Browsing by Author "Huang, CW"

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A low-complexity 3-stage parallel interference cancellation receiver (LCPIC) for DS-CDMA cellular systems
(2001)
Huang, CW
;
Wen, KA
;
電機學院
;
College of Electrical and Computer Engineering
A low complexity 3-stage parallel interference cancellation (LCPIC) receiver for DS-CDMA cellular systems is proposed and analyzed in this work. Based on numerical analyses, the power efficiency of the LCPIC receiver is close to that of the 3-stage PIC receiver and better than that of the 2-stage PIC receiver in AWGN with either perfect power control or log-normal power control error. In addition, the near-far resistance of the LCPIC, 2-stage, 3-stage PIC, and SIC receivers are analogous since their performance are undistinguishable in near-far channels. Still more, the computational complexity, which is In terms of the needs of flops per bit decision, of the LCPIC receiver is much less than that of the 3-stage PIC receiver and only a little more than that of the 2-stage PIC receiver.
A programmable pipelined digital differential matched filter for DSSS receiver
(2001-11-01)
Chiou, CH
;
Huang, CW
;
Wen, KA
;
Wu, ML
;
電子工程學系及電子研究所
A programmable pipelined digital differential matched filter (PDMF) implemented for a direct sequence spread spectrum receiver is proposed in this paper. To reduce the power consumption, the architecture PDMF is based on the synchronization combined PN code phase acquisition algorithm (Huang et al., 1999). Compared with the conventional PN code phase acquisition algorithm, the theoretical analysis result indicates that the PDMF acquires both power efficient and preferable detection. Depending on different applications, programmability allows the PDMF to implement 3-tap, 5-tap, or 11-tap Barker codes with the same hardware but different precisions for each tap coefficient. For short tap Baker codes, the architecture could adopt more precision on each tap coefficient to resist the channel noise. Simulation results also show that there are fewer errors of high sample precision with the same tape.
Efficient message flooding on DHT network
(2005)
Huang, CW
;
Yang, W
;
資訊工程學系
;
Department of Computer Science
For the high scalability, DHT network becomes popular in P2P development in these few years. In comparing to flooding-based searching in unstructured P2P network, DHT network provides an efficient lookup. However, flooding still plays an important role in P2P systems. Some fundamental functions such as information collection, dissemination, or keyword searching can benefit from an efficient flooding mechanism. In this paper, we present a DHT network in which one flooding request generates O(N) messages where N is the system size. Moreover, our method considers message locality. Message forwarding across different autonomous systems are reduced significantly. Base on our flooding mechanism, information broadcasting and aggregation are fulfilled without much effort.
Efficient pseudonoise code design for spread spectrum wireless communication systems
(2001-06-01)
Wu, ML
;
Wen, KA
;
Huang, CW
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Power and bandwidth efficient communication schemes are of major concerns in wireless communication systems. One kind of efficient pseudonoise code is proposed in this paper that provides combined power-bandwidth efficiency. A novel algorithm for verifying the power and bandwidth efficient properties of a pseudonoise code is proposed with systematic analysis on code parameters. Applications of the derived codes had been implemented on 802.11 DS/SS system, which performs 36% bandwidth reduction and 14% power consumption reduction. Several new pseudonoise codes with different code lengths are also proposed.
Electronic and magnetic instability in Pr0.65Ca0.25Sr0.1MnO3
(2003-09-01)
Mollah, S
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Huang, HL
;
Liu, SJ
;
Ho, PL
;
Huang, WL
Electronic and magnetic instability in polycrystalline Pr0.65Ca0.25Sr0.1MnO3 manganite has been established from a systematic study of resistivity (p), magnetization (M) and specific heat (C). The sample shows a charge ordering transition at T-CO similar to 200 K, an antiferromagnetic (AFM) ordering transition at T-N similar to 175 K, a metal-insulator (MI) transition at T-MI similar to 80 K and an unusual magnetic ordering transition at T-M(*) similar to 45 K in the absence of magnetic fields. Though the C data do not show any anomaly at T-MI for MI transition, these illustrate a much smaller anomaly than expected one at T-M* and is suppressed by magnetic fields. This indicates that the unusual magnetic ordering in this sample is of canted, fluctuated or phase separation of AFM and ferromagnetic in nature which is established from the T-H phase diagram, as well as the thermal and magnetic hysteresis in p, M and C. (C) 2003 Elsevier Science B.V. All rights reserved.
Hierarchical instruction encoding for VLIW digital signal processors
(2005)
Liu, CH
;
Lin, TJ
;
Chao, CM
;
Hsiao, PC
;
Lin, LC
VLIW-based architectures are very popular in high-performance DSP processors, for their relatively simpler implementations and more predictable execution times. But they need more program memory because of (1) the fixed-length instruction encoding, (2) NOP insertion due to limited parallelism, and (3) repetitive codes for loop unrolling. This paper describes a novel hierarchical instruction encoding that address these three problems to improve the VLIW code density. In our simulations, the proposed encoding scheme saves 61.4%-66.9% code sizes in highly parallel DSP kernels, and more savings can be expected for general programs. Besides, a simple decoding architecture is proposed and has been integrated into a 4-way VLIW DSP processor. The prototype is implemented in the 0.18um CMOS technology with its operating frequency at 208MHz.
Improvements on Sloan's algorithm for constructing Delaunay triangulations
(1998-03-01)
Huang, CW
;
Shih, TY
;
土木工程學系
;
Department of Civil Engineering
On preventing type flaw attacks on security protocols with a simplified tagging scheme
(2005-01-01)
Li, YF
;
Yang, W
;
Huang, CW
;
資訊工程學系
;
Department of Computer Science
A type flaw attack on a security protocol is an attack in which a field in a message that was originally intended to have one type is subsequently interpreted as having another type. Heather et al. proved that type flaw attacks can be prevented by tagging each field with the information that indicates its intended type. We simplify Heather et al.'s tagging scheme by combining all the tags inside each encrypted component into a single tag and by omitting the tags on the outermost level. The simplification process reduces the sizes of messages in the security protocol. We also formally prove that our simplified tagging scheme is as secure as Heather et al.' with the strand space method.
On the complexity of point-in-polygon algorithms
(1997-02-01)
Huang, CW
;
Shih, TY
;
土木工程學系
;
Department of Civil Engineering
Point-in-polygon is one of the fundamental operations of Geographic Information Systems. A number of algorithms can be applied. Different algorithms lead to different running efficiencies. In the study, the complexities of eight point-in-polygon algorithms were analyzed. General and specific examples are studied. In the general example, an unlimited number of nodes are assumed; whereas in the second example, eight nodes are specified. For convex polygons, the sum of area method, the sign of offset method, and the orientation method is well suited for a single point query. For possibly concave polygons, the ray intersection method and the swath method should be selected. For eight node polygons, the ray intersection method with bounding rectangles is faster. (C) 1997 Elsevier Science Ltd.
On the complexity of point-in-polygon algorithms
(1997-02-01)
Huang, CW
;
Shih, TY
;
交大名義發表
;
土木工程學系
;
National Chiao Tung University
Point-in-polygon is one of the fundamental operations of Geographic Information Systems. A number of algorithms can be applied. Different algorithms lead to different running efficiencies. In the study, the complexities of eight point-in-polygon algorithms were analyzed. General and specific examples are studied. In the general example, an unlimited number of nodes are assumed; whereas in the second example, eight nodes are specified. For convex polygons, the sum of area method, the sign of offset method, and the orientation method is well suited for a single point query. For possibly concave polygons, the ray intersection method and the swath method should be selected. For eight node polygons, the ray intersection method with bounding rectangles is faster. (C) 1997 Elsevier Science Ltd.
PROGINS Alu sequence insertion is associated with hyperprolactinaemia but not leiomyoma susceptibility
(2005-04-01)
Hsieh, YY
;
Chan, IP
;
Wang, HI
;
Chang, CC
;
Huang, CW
Objective Leiomyoma and hyperprolactinaemia are both progesterone-dependent diseases. Hormone-related genes, such as the progesterone receptor (PGR), might be involved in their pathogenesis. Design and measurements Subjects were divided into three groups: (i) leiomyoma (n = 120); (ii) hyperprolactinaemia (n = 101); (iii) normal controls (n = 140). We investigated the Alu (306-bp DNA) insertion in intron G of the PGR gene in all individuals. PGR gene polymorphisms [T1 (wild-type); T2 (PROGINS, with Alu insertion)] were determined by PCR and electrophoresis. Genotype and allele frequencies of the PROGINS in each group were detected and compared. Results We observed no significant difference of the PGR*T1/T2 genotypes and allele frequencies between leiomyoma and other two groups. The proportions of T1 homozygote/heterozygote/T2 homozygote in each group were (i) 90/8.3/1.7%; (ii) 84.2/9.9/5.9%; (iii) 92.9/6.4/0.7%. In contrast, a higher percentage of T2-related genotype and allele were noted in hyperprolactinaemic women compared to other two groups. The proportions of T1/T2 alleles in each group were: (i) 94.2/5.8%; (ii) 89.1/10.9%; (iii) 96.1/3.9%. Conclusions The PROGIN*T2-related genotype and allele are related to a higher susceptibility to hyperprolactinaemia. The PROGINS polymorphism is not associated with leiomyoma development.
Sweeping technique combined with micellar electrokinetic chromatography for the simultaneous determination of flunitrazepam and its major metabolites
(2006-03-31)
Huang, CW
;
Jen, HP
;
Wang, RD
;
Hsieh, YZ
;
應用化學系
A sweeping technique, in conjunction with micellar electrokinetic chromatography, for the simultaneous determination of flunitrazepam and its major metabolites, 7-aminoflunitrazepam and N-desmethylflunitrazepam, is described. The optimized conditions for the sweeping and separation were a pH 9.5 buffer, 25 mM borate, 50 mM cetyltrimethylammonium bromide, 30% MeOH (v/v), and a 151-mm injection length. The calibration functions were all linear with the coefficient of determination (r(2)) exceeding 0.996 for the three target compounds. Using the sweeping procedure, the limits of detection were determined to be 13.4, 5.6, and 12.0 ng/mL for flunitrazepam, 7-aminoflunitrazepam, and N-desmethylflunitrazepam, respectively, and the sensitivity enhancement for each compound was within the range of 110-200 fold. The RSDs for the retention time and the peak area were less than 4.10%. The optimized sweeping method was also used to examine a spiked urine sample. We conclude that sweeping with micellar electrokinetic chromatography has considerable potential use in clinical and forensic analyses of flunitrazepam and its metabolites. (c) 2006 Elsevier B.V. All rights reserved.
Synchronization combined PN code phase acquisition algorithm (SCA) for DSSS receiver
(1999)
Huang, CW
;
Wen, KA
;
Wu, ML
;
電機學院
;
College of Electrical and Computer Engineering
A new algorithm for PN code phase acquisition, synchronization combined PN code phase acquisition algorithm (SCA) is proposed in tills paper. Compared with the conventional PN code phase acquisition algorithm, SCA has a higher detection probability and a lower false alarm rate. The simulation of power efficiency was done with a 3-bit PN code phase synchronizer and the result also shows that power efficiency of SCA is prefer to that of the conventional PN code phase acquisition algorithm.
The electronic structure change induced by stripe phase formation in cuprates
(2004-08-01)
Lin, JY
;
Huang, CW
;
Lin, PH
;
Sun, CP
;
Lee, JM
It has been suggested that the stripe phase shows ID charge transport in the CuO2 planes instead of the 2D characteristics of the Zhang-Rice band. X-ray absorption near edge spectroscopy (XANES) has been used to study the electronic structure of the stripe phase compounds La2-xSrxCuO4, and La2-x-yNdySrxCuO4 for x around 1/8. The measurements were performed at both 300 and 28 K to examine the possible electronic structure change above and below the temperature of the stripe phase formation. (C) 2004 Elsevier B.V. All rights reserved.