Browsing by Author "Hsiao, FH"

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A DSSS receiver for dual-mode DSSS/OFDM wireless LAN systems
(2005)
Hsiao, FH
;
Guo, JH
;
Lo, SL
;
Hsu, TY
;
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
;
Hsu, TY
;
資訊工程學系
;
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.
An efficient algorithm for finding the D-stability bound of discrete singularly perturbed systems with multiple time delays
(1999-01-10)
Hsiao, FH
;
Pan, ST
;
Teng, CC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, we present an original work on the D-stabilization problem of discrete singularly perturbed systems with multiple time delays. A new robust D-stability criterion in terms of stability radius is first derived to guarantee that all poles of the discrete multiple time-delay systems remain inside the specific disk D(alpha, r) in the presence of parametric uncertainties. Then, by using the technique of time-scale separation, we derive the corresponding slow and fast subsystems of a discrete multiple time-delay singularly perturbed system. The state feedback controls for the D-stabilization of the slow and the fast subsystems are separately designed and a composite state feedback control for the original system is subsequently synthesized from these state feedback controls. Thereafter, we derive a frequency domain epsilon-dependent D-stability criterion for the original discrete multiple time-delay singularly perturbed system under the composite state feedback control. If any one of the conditions of this criterion is fulfilled, D-stability of the original closed-loop system is thus investigated by establishing that of its corresponding slow and fast closed-loop subsystems. Finally, an efficient algorithm is proposed to obtain a less conservative D-stability bound of the singular perturbation parameter and to reduce the computation time.
Application and robustness design of fuzzy controller for resonant and chaotic systems with external disturbance
(2005-06-01)
Hsiao, FH
;
Chiang, WL
;
Chen, CW
;
Xu, SD
;
Wu, SL
A robustness design of fuzzy control via model-based approach is proposed in this paper to overcome the effect of approximation error between nonlinear system and Takagi-Sugcno (T-S) fuzzy model. T-S fuzz model is used to model the resonant and chaotic systems and the parallel distributed compensation (PDC) is employed to determine structures of fuzzy controllers. Linear matrix inequality (LMI) based design problems are utilized to find common definite matrices P and feedback gains K satisfying stability conditions derived in terms of Lyapunov direct method. Finally, the effectiveness and the feasibility of the proposed controller design method is demonstrated through numerical simulations on the chaotic and resonant systems
D-stability analysis for discrete uncertain time-delay systems
(1998-03-01)
Hsiao, FH
;
Hwang, JD
;
Pan, SP
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Two cases of the robust D-stability criterion are derived for discrete uncertain systems with multiple time delays. One is a direct test and the other is a boundary test. These cases provide the sufficient conditions under which all solutions of the characteristic equation remain inside the specific disk D(alpha, r) in the presence of parametric uncertainties.
D-stability bound analysis for discrete multiparameter singularly perturbed systems
(1997-04-01)
Hsiao, FH
;
Pan, ST
;
Teng, CC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The D-stability (i.e., the stability in the sense that all the poles of a system are lying inside the disk D(alpha, r)) problem for discrete multiparameter singularly perturbed systems is considered in this brief, A two-stage method is first developed to analyze the stability relationship between the discrete multiparameter singularly perturbed systems and their corresponding reduced systems. An upper hound of the singular perturbation parameters is then derived such that the D-stability of the reduced systems implies that of the original systems, provided that the singular perturbation parameters are small enough to be within this bound. This fact enables us to investigate D-stability of the original systems by establishing that of their corresponding reduced systems.
Dynamic output feedback control of nonlinear singularly perturbed systems
(1996-11-01)
Pan, ST
;
Hsiao, FH
;
Teng, CC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, the stabilization problem of two classes of nonlinear singularly perturbed systems via dynamic output feedback is investigated. First, we consider the nonlinear singularly perturbed systems in which the nonlinearities are continuously differentiable. The theoretical result demonstrates that, using the factorization approach, the dynamic output feedback controller designed for the reduced-order model of the linearized system is a stabilizing compensator for the original nonlinear singularly perturbed system, provided that epsilon is sufficiently small. Second, the nonlinear singularly perturbed systems in which the nonlinearities are not necessarily continuously differentiable but satisfy the global Lipschtz condition are examined. Combining the dynamic output feedback controller that stabilizes the reduced-order model of the linear part of the nonlinear singularly perturbed system with the quasi-stability result of Persidskii, a two-step compensating scheme is proposed to stabilize the original nonlinear singularly perturbed system under consideration fora sufficiently small epsilon. Copyright (C) 1996 Published by Elsevier Science Ltd
Dynamic output feedback control of nonlinear singularly perturbed systems
(1996-11-01)
Pan, ST
;
Hsiao, FH
;
Teng, CC
;
交大名義發表
;
電控工程研究所
In this paper, the stabilization problem of two classes of nonlinear singularly perturbed systems via dynamic output feedback is investigated. First, we consider the nonlinear singularly perturbed systems in which the nonlinearities are continuously differentiable. The theoretical result demonstrates that, using the factorization approach, the dynamic output feedback controller designed for the reduced-order model of the linearized system is a stabilizing compensator for the original nonlinear singularly perturbed system, provided that epsilon is sufficiently small. Second, the nonlinear singularly perturbed systems in which the nonlinearities are not necessarily continuously differentiable but satisfy the global Lipschtz condition are examined. Combining the dynamic output feedback controller that stabilizes the reduced-order model of the linear part of the nonlinear singularly perturbed system with the quasi-stability result of Persidskii, a two-step compensating scheme is proposed to stabilize the original nonlinear singularly perturbed system under consideration fora sufficiently small epsilon. Copyright (C) 1996 Published by Elsevier Science Ltd
Robust Kalman filter synthesis for uncertain multiple time-delay stochastic systems
(1996-12-01)
Hsiao, FH
;
Pan, ST
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The problem of robust Kalman filter synthesis is considered in this present study for discrete multiple time-delay stochastic systems with parametric and noise uncertainties. A discrete multiple time-delay uncertain stochastic system can be transformed into another uncertain stochastic system with no delay by properly defining state variables. Minimax theory and Bellman-Gronwall lemma are employed on the basis of the upper norm-bounds of parametric uncertainties and noise uncertainties. A robust criterion can consequently be derived which guarantees the asymptotic stability of the uncertain stochastic system. Designed procedures are finally elaborated upon with an illustrative example.
Robust Kalman filter synthesis for uncertain multiple time-delay stochastic systems
(1996-12-01)
Hsiao, FH
;
Pan, ST
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The problem of robust Kalman filter synthesis is considered in this present study for discrete multiple time-delay stochastic systems with parametric and noise uncertainties. A discrete multiple time-delay uncertain stochastic system can be transformed into another uncertain stochastic system with no delay by properly defining state variables. Minimax theory and Bellman-Gronwall lemma are employed on the basis of the upper norm-bounds of parametric uncertainties and noise uncertainties. A robust criterion can consequently be derived which guarantees the asymptotic stability of the uncertain stochastic system. Designed procedures are finally elaborated upon with an illustrative example.
T-S fuzzy controllers for Nonlinear interconnected systems with multiple time delays
(2005-09-01)
Hsiao, FH
;
Chen, CW
;
Liang, YW
;
Xu, SD
;
Chiang, WL
This paper investigates the effectiveness of a passive tuned mass damper (TMD) and fuzzy controller in reducing the structural responses subject to the external force. In general, TMD is good for linear systems. We proposed here an approach of Takagi-Sugeno (T-S) fuzzy controller to deal with the nonlinear system. To overcome the effect of modeling error between nonlinear multiple time-delay systems and T-S fuzzy models, a robustness design of fuzzy control via model-based approach is proposed in this paper. A stability criterion in terms of Lyapunov's direct method is derived to guarantee the stability of nonlinear multiple time-delay interconnected systems. Based on the decentralized control scheme and this criterion, a set of model-based fuzzy controllers is then synthesized via the technique of parallel distributed compensation (PDC) to stabilize the nonlinear multiple time-delay interconnected system and the HI control performance is achieved at the same time. Finally, the proposed methodology is illustrated by an example of a nonlinear TMD system.