Dissertations / Theses on the topic 'HYBRID WDM'

Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2007.
"A thesis in computer science." Typescript. Advisor: Baek-Young Choi and E.K. Park. Vita. Title from "catalog record" of the print edition Description based on contents viewed Dec. 18, 2007. Includes bibliographical references (leaves 55-57). Online version of the print edition.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California
An advanced electro-optic hybrid rotary joint (EOHRJ) has been developed in Phase II of an AF SBIR effort with Physical Optics Corporation (POC) to replace cable wrap structure for multi-channel rotation-to-fixed (RTF) signal transmission. The EOHRJ meets AFFTC and other range special needs with a generic, high performance, rotary joint solution. At the moment, we have successfully installed and tested the EOHRJ on our KTM tracker system with the following capabilities: 1) able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low-speed signals; 2) able to accommodate multiple channel, high data rate (over gigabits per second), and bi-directional signal transmission; 3) able to be reliable for harsh environmental operation, adaptive to stringent sized requirement, and accommodating existing electrical and mechanical interfaces. The completed EOHRJ contains three uniquely integrated functional rings. The first and the outmost one is power ring, which provides RTF transmission channels for over 50 high voltage and high current channels. The second and the middle one is low speed electrical signal ring, which provides RTF transmission for over hundred control, feedback, and low speed data signals. The third and the inmost one is optical fiber slip ring, which, incorporating with current advanced signal multiplexing technologies (either time division or wavelength division multiplexing ) is able to provide multiple channel, high data rate, and bi-directional signal transmission. At the moment, the prototype module of the tree-layer EOHRJ has been successfully assembled in Air Force’s tracker system, and is providing a satisfactory performance. This paper presents our joint work on this project.

In this study, a review of research literature has been carried out to investigate Hybrid Time and wavelength Division Multiplexing techniques with respect to reach, split ratio, and speed of the network. This was done to overcome challenges presented by Passive Optical Networks, such as the reach and the high split ratio. A comparison of different methods clarifies that Hybrid PassiveOptical Networks have a high power-budget that ensure efficient signal transmission. The Optisys software has been used to analyze the performance of the different techniques.

La demande sans cesse croissante des besoins des télécommunications a mis en relief les limites intrinsèques de l’électronique. La photonique s’est révélée comme une solution appropriée à ses limitations. STMicroelectronics a développé une plateforme photonique sur silicium dénommée PIC25G permettant une transmission monocanale à 25 Gb/s. Cependant, l’augmentation du débit avec du multiplexage en longueur d’onde (WDM) se heurte à certaines contraintes. La solution suggérée repose sur une approche hybride intégrant la photonique sur silicium et sur verre par échange d’ions développée au laboratoire IMEP LaHC. La solution consiste en un interposeur verre sur lequel est assemblée une puce photonique sur silicium. Les études ont d’abord porté sur les composants de la puce silicium en particulier sur l’optimisation des coupleurs à réseau et les multiplexeurs à base d’interféromètres de Mach Zehnder cascadés. Ensuite, les composants passifs optiques et électriques de l’interposeur verre ont aussi été étudiés et réalisés. La faisabilité d’un couplage optique entre la puce silicium et l’interposeur a été démontrée. Enfin, les structures de tests nécessaires à la validation de la solution proposée ont été étudiées. Ces structures de tests ont permis de transmettre des signaux radiofréquences jusqu’à 40 GHz entre la puce silicium et l’interposeur verre. Une nouvelle approche de fabrication des guides d’onde optiques de l’interposeur a été suggérée et réalisée afin de répondre aux problèmes du procédé de fabrication. A terme, elle permettra d’avoir un module électro-optique pour des applications haut-débit
The ever-increasing demand for telecommunications needs has highlighted the intrinsic limitations of electronics. Photonics has proven to be a suitable solution to its limitations. STMicroelectronics has developed a silicon photonic platform called PIC25G that allows single-channel transmission at 25 Gb/s. The data rate increase with wavelength division multiplexing (WDM) encounter some constraints. The proposed solution is based on a hybrid approach integrating silicon photonics and glass ions exchanged photonics developed at the IMEP-LaHC laboratory. The solution consists of a glass interposer on which a silicon photonics chip is assembled. First, the studies focused on the components of the silicon chip especially on the optimization of grating couplers and (de)-multiplexers based on cascaded Mach Zehnder interferometers. Then, the optical and electrical passive components of the glass interposer were studied and realized. The feasibility of an optical coupling between the silicon chip and the glass interposer has been demonstrated. Finally, the test structures needed to validate the proposed solution were studied. These test structures allowed to transmit radiofrequency signals up to 40 GHz between the silicon chip and the glass interposer. A new approach to realize the optical waveguides of the interposer has been suggested and carried out in order to address the fabrication issues. Ultimately, this approach will provide an electro-optical module for high-speed applications

L'optique intégrée est une technique très prometteuse pour une fabrication de masse de circuits optiques pour les télécommunications et/ou l'instrumentation.
La technologie sol-gel a déjà démontré son potentiel. Un nouveau matériau sol-gel hybride à polymérisation cationique de type Epoxy a été développé dans le but de la simplification de la synthèse et de l'amélioration des performances en particulier l'adhérence.
Ce travail a pour objectif le développement d'un banc d'écriture laser UV dans une couche Epoxy et l'établissement du protocole de fabrication associé. Ce procédé de polymérisation locale est une alternative prometteuse aux techniques lithographiques par masque.
Ce nouveau banc utilise un laser pulsé travaillant à faible longueur d'onde pour une meilleure résolution et une meilleure polymérisation.
Ce travail a montré la faisabilité de circuits complexes de type multiplexeurs WDM avec un procédé d'inscription à faible coût. Nous avons réalisé les premiers prototypes de circuits dédiés à la sélection multiple de longueurs d'onde pour le (dé)codage du CDMA optique spectral.

Die dynamische Regulation von Protein-Protein Interaktionen (PPIs) ist wichtig für den Ablauf von biologischen Prozessen. Die circadiane Uhr, die einen ~24 Stunden Rhythmus generiert und eine Vielzahl von physiologischen Parametern steuert kann auch die Dynamik von PPIs regulieren. Um neue Erkenntnisse über regulatorische Mechanismen innerhalb des molekularen Oszillators zu gewinnen, habe ich zunächst alle möglichen PPIs zwischen 46 circadianen Komponenten mittels eines systematischen yeast-two-hybid (Y2H) Screens bestimmt. Dabei habe ich 109 bis dahin noch unbekannte PPIs identifiziert und einen repräsentativen Anteil mittels Co-Immunopräzipitationsexperimenten in humanen Zellen validiert. Unter den neuen PPIs habe ich bis dahin unbekannte Modulatoren der CLOCK/BMAL1 Transaktivierung identifiziert und dabei die Rolle der Proteinphosphatase 1 (PP1) als dynamischen Regulator der BMAL1 Stabilität funktionell charakterisiert. Das experimentelle PPI Netzwerk wurde mit bereits aus der Literatur bekannten PPIs und Interaktionspartnern ergänzt. Eine systematische RNAi Studie belegte außerdem die Relevanz der aus der Literatur stammenden Interaktoren für die ~24 Stunden Periodizität. Um eine Aussage über die Dynamik der PPIs im Netzwerk treffen zu können, wurden circadiane mRNA Expressionsdaten in das PPI Netzwerk integriert. Systematische Perturbationsstudien, in denen alle Komponenten des experimentellen Netzwerkes mittels RNAi herunterreguliert oder überexprimiert wurden, zeigten eine essentielle Bedeutung für die dynamischen PPIs innerhalb des circadianen Oszillators auf. Desweiteren wurden im circadianen PPI Netzwerk funktionelle Module identifiziert, welche dynamisch organsiert sind. Durch eine systemweite Analyse des humanen Proteoms wurden viele dynamische PPIs identifiziert, die biologische Prozesse wie z.B. Signaltransduktion und Zellzyklus miteinander verbinden. Rhythmische PPIs sind daher von Bedeutung für die zeitliche Organisation zellulärer Physiologie.
Essentially all biological processes depend on protein-protein interactions (PPIs). Timing of such interactions is crucial for regulatory function. Although circadian (~24 hrs) clocks constitute fundamental cellular timing mechanisms regulating important physiological processes PPI dynamics on this timescale are largely unknown. To elucidate so far unknown regulatory mechanisms within the circadian clockwork, I have systematically mapped PPIs among 46 circadian components using high-throughput yeast-two-hybrid (Y2H) interaction experiments. I have identified 109 so far uncharacterized interactions and successfully validated a sub-fraction via co-immunoprecipitation experiments in human cells. Among the novel PPIs, I have identified modulators of CLOCK/BMAL1 function and further characterized the role of protein phosphatase 1 (PP1) in the dynamic regulation of BMAL1 abundance. Furthermore, to generate a more comprehensive circadian PPI network, the experimental network was enriched and extended with additional interactions and interaction partners from literature, some of which turned out to be essential for normal circadian dynamics. The integration of circadian mRNA expression profiles allowed us to determine the interaction dynamics within our network. Systematic genetic perturbation studies (RNAi and overexpression in oscillating human cells) revealed a crucial role of dynamic regulation (via rhythmic PPIs) for the molecular clockwork. Furthermore, dynamic modular organization as a pervasive circadian network feature likely contributes to time-of-day dependent control of many cellular processes. Global analysis of the proteome regarding circadian regulation of biological processes via rhythmic PPIs revealed time-of-day dependent organization of the human interactome. Circadian PPIs dynamically connect many important cellular processes like signal transduction and cell cycle, which contribute to temporal organization of cellular physiology.

Proteinmethylierung spielt eine immer größere Rolle in der Regulierung zellulärer Prozesse. Die Entwicklung effizienter proteomweiter Methoden zur Detektion von Methylierung auf Proteinen ist limitiert und technisch schwierig. In dieser Arbeit haben wir einen neuen Hefe-Zwei-Hybrid-Ansatz (Y2H) entwickelt, der Proteine, die miteinander wechselwirken, mit Hilfe von Sequenzierungen der zweiten Generation identifiziert (Y2H-Seq). Der neue Y2H-Seq-Ansatz wurde systematisch mit dem Y2H-Seq-Ansatz verglichen. Dafür wurde ein Bait-Set von 8 Protein-Arginin-Methyltransferasen, 17 Protein-Lysin-Methyltransferasen und 10 Demethylasen gegen 14,268 Prey-Proteine getestet. Der Y2H-Seq-Ansatz ist weniger arbeitsintensiv, hat eine höhere Sensitivität als der Standard Y2H-Matrix-Ansatz und ist deshalb besonders geeignet, um schwache Interaktionen zwischen Substraten und Protein-Methyltransferasen zu detektieren. Insgesamt wurden 523 Wechselwirkungen zwischen 22 Bait-Proteinen und 324 Prey-Pr oteinen etabliert, darunter 11 bekannte Methyltransferasen-Substrate. Netzwerkanalysen zeigen, dass Methyltransferasen bevorzugt mit Transkriptionsregulatoren, DNA- und RNA-Bindeproteinen wechselwirken. Diese Daten repräsentieren das erste proteomweite Wechselwirkungsnetzwerk über Protein-Methyltransferasen und dienen als Ressource für neue potentielle Methylierungssubstrate. In einem in vitro Methylierungsassay wurden exemplarisch mit Hilfe massenspektrometrischer Analysen die methylierten Aminosäurereste einiger Kandidatenproteine bestimmt. Von neun getesteten Proteinen waren sieben methyliert, zu denen gehören SPIN2B, DNAJA3, QKI, SAMD3, OFCC1, SYNCRIP und WDR42A. Wahrscheinlich sind viele Methylierungssubstrate im Netzwerk vorhanden. Das vorgestellte Protein-Protein-Wechselwirkungsnetzwerk zeigt, dass Proteinmethylierung sehr unterschiedliche zelluläre Prozesse beeinflusst und ermöglicht die Aufstellung neuer Hypothesen über die Regulierung Molekularer Mechanismen durch Methylierung.
Protein methylation on arginine and lysine residues is a largely unexplored posttranslational modification which regulates diverse cellular processes. The development of efficient proteome-wide approaches for detecting protein methylation is limited and technically challenging. We developed a novel workload reduced yeast-two hybrid (Y2H) approach to detect protein-protein interactions utilizing second generation sequencing. The novel Y2H-seq approach was systematically evaluated against our state of the art Y2H-matrix screening approach and used to screen 8 protein arginine methyltransferases, 17 protein lysine methyltransferases and 10 demethylases against a set of 14,268 proteins. Comparison of the two approaches revealed a higher sensitivity of the new Y2H-seq approach. The increased sampling rate of the Y2H-seq approach is advantageous when assaying transient interactions between substrates and methyltransferases. Overall 523 interactions between 22 bait proteins and 324 prey proteins were identified including 11 proteins known to be methylated. Network analysis revealed enrichment of transcription regulator activity, DNA- and RNA-binding function of proteins interacting with protein methyltransferases. The dataset represents the first proteome-wide interaction network of enzymes involved in methylation and provides a comprehensively annotated resource of potential new methylation substrates. An in vitro methylation assay coupled to mass spectrometry revealed amino acid methylation of candidate proteins. Seven of nine proteins tested were methylated including SPIN2B, DNAJA3, QKI, SAMD3, OFCC1, SYNCRIP and WDR42A indicating that the interaction network is likely to contain many putative methyltransferase substrate pairs. The presented protein-protein interaction network demonstrates that protein methylation is involved in diverse cellular processes and can inform hypothesis driven investigation into molecular mechanisms regulated through methylation.

碩士
國立臺北科技大學
光電與通訊產業研發碩士專班
95
In this paper﹐we proposed two WDM-PON systems﹒We transported CATV analog signals and OC-48 digital signals in the systems﹒We will discuss the affect of external light injection technique to transport effect and CATV system performance﹒ First﹐we proposed a WDM-PON system﹐in that﹐we used external modulation to transport CATV analog signals and OC-48 digital signals﹒We used distributed feedback(DFB) laser diode to externally modulated the analog signals﹒On the other hand﹐we used external light injection technique to transport OC-48 digital signals﹒The character of DFB LD is better than FP LD﹐so we could get better CATV performance and video quality﹒We injected external light into FP LD and get the BER less than 10-9﹒ Second﹐we proposed another WDM-PON system to transport CATV analog signals and OC-48 digital signals﹒We injected external light into FP LD to transport both analog and digital signals﹒We could obtain the result that external light injection technique could improve the transport character and CATV performance﹒The performance of CATV analog signals could be as good as in DFB LD transport part﹒The BER of digital signals transport could less 10-9 ﹒ An optical single sideband(SSB) modulation technique is proposed and demonstrated﹒Simultaneous transmission of CATV and OC-48 signals﹐good performance of CNR﹐CSO﹐and CTB were obtained for CATV signals；low bit-error rate were achieved for didital signal﹒ We present the investigation of the fiber Bragg grating(FBG) filter as an optical single sideband filter at the receiving site﹒The function of the optical SSB filter is employed to replace the optical SSB transmitter﹒Using simple FBG filter as an optical SSB filter in CATV and OC-48 transport system is a very attractive option﹐as it is passive and potentially low cost﹒

Recent advancements in internet services have brought attention to access networks to have their bandwidth increased as they represent the last hurdle to the customer. Emphasis is put on high bit-rate transmission, network reliability and survivability as ways to reduce operational costs and enhance network coverage, scalability to curb capital costs. Researchers are seeking at improving the optical access network concepts known as hybrid wavelength-division-multiplexed and time-division multiple access passive optical networks. The networks are designed to be beneficial for operators due to low capital and operating expenditures. The passive optical network comprises of a centralized optical line terminal (OLT), situated in the central office and a number of optical network units (ONUs) are positioned some distance away from the OLT at the user end. Due to the need for longer and unrepeated transmission distances and higher capacity transmission, Hybrid WDM/TDM Passive optical transport networks are primed to give the capacity needed to meet the exponentially exploding telecommunications traffic in a cost-reduced way and used in conjunction with appropriate hybrid amplifiers great results have been realised. In this thesis, a hybrid WDM/TDM PON with a split ratio of 128 ONUs in the absence of amplification is investigated and a maximum transmission distance of 28km realised. Similarly, a Hybrid WDM/TDM PON with various Hybrid Optical Amplifiers for mid-range amplification is simulated and the performance is compared on the basis of BER, Quality factor (Q), eye opening and the maximum reach. The hybrid amplifiers RA –EDFA and EDFA-RA, RA-SOA and SOA-RA and SOA-EDFA and EDFA-SOA are simulated and compared to each other. It is seen that the hybrid amplifier RA-EDFA provides the highest output quality factor of 6.25257 and least bit error rate of 2.00309 x 10-10 at 95 km. Thus, a hybrid WDM/TDM PON with a hybrid amplifier improves the reach by 67 km with an increased number of users up to 256.

碩士
國立臺北科技大學
光電工程系所
93
In this paper, we propose several methods to improve fiber optical CATV/radio-on-fiber (ROF) transport systems performances. First, We proposed and demonstrated a full-duplex ROF transport system based on wavelength-division-multiplexing (WDM) and optical add-drop multiplexing techniques (OADM), as well as employed fiber Bragg grating (FBG) in combination with optical circulator (OC) as the optical single sideband (SSB)/vestigial sideband (VSB) filter at the receiving site to improve system performance. Second, a directly modulated lightwave transport system based on external light injection technique and optical SSB filter at the receiving site is proposed and demonstrated, simultaneous transmission of CATV and microwave signals. Over an 80 km SMF transport, good performances of carrier-to-noise ratio (CNR), composite second order (CSO) and composite triple beat (CTB) were obtained for CATV signals; as well as low bit error rate (BER) value was achieved for ROF applications. Third, a radio-on-hybrid WDM transport system based on distributed feedback laser diodes (DFB LDs) and semiconductor optical amplifiers (SOAs) with double external light injection techniques is proposed and demonstrated. The double external light injection techniques increases laser’s frequency response and SOA’s output saturation power, respectively. Over an 100 km SMF transport, good performances of BER, modulation error ratio (MER), CNR, error vector magnitude (EVM) and third order intermodulation distortion to carrier ratio (IMD3/C) were achieved in our proposed systems.

碩士
國立東華大學
電機工程學系
99
We demonstrate the characteristics of the hybrid optical fiber amplifiers in considering net gain, noise figure (NF) and stimulated Brillouin scattering (SBS) induction penalty. The gain media of C-band and L-band are erbium-doped fiber (EDF) and dispersion compensating fiber (DCF), respectively. First, the gain media are series and the signals can be amplified at EDF and DCF, respectively (One Pass). Then, we add the optical circulator and the Faraday rotator mirror. The configurations can make the reflected lights make a second pass through the gain medium (Double Pass). But the Stimulated Brillouin Scattering (SBS) induces penalty. We adjust pumping to reduce the SBS penalty, then show the comparison of the One Pass and Double Pass configurations, respectively. First, we measure signal gains of one pass configuration. The pump soureces consists of four laser diodes operating at 1480 and 1510 nm, respectively. The pump power is launched into the gain medium fiber from each pumping laser diodes as an one-stage configuration. According to the signals amplified at the DCF or the EDF first and through the different direction of the pumping, we design four configurations. The configuration having the signals amplified at EDF first with backward pumping gets the best performance. The signal gains of C-band and L-band are 20.7~27.9 dB and 22.3~25.2 dB, respectively. It is not a gain-flattened fiber amplifier although the gain value is not so bad. Then, we measure the signal gains of double pass configuration. We design four configurations according to the gain-flattened characteristics. The configuration of the signals amplified at EDF first and then amplified at DCF twice with backward pumping (HFA Double Pass TypeⅣ) is the best performance. The gain-flattened performance of the Double Pass configuration is better than that of the One Pass configuration. However, both methods produce the SBS induction penalty. The SBS can decrease the net gain and increase the NF. We adjust pumping to reduce the SBS penalty, then show the comparison of the One Pass and Double Pass configurations, respectively. As a result, the HFA Double Pass TypeⅣ configuration still has the best performance with input signal power of -20 dBm. This amplifier can provide the net gain of 18.3~23.3 dB at C-Band and 18.9~21.9 dB at L-Band, respectively. But when the signals power increase, the SBS penalty limits the functioning of amplifier. The configuration of the signals amplified at DCF first and then amplified at EDF with backward pumping is the best performance. The gain-flattened performance of the One Pass configuration is better than that of the Double Pass configuration. The signal gains of 1530~1570 nm and 1570~1610 nm are 15.7~20.5 dB and 12.2~15.5 dB, respectively. This amplifier design has the advantages of high gain, low NF and gain flattened characteristics at low signal level. It has been proved by this study to be better than the exsiting in-line and pre amplifier.

碩士
國立臺灣科技大學
電子工程系
89
In the thesis, we propose a novel hybrid fiber amplifier, and it is connected with erbium-doped fiber amplifier and fiber Raman amplifier. The hybrid fiber amplifier structure can provide the property of both EDFA and Raman amplifier. It maintains the stabilization of EDFA character and has great gain of Raman amplifier. We add L-band EDFA to extend transmission bandwidth. The L-band EDFA is made by conventional erbium doped fiber, utilizing the phenomenon of EDFA gain shift. Therefore, we utilize L-band EDFA to extend transmissible capacity. Because the Raman amplifier can be operated at any wavelength windows, it can compensate the C-band and L-band of amplifier. For Raman amplifier, the C-band and L-band can be used. It just needs to adjust the wavelength of Raman pump. Because it strongly depended on the wavelength and power of Raman pump, it is a broadband component, and it is widely used. The novel hybrid fiber amplifier can bring great capacity for conventional EDFA. It used bidirectional data flowed to help upgrade the sys

碩士
國立東華大學
電機工程學系
97
This paper is specifically for the design of hybrid optical fiber amplifier which provides efficacious gain reaching up to 25.96dB when pumping power is less than 1W in L-band wavelength range. 　　We analyze individually the double-pass Raman fiber oscillator as Raman fiber amplifier and the L-band erbium-doped fiber amplifier, then compose this two to L-band hybrid EDF/Raman amplifier, with 900mW total pumping power, the 3dB gain bandwidth of L-band hybrid EDF/Raman amplifier can attain 47.15nm which covers entire L-band wavelength range. The gain in L-band reaches up to 22.78dB and 19.79dB at least and the gain flatten is 2.99dB. 　　For improving the performance, we adjust the pumping power. The 3dB gain bandwidth can attain 54.12nm which covers entire L-band wavelength range, and part of L+-band range. The gain can reach up to 25.96dB and 23.22dB at least in the range of L-band and L+-band, respectively. The gain flatten is also improved to 2.74dB. Eventually, we demonstrate the L and L+ band hybrid EDF/Raman amplifier with high gain and low noise.

碩士
國立臺北科技大學
光電工程系研究所
96
In the thesis, we propose and demonstrate various fiber optical cable television (CATV) and radio-on-fiber (ROF) transport system, which include architectures of bidirectional system, wavelength-division-multiplexing (WDM) techniques, full-duplex ring network and hybrid signals transmission. In the first architecture, we study a full-duplex radio-over-fiber (ROF) transport system based on two modes injection-locked Fabry-Perot laser diode (FP LD) is proposed and demonstrated. Transmission performances over 40 km of a standard single-mode fiber (SMF) for full-duplex transmission were investigated. Good performances of bit error rate (BER) and error vector magnitude (EVM) were obtained in our proposed systems. In the second architecture, we propose a one distributed feedback (DFB) laser diode with main and multiple side modes injection-locked is proposed and demonstrated. DFB laser diode can be successfully injection-locked not only in the main mode but also in different side modes. Besides, the side-mode suppression ratio (SMSR) value of each injection-locked mode is enhanced, it means that a new approach is suitable for the use of multiple optical sources. Our proposed scheme has the potential to be used as optical sources for radio-on-wavelength division multiplexing (WDM) transport systems to provide multi-service. In the third architecture, we build a hybrid wavelength-division-multiplexing (WDM) transport system based on mutually injection-locked Fabry-Perot laser diodes (FP LDs) for CATV, 256-QAM and OC-48 transmission is proposed and demonstrated. Mutually injection-locked FP LDs as broadband light source could be relatively simple and cost-effective compared with other demonstrated light source schemes. The proposed hybrid WDM transport system employs four filtered wavelengths (modes) to transmit one hundred and eleven AM-VSB channels, four 256-QAM digital passband channels, and one OC-48 digital baseband channel simultaneously. Since our proposed system does not use multiple distributed feedback (DFB) LDs, it reveals a prominent one with simpler and more economic advantages. In the final architecture, we propose a radio-on-hybrid wavelength-division- multiplexing (WDM) transport system employing mutually injection-locked Fabry-Perot laser diodes (FP LDs) is proposed and demonstrated. System performances evaluated by carrier to noise ratio (CNR), composite second order (CSO), composite triple beat (CTB), bit error rate (BER) and third order intermodulation distortion to carrier ratio (IMD3/C) for simultaneous transmission of CATV/LAN/ITS are improved. Our proposed systems are relatively simple and potentially low cost due to the use of mutually injection-locked FP LDs as broadband light source (BLS).

Photonics and Optical techniques have advanced recently by a great extend to play an important role in Microwave and Radar applications. Antenna array of modern active phased array radars consist of multiple low power transmit and receive mod- ules. This demands distribution of the various Local Oscillator(LO) signals for up conversion of transmit signals and down conversion of receive signals during various modes of operation of a radar system. Additionally, these receivers require control and clock signals which are digital and low frequency analog, for the synchronization between receive modules. This is normally achieved through RF cables with complex distribution networks which add significantly higher additional weight to the arrays. During radar operations, radio frequency (RF) transmit signal needs to be distributed through the same modules which will in turn get distributed to all antenna elements of the array using RF cables. This makes the system bulky and these large number of cables are prone to Electromagnetic Interference (EMI) and need additional shielding. Therefore it is very desirable to distribute a combination of these RF, analog and digital signals using a distribution network that is less complex, light in weight and immune to EMI. Advancements in Optical and Microwave photonics area have enabled carrying of higher datarate signals on a single fiber due to its higher bandwidth capability including RF signals. This is achieved by employing Wavelength Division Multi- plexing (WDM) that combine high speed channels at different wavelengths. This work proposes, characterizes and evaluates an optical Wavelength Division Multiplexed(WDM) distribution network that will overcome the above mentioned problems in a phased array radar application. The work carries out a feasibility analysis supported with experimental measurements of various physical parameters like am- plitude, delay, frequency and phase variation for various radar waveforms over WDM links. Different configurations of optical distribution network are analyzed for multipoint distribution of both digital and RF signals. These network configurations are modeled and evaluated against various parameters that include power level, loss, cost and component count. A configuration which optimizes these parameters based on the application requirements is investigated. Considerable attention is paid to choose a configuration which does not provide excess loss, which is economically viable, compact and can be realized with minimum component count. After analysing the link configuration, multiplexing density of the WDM link is considered. In this work, since the number of signals to be distributed in radar systems are small, a coarse WDM(CWDM) scheme is considered for evaluation. A comparative study is also performed between coarse and dense WDM (DWDM) links for selection of a suitable multiplexing scheme. These configurations are modeled and evaluated with power budgeting. Even though CWDM scheme does not permit the utilisation of the available bandwidth to the fullest extent, these links have the advantage of having less hardware complexity and easiness of implementation. As the application requires signal distribution to thousands of transmit-receive modules, amplifiers are necessary to compensate for the reduction of signal level due to the high splitting ratio. Introduction of commonly available optical amplifiers like Erbium Doped Fiber Amplifier (EDFA), affect the CWDM channel output powers adversely due to their non-flat gain spectrum. Unlike DWDM systems, the channel separation of CWDM systems are much larger causing significantly high channel gain differences at the EDFA output. So an analysis is carried out for the selection of a suitable wavelength for CWDM channels to minimize the EDFA output power variation. If the gain difference is still significant, separate techniques needs to be implemented to flatten the output power at the antenna end. A CWDM configuration using C-band and L-band EDFAs is proposed and is supported with a feasibility analysis. As a part of evaluation of these links for radar applications, a mathematical model of the WDM link is developed by considering both the RF and digital sig- nals. A generic CWDM system consisting of transmitters, receivers, amplifiers, multiplexers/ demultiplexers and detectors are considered for the modeling. For RF signal transmission, the transmitters with external modulators are considered. Mod- eling is done based on a bottom-top approach where individual component models are initially modeled as a function of input current/power and later cascaded to obtain the link model. These models are then extended to obtain the wavelength dependent model ( spectral response) of the hybrid signal distribution link Further mathematical analysis of the developed link model revealed its variable separable nature in terms of the input power and wavelength. This led to significant reduction in the link equation complexity and development of some approximation techniques to easily represent the link behavior. The reduced form of the link spectral model was very essential as the initially developed wavelength model had a lot of parametric dependency on the component models. This mathematical reduction process led to simplification of the spectral model into a product of two independent functions, the input current and wavelength. It is also noticed that the total link power within specific wavelength range can be obtained by the integrating these functions over a specific link input power. After the mathematical modelling, an experimental prototype physical link is set up and characterized using various radar signals like continuous wave (CW) RF, pulsed RF, non linear frequency modulated signal (NLFM) etc. Additionally a proof of concept Radio-Over-Fiber (RoF) link is established to prove the superior transmission of microwave signal through an optical link. The analysis is supported with measurements on amplitude, delay, frequency and phase variations. The NLFM waveforms transmissions are further analysed using a matched _ltering process to confirm the side lobe requirement. Further a prototype WDM link is built to study the performance when digitally modulated channels are also multiplexed into the link. The link is again validated for signal levels, delay, frequency and phase parameters. Since amplitude and delay are deterministic, it is proposed that these parameter variations can be compensated by using suitable components either in the electrical or the optical domain. Radar systems use low frequency digital signals of different duty-cycles for synchronization and control across various transmit-receive modules. In the proposed link, these digital signals also modulate a WDM channel and hence the link is called a hybrid system. As the proposed link has EDFA to compensate for the splitting losses, there are chances of transient effects at the EDFA output for these low bitrate channels. Owing to the long carrier lifetime, low bitrate digital channels are prone to EDFA transient effects under specific signal and pump power conditions. Additionally, the synchronization signals used in radar application vary the duty-cycle over time, which is found to introduce variations in transient output. This practical challenge is further studied and the thesis for the first time, includes an analysis of EDFA transient e_ects for variable duty-cycle pulsed signals. The analysis is carried out for various parameters like bitrate, input power, pump power and duty-cycle. Investigations on EDFA transients on variable duty-cycle signals help in proposing a viable method to predict the lower duty-cycle transients from higher duty-cycle transients. The predicted transients were again validated against simulated transients and experimental results. As these transient effects are not desirable for radar signals, we propose a novel transient suppression techniques in optical and electrical domain which are validated with simulation and experimental measures. One suppression technique tries to avoid transient effect by keeping the optical input to EDFA always constant by feeding an inverted version of the original pulse into the EDFA along with the actual pulse. It is observed that as the wavelength of the inverted pulse is closer to the original input pulse, the transient effect settles faster. These EDFA transients are evaluated with WDM link configurations, where both high and low bitrate signals are co-propagated. Another challenging aspect of the link operation is the non-at gain spectrum of EDFA. i.e., EDFA provides unequal power level for various signals at WDM link output. This is especially true in the case of local oscillator signals, where it is preferable to have the same amplitude signals before feeding it to the mixer stages. But in the radar applications, this will require additional hardware circuits to equalize the signal level within a phased array antenna. This work also proposes some of the power equalization methods that can be used along with the WDM links. This part of the work is also supported with simulation model and experimental results. The analytical and experimental study of this thesis aids the evaluation process of a suitable optical Wavelength Division Multiplexed(WDM) distribution network that can be used for the distribution of both RF and digital signals. The optical WDM links being superior with its light weight, less loss and EMI/ EMC immunity provides a better solution to future class of radars.

Photonics and Optical techniques have advanced recently by a great extend to play an important role in Microwave and Radar applications. Antenna array of modern active phased array radars consist of multiple low power transmit and receive mod- ules. This demands distribution of the various Local Oscillator(LO) signals for up conversion of transmit signals and down conversion of receive signals during various modes of operation of a radar system. Additionally, these receivers require control and clock signals which are digital and low frequency analog, for the synchronization between receive modules. This is normally achieved through RF cables with complex distribution networks which add significantly higher additional weight to the arrays. During radar operations, radio frequency (RF) transmit signal needs to be distributed through the same modules which will in turn get distributed to all antenna elements of the array using RF cables. This makes the system bulky and these large number of cables are prone to Electromagnetic Interference (EMI) and need additional shielding. Therefore it is very desirable to distribute a combination of these RF, analog and digital signals using a distribution network that is less complex, light in weight and immune to EMI. Advancements in Optical and Microwave photonics area have enabled carrying of higher datarate signals on a single fiber due to its higher bandwidth capability including RF signals. This is achieved by employing Wavelength Division Multi- plexing (WDM) that combine high speed channels at different wavelengths. This work proposes, characterizes and evaluates an optical Wavelength Division Multiplexed(WDM) distribution network that will overcome the above mentioned problems in a phased array radar application. The work carries out a feasibility analysis supported with experimental measurements of various physical parameters like am- plitude, delay, frequency and phase variation for various radar waveforms over WDM links. Different configurations of optical distribution network are analyzed for multipoint distribution of both digital and RF signals. These network configurations are modeled and evaluated against various parameters that include power level, loss, cost and component count. A configuration which optimizes these parameters based on the application requirements is investigated. Considerable attention is paid to choose a configuration which does not provide excess loss, which is economically viable, compact and can be realized with minimum component count. After analysing the link configuration, multiplexing density of the WDM link is considered. In this work, since the number of signals to be distributed in radar systems are small, a coarse WDM(CWDM) scheme is considered for evaluation. A comparative study is also performed between coarse and dense WDM (DWDM) links for selection of a suitable multiplexing scheme. These configurations are modeled and evaluated with power budgeting. Even though CWDM scheme does not permit the utilisation of the available bandwidth to the fullest extent, these links have the advantage of having less hardware complexity and easiness of implementation. As the application requires signal distribution to thousands of transmit-receive modules, amplifiers are necessary to compensate for the reduction of signal level due to the high splitting ratio. Introduction of commonly available optical amplifiers like Erbium Doped Fiber Amplifier (EDFA), affect the CWDM channel output powers adversely due to their non-flat gain spectrum. Unlike DWDM systems, the channel separation of CWDM systems are much larger causing significantly high channel gain differences at the EDFA output. So an analysis is carried out for the selection of a suitable wavelength for CWDM channels to minimize the EDFA output power variation. If the gain difference is still significant, separate techniques needs to be implemented to flatten the output power at the antenna end. A CWDM configuration using C-band and L-band EDFAs is proposed and is supported with a feasibility analysis. As a part of evaluation of these links for radar applications, a mathematical model of the WDM link is developed by considering both the RF and digital sig- nals. A generic CWDM system consisting of transmitters, receivers, amplifiers, multiplexers/ demultiplexers and detectors are considered for the modeling. For RF signal transmission, the transmitters with external modulators are considered. Mod- eling is done based on a bottom-top approach where individual component models are initially modeled as a function of input current/power and later cascaded to obtain the link model. These models are then extended to obtain the wavelength dependent model ( spectral response) of the hybrid signal distribution link Further mathematical analysis of the developed link model revealed its variable separable nature in terms of the input power and wavelength. This led to significant reduction in the link equation complexity and development of some approximation techniques to easily represent the link behavior. The reduced form of the link spectral model was very essential as the initially developed wavelength model had a lot of parametric dependency on the component models. This mathematical reduction process led to simplification of the spectral model into a product of two independent functions, the input current and wavelength. It is also noticed that the total link power within specific wavelength range can be obtained by the integrating these functions over a specific link input power. After the mathematical modelling, an experimental prototype physical link is set up and characterized using various radar signals like continuous wave (CW) RF, pulsed RF, non linear frequency modulated signal (NLFM) etc. Additionally a proof of concept Radio-Over-Fiber (RoF) link is established to prove the superior transmission of microwave signal through an optical link. The analysis is supported with measurements on amplitude, delay, frequency and phase variations. The NLFM waveforms transmissions are further analysed using a matched _ltering process to confirm the side lobe requirement. Further a prototype WDM link is built to study the performance when digitally modulated channels are also multiplexed into the link. The link is again validated for signal levels, delay, frequency and phase parameters. Since amplitude and delay are deterministic, it is proposed that these parameter variations can be compensated by using suitable components either in the electrical or the optical domain. Radar systems use low frequency digital signals of different duty-cycles for synchronization and control across various transmit-receive modules. In the proposed link, these digital signals also modulate a WDM channel and hence the link is called a hybrid system. As the proposed link has EDFA to compensate for the splitting losses, there are chances of transient effects at the EDFA output for these low bitrate channels. Owing to the long carrier lifetime, low bitrate digital channels are prone to EDFA transient effects under specific signal and pump power conditions. Additionally, the synchronization signals used in radar application vary the duty-cycle over time, which is found to introduce variations in transient output. This practical challenge is further studied and the thesis for the first time, includes an analysis of EDFA transient e_ects for variable duty-cycle pulsed signals. The analysis is carried out for various parameters like bitrate, input power, pump power and duty-cycle. Investigations on EDFA transients on variable duty-cycle signals help in proposing a viable method to predict the lower duty-cycle transients from higher duty-cycle transients. The predicted transients were again validated against simulated transients and experimental results. As these transient effects are not desirable for radar signals, we propose a novel transient suppression techniques in optical and electrical domain which are validated with simulation and experimental measures. One suppression technique tries to avoid transient effect by keeping the optical input to EDFA always constant by feeding an inverted version of the original pulse into the EDFA along with the actual pulse. It is observed that as the wavelength of the inverted pulse is closer to the original input pulse, the transient effect settles faster. These EDFA transients are evaluated with WDM link configurations, where both high and low bitrate signals are co-propagated. Another challenging aspect of the link operation is the non-at gain spectrum of EDFA. i.e., EDFA provides unequal power level for various signals at WDM link output. This is especially true in the case of local oscillator signals, where it is preferable to have the same amplitude signals before feeding it to the mixer stages. But in the radar applications, this will require additional hardware circuits to equalize the signal level within a phased array antenna. This work also proposes some of the power equalization methods that can be used along with the WDM links. This part of the work is also supported with simulation model and experimental results. The analytical and experimental study of this thesis aids the evaluation process of a suitable optical Wavelength Division Multiplexed(WDM) distribution network that can be used for the distribution of both RF and digital signals. The optical WDM links being superior with its light weight, less loss and EMI/ EMC immunity provides a better solution to future class of radars.

碩士
國立臺北科技大學
光電工程系研究所
98
In this thesis, a bi-directional long-reach wavelength division multiplexing Passive Optical Network (WDM-PON), with 10 Gb/s bit rate in downlink and 5 Gb/s bit rate in uplink, are proposed. There are two channels with 0.4 nm channel spacing in downstream and upstream, respectively. The dispersion-compensating Raman amplifier /EDFA hybrid amplifier (DCRA/EDFA) which based on dispersion compensating fiber (DCF) is built in the local exchange. The DCRA/EDFA hybrid amplifier not only boost up the power budget, but also reduce the noise in long-reach transmission, including the chromatic dispersion and the effect of amplified spontaneous emission (ASE). Colorless operation is implemented by an electro-absorption modulator (EAM) to re-modulate the downstream signal in each reflective optical network units (R-ONUs) for uplink signals. In this thesis, the hybrid DCRA/EDFA amplifier is verified to improve the fiber dispersion and reduce the loss through the long reach transmission. Due to this scheme, the fiber link can be extended to 120 km transmission and reduced the number of optical amplifiers. The comparison of different pumping type between the feed-forward and backward pumping in RZ-DPSK downlink signal and RZ-OOK uplink signal are presented. And the power penalty are less than 1dB in at 10-9 bit-error-rate in bi-directional fiber link . The results showed that the feed-forward pumping in hybrid amplifier integrated with colorless technique in long-reach WDM-PON transport system not only can reduce capital expenditures, but also can improve the signal performance. Furthermore, it will provide the better sensitivity in transmission.

碩士
國立臺北科技大學
電腦與通訊研究所
101
In the thesis, we propose Optical Frequency Comb Generation (OFCG) which consists of a Dual-drive Mach-Zehnder Modulator (DD-MZM), phase shift, attenuator, Electrical Amplifier (EA), and an oscillator. The proposed OFCG can be applied to bidirection Long-Reach Wavelength Division Multiplexing Passive Optical Network. Utilizes OFCG to generate 76 carriers as transmission channels, and the space among channels is 0.16 nm, includes C-band and L-band. We use Hybrid Fiber Amplifier (HFA) as a power amplifier to compensate fiber attenuation and amplify spectra of C-band and L-band, simultaneously. The even channels are chosen as the downstream channels with 10Gbit/s bit rate. In addition, the odd channels which are chosen as the upstream channels with 5 Gbit/s bit rate, and which use colorless techniqueare implementedin each Optical Network Unit (ONU) in order to reduce the cost. This thesis proposes Raman(B)-EDFA system can set all active conponents at the Local Exchange (LE). To summarize, using OFCG and colorless technique in remote pumping system can reduce the cost effectively. The results show that use odd and even channels as upstream and downstream channels respectively not only avoids Rayleigh backscattering effect to bidirection WDM-PON, but also raises the transmission distance of PON to 105 km and achieves the Long-Reach PON.

碩士
國立東華大學
光電工程研究所
96
In this thesis, we design dispersion-compensated Raman/erbium-doped fiber hybrid amplifiers recycling residual Raman pump for wavelength-division multiplexing (WDM) systems. The hybrid amplifiers system only require single Raman pump source. The experimental results showed that the hybrid amplifiers scheme have net gain of more than 17 dB which provide gain bandwidth over 70 nm from 1525 to 1595 nm for input signal power of -20 dBm. Compared with the conventional dispersion-compensated Raman amplifiers (DCRA), the net gain increases 4.36 dB and the gain bandwidth broadens 50 nm. Besides, there is no significant increase of noise figure (NF) in our experimental setup. The NF is about 6.79 dB. In order to increase gain bandwidth and to flatten gain of the hybrid amplifiers. We used multiple wavelengths Raman pump units to pump the Raman fiber amplifiers. The gain ripple of less than ±1.47 dB can be achieved over 65 nm from 1525 to 1590 nm by the optimal combination of pump wavelength at 1435 and 1480 nm. The gain bandwidth is over 80 nm at a wavelength range of 1520 to 1600 nm. The net gain and NF are 20.01 dB and 5.74 dB for input signal power of -20 dBm, respectively. The all-optical gain clamped technique is a simple and effective way to achieve constant gain characteristics regardless of input signal power variations. To our knowledge, this is the first experimentally demonstration gain-clamped broad band and gain flattened dispersion-compensated Raman/erbium-doped fiber hybrid amplifiers by recycling residual Raman pump with only using a single FBG for WDM systems. The optimum gain clamped wavelength is 1564 nm. The gain variation of less than 0.21 dB can be achieved over 100 nm from 1525 to 1625 nm and the dynamic signal input exceed 18 dBm ranging from -20 to -2 dBm. Besides, the gain ripple of less than ±1.75 dB is achievable over 65 nm from 1530 to 1595 nm. The gain bandwidth is over 80 nm from 1520 to 1600 nm. This hybrid amplifiers system has the advantages of the high transmission capacity, high gain, low noise, broad gain bandwidth, high flattened gain and large dynamic range of input power.

碩士
國立東華大學
電機工程學系
90
In recent years, the requirement of the bandwidth and capacity for wired network keeps increasing because of the easy-access network and low-cost computer. The pursuit of quality (security, stable, etc.) and the use of multimedia (video, real-time transmission etc.) also mean that today’s bandwidth and capacity cannot meet the demand. On the other hand, the optical transmission meets the demand. For the optical communication, the WDMA (Wavelength Divided Multiple Access) system has been developed at first and maturely commercialized. Although WDMA can be used to satisfy the requirement, it has the disadvantage of low efficiency in utilizing bandwidth (for the high bandwidth optical communication system). Thus, the OCDMA (Optical Code Divided Multiple Access) is developed in order to compensate for the disadvantage of WDMA. Furthermore, our system is based on the hybrid system of OCDMA+WDMA, and our research focuses on improving the transmission performance. In the thesis, we access an OCDMA user’s signal as the desired signal and view WDMA users as narrowband interference. Our research is to suppress or reject the WDMA signals. We redesign the pixels of liquid crystal modulator, and use this modified liquid crystal modulator (modified LCM) to replace the original liquid crystal modulator (original LCM) so that the interference of WDMA signals will be suppressed. In addition, our approach also suppresses the effect of MAI (multiple access interference). For the performance of the entire system, it is obviously improved.

碩士
國立東華大學
電機工程學系
90
Optical fiber communication is the most popular type of computer network communication. Fiber is the best waveguide of light applications. It has lots of advantages such as low loss, high bandwidth, high security, etc. Coventional communication cable is short of these advantages. Optical communication has various ways for transmission. Because of the high frequency of light, if we could control and use light for carrier of communication, capacity would be larger than conventional communication. Today’s optical Wavelength-Division Multiple-Access (WDMA) networks achieve total throughputs of at most ten Gbps, primarily because the use of inchherent optical techniques limits their total throughput to the speeds that be handled by electronics technology. One significant possibility for Local Area Networks (LANs) is Code-Division Multiple-Access (CDMA) which does not need the stable, tunable lasers with accurate wavelength control that WDMA needs. In this thesis, we propose a hybrid CDMA/WDMA architecture of LAN. The CDMA scheme is based upon spectral coding. The system description of CDMA is reviewed, and the CDMA/WDMA system model is developed. The bit error rate (BER), numbers of CDMA and WDMA users, and receiver threshold of CDMA are calculated at BER of . For CDMA, system performance will be improved greatly by increasing code length (No) so that it can accommodate more users. We calculate three types of code length, namely 128, 256, and 512. When the proportion of usable bandwidth that is allocated to CDMA users is decreased, the total number of users of hybrid system will decrease but the total bit rate will increase. We calculate two types of channel interval of WDMA, namely 100GHz and 50GHz. We also list other types of feasible allocation, and calculate total number of users and bit rate. More users can be allowed in these types of allocation and total bit rate will be increased slightly. The bit rate of CDMA (60Mbps) is less than WDMA (1.2Gbps). Bit rate of WDMA that can reach 10Gbps has been proposed. We use this data to calculate total bit rate of the system again. Although total number of users is less than that in the pure CDMA system, total bit rate will increase.

碩士
國立東華大學
電機工程學系
93
Nowadays, because the requirement for the bandwidth and capacity keeps increasing, conventional communication systems can not satisfy the demand. The unique solution for bandwidth and capacity of wired network is optical communication. Fiber is the best waveguide in light applications. It has lots of advantages such as low loss, high bandwidth, high security, etc. Conventional communication cable is short of these advantages. Optical communication has various ways for transmission. Because of the high frequency of light, if we could control and use light as the carrier of communication, capacity would be larger than that of conventional communication systems. For the optical communication, the Wavelength Division Multiple Access (WDMA) system has been developed at first and maturely commercialized. Although WDMA can be used to satisfy the requirement mentioned above, it has the disadvantage of low efficiency in utilizing bandwidth (for the high bandwidth optical communication system). Thus, the Optical Code Division Multiple Access (OCDMA) is developed in order to work out with the disadvantage of WDMA, but its data rate is limited by the low repetition rate of the ultrashort pulse laser source. Hence, in this thesis, we proposed a Multi-slot OCDMA system to resolve the issue of low data rate. Data rate and total throughput can be really increased with the increased number of slots with the proposed system. For example, if 512 chips are used to spread each pulse, the system can simultaneously accommodate more than 10 6-slot OCDMA and 30 WDMA users, achieving a total throughput of around 660Gbps at a BER of 10e-9.

碩士
國立東華大學
電機工程學系
95
Today’s optical Wavelength-Division Multiple-Access (WDMA) networks achieve total throughputs of at most a few hundreds of Gbps, primarily because the use of incoherent optical techniques limits total throughput to speeds that can be handled by available electronics technology. This bottleneck can be eliminated by the use of optical switching, narrowlinewidth tunable lasers and coherent detection. Until these developments in WDMA networks take place, other alternatives for increasing the capacity　of all optical networks must be examined. The optical code division multiple access (OCDMA) system has better bandwidth utilization than WDMA system, and the WDMA system has faster data rate, which can redeemed that the data rate of OCDMA system is limited by ultrashort laser (nearly to 60Mbps). In the past, it was the purpose of our research to suppress the interference between WDMA and OCDMA, and then we obtained better performances. We have an ideal to modify the OCDMA system itself nowadays. In addition, we apply the modified system to the hybrid OCDMA/WDMA system. We propose to implement CDMA by using a spectral coding scheme that eliminates the need for the ultra-high speed synchronization and device operation that make traditional spread spectrum (SS) approaches unsuitable for high data-rate optical networks. The technology of the CDMA system is limited to LANs because the broad bandwidth that makes CDMA desirable leads to severe problems with dispersion. At the scale of a LAN, though, these problems can be alleviated with Dispersion Compensated Fiber (DCF). The feasibility of this spectral coding scheme has already been demonstrated at visible wavelengths. 　In our research, we design the new system, called Sub-band hybrid OCDMA/WDMA system, to achieve efficient power control, and consider that the error control codes can be used in our sub-band hybrid communication system. That is, we utilize each sub-band to deliver each error control code. This approach can effectively reduce the bit error rate (BER), compared with that in the sub-band system without applying the error control codes. We also pay attention to the comparisons of the number of the combined users (CDMA+WDMA) between original system and our proposed system. In the simulation, we discover that the total numbers of users in our proposed system become more than those in the original system as the code length M is less than 256 (that is, sub code length N≒M/J0). Due to utilizing the sub-band approach from our conception and using the error-control coding application, our proposed system does not need more code length than before (the original hybrid system). Thus it may reduce the cost and if we increase the code length of each sub-band, it will be applied in many aspects, for example, the increase of the data rates as well as the system capacity.

碩士
國立東華大學
電機工程學系
94
Nowadays, because the requirement for the bandwidth and capacity keeps increasing, conventional communication systems can not satisfy the demand. The unique solution for bandwidth and capacity of wired network is optical communication. Fiber is the best waveguide in high frequency applications. It has lots of advantages such as low loss, high bandwidth, high security, etc. Conventional communication cable is short of these advantages. In addition, optical communication has various ways for transmission. For the optical communication, the Wavelength Division Multiple Access (WDMA) system has been developed at first and maturely commercialized. Although WDMA can be used to satisfy the requirement mentioned above, it has the disadvantage of low efficiency in utilizing bandwidth. Thus, the Optical Code Division Multiple Access (OCDMA) is developed in order to work out with the disadvantages of WDMA, but its data rate is limited by the low repetition rate of the ultrashort light pulse laser source. Hence, in this thesis, we proposed an OCDMA system with the position code to re-utilize the time slots wasted. We find that the performance of the new system will be better than that of original system. For example, it can accommodate at least 50 more users in the worst performance when BER is 10-9, and suppress the NBI caused by WDMA signals in the hybrid OCDMA/WDMA system.

碩士
國立東華大學
電機工程學系
102
Recently, conventional communication systems have been unable to meet the requirement of customers due to the increasing demand on bandwidth and transmission capacity. Optical communication systems, as a result, become the trend at present and in the future. They possess the advantages such as low loss, broad bandwidth, high security, light weight and small volume. Many transmission schemes have been developed for optical communication systems so far. The transmission capacity among all of them can be much higher than that of the wireless communication systems because of their intrinsic broad bandwidths. Wavelength Division Multiple Access (WDMA) techniques are first developed and widely used in optical communication systems. Although they satisfy the demand for bandwidth, they suffer from the drawbacks of low spectrum efficiency, and Optical Code Division Multiple Access (OCDMA) techniques are therefore developed. Nevertheless, the transmission rate of OCDMA systems is constrained by the laser source they use. In this thesis, an OCDMA system with the position code is combined with the multi-slot scheme so that the unused time slots can be utilized to enhance the system performance. It is then hybridized with the WDMA system to form a hybrid multi-slot OCDMA/WDMA system with the position code. The performance analysis shows that it may accommodate at least 44 users at an error probability of 10−9 , with the total data rate reaching 110Gbps.

碩士
國立東華大學
電機工程學系
91
Nowadays, the requirement for the bandwidth and capacity of wired network keeps increasing because of the easy-access network and low-cost computer. The pursuit of quality (security, stability … etc.) and the use of multimedia (video, real-time transmission ... etc.) also mean that today’s bandwidth and capacity cannot satisfy the demand. The unique solution for bandwidth and capacity of wired network is optical transmission. For the optical communication, the Wavelength Division Multiple Access (WDMA) system has been developed at first and maturely commercialized. Although WDMA can be used to satisfy the requirement, it has the disadvantage of low efficiency in utilizing bandwidth (for the high bandwidth optical communication system). Thus, the Optical Code Division Multiple Access (OCDMA) is developed in order to work out with the disadvantage of WDMA. This is extended further to hybrid WDMA and OCDMA system into one optical communication system in which the form of transmitted signal from the transmitter is WDMA+OCDMA, so is the received signal at the receiver. From WDMA users’ point of view, OCDMA users are wide-band interference (WBI), and from OCDMA users’ viewpoint, WDMA users are narrowband interference (NBI), so receiver design for WBI/NBI suppression in hybrid OCDMA/WDMA system is needed. In this thesis, based on the hybrid OCDMA/WDMA system, we propose two receiver designs, one for WDMA and the other for OCDMA, which can receive the desired signal with the least interference, and the performance of the entire system is obviously improved with the proposed receiver.

碩士
國立成功大學
高階管理碩士在職專班(EMBA)
104
This study proposes a hybrid model in order to connect customers’ emotional factors and business goals, faciliate enterprises gain specialized knowledge and achivements. The advocate of electronic word-of-mouth (e-WOM) has received considerable attention in business communitiesand far-reaching consequences in emotional for consumers. In addition, more and more companies regconized that the payoff would be huge if they connect with customers’ emotions. Kansei words are the key to describe customers’ demands. This study uses use blog article as the source to extract customer’s emotional factors. Text mining technique, Kansei engineering and Google Analytics solutions are applied to extract Kansei words from blog articles and filter out those articles that could effectively bring network traffic to e-commerce websites. The results of this study are desired to build up a novel application that could help enterprises in their marketing activities.