Browsing by Author "Chiang, PY"

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33-channel 64-QAM signal transmission using a 1.3-mu m semiconductor optical amplifier
(1996-01-01)
Chiang, PY
;
Tai, C
;
Way, WI
;
電信工程研究所
;
電信研究中心
From the network evolution point of view, optical amplifiers in a hybrid fiber coaxial (HFC) system may become extensively deployed at approximately the same time as when analog AM-VSB video signals are all replaced by digital M-QAM or M-VSB signals. This letter demonstrates the feasibility of using a 1.3-mu m semiconductor optical amplifier to transport 33 channels of 64-QAM signals with 30 Mbps/channel. A total system power budget of 20.3 dB was obtained.
A novel leakage current separation technique in a direct Tunneling regime gate oxide SONOS memory cell
(2003)
Chung, SS
;
Chiang, PY
;
Chou, G
;
Huang, CT
;
Chen, P
In this paper, data retention for various top and bottom oxide (tunnel oxide) SONOS cells has been extensively investigated. For the first time, a leakage current separation technique has been developed to distinguish the two leakage current components via thermionic and direct tunneling (DT) in the ONO layer. Results show that the short-term leakage is dominated by the direct tunneling, while the long-term leakage is dominated by the thermionic emission. The direct tunneling through either tunnel or blocking oxide can also be identified experimentally. These results are useful toward an understanding of the scaling of SONOS cell with focus on its reliabilities.
Eight-way, 70-km transmission of 33-channel 64-QAM signals utilizing a 1.3-mu m external modulation system and semiconductor optical amplifier
(1996-09-01)
Tai, C
;
Chiang, PY
;
Way, WI
;
電信工程研究所
;
電信研究中心
By using a 1.3-mu m external modulation system and a semiconductor optical amplifier, we experimentally demonstrated the feasibility of broadcasting 33 channels of 64-QAM digital CATV signals to eight 70-km optical fiber links, The presented results show that, with the vast momentum on developing M-QAM modems, potentially low-cost semiconductor optical amplifiers can possibly expedite the penetration pace of optical fibers in broad-band access networks.
Eight-way, 70-km transmission of 33-channel 64-QAM signals utilizing a 1.3-mu m external modulation system and semiconductor optical amplifier
(1996-09-01)
Tai, C
;
Chiang, PY
;
Way, WI
;
電信工程研究所
;
光電工程學系
By using a 1.3-mu m external modulation system and a semiconductor optical amplifier, we experimentally demonstrated the feasibility of broadcasting 33 channels of 64-QAM digital CATV signals to eight 70-km optical fiber links, The presented results show that, with the vast momentum on developing M-QAM modems, potentially low-cost semiconductor optical amplifiers can possibly expedite the penetration pace of optical fibers in broad-band access networks.
Large-signal spurious-free dynamic range due to static and dynamic clipping in direct and external modulation systems
(1998-10-01)
Wang, BH
;
Chiang, PY
;
Kao, MS
;
Way, WI
;
電信工程研究所
Large-signal spurious-free dynamic range (SFDR) is useful in an optical system with a high intensity noise level, which can be due to optical reflections or optical beat interference, and with large modulating signals to achieve sufficient carrier-to-noise ratio (CNR). A closed-form analysis on large-signal SFDR due to static and dynamic clipping for direct and external modulation systems is presented in this paper. The analysis can be applied to laser diodes (LD's) and external modulators with arbitrary transfer functions. We have used the analysis to predict the theoretical upper-bound for large-signal SFDR due to static clipping in an ideal LD add external modulators with various linearization techniques. We have also used the analysis to predict the dynamic-clipping-induced nonlinear distortions (NLD's) id. a weakly clipped LD, and confirm that dynamic clipping is more important to consider than static clipping when weak LD clipping takes place. Large-signal SFDR's in practical LD's and external modulators were also compared. The validity of our analysis is confirmed through computer simulation and actual measurement of clipping-induced NLD's in a typical CATV-quality DFB LD.
On the validity of using CW tones to test the linearity of multichannel M-QAM subcarrier multiplexed lightwave systems
(2000-04-01)
Wu, MC
;
Chiang, PY
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
This paper investigates the validity of using multiple continuous-wave (CW) tones as the signal source to test the linearity of a multichannel M-ary quadrature-amplitude-modulation (M-QAM) subcarrier multiplexed lightwave system. We consider the following representative optical fiber system nonlinearities: 1) laser clipping and 2) the combined effect of laser frequency chirp and fiber dispersion. Our results show that if all orders of nonlinear distortions (NLD's) in a signal bandwidth are included in the total NLD power, the error caused by replacing M-QAM signals with CW tones can be within measurement uncertainty.
The performance and reliability enhancement of ETOX P-channel flash EEPROM cell with P-doped floating-gate
(2003)
Tsai, HW
;
Chiang, PY
;
Chung, SS
;
Kuo, DS
;
Liang, MS
In this paper, we proposed a simple approach for designing reliable and high performance p-channel Flash EEPROM cell from the floating-gate engineering point of view. In other words, a p-type doped floating gate used in a p-channel flash cell can achieve this goal. Results show that the programming speed, gate/drain disturb, read lifetime, and data retention in p-type floating-gate cell are much better than those of n-type floating-gate cell; except that p-type floating-gate cell has slower erasing speed. These results can be used as a guideline for designers to choose.
Ultimate capacity of a laser diode in transporting multichannel M-QAM signals
(1997-10-01)
Chiang, PY
;
Way, WI
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
In this paper, we investigate the ultimate M-ary quadrature amplitude modulated (M-QAM) channel capacity of a laser diode which is limited by the laser clipping induced nonlinear distortions, Our study includes a spectral analysis, a complete system simulation, and an experiment which used up to 70 channels of vector arbitrary waveform synthesizer generated quadrature phase shift keyed (QPSK) or 16-QAM signals to modulate an isolated/cooled distributed-feedback (DFB) laser and two unisolated/uncooled Fabry-Perot (FP) lasers, respectively, Our analytical results show that for an upstream laser diode, over 1000 QPSK channels or 170 16-QAM channels can be delivered, even in the presence of a high relative intensity noise (RIN) of -115 dB/Hz, However, these high capacities are reduced significantly when we consider the effect of collision-based medium access control (MAC) protocols, We found that, in the worst case condition (collisions occur in all but one channels), the ultimate QPSK channel capacity of an upstream laser diode is dramatically reduced from over 1000 to 125 for eight collisions/channel. These results have important implications to systems transporting frequency-stacked return-path bands with or without collision-based MAC channels, As regard to the ultimate capacity of a down-stream laser diode with a RIN level of -135 dB/Hz, we found that as high as 600 and 128 channels of 64-QAM and 256-QAM signals (equivalent to 3600 and 1152 channels of MPEG-II live video signals) can be transported, respectively.
Ultimate capacity of a laser diode in transporting multichannel M-QAM signals (vol 15, pg 1914, 1997)
(1998-02-01)
Chiang, PY
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
Using preceding technique to reduce the BER penalty of an M-QAM channel in hybrid AM-VSB/M-QAM subcarrier multiplexed lightwave systems
(1998-08-01)
Chiang, PY
;
Hsiao, CC
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
We propose and verify through computer simulations the use of a preceding technique to eliminate the nonlinear distortions in an M-QAM channel, which is transported along with multiple AM-VSB channels by a laser diode. We show that the preceding technique can completely remove the clipping-induced bit-error-rate (BER) floor at a cost of a 3-dB signal-to-noise ratio reduction.
Using precoding technique to reduce the BER penalty of an M-QAM channel in hybrid AM-VSB/M-QAM subcarrier multiplexed lightwave systems
(1998)
Chiang, PY
;
Hsiao, CC
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
We propose and verify through computer simulations the use of a preceding technique to eliminate the nonlinear distortions (NLD's) in an M-QAM channel which is transported along with multiple AM-VSB channels by a laser diode. We show that the preceding technique can completely remove the clipping-induced bit-error-rate (BER) floor at a cost of a 3 dB signal-to-noise ratio (SNR) reduction.