Browsing by Author "Hsu, TY"

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A 1.5-V, 2.4GHz CMOS low-noise amplifier
(2000)
Yang, JN
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Lee, CY
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Hsu, TY
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Hsu, TR
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Wang, CC
A 2.4GHz low noise amplifier has been designed in a standard CMOS 0-35 um process. The transistor model is Bsim3 for 0.35um process. The amplifier provides a forward gain of 33dB with a noise figure only 0.92dB while drawing 17mw from a 1.5 V supply. Design simulation results are presented In this paper.
A 1.75GHz inductor-less CMOS low noise amplifier with high-Q active inductor load
(2001)
Yang, JN
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Cheng, YC
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Hsu, TY
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Hsu, TR
;
Lee, CY
A 1.75GHz CMOS inductor-less low noise amplifier with high-Q active inductor load using 0.35um. standard CMOS digital process is presented. In this low noise amplifier, the compact tunable high-Q active inductor load is connected to the common-gate configuration to improve the performance of the high power gain, low power consumption and simple matching characteristics. Not using any passive components is to reduce the area of chip and the complexity. HSPICE simulation has been performed to verify the performance of the designed low noise amplifier. It has been shown that the amplifier has a power gain of 24dB(S21), S11 of -31dB, S12 of -38.5dB and S22 of -21.4dB under 3.3V power supply with 9.3mW power consumption around at 1.75GHz center frequency. The experimental chip fabricated occupies 0.057x0.056 mm(2) chip area.
A COMM baseband processor with robust synchronization for high-speed WLAN applications
(2004)
Liu, HY
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Yu, YH
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Lin, CC
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Chung, CC
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Hsu, TY
in this paper, a high-performance and low-cost COFDM baseband processor is presented. With algorithm exploration in channel estimation and phase error tracking, synchronization becomes more robust to enhance system performance. And better design SNR (1.35similar to7.16 dB) can be achieved compared to current solutions. Moreover through architectural exploration, the proposed baseband processor designed in 0.18 um CMOS process contains only 370 K logic gates and 3.3 K byte memory. Measurement results show that better hardware efficiency and performance enhancement is achieved for high-speed WLAN applications.
A DSSS receiver for dual-mode DSSS/OFDM wireless LAN systems
(2005)
Hsiao, FH
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Guo, JH
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Lo, SL
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Hsu, TY
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資訊工程學系
This paper introduces a DSSS baseband receiver suitable for a dual mode DSSS/OFDM wireless LAN system. Packet synchronizer with a pair of ADCs with dynamic sampling is used for detecting both DSSS and OFDM packets. For differentially encoded symbols, frequency offset and phase offset can be compensated based on their inherent characteristics. For high data rate DSSS based modulations, channel estimation and equalization with receive diversity combining in frequency domain is applied to resolve the multipath distortions. With channel equalization and diversity combining of the DSSS receiver achieved in frequency domain the overall complexity of the dual mode DSSS/OFDM equalization can be realized.
A frequency domain equalizer for WLAN 802.11g single-carrier transmission mode
(2005)
Hsiao, FH
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Hsu, TY
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資訊工程學系
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Department of Computer Science
In this paper a frequency domain equalizer is proposed for WLAN 802.11g single-carrier transmission mode. Channel estimation is achieved with modified recursive least square (RLS) algorithm in frequency domain. For channel compensation, OFDM like frequency domain zero-forcing equalization is performed with FFT units and complex divider. In 802.11g single-carrier mode, transmission packets are not equipped with cyclic prefixes so signal overlapping and discarding using sliding windows are maintained at each equalization process to decrease the symbol estimation error caused by circularly de-convoluting a linear channel convolution process. With the equalizer of single-carrier mode implemented in frequency domain many of their computation resources can be shared with 802.11g OFDM equalizer offering a low complexity multimode receiver solution.
A novel technique for I/Q imbalance and CFO compensation in OFDM systems
(2005)
Yu, JY
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Sun, MF
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Hsu, TY
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Lee, CY
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電子工程學系及電子研究所
In this paper, a novel baseband IQ estimation and compensation technique is proposed to overcome the joint effects of CFO and IQ imbalance. The proposed method uses a one-shot algorithm which is able to estimate and compensate the non-ideal effect up to gain error 1 dB, phase error 10 degree, and CFO 50 ppm at carrier frequency 2.5GRz in 64QAM OFDM system. Under this condition, the system performance has less than 0.8 dB design loss in terms of PER and is shown to have more than 10 dB improvement compared with the reference design.
An all-digital phase-locked loop (ADPLL)-based clock recovery circuit
(1999-08-01)
Hsu, TY
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Shieh, BJ
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Lee, CY
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A new algorithm for all-digital phase-locked loops (ADPLL) with fast acquisition and large pulling range is presented in this paper. Based on the proposed algorithm, portable cell-based implementations for clock recovery with functions of a frequency synthesizer and on-chip clock generator are completed by standard cell, These modules have been designed and verified on a 0.6-mu m CMOS process. Test results are summarized as follows: 1) the proposed ADPLL can satisfy full locked bandwidth and fast acquisition within one data transition; 2) the on-chip clack generator can generate any target clock rate f(clock); and 3) the function of nonreturn-to-zero clock recovery has a maximum f(clock)/4 recovering capability vith a locking range of (tau(input) + tau(input)/2), where tau(input) is the input period.
Combining adaptive smoothing and decision-directed channel estimation schemes for OFDM WLAN systems
(2003)
Liu, HY
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Yu, YH
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Hung, CJ
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Hsu, TY
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Lee, CY
In this paper, a new channel estimation method for OFDM WLAN systems is proposed. This proposal mainly consists of smoothing filtering and decision-directed tracking loop schemes, where the former is used to enhance performance at low SNR and the latter is exploited to enhance performance at high SNR respectively. Together with an adaptive channel management, better performance in terms of MSE and PER can be achieved. Simulation shows the proposed method (1) achieves better 9.0dB similar to 13.0dB gain in MSE than zero forcing criterion and better 2.0dB gain in MSE than conventional approaches in BPSK transmission, and (2) contributes 0.8dB similar to 2.0dB gain in SNR for 10% PER in different transmission modes.
Effects of shadowing, multipath fading, antenna diversity in DS/CDMA for cellular mobile radio with reverse-link power control
(1997)
Hsu, TY
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Lee, CY
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交大名義發表
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電子工程學系及電子研究所
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National Chiao Tung University
In this paper, we do mathematic derivations for multiple-cell system to estimate system performance with considerations of shadowing, multipath fading, antenna diversity, a voice active factor, and reverse-link power control. Complex statistic models for channels and systems are considered in the analysis. From our numerical results, the system performance is dependent on fading environment, such as numbers of multipath and different fading limit, whether what kinds of power control schemes were used in designs. However, simulation results also show that antenna diversity can compensate for this effect. With considerations of fading, the average power control is not capable enough to keep systems working. Finally, both antenna diversity and strength-based power control are requested to maintain a minimum required number of subscribers per sectorization in fading environment.
The outage probability in DS/CDMA for cellular mobile radio with imperfect power control
(1996)
Hsu, TY
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Lee, CY
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交大名義發表
;
電子工程學系及電子研究所
;
National Chiao Tung University
In this paper, we establish a system model, including shadowing, multiapth fading, antenna diversity and voice active factor, to estimate the system performance with considerations of the perfect and imperfect power control by using outage probability. Based on our calculations, it is shown that the system performance is sensitive to multipath fading, antenna diversity, and the power-control error. From our simulation results, three schemes are derived as follows: (1) The average power control is not powerful enough to maintain a minimum required number of subscribers per cell in fading environment or imperfect conditions; (2) Antenna diversity can be used to improve the system capacity in all conditions, not only considerations with the perfect power control, but also with the imperfect power control; (3) The system capacity is decreased rapidly by multipath fading and the power-control error.
Unified knowledge-based content management for digital archives in museums
(2006)
Hsu, TY
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Ke, HR
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Yang, WP
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圖書館
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Library
Purpose - This paper sets out to present a new model to avoid the content silo trap, satisfy the knowledge management requirement and support the long-term perspective of developing academic, exhibition, and education applications among various domains for museums. Design/methodology/approach - This paper presents a unified knowledge-based content management (UKCM) model, which comprises the unified knowledge content processes, multi-layer reusable knowledge content structures and an integrated knowledge-based content management system to solve the content silo trap problem. The extended entity-relationship (EER) conceptual model is applied to design a global view of the integrated knowledge system and completely represent multi-layer reusable knowledge content structures for the spectrum of various knowledge assets for all domains and applications in a museum. Findings - A practical case of a large-scale digital archives project that includes various domains of a natural science museum has been successfully implemented to demonstrate the feasibility of the proposed model. Originality/value - This paper integrates content management and knowledge management. Digital archives programs in museums can apply the model presented in this study to satisfy the knowledge management requirement and support the long-term perspective of developing academic, exhibition, and education applications among various domains.