Browsing by Author "Yu, CM"

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A novel DCT-based bit plane error resilient entropy coding for wireless multimedia communication
(2002)
Lee, YS
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Yu, CM
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Lee, CY
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交大名義發表
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National Chiao Tung University
A novel thin-film transistor with self-aligned field induced drain
(2001-01-01)
Lin, HC
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Yu, CM
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Lin, CY
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Yeh, KL
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Huang, TY
In this letter, a novel thin-film transistor with a self-aligned field-induced-drain (SAFID) structure is reported for the first time. The new SAFID TFT features a self-aligned sidewall spacer located on top of the drain offset region to set its effective length, and a bottom gate (or field plate) situated under the drain offset region to electrically induce the field-induced-drain (FID). So, unlike the conventional off-set-gated TFTs with their effective FID length set by two separate photolithographic masking layers, the new SAFID is totally immune to photomasking misalignment errors, while enjoying the low off-state leakage as well as high turn-on characteristics inherent in the FID structure. Polycrystalline silicon TFTs with the new SAFID structure have been successfully fabricated with significant improvement in the on/off current ratio.
A simulation study of a distributed antenna-based CDMA system
(1996)
Chen, GH
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Yu, CM
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Huang, CC
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交大名義發表
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電信工程研究所
In this paper, a computer simulation study on both coverage and capacity performance of a distributed antenna based CDMA system is presented. Wideband direct sequence spread spectrum signalling with a perfect RAKE receiver is assumed. Computer simulations are used to evaluate the distribution of received signal strength in a single cell architecture, and the distribution of received signal's SIR in a cellular architecture, for both a central antenna based system and a distributed antenna based system. It is found from our simulation that a distributed antenna based system has the potential to provide larger coverage area and higher capacity as compared with a central antenna based system.
Characterization of polysilicon thin-film transistors with asymmetric source/drain implantation
(2005-08-01)
Shieh, MS
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Lin, YJ
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Yu, CM
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Lei, TF
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電子工程學系及電子研究所
The effect of asymmetry tilt angle ion implantation on polysilicon thin-film transistors (TFTs) device characteristics are investigated. This asymmetric source/drain (S/D) TFTs structure exhibits low leakage current and suppressed kink effect due to the relief of higher electric field near the drain junction side. It is shown that the optimal implantation tilt angle is 30 degrees in our annealing condition. And the anomalous off-state current is more than two orders of magnitude lower than that of the conventional TFTs. By well controlled the LDD region, this structure can act as a conventional structure in the on-state and the turn-on current will not be degraded. Besides, the device under severe hot carrier bias stress shows better hot carrier endurance. (c) 2005 Elsevier B.V. All rights reserved.
Effects of plasma treatments on the characteristics of poly-Si thin-film transistors having electrical junctions induced by a bottom sub-gate
(2003)
Yu, CM
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Lin, HC
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Lei, TF
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Huang, TY
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電子工程學系及電子研究所
The effects of H-2 and NH3 plasma on poly-Si thin-film transistors with source/drain extensions induced by a bottom sub-gate were investigated. Significant improvement in device characteristics could be made using the two methods, though the NH3-plasma-treated devices show better performance than the H-2-plasma-treated counterparts in terms of lower off-state leakage, smaller subthreshold swing, and improved mobility, etc. Moreover, an anomalous subthreshold hump phenomenon observed in short-channel devices is also less significant for the devices treated by NH3 plasma. Our analysis indicates that the NH3 plasma is more effective in passivating the traps distributing in both front and back sides of the channel.
H-2 and NH3 plasma passivation on poly-Si TFTs with bottom-sub-gate induced electrical junctions
(2003-12-01)
Yu, CM
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Lin, HC
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Huang, TY
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Lei, TF
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電子工程學系及電子研究所
The effects of NH3 and H-2 plasma passivation on the characteristics of poly-Si thin-film transistors (TFTs) with source/drain extensions induced by a bottom sub-gate were studied. Our results show that although significant improvements in device performance can be obtained by either passivation method, the NH3-plasma-treatment appears to be more effective in reducing the off-state leakage, subthreshold swing, and in improving mobility compared to H-2 plasma passivation. Furthermore, NH3 plasma treatment is also found to be more effective in reducing the anomalous subthreshold hump phenomenon observed in nonplasma-treated short-channel devices. Detailed analysis suggests that all these improvements can be explained by the more effective passivation of traps distributed in both the front and back sides of the channel by NH3 plasma treatment. (C) 2003 The Electrochemical Society.
HVLC: Error correctable hybrid variable length code for image coding in wireless transmission
(2000)
Lee, YS
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Yu, CM
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Chang, WS
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Lee, CY
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電子工程學系及電子研究所
Variable length code (VLC), also called Huffman code [1] is the most popular data compression technique used for solving transmission channel bandwidth bottleneck in image compression standards such as JPEG, MPEG, and H263. But, it is vulnerable to loss of synchronization if they are transmitted consecutively through a noisy wireless channel. It will result in large drops in video transmission quality. We propose a novel Hybrid VLC (HVLC) coding scheme to provide high tolerances to random and burst errors in worsening channel conditions. It exhibits high synchronization, error correction capability and low redundancy. For erroneous HVLC bitstream, it is able to self-synchronize within one codeword. The result shows that it achieves high signal-to-noise ratio (PSNR=30dB) compared to existing VLC schemes at bit error rate (BER) of 10(-3) environment. With efficient memory mapping, HVLC requires low memory spaces and achieves high throughput rate. It is very suitable for VLSI implementation in wireless application.
Introduction to blueweb: A new bluetooth-based multihop ad hoc network
(2004)
Yu, CM
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Huang, CC
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電信工程研究所
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Institute of Communications Engineering
In this paper we present Blueweb, a self-organizing Bluetooth-based multihop network with an efficient scatternet formation algorithm and a hybrid routing protocol. The Blueweb is designed from the original idea of Bluetree. Blueweb scatternet formation uses two mechanisms. One is the role exchange mechanism in which only slave nodes serve as relays throughout the whole scatternet. The other one is the return connection mechanism in which we convert the scatternet from a tree-shaped to a web-shaped topology. Meanwhile, a modified source routing protocol is designed for Blueweb in which we combine the proactive method with the reactive method to discover the optimal path for packet transmission. Qualitative performance analysis shows that Blueweb generates an efficient scatternet architecture and achieves good routing performance.
On the architecture and performance of blueweb: A bluetooth-based multihop ad hoc network
(2006-02-01)
Yu, CM
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Lin, SJ
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Huang, CC
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電信工程研究所
;
Institute of Communications Engineering
In this paper, we present Blueweb, a new Bluetooth-based multihop network with an efficient scatternet formation algorithm and a hybrid routing protocol. The Blueweb is designed from the original idea of Bluetree. Blueweb's scatternet formation uses two mechanisms. One is the role exchange mechanism in which only slave nodes serve as the role of relay through the whole scatternet. The other one is the return connection mechanism in which we convert the scatternet from a tree-shaped to a web-shaped topology. Meanwhile, a modified source routing protocol is designed for Blueweb in which we combine the proactive method with the reactive method to discover the optimal path for packet transmission. Furthermore, using computer simulations we compared the system performance of Blueweb and Bluetree with both a static model and a uniform traffic model. With the static model we evaluate the scatternet performance and with the uniform traffic model we evaluate the transmission performance. Our simulation results show that Blueweb achieves superior system performance than Bluetree on both scatternet performance and transmission performance.
On the performance of a hybrid routing protocol for blueweb: A bluetooth-based multihop ad hoc network
(2006)
Yu, CM
;
Huang, CC
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電信工程研究所
;
Institute of Communications Engineering
Blueweb is a self-organizing Bluetooth-based multihop network with an efficient scatternet formation algorithm. Blueweb's scatternet formation uses two mechanisms. One is the role exchange mechanism in which only slave nodes serve as relays throughout the whole scatternet. The other one is the return connection mechanism in which we convert the scatternet from a tree-shaped to a web-shaped topology. In this paper, a modified source routing protocol is proposed for Blueweb in which we combine the proactive method locally with the reactive method globally to discover the optimal path for packet transmission. In addition, we use computer simulations to evaluate the routing performance of Blueweb with a uniform end-to-end traffic model. Our simulation results show that Blueweb can achieve good system performance with the modified source routing protocol.
Self-aligned fabrication of thin-film transistors with field-induced drain
(2002-08-01)
Yu, CM
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Lin, HC
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Lin, CY
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Yeh, KL
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Huang, TY
Thin-film transistor (TFT) devices with either a top or a bottom sub-gate were fabricated and characterized. The top sub-gate scheme allows the self-aligned formation of main-gate with respect to the sub-gate. On the other hand, the bottom sub-gate scheme features a self-aligned field-induced drain with a sidewall spacer located on its top to set the effective field-induction-drain (FID) length. Unlike the conventional TFTs, the FID serves to distribute the high drain electric field and thereby eliminates gate-induced drain leakage-like off-state leakage current. Superior device performance is realized with the bottom sub-gate structure. (C) 2002 Elsevier Science Ltd. All rights reserved.