Browsing by Author "Dai, Sheng-Peng"

Now showing 1 - 12 of 12

A novel direct detection microwave photonic vector modulation scheme for radio-over-fiber system
(2008-07-01)
Lin, Chun-Ting
;
Dai, Sheng-Peng
;
Chen, Jason (Jyehong)
;
Shih, Po Tsung
;
Peng, Peng-Chun
This letter demonstrates the feasibility of a novel direct detection microwave photonic vector modulation scheme for the radio-over-fiber (RoF) system. Unlike the traditional double-sideband with optical carrier suppression modulation scheme, which can carry only the on-off keying data format, the proposed scheme encodes the electrical vector signal on either the upper sideband (USB) or the lower sideband (LSB) only and a pure optical subcarrier on the other sideband. Therefore, phase and amplitude information will be preserved after direct detection. A frequency doubling scheme is employed to reduce the cost of RoF systems. Additionally, the relative intensity between USB and LSB can be easily tuned by adjusting the individual power of electrical driving signals to optimize the performance of the optical radio-frequency signals. A proof-of-concept experiment is conducted by using a 1.25 Gb/s BPSK signal at a carrier frequency of 20 GHz. After transmission over 50-km single-mode fiber, the receiver sensitivity penalty is less than 0.5 dB.
Cost-effective multiservice's hybrid access networks with no optical filter at remote nodes
(2008-05-01)
Lin, Chun-Ting
;
Shih, Po Tsung
;
Chen, Jason (Jyehong)
;
Peng, Peng-Chun
;
Dai, Sheng-Peng
This letter experimentally demonstrates a multi-services hybrid access network integrated radio-over-fiber and fiber-to-the-home systems which share the same distributed architecture. A 1.25-Gb/s baseband signal and a 14.375-GHz radio-frequency (RF) signal with 625-Mb/s binary phase-shift keying data are generated and transmitted employing a commercially available dual-electrode Mach-Zehuder modulator. The proposed scheme offers better performance, has no RF fading issue, can carry vector signals, and requires no optical filter at remote nodes. After transmission over 25-km single-mode fiber, the proposed scheme successfully achieves less than 0.5-dB sensitivity penalties.
Experimental Demonstration of Optical 5-Gb/s 16-QAM OFDM Signal Generation and Wavelength Reuse for 1.25-Gbit/s Uplink Signal
(2008)
Lin, Chun-Ting
;
Jiang, Wen-Jr
;
Chen, Jason (Jyehong)
;
Wong, Er-Zih
;
Dai, Sheng-Peng
5Gb/s 16QAM OFDM signal for ROF downstream link and 1.25Gb/s OOK signal via RSOA for upstream link are demonstrated. Negligible penalty is observed after 25km SMF.
Experimental Demonstration of Optical Colorless Direct-Detection OFDM Signals with 16-and 64-QAM Formats beyond 15 Gb/s
(2008)
Lin, Chun-Ting
;
Dai, Sheng-Peng
;
Jiang, Wen-Jr
;
Chen, Jason (Jyehong)
;
Lin, Yu-Min
Both highly spectral-efficient direct-detection 15-Gb/s 64-QAM and 20-Gb/s 16-QAM OFDM signals are demonstrated. Negligible penalty is observed following 25-km SMF transmission.
Generation of carrier suppressed optical mm-wave signals using frequency quadrupling and no optical filtering
(2008)
Lin, Chun-Ting
;
Shih, Po Tsung
;
Chen, Jason (Jyehong)
;
Peng, Peng-Chun
;
Dai, Sheng-Peng
This work demonstrates a novel mm-wave generation using a frequency quadrupling technique. Only one external MZM is used and no optical filter is needed. It provides a simple and inexpensive choice for WDM RoF applications. (C)2008 Optical Society of America.
Generation of direct-detection optical OFDM signal for radio-over-fiber link using frequency doubling scheme with carrier suppression
(2008)
Lin, Chun-Ting
;
Lin, Yu-Min
;
Chen, Jason (Jyehong)
;
Dai, Sheng-Peng
;
Peng, Peng-Chun
This investigation demonstrates the generation of OFDM-RoF signal using frequency doubling. Benchmarked against the OOK format, the 4-Gb/s, 16-QAM OFDM format has four times the higher spectral efficiency with a sensitivity penalty of under 2.6-dB. (c) 2007 Optical Society of America.
Generation of optical millimeter-wave signals and vector formats using an integrated optical I/Q modulator [Invited]
(2009-02-01)
Chen, Jyehong
;
Lin, Chun-Ting
;
Shih, Po Tsung
;
Jiang, Wen-Jr
;
Dai, Sheng-Peng
This study discusses two key technologies used in radio-over-fiber (RoF) systems, namely, the generation and transmission of millimeter-wave signals and optical modulation schemes capable of carrying vector signal formats and utilizing the continuous performance improvements offered by digital signal processing. A cost-effective frequency-quadrupling technique capable of generating millimeter-wave signals up to 72 GHz is proposed. The generated optical millimeter-wave signals have very high quality, with an optical carrier and harmonic distortion suppression ratio exceeding 36 dB. An optical modulation scheme that can support a 64-QAM, 16 Gbits/s orthogonal frequency-division multiplexing RoF system is also demonstrated. Results of this study demonstrate that both methods offer realistic solutions to support future wireless systems. (C) 2009 Optical Society of America
Impact of Nonlinear Transfer Function and Imperfect Splitting Ratio of MZM on Optical Up-Conversion Employing Double Sideband With Carrier Suppression Modulation
(2008-07-01)
Lin, Chun-Ting
;
Chen, Jason (Jyehong)
;
Dai, Sheng-Peng
;
Peng, Peng-Chun
;
Chi, Sien
Generation of optical millimeter-wave (mm-wave) signal using a Mach-Zehnder modulator (MZM) based on double-sideband (DSB), single-sideband (SSB), and double-sideband with carrier suppression (DSBCS) modulation schemes have been demonstrated for various applications, such as broadband wireless signals or optical up-conversion for wavelength-division-multiplexing (WDM) radio-over-fiber (RoF) network, wideband surveillance, spread spectrum, and software-defined radio. Among these schemes, DSBCS modulation offers the best receiver sensitivity, lowest spectral occupancy, the least stringent requirement of electrical bandwidth, and the smallest receiving power penalty after long transmission distance. Nonetheless, the inherent nonlinear E/O (electrical/optical) conversion response of a MZM is such that the signal quality of the optical mm-wave suffers. Fabrication tolerances make a balanced 50150 splitting ratio of the MZM's y-splitter particularly difficult to achieve. As a result, imbalanced MZMs have a finite extinction ratio (ER) and degrade the optical carrier suppression ratio (OCSR) using DSBCS modulation. In this paper, the effect of the MZM nonlinearity and imbalanced y-splitter on optical mm-wave generation by DSBCS modulation is theoretically and experimentally investigated. A novel approach with better performance and greater cost-effectiveness than dual-electrode MZM (DD-MZM) is presented to realize a DSBCS modulation scheme based on a single-electrode MZM (SD-MZM).
Optical access system for dual service network
(2010-01-14)
Chen, Jyehong
;
Lin, Chun-Ting
;
Shih, Po-Tsung
;
Peng, Peng-Chun
;
Dai, Sheng-Peng
The present invention relates to an optical access system for dual service network, which mainly comprises an optical modulation device which is used to receive on-off keying (OOK) signal from cable network and radio frequency (RF) signal from wireless network, the optical modulation device then modulates the OOK signal and the RF signal to an optical signal and send out an output optical signal. Lastly, the output optical signal is being delivered to an optical receiving device through an optical fiber transmission channel, and the optical receiving device can access the OOK signal and RF signal from the output optical signal. In addition, the present invention does not require remote nodes (receiver side) to use any optical filter to discern on-off keying signal from cable network and RF signal from wireless network. The present invention can also apply to the field of wavelength-division multiplexing system.
Optical direct-detection OFDM signal generation for radio-over-fiber link using frequency doubling scheme with carrier suppression
(2008-04-28)
Lin, Chun-Ting
;
Lin, Yu-Min
;
Chen, Jason (Jyehong)
;
Dai, Sheng-Peng
;
Shih, Po Tsung
This investigation demonstrates the generation of OFDM-RoF signal using frequency doubling technique for the first time, to the author's best knowledge. The 4-Gb/s OFDM signal using 16-QAM format modulated on each subcarrier at a center frequency of 19GHz is experimentally demonstrated. Benchmarked against the OOK format, the 16-QAM OFDM format has the higher spectral efficiency with a sensitivity penalty of less than 2.6 dB. After transmission over 50-km single mode fiber, the power penalties of RF OOK and OFDM signals are less than 0.5dB. (c) 2008 Optical Society of America.
Optical Millimeter-Wave Up-Conversion Employing Frequency Quadrupling Without Optical Filtering
(2009-08-01)
Lin, Chun-Ting
;
Shih, Po-Tsung
;
Chen, Jason (Jyehong)
;
Jiang, Wen-Jr
;
Dai, Sheng-Peng
This study presents two optical frequency quadrupling techniques for generating high-purity millimeter-wave signals with optical carrier suppression. To our best knowledge, this investigation demonstrates for the first time that a frequency quadrupling system requires only a single integrated Mach-Zehnder modulator without an optical narrowband filter to remove undesired optical sidebands. Since no optical filter is needed, fast frequency tuning is straightforward and this approach is particularly attractive for the optical up-conversion in the wavelength-division-multiplexing radio-over-fiber systems. This study provides both theoretical analysis and experimental demonstration. The generated optical millimeter-wave signals are of very high quality with optical carrier and undesired harmonic distortion suppression ratio of more than 36 dB.
Optical modulating device with frequency multiplying technique for electrical signals
(2010-01-14)
Chen, Jyehong
;
Lin, Chun-Ting
;
Dai, Sheng-Peng
;
Peng, Peng-Chun
;
Shih, Po-Tsung
The present invention relates to an optical modulating device with frequency multiplying technique for electrical signals, which primary comprises a mixer, which generates a mixed data signal from a first electrical signal and a second electrical signal. The mixed data signal is then received by a first phase shift device to have its phase shifted and becomes a first shifted signal. The first electrical signal is further received by a second phase shift device to have its phase shifted and becomes a second shifted signal. The present invention further comprises an integrated electro-optic modulator (Mach-Zehnder modulator), which is used to receive an input optical signal, the mixed data signal, the first shifted signal, the second shifted signal and the first electrical signal mentioned above, the integrated electro-optic modulator will then modulates the input optical signal into a frequency multiplying output optical signal that carries the first electrical signal and the second electrical signal. The present invention can carry and transmit amplitude shift keying signals and vector modulation signals, thereby provides a more advanced optical communication transmission service.