optical fiber based ...
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Optics express, Jan 5, 2015
We propose and experimentally demonstrate a method for sampling frequency offset (SFO) estimation... more We propose and experimentally demonstrate a method for sampling frequency offset (SFO) estimation in optical communication systems based on periodically inserted identical binary prefix. Different from conventional cyclic prefix, binary prefix provides not only high tolerance to chromatic dispersion in dispersive fiber transmission, but also the ability to estimate SFO by simple receiver-side digital signal processing. Moreover, this binary prefix based scheme is generally applicable to any advanced modulation formats. A proof-of-concept experiment is conducted to quantify the accuracy and tolerance of the scheme in estimating SFO. It is found that over a wide SFO range up to 341 ppm, the estimation error is kept under 20 ppb and signals are recovered with the same quality as with zero-offset sampling. The experimental results also confirm that this method is tolerant to link signal-to-noise ratio loss and dispersion, showing no additional penalty after transmission over a 40-km sta...
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33rd European Conference and Exhibition on Optical Communication - ECOC 2007, 2007
Page 1. 100Gbit/s packet generation with spectral efficiency larger than 1bit/Hz/s by using optic... more Page 1. 100Gbit/s packet generation with spectral efficiency larger than 1bit/Hz/s by using optical carrier suppression and separation and vestigial sideband filtering techniques Jianjun Yu1, Lei Xu1, Philip Nan Ji1, Zhensheng ...
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2012 IEEE Photonics Society Summer Topical Meeting Series, 2012
Bookmarks Related papers MentionsView impact
2011 XXXth URSI General Assembly and Scientific Symposium, 2011
Bookmarks Related papers MentionsView impact
Journal of Lightwave Technology, 2019
Bookmarks Related papers MentionsView impact
Journal of Lightwave Technology
Bookmarks Related papers MentionsView impact
The paper presents the architecture and experimentation of a 10-Gb/s QoS-enabled almost-all-optic... more The paper presents the architecture and experimentation of a 10-Gb/s QoS-enabled almost-all-optical packet switching system (QOPS) for metro WDM networks. By applying cluster-based wavelength sharing and downsized single-staged optical buffers, QOPS is featured ...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Small-cell systems based on cloud radio access network (cloud-RAN) architecture have been propose... more Small-cell systems based on cloud radio access network (cloud-RAN) architecture have been proposed as promising solutions to meet the ever-increasing capacity demand of the next-generation wireless access networks. By centralizing the processing power to reduce the complexity of conventional cell sites, the cloud-RAN architecture is ideal for large-scale small-cell system at reduced capital and operational expenses. However, high-speed, flexible, and scalable backhaul links between the centralized baseband processing unit (BBU) and the remote antenna units (RAUs) are required to support the high throughput of the small-cell cloud-RANs, and the conventional approaches are based on digital baseband signal transmission in the backhaul links. In this paper, we propose a novel multi-service small-cell wireless access architecture based on radio-over-fiber (RoF) technologies. By utilizing analog radio frequency (RF) signal transmission in the optical backhaul links, the design of RAUs can...
Bookmarks Related papers MentionsView impact
We have experimentally compared the performances of optical millimeter-wave generation or up-conv... more We have experimentally compared the performances of optical millimeter-wave generation or up-conversion using external modulators based on different modulation schemes. The generated or up-converted optical millimeter wave using the optical carrier suppression (OCS) modulation scheme shows the highest receiver sensitivity, highest spectral efficiency, and smallest power penalty over long-distance delivery. Moreover, the OCS modulation scheme has a simple configuration and low-frequency bandwidth requirement for both electrical and optical components. Employing an OCS modulation scheme, 16-channel dense wavelength-division multiplexing signals at 2.5-Gb/s per channel have been up-converted to a 40-GHz carrier simultaneously.
Bookmarks Related papers MentionsView impact
This paper introduces two radio-over-fiber (RoF) architectures for the future broadband optical-w... more This paper introduces two radio-over-fiber (RoF) architectures for the future broadband optical-wireless access network-all-band RoF and band-mapped 60-GHz RoF that can be integrated in ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON). Legacy wireless services and multi-gigabit millimeter-wave (mm-wave) applications are integrated and delivered simultaneously under one shared infrastructure. With centralized system control and signal processing, the proposed systems provide cost-effective and protocol-transparent solutions for the next-generation multi-service bundle in heterogeneous networks (HetNets). In the all-band RoF network where wireless services are kept at their original carrier frequencies, Wi-Fi, WiMAX, and 60-GHz high-speed mm-wave services are transmitted based on subcarrier multiplexing (SCM) and dual-wavelength heterodyne beating techniques in avoidance of optical filters and large-bandwidth optoelectronic components. In the indoor env...
Bookmarks Related papers MentionsView impact
Journal of Lightwave Technology
Bookmarks Related papers MentionsView impact
Journal of Lightwave Technology
Bookmarks Related papers MentionsView impact
Optics express, Jan 3, 2016
We propose a simple and reconfigured dispersion-tolerant single sideband (SSB) orthogonal frequen... more We propose a simple and reconfigured dispersion-tolerant single sideband (SSB) orthogonal frequency division multiplexing (OFDM) radio over fiber (RoF) system enabled by digital signal processing (DSP), one in-phase/quadrature (I/Q) modulator and direct-detection. The generated radio frequency (RF) is based on DSP and the frequency can be flexibly adjusted, which can be employed in the future software-defined radio access network (RAN). Based on our proposed system, we have experimentally demonstrated 16-ary quadrature amplitude modulation (16QAM) 21.87-Gb/s 21-GHz and 38-GHz SSB-OFDM RoF signal generation and transmission over 80-km single-mode fiber (SMF), respectively.
Bookmarks Related papers MentionsView impact
We demonstrate a novel frequency-doubled wireless over fiber system to offer multiband services i... more We demonstrate a novel frequency-doubled wireless over fiber system to offer multiband services including baseband, 60-GHz millimeter-wave and 15-GHz microwave without carrier suppression. Multiband wireless signals are successfully transmitted through both fiber and air channels.
Bookmarks Related papers MentionsView impact
Photonics Packaging and Integration VI, 2006
Bookmarks Related papers MentionsView impact
Optical Fiber Communication Conference, 2016
We propose and demonstrate a novel sub-Nyquist sampling technique for bandwidth-efficient and har... more We propose and demonstrate a novel sub-Nyquist sampling technique for bandwidth-efficient and hardware-efficient mobile fronthaul supporting massive MIMO, simultaneously achieving 32-fold reduction in sampling rate and 1.5-dB improvement in performance in a 128×128 MIMO experiment.
Bookmarks Related papers MentionsView impact
OFC/NFOEC 2007 - 2007 Conference on Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007
ABSTRACT
Bookmarks Related papers MentionsView impact
56th Electronic Components and Technology Conference 2006, 2006
We have developed a parallel process for the cost effective fabrication of active lightwave circu... more We have developed a parallel process for the cost effective fabrication of active lightwave circuits and optical transceivers. In this novel process no out-of-plane beam turning components (mirrors or lenses) are used and light never leaves the waveguide except at the photodetector
Bookmarks Related papers MentionsView impact
2006 Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference, 2006
There is a strong interest in providing both broadband wireless and wired access services in the ... more There is a strong interest in providing both broadband wireless and wired access services in the emerging optical-wireless networks [1-8]. We proposed a novel ROF architecture which provides not only wireless based access at carried band in high frequency, but optical fiber based ...
Bookmarks Related papers MentionsView impact
Optics express, Jan 5, 2015
We propose and experimentally demonstrate a method for sampling frequency offset (SFO) estimation... more We propose and experimentally demonstrate a method for sampling frequency offset (SFO) estimation in optical communication systems based on periodically inserted identical binary prefix. Different from conventional cyclic prefix, binary prefix provides not only high tolerance to chromatic dispersion in dispersive fiber transmission, but also the ability to estimate SFO by simple receiver-side digital signal processing. Moreover, this binary prefix based scheme is generally applicable to any advanced modulation formats. A proof-of-concept experiment is conducted to quantify the accuracy and tolerance of the scheme in estimating SFO. It is found that over a wide SFO range up to 341 ppm, the estimation error is kept under 20 ppb and signals are recovered with the same quality as with zero-offset sampling. The experimental results also confirm that this method is tolerant to link signal-to-noise ratio loss and dispersion, showing no additional penalty after transmission over a 40-km sta...
Bookmarks Related papers MentionsView impact
33rd European Conference and Exhibition on Optical Communication - ECOC 2007, 2007
Page 1. 100Gbit/s packet generation with spectral efficiency larger than 1bit/Hz/s by using optic... more Page 1. 100Gbit/s packet generation with spectral efficiency larger than 1bit/Hz/s by using optical carrier suppression and separation and vestigial sideband filtering techniques Jianjun Yu1, Lei Xu1, Philip Nan Ji1, Zhensheng ...
Bookmarks Related papers MentionsView impact