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Projeto de amplificadores a fibra dopada com érbio para sistemas baseados em multiplexação modal; Erbium doped fiber amplifiers design for modal-division multiplexing systems

Herbster, Adolfo Fernandes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/06/2015 Português
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Os sistemas ópticos atuais, baseados em fibras monomodo, operam próximos ao limite teórico da capacidade. Sistemas ópticos baseados em multiplexação modal (Mode Division Multiplexing – MDM) possibilitam o aumento da capacidade do sistema por meio do uso de fibras de poucos modos. Nestes sistemas, a propriedade de ortogonalidade entre os modos propagantes permite que cada modo espacial carregue um sinal óptico específico. O amplificador à fibra dopada com érbio (Erbium-Doped Fiber Amplifier – EDFA) segue fundamental para assegurar a transmissão em longas distâncias. No entanto, devido às distintas distribuições de intensidade dos modos que compõem o sinal de entrada, cada modo experimenta diferentes valores de ganho. Desta forma, o objetivo principal no projeto de EDFAs de poucos modos (Few-Mode Erbium-Doped Fiber Amplifier – FM-EDFA) é determinar os melhores parâmetros opto-geométricos da fibra para produzir uma amplificação eficiente. A metodologia normalmente empregada é baseada na resolução das equações de taxa e de propagação. Nesta tese, é proposta uma metodologia alternativa de projeto de FM-EDFA, baseada em uma nova figura de mérito. Este parâmetro quantifica o nível de inversão da população dos íons na fibra a partir da integral de superposição (overlap integral)...

Multiplexação adaptativa baseada no e-model para redução do overhead na rede em ligações VoIP sobre IP security mantendo qualidade nas conversações; Adaptive multiplexing based on e-model for reducing network overhead on VoIP calls over IP security ensuring conversation quality

Pereira, Rafael Mendes
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
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A tecnologia de Voz sobre IP (VoIP) traz novas oportunidades como também novos riscos. Desse modo, diversas soluções vêm sendo propostas com o objetivo de assegurar premissas de segurança nas conversações. Contudo, a aplicação de segurança em VoIP apresenta-se como uma tarefa complexa devido às características peculiares dessa tecnologia. Um exemplo consiste na proteção das conversações por meio do IPSec, o qual diminui, substancialmente, o uso efetivo da banda. A multiplexação das ligações apresenta-se como uma alternativa para melhoria do desempenho da aplicação do IPSec em VoIP. Nessa técnica quanto mais pacotes agrupados, melhor é o resultado obtido. Entretanto, essa técnica mostra-se menos eficaz em cenários com poucas ligações simultâneas. Assim, nesse trabalho é apresentada uma evolução da técnica de multiplexação, onde propõem-se um modelo adaptativo baseado no E-Model, cujos objetivos consistem em melhorar a redução do overhead na rede, respeitando os limites desejáveis de qualidade nas conversações. Na proposta, em boa conjuntura dos fatores que influenciam o desempenho das ligações, expande-se o tempo de retenção, aumentando o número de pacotes agrupados e conseqüentemente obtendo maior taxa de compressão. O acréscimo é realizado respeitando os limiares de qualidade de cada ligação envolvida na multiplexação. Em situações críticas...

Vector Mode Analysis of Ring-Core Fibers: Design Tools for Spatial Division Multiplexing

Brunet, Charles; Ung, Bora; Belanger, Pierre-andre; Messaddeq, Younes; Larochelle, Sophie; Rusch, Leslie Ann
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 4648-4659
Português
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Design tools have existed for decades for standard step-index fibers, with analytical expressions for cutoff conditions as a function of core size, refractive indexes, and wavelength. We present analytical expressions for cutoff conditions for fibers with a ring-shaped propagation region. We validate our analytical expressions against numerical solutions, as well as via asymptotic analysis yielding the existing solutions for standard step-index fiber. We demonstrate the utility of our solutions for optimizing fibers supporting specific eigenmode behaviors of interest for spatial division multiplexing. In particular, we address large mode separation for orbital angular momentum modes and fibers supporting only modes with a single intensity ring.

Analise de atraso dos pacotes de voz em redes IP utilizando a tecnica de multiplexagem de quadros de voz; Voice packet delay evaluation in an IP network using voice stream multiplexing scheme

Carlos Fielde de Campos
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/10/2008 Português
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Neste estudo são avaliados o desempenho e o impacto do tráfego de voz em uma rede IP. Na rede IP o sinal de voz é transmitido através de pacotes que são identificados por um conjunto de cabeçalhos. Cada pacote de voz tem a carga útil, composta por um quadro (frame) de voz, muito menor que a carga útil de um pacote de dados. Desta forma, a rede IP pode tornar-se pouco eficiente para transportar sinal de voz. Além disso, o serviço de voz requer também interatividade o que implica em realocar, através de mecanismos apropriados, os recursos da rede IP. Uma das técnicas que pode ser usada é a aplicação de política de priorização do tráfego de voz que em contrapartida pode degradar o desempenho de tráfego com prioridade menor. A previsão de tráfego de voz crescente na rede IP pode torná-la bastante ineficiente, além de degradar o desempenho do tráfego de dados. Para minimizar este problema o esquema de multiplexagem dos quadros de voz pode ser usado. Um modelo matemático é proposto neste estudo para analisar o impacto do tráfego do pacote de voz em uma rede IP. O estudo é conduzido considerando-se sem e com a aplicação de multiplexagem de quadros de voz nos pacotes de voz e o parâmetro de desempenho é o atraso de cada pacote na rede IP. Em seguida...

Avaliação de desempenho da técnica de multiplex espacial na presença de interferência de co-canal; Performance evaluation of spatial multiplexing technique in the presence of co-channel interference

Juan Carlos Minango Negrete
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/08/2014 Português
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O uso da técnica de multiplex espacial, transmissão de feixes de símbolos independentes usando múltiplas antenas de transmissão, tem sido proposta para atingir a exigência de taxas de dados maiores dos futuros sistemas de comunicações sem fio de banda larga. No entanto, quando a técnica de multiplex espacial é aplicada a uma rede celular, seu desempenho é afetado pela interferência de co-canal. Este trabalho avalia e compara os efeitos da interferência de co-canal na taxa de erro de bit média, BER, entre sistemas de transmissão digital com multiplex espacial e sistemas de transmissão digital com uma única antena de transmissão, onde os parâmetros da potência de transmissão e eficiência espectral são levados em consideração, a fim de se fazer comparações justas entre os dois sistemas. O enlace direto em um ambiente com desvanecimento plano e lento do tipo Rayleigh na presença de um interferente de co-canal dominante foi considerado. Além disso, o uso do detector ótimo, MV, no receptor e os esquemas de modulação BPSK, QPSK e M-QAM foram também considerados. Simulações de Monte Carlo foram feitas para a obtenção dos desempenhos em termos da BER como uma função da relação sinal-ruído por bit, Eb/N0...

End-to-end inverse multiplexing for mobile hosts

Magalhaes,Luiz; Kravets,Robin
Fonte: Sociedade Brasileira de Computação Publicador: Sociedade Brasileira de Computação
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2001 Português
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This paper presents a framework for the creation of transport protocols for mobile hosts that use multiple link layers simultaneously for the same connection. This abstraction provides an end-to-end transport layer channel between two applications that do not have to be aware of host mobility. The channel is composed of multiple network layer sub-channels. A sub-channel is an end-to-end network layer connection that is mapped to one physical interface. Inverse multiplexing is used at the transport level to divide application data into sub-channels, and a rate-based transmission mechanism provides congestion avoidance. The same mechanism is used to differentiate transmission losses from congestion losses, resulting in good throughput in lossy wireless links. Experimental results for two protocols created using this framework validate our design choices.

The effects of object activity distribution on multiplexing multi-pinhole SPECT

Mok, Greta S P; Tsui, Benjamin M W; Beekman, Freek J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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We aim to study the effects of activity distribution for multiplexing multi-pinhole (MPH) SPECT. Three digital phantoms, including a hot rod, a cold rod and a cold sphere phantom, were used. Different degrees of multiplexing were obtained by (i) adjusting the MPH pattern for the same 4-pinhole collimator (scheme 1) and (ii) increasing the number of pinholes (scheme 2). Noise-free and noisy projections were generated using a 3D analytical MPH projector based on the same acquisition time. Projections were reconstructed using OS–EM without resolution recovery. Normalized mean-square-error (NMSE), noise, image profiles and signal-to-background ratios (SBR) were assessed. For the hot rod phantom, the NMSE-noise trade-offs slightly improves for multiplexing designs in scheme 2. Substantial artifacts were observed and the NMSE-noise trade-offs slightly worsened for multiplexing designs for the cold phantoms. Resolutions slightly degraded for higher degrees of multiplexing (~39–65%) for the cold rod phantom. For the cold sphere phantom, image profiles showed non-multiplexing designs better emulated the phantom, while ~20% multiplexing performs similarly as compared to non-multiplexing in SBR. Our results indicate that multiplexing can help for sparse objects but leads to a significant image degradation in non-sparse distributions. Since many tracers are not highly specific...

Quantification of the Multiplexing Effects in Multi-Pinhole Small Animal SPECT: A Simulation Study

Mok, Greta S. P.; Wang, Yuchuan; Tsui, Benjamin M. W.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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Our goal is to study the trade-off between image degradation and improved detection efficiency and resolution from allowing multiplexing in multi-pinhole (MPH) SPECT, and to determine the optimal pinhole number for MPH design. We used an analytical 3D MPH projector and two digitized phantoms: the mouse whole body (MOBY) phantom and a hot sphere phantom to generate noise-free and noisy projections, simulating pinhole collimators fitted with pre-studied pinhole patterns. We performed three schemes to achieve different degrees of multiplexing: 1. Fixed magnification and detection efficiency; 2. Fixed detection efficiency and changed magnification; 3. Fixed magnification and changed detection efficiency. We generated various noisy data sets by simulating Poisson noise using differently scaled noise-free projections and obtained 20 noise realizations for each setting. All datasets were reconstructed using 3D MPH ML-EM reconstruction method. We analyzed the quantitative accuracy by the normalized-mean-square-error. We evaluated the image contrast for the hot sphere phantom simulation, and also the image noise by the average normalized-standard-deviation of certain pixels for different degrees of multiplexing. Generally, no apparent artifacts were observed in the reconstructed images...

Mass Spectrometry-Based Multiplexing for the Analysis of Biomarkers in Drug Development and Clinical Diagnostics- How Much is too Much?

Christians, Uwe; Klepacki, Jacek; Shokati, Touraj; Klawitter, Jost; Klawitter, Jelena
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Biomarkers, or more specifically molecular markers, can detect biochemical changes associated with disease processes and drug effects before histopathological and pathophysiological changes occur. Multiplexing technologies such as high-performance liquid chromatography/mass spectrometry (LC-MS) allow for the measurement of molecular marker patterns that confer significantly more information than the measurement of a single parameter alone. The use of multiplexing assays for drug development, and as diagnostic tools, is attractive but will require regulatory review and approval and thus requires validation following regulatory guidances. Multiplexing assays always constitute a compromise. The number of analytes that can reasonably be included in a mass spectrometry-based multiplexing assay depend on the physico-chemical properties of the analytes and their integration into a single assay in terms of extraction, HPLC separation, ionization conditions and mass spectrometry detection. Another aspect includes biomedical considerations such as the differences in physiological concentrations of analytes, the required concentration range, and how much variability is acceptable before the clinical utility of a marker is negatively affected. Regulatory considerations include validation and quality control during sample analysis. Current bioanalytical regulatory guidelines have mostly been developed for single drug compounds and are not always adequate for multiplexing molecular marker assays that often quantify endogenous compounds. Specific guidances for multiplexing assays should be developed. Even if it is possible to integrate a wide variety and large number of analytes into a multiplexing assay...

Multiuser Detection in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing Systems by Blind Signal Separation Techniques

Du, Yu
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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This dissertation introduces three novel multiuser detection approaches in Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems by blind signal separation (BSS) techniques. The conventional methodologies for multiuser detection have to retransmit channel state information (CSI) constantly from the transmitter in MIMO ODFM systems at the cost of economic efficiency, because they require more channel resources to improve the communication quality. Compared with the traditional methodologies, the proposed BSS methods are relatively efficient approaches without the unnecessary retransmission of channel state information. The current methodologies apply the space-time coding or the spatial multiplexing to implement an MIMO OFDM system, which requires relatively complex antenna design and allocation in the transmitter. The proposed Spatial Division Multiple Access (SDMA) method enables different mobile users to share the same bandwidth simultaneously in different geographical locations, and this scheme requires only one antenna for each mobile user. Therefore, it greatly simplifies the antenna design and allocation. The goal of this dissertation is to design and implement three blind multiuser detection schemes without knowing the channel state information or the channel transfer function in the SDMA-based uplink MIMO OFDM system. The proposed scenarios include: (a) the BSS-only scheme...

On Diversity and Multiplexing Gain of Multiple Antenna Systems with Transmitter Channel Information

Khoshnevis, Ahmad; Sabharwal, Ashutosh; Khoshnevis, Ahmad; Sabharwal, Ashutosh
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Conference paper
Português
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Conference Paper; We quantify the multiplexing-diversity tradeoff of a multiple-input multiple-output (MIMO) system, when the channel state information (CSI) is known perfectly at the receiver and partially at the transmitter. The partial knowledge of CSI at the transmitter consists of the quantized value of one of the eigenvalues and perfect knowledge of eigenvectors of the channel matrix. The key result is that while multiplexing gain cannot be increased beyond minimum number of transmit and receive antennas, diversity order for each multiplexing gain can be substantially increased by using only a few bits of feedback at the transmitter. For example, with 1 bit of feedback in a 2x3 system, for multiplexing gains of 0, 1, and 2, diversity gains of 42, 6, and 2 can be achieved, respectively. Thus, while the tradeoff between diversity advantage and multiplexing gain is still present, its behavior is significantly changed by channel knowledge at the transmitter. The major reason for this different tradeoff can be attributed to addition of long-term power control, which allows the transmitter to switch between modes for reducing outage and increasing throughput based on signal to noise ratio along different eigenvalues.

Achievable Diversity and Multiplexing in Multiple Antenna Systems with Quantized Power Control

Khoshnevis, Ahmad; Sabharwal, Ashutosh; Khoshnevis, Ahmad; Sabharwal, Ashutosh
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Conference paper
Português
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Conference paper; We consider a multiple antenna system with finite rate feedback, in which the quantized channel state information at the transmitter is used solely for temporal power control. We show that similar to systems without feedback, the tradeoff between diversity order and multiplexing gain exists. However, unlike the systems with feedback that apply both rate and power control, systems with only power control are unable of achieving non-zero diversity order at the maximum multiplexing gain. The analysis is based on asymptotic behavior of the distribution of order statistics of the eigenvalues of channel matrix, which is a key step in evaluating the diversity order.

Highly nonlinear fiber as pre-amplifier in distributed fiber Raman amplifier bus networks for sensors multiplexing

Díaz Lucas, Silvia; López Amo, Manuel; Urquhart, Paul; Jáuregui Misas, César; López Higuera, José Miguel
Fonte: Optical Society of America Publicador: Optical Society of America
Tipo: info:eu-repo/semantics/conferenceObject; publishedVersion
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We experimentally compare two distributed fiber Raman amplified bus networks for the wavelength-division multiplexing of optical sensors. The main difference between them is the type of fiber used in the pre-amplifier in each case.

A technique for multiplexing 3x3-coupler terminated interferometric fiber-optic sensors

Reid, Gregory John.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: 99 p. :|bill.
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Approved for public release; distribution is unlimited.; This thesis investigates the multiplexing of Mach-Zehnder type 3x3 terminated fiber-optic sensors demodulated by either 'quadrature'or'symmetric' methods using intensity modulation of the source. 3x3-couplers produce signals that permit unmodulated passive demodulation of interferometric signals. The theory is described and the results of a 2xl element array optical demonstration are presented. Possible architectures using this demultiplexing technique are presented for several applications with different return line requirements. The technique was successfully demonstrated and warrants further investigation to increase the number of sensors and reduce the number of return lines for specific applications. The multiplexing technique presents the opportunity for possible cost savings over other phase generated carrier techniques, which require wavelength modulation of the source, and significant optical path differences in the interferometers, and are therefore constrained to presently very expensive sources. The technique presented uses compatible low coherent laser sources such as Compact Disc quality (830 nm) devices.; Lieutenant, Royal Australian Navy

A Comparison and Outline of Tolerances in Performing Optical Time Division Multiplexing using Electro-Absorption Modulators

Owsiak, Mark
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
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As high bandwidth applications continue to emerge, investigation in technologies that will increase transmission capacity become necessary. Of these technologies, Optical Time Division Multiplexing (OTDM) has been presented as a possible solution, supporting a next generation bit rate of 160 Gbit/s. To perform the demultiplexing task, the use of tandem electro-absorption modulators (EAMs) has been widely studied, and due to its benefits was chosen as the topology of this thesis. To create an effective model of an OTDM system, the vector based mathematical simulation tool MatLab is used. Care was taken to create an accurate representation of an OTDM system, including: the development of a realistic pulse shape, the development of a true pseudo-random bit sequence in all transmitted channels, the optimization of the gating function, and the representation of system penalty. While posing impressive bit rates, various sources of system performance degradation pose issues in an OTDM system, owning to its ultra-narrow pulse widths. The presence of dispersion, timing jitter, polarization mode dispersion, and nonlinear effects, can sufficiently degrade the quality of the received data. This thesis gives a clear guideline to the tolerance an OTDM system exhibits to each of the aforementioned sources of system penalty. The theory behind each impairment is thoroughly discussed and simulated using MatLab. From the simulated results...

Proposta e implementação de um receptor optoeletrônico integrado para redes ópticas passivas (PONs) empregando multiplexação por divisão de comprimento de onda (WDM); Proposal and implementation of a optoelectronic integrated receiver for passive optical networks (PONs) employing wavelength division multiplexing (WDM)

Manfrin, Stilante Koch
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/07/2003 Português
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O presente trabalho descreve o desenvolvimento e implementação de duas configurações distintas de um receptor optoeletrônico integrado. A primeira configuração é similar a um projeto encontrado na literatura mas apresenta diversas modificações que lhe conferiram melhor desempenho em comparação ao projeto original. A segunda configuração é uma nova proposta deste trabalho. O receptor foi desenvolvido e implementado visando sua aplicação em redes de comunicações ópticas passivas (PONs) de alta velocidade comutadas a pacote, para possibilitar a utilização da técnica de multiplexação em comprimento de onda (WDM), aumentando assim a capacidade de transmissão da rede, em particular no ramo de ligação da rede de serviços com o usuário final, denominado rede de acesso. O principal objetivo do receptor aqui desenvolvido foi proporcionar uma sintonia rápida entre os canais disponíveis na rede, possibilitando sua seleção num tempo inferior àquele necessário para a transmissão de um único pacote de informação, diminuindo assim o atraso de sintonia e, por conseguinte, a perda de informação. Para tanto, os circuitos integrados implementados e caracterizados referem-se aos circuitos de chaveamento eletrônico e do amplificador de transimpedância das duas configurações investigadas. Os dados experimentais obtidos para as duas configurações confirmaram a previsão de chaveamento dos canais de entrada num intervalo de tempo da ordem de alguns nanosegundos...

Multiplexing and transmission of RF signals using an optical fiber

Curpián Alonso, José; Montero de Espinosa Freijo, Francisco; López-Amo, Manuel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 20888 bytes; application/pdf
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4 pages.-- Final full-text version of the paper is available at: http://dx.doi.org/10.1016/S0041-624X(99)00058-X.; Ultrasonic non-destructive testing systems designed to control huge structures normally use several transducers in the reception stage. To avoid increasing the cost of electronics, a multiplexer is used to send all received signals to the same processing module. Traditionally, transmission of such signals is carried out using copper cables. For special applications (i.e. continuous monitoring of nuclear plants) metallic cables are not suitable because of their high sensitivity to electromagnetic perturbations. Moreover, the multiplexing is made electronically. When the distance between the transducers and the reception unit is large and/or electromagnetic noise is important, signal degradation takes place. The proposed system implements the transmission and multiplexing of ultrasonic electrical signals obtained by means of broadband transducers (up to 1 MHz), using an optical fiber. Optical fibers are made of dielectric materials (silica or plastic) so they are inherently passive to electromagnetic noise. Wavelength division multiplexing is utilized for adding channels to the system by means of fiber optic couplers and different light sources. The wavelengths of the optical signals utilized are located far apart in the optical spectrum in order to avoid serious crosstalk in transmission. The limit to the number of multiplexed channels depends on the optical fiber selected...

Multiplexing Techniques and Design-Automation Tools for FRET-Enabled Optical Computing

Mottaghi, Mohammad
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014 Português
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FRET-enabled optical computing is a new computing paradigm that uses the energy of incident photons to perform computation in molecular-scale circuits composed of inter-communicating photoactive molecules. Unlike conventional computing approaches, computation in these circuits does not require any electric current; instead, it relies on the controlled-migration of energy in the circuit through a phenomenon called Förster Resonance Energy Transfer (FRET). This, coupled with other unique features of FRET circuits can enable computing in new domains that are unachievable by the conventional semiconductor-based computing, such as in-cell computing or targeted drug delivery. In this thesis, we explore novel FRET-based multiplexing techniques to significantly increase the storage density of optical storage media. Further, we develop analysis algorithms, and computer-aided design tools for FRET circuits.

Existing computer-aided design tools for FRET circuits are predominantly ad hoc and specific to particular functionalities. We develop a generic design-automation framework for FRET-circuit optimization that is not limited to any particular functionality. We also show that within a fixed time-budget, the low-speed of Monte-Carlo-based FRET-simulation (MCS) algorithms can have a potentially-significant negative impact on the quality of the design process...

Analysis of a new modulation/ multiplexing technique using mutually orthogonal chaotic waveforms

Jidge, Chaitanya
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
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A new digital modulation technique proposed [3] by Dr. Chance M. Glenn is presented and analyzed in this report. The report explains the MOC algorithm as a means of creating information-bearing baseband signals for modulation in digital communications. The process uses the natural diversity of chaotic oscillations. An orthogonal triplet of waveforms is extracted from the oscillations produced by a chaotic process. A simple digital communication system is built, which uses this triplet as basis waveforms to formulate a baseband waveform. There is a lot of research work done and still going on to use chaotic oscillations in the communication system. The previously proposed communication systems have a disadvantage of not retrieving the data back at the demodulator as the demodulator need to be synchronized with the modulator, which cannot be implemented in real time. We propose a new way of using chaotic oscillations. The work done and contribution toward the thesis includes finding sets of mutually orthogonal chaotic waveforms using the data collected from the various chaotic oscillations, finding an optimal set of chaotic waveforms that can be used in the communication system. We demonstrated the implementation of the communication system using Matlab and Simulink. We simulated and analyzed the communication system built based on the MOC waveforms. We compared the results yielded with other modulation schemes like QAM...

Acousto-optic wavelength division multiplexing system

Helaly, Anwar; Abushagur, Mustafa
Fonte: Wiley Periodicals - Microwave and Optical Technology Letters Publicador: Wiley Periodicals - Microwave and Optical Technology Letters
Tipo: Artigo de Revista Científica
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A novel wavelength division multiplexing/demultiplexing (WDM) system using acousto-optic Bragg cell is presented. The system is adaptable for any wavelength deviation of light sources caused by temperature changes and allows changing the operating wavelengths over a wide range. High diffraction efficiency, high resolution, and a large number of channels are obtained. Computer simulation for a five-channel system in the 0.8-m region is presented.; Microwave and Optical Technology Letters article. Please see www3.interscience.wiley.com for more information.