Дисертації з теми "Optical Coherent Transmission System"
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Leong, Miu Yoong. "Coherent Optical Transmission Systems : Performance and Coding Aspects." Doctoral thesis, KTH, Optik och Fotonik, OFO, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176637.
Повний текст джерелаQC 20151119
Oliveira, Inês do Vale Marques. "Digital chromatic dispersion equalization in optical coherent transmission systems." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21735.
Повний текст джерелаA crescente procura de largura de banda tem obrigado a área de comunicações óticas a explorar diferentes soluções, de forma a evitar a ”crise de capacidade” [1]. O investigadores têm trabalhado no sentido de atingir o equilíbrio entre os vários compromissos, repensando a forma como o sinal ótico é enviado e recebido, para que a perda de informação seja mínima ao longo do canal de propagação. No inıcio desta década, começaram a ser adotados formatos de modulação avançada, os quais apresentam elevada eficiência espetral, bem como deteção coerente, que permite extrair a informação da amplitude e da fase do campo ótico. Estas técnicas são complementadas pelo pós-processamento digital de sinal, que é atualmente muito importante na mitigação das distorções do sinal e imperfeiçoes do recetor. As distorções do sinal podem ser causadas, por exemplo, pela dispersão cromática na fibra. Esta dissertação engloba o estudo e simulação de um sistema de transmissão coerente PM-QPSK, bloco-a-bloco, fazendo uma abordagem detalhada dos conceitos supramencionados. O sistema foi então simulado na presença de dispersão cromática e de ruído, alternada e simultaneamente. Os resultados mostram que o sinal recebido apresenta uma distribuição quase Gaussiana em todos os casos. Com vista a recuperar o sinal transmitido, e no caso em que só se considerou o efeito da dispersão cromática, aplicou-se um filtro linear de resposta impulsional inversa à da fibra, conseguindo assim uma equalização digital perfeita do sinal recebido. Também foi implementado um filtro adaptado no receptor para minimizar o efeito do ruído, obtendo não uma equalização perfeita, mas ótima.
The crescent demand on high bandwidth has been compelling the optical communications area to explore di erent solutions, in order to avoid the \capacity crunch" of the optical bres [1]. Researchers have been working towards reaching the best tradeo s balance, rethinking the way as the optical signal is sent and received, so the loss of information is minimum throughout the propagation channel. Advanced modulation formats became adopted in the beginning of this decade, presenting high spectral e ciency, as well as coherent detection, which allows extracting information from the amplitude and phase of the optical eld. These techniques are complemented by post-digital signal processing, which is nowadays very important at mitigating signal distortions and receiver imperfections. Those impairments result, for instance, of the chromatic dispersion at the bre. This dissertation covers the study and simulation of a PM-QPSK transmission system, block-by-block, approaching in detail the concepts mentioned above. The system was then simulated with chromatic dispersion and with noise, alternately and simultaneously. The results show that the received signal presents an almost Gaussian distribution in every case. In order to retrieve the transmitted signal, and in the case that only chromatic dispersion's e ect was considered, a linear lter was applied with an inverse impulse response of the bre, achieving such a perfect digital equalization of the received signal. A matched lter was also implemented in the receptor to minimize the noise e ect, obtaining not a perfect equalization, but an optimal one.
Gu, Xuanye. "Very long distance optical fibre transmission using coherent systems and optical amplifiers." Thesis, University of East London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334070.
Повний текст джерелаXu, Tianhua. "Digital Dispersion Equalization and Carrier Phase Estimation in 112-Gbit/s Coherent Optical Fiber Transmission System." Licentiate thesis, KTH, Optik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34034.
Повний текст джерелаQC 20110629
Chochol, Marcin. "Characterization and design of coherent optical OFDM transmission systems based on Hartley Transform." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/129677.
Повний текст джерелаHoy en día, debido al gran despliegue de las redes de ópticas de transporte, se espera un aumento continuado hacia mayores velocidades de datos, hasta 100 Gb/s y más allá. Por otra parte, la evolución que se prevé para las redes ópticas actuales, incluye la adquisición de nuevas funcionalidades, por ejemplo, la asignación del espectro de forma elástica para las señales ópticas. Por tanto, el claro desafío en cuanto a las tecnologías de transmisión es encontrar técnicas preparadas para hacer frente a un crecimiento de la demanda de ancho de banda; demanda que continuamente se incrementa por parte de los operadores de red, para quienes los sistemas estándar no se acaban de ajustar a las nuevas funcionalidades que esperan para la red. Una solución para cubrir todas estas necesidades es la adaptación de técnicas capaces de hacer frente a estas velocidades de datos enormes, y garantizar el mismo nivel de eficiencia para las largas distancias y mitigar las deficiencias ópticas acumuladas a lo largo de la ruta de transmisión. Además, se espera que estas técnicas de transmisión puedan proporcionar cierto grado de flexibilidad, a fin de mejorar y hacer más eficiente la gestión de la red. Una tecnología prometedora que puede hacer frente a estos requisitos es lo que se llama multiplexación por división de frecuencias ortogonales, combinado con la detección óptica coherente (CO-OFDM). CO-OFDM ofrece varias ventajas, entre otras: alta sensibilidad y eficiencia espectral y, sobre todo, la posibilidad de recuperar por completo de una señal en fase, la amplitud y la polarización. Estos sistemas están compuestos por bloques de procesado de señales digitales (DSP) que permiten detectar los datos fácilmente así como también compensar las principales degradaciones, proporcionando alta tolerancia a los efectos de dispersión. Sin embargo, los sistemas CO-OFDM no están exentos de inconvenientes. Su alta relación de potencia de pico a potencia media (PAPR) reduce sensiblemente la tolerancia no linealidades. Por otra parte, los sistemas CO-OFDM son sensibles a cualquier cambio de frecuencia y desplazamiento de fase. Por tanto, se propone un sistema OFDM de envolvente constante (CE-OFDM) para reducir significativamente la PAPR y solucionar la alta sensibilidad a las degradaciones no lineales. Consiste en una señal OFDM modulada en fase, que se detecta coherentemente en el receptor. Una transformada alternativa, la transformada discreta de Hartley, se propone para acelerar los cálculos en el DSP. El sistema CE-OFDM por su flexibilidad y escalabilidad única, resulta una tecnología aplicable a diferentes escenarios, que van desde las redes de acceso hasta las redes troncales. En el caso de las soluciones de acceso, se investigan varios casos. En primer lugar, el CE-OFDM aplica para el desarrollo y soporte de datos de una red radio, reutilizando una red óptica de acceso ya desplegada. A continuación, se investiga la transmisión bidireccional dúplex a 10 Gb / s sobre una sola longitud de onda empleando un RSOA a las unidades de usuario. El punto clave de este sistema es la transmisión en sentido ascendente, que se consigue re-modulando la fase de una señal de intensidad modulada después de saturar de forma adecuada. A continuación, se estudia una red de área metropolitana flexible de hasta 100 km. Concretamente el efecto de concatenación de filtros ópticos es el objetivo de este estudio. Finalmente, se propone una actualización elástica del modelo de Telefónica I+D para la red troncal española. Por ello, se propone operar el CE-OFDM en multiplexación de polarización. Los resultados muestran que esta combinación reduce sensiblemente el empleo de ancho de banda esto como los requisitos de los enlaces transmisión, reduciendo también los costes tanto de desarrollo como de operación y mantenimiento de la red.
Avui dia, a causa del gran desplegament de les xarxes de òptiques de transport, s'espera un augment continuat cap a majors velocitats de dades, fins a 100 Gb/s i més enllà. D'altra banda, l'evolució que es preveu per a les xarxes òptiques actuals, inclou l'adquisició de noves funcionalitats, per exemple, assignació de l'espectre de forma elàstica per als senyals òptics. Per tant, el clar desafiament pel que fa a les tecnologies de transmissió és trobar tècniques preparades per fer front a un creixement de la demanda d'ample de banda; demanda que contínuament es fa per part dels operadors de xarxa, per als qui els sistemes estàndard no s'acaben d'ajustar a les noves funcionalitats que esperen per a la xarxa. Una solució per a cobrir totes aquestes necessitats és l'adaptació de tècniques capaces de fer front a aquestes velocitats de dades enormes, i garantir el mateix nivell d'eficiència per a les llargues distàncies i mitigar les deficiències òptiques acumulades al llarg de la ruta de transmissió. A més, s'espera que aquestes tècniques de transmissió puguin proporcionar cert grau de flexibilitat, per tal de millorar i tornar més eficient la gestió de la xarxa. Una tecnologia prometedora que pot fer front a aquests requisits és el que s'anomena multiplexació per divisió de freqüències ortogonals, combinat amb la detecció òptica coherent (CO-OFDM). CO-OFDM ofereix diversos avantatges, entre altres: alta sensibilitat i eficiència espectral i, sobretot, la possibilitat de recuperar per complet d'una senyal en fase, l'amplitud i la polarització. Aquests sistemes estan compostos per blocs de processament de senyals digitals (DSP) que permeten detectar les dades fàcilment així com també compensar les principals degradacions, proporcionant alta tolerància pels efectes de dispersió. No obstant això, els sistemes CO-OFDM no estan exempts d'inconvenients. La seva alta relació de potència de pic a potència mitjana (PAPR) redueix sensiblement la tolerància a no linealitats. D'altra banda, els sistemes de CO-OFDM són sensibles a qualsevol canvi de freqüència i desplaçament de fase. Per tant, es proposa un sistema OFDM d'envolvent constant (CE-OFDM) per a reduir significativament la PAPR i solucionar l'alta sensibilitat a les degradacions no lineals. Consisteix en un senyal OFDM modulat en fase, que es detecta coherentment en el receptor. Una transformada alternativa, la transformada discreta d'Hartley, es proposa accelerar els càlculs en el DSP. El sistema CE-OFDM per la seva flexibilitat i escalabilitat única, resulta una tecnologia aplicable a diferents escenaris, que van des de les xarxes d'accés fins a les xarxes troncals. En el cas de les solucions d'accés, s'investiguen diversos casos. En primer lloc, el CE-OFDM s'aplica per al desplegament i suport de dades d'una xarxa radio, reutilitzant una xarxa òptica d'accés ja desplegada. A continuació, s'investiga la transmissió bidireccional dúplex a 10 Gb/s sobre una sola longitud d'ona emprant un RSOA a les unitats d'usuari. El punt clau d'aquest sistema és la transmissió en sentit ascendent, que s'aconsegueix re-modulant la fase d'un senyal d'intensitat modulada després de saturar-la de forma adequada. A continuació, s'estudia una xarxa d'àrea metropolitana flexible de fins a 100 km. Concretament l'efecte de concatenació de filtres òptics és l'objectiu d'aquest estudi. Finalment, es proposa una actualització elàstica del model de Telefónica I+D per a la xarxa troncal espanyola. Per això, es proposa operar el CE-OFDM en multiplexació de polarització. Els resultats mostren que aquesta combinació redueix sensiblement l'ocupació d'ample de banda això com també els requisits dels enllaços transmissió, reduint també els costos tant de desplegament com d'operació i manteniment de la xarxa.
Iqbal, Md Asif. "Advanced Raman amplification techniques for high capacity and broadband coherent optical transmission systems." Thesis, Aston University, 2018. http://publications.aston.ac.uk/37651/.
Повний текст джерелаLiu, Tao. "Advanced Coded Modulation for High Speed Optical Transmission." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/613291.
Повний текст джерелаAdhikari, Susmita [Verfasser]. "Investigation of Coherent Optical OFDM Systems and Algorithms for Long-haul Transmission / Susmita Adhikari." Aachen : Shaker, 2016. http://d-nb.info/1120863597/34.
Повний текст джерелаZou, Ding, and Ivan B. Djordjevic. "FPGA-Based Rate-Compatible LDPC Codes for the Next Generation of Optical Transmission Systems." IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2016. http://hdl.handle.net/10150/621685.
Повний текст джерелаGuiomar, Fernando Pedro Pereira. "Digital nonlinear equalization for optical transmission systems." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15977.
Повний текст джерелаThis thesis focuses on digital equalization of nonlinear fiber impairments for coherent optical transmission systems. Building from well-known physical models of signal propagation in single-mode optical fibers, novel nonlinear equalization techniques are proposed, numerically assessed and experimentally demonstrated. The structure of the proposed algorithms is strongly driven by the optimization of the performance versus complexity tradeoff, envisioning the near-future practical application in commercial real-time transceivers. The work is initially focused on the mitigation of intra-channel nonlinear impairments relying on the concept of digital backpropagation (DBP) associated with Volterra-based filtering. After a comprehensive analysis of the third-order Volterra kernel, a set of critical simplifications are identified, culminating in the development of reduced complexity nonlinear equalization algorithms formulated both in time and frequency domains. The implementation complexity of the proposed techniques is analytically described in terms of computational effort and processing latency, by determining the number of real multiplications per processed sample and the number of serial multiplications, respectively. The equalization performance is numerically and experimentally assessed through bit error rate (BER) measurements. Finally, the problem of inter-channel nonlinear compensation is addressed within the context of 400 Gb/s (400G) superchannels for long-haul and ultra-long-haul transmission. Different superchannel configurations and nonlinear equalization strategies are experimentally assessed, demonstrating that inter-subcarrier nonlinear equalization can provide an enhanced signal reach while requiring only marginal added complexity.
A presente tese foca-se no tema da equalização digital de distorções não lineares da fibra em sistemas coerentes de transmissão ótica. Tirando partido de modelos físicos bem conhecidos para a propagação de sinal em fibras óticas mono-modo, novas técnicas de equalização não linear são propostas, testadas numericamente e validadas por demonstração experimental. A estrutura dos algoritmos propostos é fortemente condicionada pela otimização do compromisso entre complexidade e desempenho, tendo em conta a sua futura implementação prática em transcetores comerciais operando em tempo-real. O trabalho desenvolvido foca-se inicialmente na mitigação das distorções não lineares intra-canal, aplicando o conceito de propagação digital inversa realizado através de filtros de Volterra. Após uma análise sistemática do núcleo de Volterra de terceira ordem, é identificado um conjunto de simplificações críticas, culminando no desenvolvimento de algoritmos de equalização não linear de baixa complexidade, formulados no domínio do tempo e frequência. A complexidade de implementação das técnicas propostas e analiticamente descrita em termos de esforço computacional e latência de processamento, através da determinação do número de multiplicações reais por amostra e do número de multiplicações realizadas em série, respetivamente. O desempenho da equalização e avaliado recorrendo a simulação numérica e validação experimental através da medição da taxa de erros. Por fim, a questão da compensação não linear inter-canal é abordada no contexto da propagação de supercanais 400G para sistemas de transmissão metro e longa distância. Nesse âmbito são experimentalmente testadas diferentes configurações de supercanal e estratégias de equalização não linear, demonstrando assim que a implementação de equalização inter-subportadora permite estender consideravelmente o alcance, requerendo apenas um esforço computacional ligeiramente superior.
Prodaniuc, Cristian. "Advanced Signal Processing for Pulse-Amplitude Modulation Optical Transmission Systems." Doctoral thesis, Universitat Politècnica de València, 2019. http://hdl.handle.net/10251/117315.
Повний текст джерела[CAT] Actualment, s'utilitzen sistemes òptics no coherents en xarxes òptiques de curt abast ( < 80 km), com són les xarxes d'àmbit metropolità. La implementació més comuna que podem trobar en l'estat de l'art es correspon amb sistemes emplenant multiplexació per divisió en longitud d'ona (WDM, wavelength division multiplexing) de quatre longituds d'ona (¿) proporcionant un règim binari de 100 Gbps (4¿×25 Gbps). En els últims anys, els sistemes de transmissió òptica no-coherents han evolucionat des de 100 Gbps cap a 400 Gbps (100 Gbps/¿). Atès que el mercat de sistemes de curt abast compren un gran volum de dispositius òptics instal·lats, el cost unitari és molt important i ha de ser el més baix possible. L'objectiu d'aquesta tesi és analitzar aspectes del processament de senyal en general i, específicament, investigar noves tècniques de processament digital de senyal (DSP, digital signal processing) que puguen ser utilitzades en sistemes de transmissió òptica no-coherent que utilitzen la modulació per amplitud d'impulsos (PAM, pulse-amplitude modulation). Per tal que una tècnica DSP es considere interessant per a una xarxa òptica WDM no-coherent, aquesta ha de mitigar efectivament almenys una de les tres principals limitacions que afecten aquests sistemes: limitacions d'ample de banda, limitacions per dispersió cromàtica (CD), i el soroll. En aquesta tesi s'examinen una sèrie d'algoritmes, el seu rendiment s'analitza per simulació i experimentalment en laboratori: - Feed-forward equalizer (FFE): aquest és l'esquema d'equalització més comú i s'utilitza bàsicament en les transmissions òptiques no coherents d'alt règim binari. Pot compensar grans quantitats de limitacions d'ample de banda. - Estimació de la seqüència de probabilitat màxima (MLSE): el MLSE és un detector òptim i, per tant, proporciona el millor rendiment quan es tracta de limitacions d'ample de banda i de CD. - Conformació geomètrica de la constel·lació: en esquemes de modulació òptica d'intensitat multinivell es pot ajustar la distància entre els nivells d'amplitud (de manera que ja no són equidistants) per augmentar la tolerància del senyal al soroll. - Conformació probabilística: una tècnica dissenyada específicament per als esquemes de modulació multinivell; ajusta la probabilitat de cada nivell d'amplitud de manera que augmenta la tolerància al soroll òptic. - Senyalització de resposta parcial (PRS, partial signaling response): és un enfocament basat en DSP on la interferència entre símbols (ISI, inter-symbol interference) controlada s'introdueix intencionalment de manera que el senyal resultant requereix menys ample de banda. La tècnica PRS es pot adaptar per combatre els efectes del CD. - Pre-èmfasi digital (DPE, digital pre-emphasis): aquesta tècnica consisteix a aplicar la inversió de la funció de transferència del sistema a la senyal en el transmissor de manera que es redueix l'impacte de les limitacions d'ample de banda en la senyal en el receptor. - Modulació amb codificació Trellis (TCM, Trellis-coded modulation): esquema de modulació que combina els elements de correcció d'errors avançats (FEC, forward error correction) amb tècniques de partionament de conjunts i modulació multidimensional per generar un senyal més resistent al soroll. - Modulació multidimensional per partició en conjuntes: molt similar a TCM però sense elements FEC. Té guanys menors que TCM en termes de tolerància al soroll, però no és tan sensible a l'ISI. Mitjançant l'ús d'aquestes tècniques, aquesta tesi demostra que és possible aconseguir una transmissió òptica amb un règim binari de 100 Gbps/¿ utilitzant components de baix cost. Esta tesi també demostra règims binaris de més de 200 Gbps, el que indica que la tecnologia no-coherent amb modulació PAM és una solució viable i eficient en cost per a una nova generació de sistemes transceptors òptics WDM funcionant a 800 Gbps (4¿×200 G
[EN] Non-coherent optical transmission systems are currently employed in short-reach optical networks (reach shorter than 80 km), like metro networks. The most common implementation in the state-of-the-art is the four wavelength (¿) 100 Gbps (4¿×25 Gbps) wavelength division multiplexing (WDM) transceiver. In recent years non-coherent optical transmissions are evolving from 100 Gbps to 400 Gbps (4¿×100 Gbps). Since in the short-reach market the volume of optical devices being deployed is very large, the cost-per-unit of the devices is very important, and it should be as low as possible. The goal of this thesis is to investigate some general signal processing aspects and, specifically, digital signal processing (DSP) techniques required in non-coherent pulse-amplitude modulation (PAM) optical transmission, and also to investigate novel algorithms which could be applied to this application scenario. In order for a DSP technique to be considered an interesting solution for non-coherent WDM optical networks it has to effectively mitigate at least one of the three main impairments affecting such systems: bandwidth limitations, chromatic dispersion (CD) and noise (in optical or electrical domain). A series of algorithms are proposed and examined in this thesis, and their performance is analyzed by simulation and also experimentally in the laboratory: - Feed-forward equalization (FFE): this is the most common equalizer and it is basically employed in every high-speed non-coherent optical transmission. It can compensate high bandwidth limitations. - Maximum likelihood sequence estimation (MLSE): the MLSE is the optimum detector and thus provides the best performance when it comes to dealing with CD and bandwidth limitations. - Geometrical constellation shaping: in multilevel optical intensity modulation schemes the distance between amplitude levels can be adjusted (such that they are no longer equidistant) in order to increase the signal's tolerance to noise. - Probabilistic shaping: another technique designed specifically for multilevel modulation schemes; it adjusts the probability of each amplitude level such that the tolerance to optical noise is increased. - Partial response signaling (PRS): this is a DSP-based approach where a controlled inter-symbol interference (ISI) is intentionally introduced in such a way that the resulting signal requires less bandwidth. PRS can be customized to also mitigate CD impairment, effectively increasing transmission distances up to three times. - Digital pre-emphasis (DPE): this technique consists in applying the inverse of the transfer function of the system to the signal at the transmitter side which reduces the impact of bandwidth limitations on the signal at the receiver side. - Trellis-coded modulation (TCM): a modulation scheme that combines forward error correction (FEC) elements with set-partitioning techniques and multidimensional modulation to generate a signal that is more resistant to noise. - Multidimensional set-partitioned modulation: very similar with TCM but without any FEC elements. It has lower gains than TCM in terms of noise tolerance but is not so sensitive to ISI. By using the techniques enumerated above, this thesis demonstrates that is possible to achieve 100 Gbps/¿ optical transmission bitrate employing cost-effective components. Even more, bitrates higher than 200 Gbps are also demonstrated, indicating that non-coherent PAM is a viable cost-effective solution for next-generation 800 Gbps (4¿×200 Gbps) WDM transceivers.
Prodaniuc, C. (2019). Advanced Signal Processing for Pulse-Amplitude Modulation Optical Transmission Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/117315
TESIS
Saleh, Ibrahim Saied Saleh Hussin [Verfasser]. "Investigation on high spectral efficiency coherent optical OFDM transmission systems / Hussin Saleh Ibrahim Saied Saleh." Paderborn : Universitätsbibliothek, 2015. http://d-nb.info/1074192168/34.
Повний текст джерелаDetwiler, Thomas Frederick. "Continuous phase modulation for high speed fiber-optic links." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42867.
Повний текст джерелаJarajreh, Mutsam Abdel-karim. "Coherent optical OFDM modem employing artificial neural networks for dispersion and nonlinearity compensation in a long-haul transmission system." Thesis, Northumbria University, 2012. http://nrl.northumbria.ac.uk/9596/.
Повний текст джерелаXu, Tianhua. "DSP based Chromatic Dispersion Equalization and Carrier Phase Estimation in High Speed Coherent Optical Transmission Systems." Doctoral thesis, KTH, Optik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-94835.
Повний текст джерелаQC 20120528
Carbó, Meseguer Alexis. "Semiconductor optical amplifiers for ultra-wideband optical systems." Thesis, Evry, Institut national des télécommunications, 2018. http://www.theses.fr/2018TELE0010/document.
Повний текст джерелаOver the last few decades the world has undergone a major revolution that has deeply affected the way we use communication networks. New services and applications have appeared demanding a constant increase of the channel capacity. In this period, optical systems have been upgraded at pair with advanced signal processing techniques which have permitted the increase of the spectral efficiency approaching the system capacity to the fundamental limit. It is because is becoming extremely challenging to keep growing the system capacity by this means. In this work, an orthogonal direction is studied to further increase the fibre capacity: extending the optical bandwidth. With this purpose, the use of semiconductor optical amplifiers (SOA) is investigated to be implemented in future ultra-wideband (UWB) systems. The use of SOA amplification changes completely the paradigm in the design of an optical system since all the impairments added by the SOA must be considered. In this work, we assess the reservoir model, a simple yet powerful model, to analyze numerically the nonlinear regime of the SOA for WDM systems. We also show for the first that the linewidth enhancement factor of an SOA can be estimated with a coherent receiver. Finally, it is also studied how the correlation between channels degrades significantly the performance of the SOA and the inclusion of a decorrelation fibre is investigated. The conception of a UWB system is then studied. We characterize a novel ultra-wideband SOA developed by the French project CALIPSO which presents high gain in a 100-nm optical bandwidth with high output saturation power and 6-8 dB of noise figure. We analyze its nonlinear regime for WDM systems and we show for QPSK and 16 QAM modulation formats that the input saturation power can be overtaken by serveral dBs without important nonlinear penalty. On the other hand, a novel technique is studied to compensate fibre nonlinearities in UWB systems: the multicarrier multiplexing, which tries to exploit the concept of symbol rate optimization. Finally, we assess the capabilities of this novel UWB SOA for data-centre interconnection applications with two experiments transmitting up to 113 Tbps data troughput in a 100-nm continuous bandwidth link over 100 km of fibre and then testings is stability with real-time line cards between two points of presence (POP)of Facebook deployed in the Paris area
Koebele, Clemens. "Mode-division-multiplexing as a possibility to cope with the increasing capacity demand in optical transmission systems." Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00762642.
Повний текст джерелаAl-Bermani, Ali Verfasser], Reinhold [Akademischer Betreuer] Noé, and Ulrich [Akademischer Betreuer] [Rückert. "Implementation and investigation of a real-time optical 16-QAM transmission system with FPGA-based coherent receiver / Ali Al-Bermani. Betreuer: Reinhold Noé ; Ulrich Rückert." Paderborn : Universitätsbibliothek, 2013. http://d-nb.info/1042230412/34.
Повний текст джерелаFernandez, de Jauregui Ruiz Ivan. "Advanced modulation formats and nonlinear mitigation for spectral efficient optical transmission systems." Thesis, Evry, Institut national des télécommunications, 2018. http://www.theses.fr/2018TELE0009/document.
Повний текст джерелаGlobal data traffic is expected to reach up to 4.3 ZB per year by 2020. With the majority of the global communications being transported on submarine point-to-point fiber-optic systems, different cutting-edge technologies have been under research to cope with this unprecedented traffic growth. Continuous advances in high-speed integrated circuits have allowed the use of advanced modulation formats and digital signal processing (DSP) techniques to maximize the transmission spectral efficiency. With mitigation of fiber linear effects efficiently carried out by DSP with relative low-complexity, the capacity of modern fiber optic systems rests limited by fiber nonlinearities. To this extent, in the first part of this work, the performance and achievable benefits of low-complexity DSP techniques aiming to mitigate fiber Kerr nonlinear effects are investigated. Besides nonlinear compensation techniques, the use of multi-level modulation formats beyond 16QAM and high symbol rate channels have gained momentum to increase the system spectral efficiency. One of the major breakthroughs in the recent years, has been the introduction of QAM-based probabilistic constellation shaping (PCS-QAM), which has proven to outperform regular QAM formats. In this sense, in the second part of this work, the practical achievable rate increase brought by PCS-QAM for transoceanic distances is investigated. A theoretical and experimental comparison with other high-capacity formats is performed, and the design of a PCS-QAM for trans-Pacific distances is addressed. Finally, in the last section, several transmission records using the two above techniques are reported
Silva, Edson Porto da 1988. "Transmissão óptica com recepção coerente e alta eficiência espectral aplicando sequências de pulsos RZ e pré-filtragem optica em canais limitados em banda." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259687.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: O Resumo poderá ser visualizado no texto completo da tese digital
Abstract: The complete Abstract is available with the full electronic document.
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica
James, Jonathan C. "Imaging systems based on the encoding of optical coherence functions." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/15607.
Повний текст джерелаTabares, Giraldo Jeison. "Transmission impairments mitigation in next generation coherent optical access networks." Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672695.
Повний текст джерелаA nivel mundial, las tecnologías coherentes han revolucionado los sistemas de comunicaciones ópticas, aumentando significativamente la capacidad del canal de fibra gracias a la transmisión de formatos de modulación avanzados y a la mitigación efectiva de las degradaciones en la propagación. Sin embargo, las soluciones comerciales actuales para redes troncales de largo alcance siguen siendo complejas y costosas y, por lo tanto, difícilmente viables para su implementación en redes ópticas de acceso. En particular, las principales limitaciones surgen del equipo de usuario cuyo coste, tamaño y consumo de energía deben mantenerse bajos. Por lo tanto, las soluciones óptimas para las redes ópticas de acceso coherentes de nueva generación deben lograr un alto rendimiento pero con menor complejidad y coste, ya que en el escenario de acceso la relación coste-eficiencia toma más relevancia que lograr el mejor rendimiento del sistema. La investigación descrita en esta tesis se enfoca principalmente en el desarrollo del equipo de usuario, es decir, el transceptor coherente¿, para una red óptica pasiva de acceso que implementa el nuevo concepto de longitud de onda al usuario, al servir a cientos de usuarios (e.g., 256 usuarios) con longitudes de onda dedicadas y asignadas en una rejilla óptica ultra estrecha. La red de acceso propuesta implementa tecnologías coherentes de complejidad reducida al aprovechar la integración fotónica, láseres y dispositivos ópticos comerciales y de bajo coste, y electrónica de consumo. Con tal fin, la tesis investiga las principales degradaciones en la transmisión que afectan la integridad de la señal desde la fuente hasta el destino en la red de acceso, y propone nuevas y mejoradas estrategias de mitigación usando tanto procesamiento digital de señales de baja complejidad como diseño de hardware analógico. Los temas tratados abarcan desde el transmisor óptico hasta los subsistemas del receptor coherente. La modulación óptica simplificada se aborda mediante modulación directa de fase de láseres de semiconductor, aprovechando el chirp del láser. Se investiga la pre-ecualización digital de la respuesta frecuencial no ideal de dispositivos electrónicos/fotónicos tales como láseres, amplificadores y conversores de datos, centrándose en la tolerancia al ruido de cuantificación de los conversores digital-analógico con resolución limitada. Las estrategias para la recuperación de la portadora óptica basadas en la detección diferencial de fase y eficientes en hardware, se exploran en dos escenarios: receptores homodinos asistidos por procesamiento digital de señales, o receptores heterodinos completamente analógicos. Finalmente, para hacer frente al crítico ajuste de la polarización en sistemas coherentes, se investigan arquitecturas simplificadas para receptores coherentes independientes de la polarización utilizando óptica de bajo coste y un front-end óptico del receptor más simple.
Teoria del senyal i comunicacions
Karaki, Julie. "100 Gbps coherent MB-OFDM for long-haul WDM optical transmission." Thesis, Paris, ENST, 2013. http://www.theses.fr/2013ENST0019/document.
Повний текст джерелаToday the 100 Gbps coherent dual polarization quadrature phase shift keying (Co-DP-QPSK) is standardized as the industrial solution for long-haul WDM transmission. Another alternative format to DP-QPSK that permits also to reach a data rate of 100 Gbps and beyond is the coherent orthogonal frequency division multiplexing (OFDM) format. However a doubt exists over the ability of OFDM to be as efficient as QPSK for long-haul WDM transmission due to its supposed higher sensitivity to nonlinear effects . In this thesis, we have investigated the potential of Co-DP-OFDM for 100 Gbps WDM transport. The digital signal processing algorithms are detailed as well as the various experimental set-ups required to carry out and validate the 100 Gbps transceiver. We also present the transmission results obtained with several configurations. In one of these configurations, the 100 Gbps Co-DP-OFDM channel is multiplexed with forty 100 Gbps DP-QPSK channels and all these channels are transmitted over 1000 km of DCF-free G.652 fiber, while in another configuration, the Co-DP-OFDM and Co-DP-QPSK channels are combined with seventy eight 10 Gbps NRZ-OOK channels and transmitted over 1000 km of dispersion managed G.652 fiber line. We have demonstrated that OFDM and QPSK have nearly the same performance after a transmission over 1000 km, and also we have demonstrated that the transmission of these two formats over legacy fiber infrastructure is possible under the condition of decreasing by 5 dB the 10 Gbps NRZ-OOK channel power with respect to the 100 Gbps channels. The results presented in this thesis are very valuable when considering the next generation of 400 Gbps or 1 Tbps for WDM systems
Pan, Jie. "Nonlinear Electrical Compensation For The Coherent Optical OFDM System." Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1292443382.
Повний текст джерелаHsu, Paul Steve. "Magneto-optical control of coherent nonlinear processes." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2813.
Повний текст джерелаNam, Ahhyun. "Development of a coherent optical imaging system for clinical dermatology." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74928.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 65-67).
The abnormal structure of cutaneous capillaries is associated with many skin diseases including skin cancer and port wine stain. Consequently, the demand for an imaging modality that can provide non-invasive visualization of capillary level blood flow is high. The major challenge in such imaging is to achieve high resolution and great flow sensitivity over a sufficient depth. Numerous imaging techniques derived from optical coherence tomography have provided a technical breakthrough and produced promising images of capillary networks of retina and brain tumors. However, these modalities have never been applied in clinical dermatological studies. This thesis illustrates the process of design and complete construction of an optical frequency domain imaging (OFDI) system for dermal vasculature imaging that can be used in a clinical environment. The system consists of optical hardware, electronics, and a microscope; every part is contained in a portable cart that can be readily carried to a clinic. The optical subsystem includes a wavelength-swept laser source, a fiber optic interferometer with a delay stage and a polarization-sensitive balanced receiver. All power supplies, control drivers and monitoring circuits are integrated and enclosed in a case with a control interface. The microscope is attached to an articulating arm to be positioned as desired while the patient sits at ease. The system performance is summarized as 10 [mu]m resolution with frame rate of 100 frames per second. Further studies, in collaboration with dermatologists, will involve imaging the vascular structure of port wine stain lesions and investigating their correlation to laser treatment.
by Ahhyun Nam.
S.M.
LI, XIAOXU. "WAVELENGTH-DIVISION-MULTIPLEXED TRANSMISSION USING SEMICONDUCTOR OPTICAL AMPLIFIERS AND ELECTRONIC IMPAIRMENT COMPENSATION." Doctoral diss., University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4025.
Повний текст джерелаPh.D.
Optics and Photonics
Optics and Photonics
Optics PhD
Cai, Yangjian. "Propagation of some coherent and partially coherent laser beams." Doctoral thesis, Stockholm : Electromagnetic Engineering, School of Electrical Engineering, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4034.
Повний текст джерелаBatshon, Hussam George. "Coded Modulation for High Speed Optical Transport Networks." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194075.
Повний текст джерелаCarvalho, Luis Henrique Hecker de 1988. "Avaliação experimental da transmissão óptica em altas taxas de supercanais com diferentes técnicas de multiplexação de subportadoras : Experimental evaluation of high-speed optical transmission of superchannels formed by different subcarrier multiplexing techniques." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261925.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: Uma das alternativas para os sistemas de transmissão óptica de próxima geração é o uso de múltiplos subcanais ópticos densamente multiplexados em frequência (supercanais) com alta eficiência espectral. Supercanais ópticos empregam o processamento paralelo de sinais para alcançar taxas de transmissão além dos limites da eletrônica. Atualmente, as técnicas CO-OFDM e Nyquist WDM são vistas como as principais para a implementação de supercanais ópticos. Neste trabalho, estudam-se abordagens para aumentar a capacidade de transmissão dos sistemas ópticos por meio da realização de supercanais. A implementação em laboratório, análise de desempenho e comparativo entre as técnicas CO-OFDM e Nyquist WDM são realizadas para sistemas operando a 400 Gb/s e 1 Tb/s por canal, com modulação DP-16QAM e eficiências espectrais que chegam a 6 b/s/Hz e acima. Os principais desafios e soluções para a implementação de sistemas de transmissão óptica de próxima geração baseados em supercanais são identificados
Abstract: One of the options for the next generation of optical transmission systems is the use of multiple optical subchannels densely multiplexed in frequency (superchannels) with high spectral efficiency. Optical superchannels employ parallel signal processing to achieve transmission rates beyond the limits of electronics. Currently, CO-OFDM and Nyquist WDM are seen as the main techniques to the implementation of optical superchannels. In this work, different ways to increase the capacity of the current optical systems by the realization of superchannels are studied. The experimental implementation, performance analysis, and comparison between CO-OFDM and Nyquist WDM techniques are performed for systems operating at 400 Gb/s and 1 Tb/s per-channel with DP-16QAM modulation and spectral efficiencies of 6 b/s/Hz and beyond. The main challenges and solutions for the implementation of next generation optical transmission systems based on superchannels are identified
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica
Xiaoqi, Han. "Nonlinear Equalization Based on Decision Feedback Equalizer for Optical Communication System." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1386170540.
Повний текст джерелаMoura, Luis Miguel da Silva Carvalho de. "Circuit techniques for very high speed digital optical transmission : timing extraction sub-system." Thesis, Bangor University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262231.
Повний текст джерелаLarson, Bruce C. (Bruce Carl). "An optical telemetry system for wireless transmission of biomedical signals across the skin." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/16716.
Повний текст джерелаVita.
Includes bibliographical references (p. 236-239).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
A technology base for optically-coupled systems was developed that permits in-vivo transmission of biomedical signals across the skin. By complete implantation of sensors and instrumentation electronics, problems with percutaneous connectors were eliminated. Optical power and signal transmission was accomplished with smaller and lighter implant structures than previously achieved with radio frequency (RF) coupling techniques. This is particularly valuable in the field of neuroprosthetics, because it may be possible to implant an optical telemeter directly on the surface of the brain to make mechanically stable connections to microelectrode arrays for neuroelectric recordings. Miniature optical power panels (2.5 mm x 2.5 mm) were developed from arrays of photodiodes. Infrared light of 880 nm wavelength was effective for delivering power across the skin. Panels composed of silicon photodiodes were 14% efficient at converting this light to electrical power, and GaAlAs panels were 41% efficient. Tissue heating experiments demonstrated the safety of optical power transmission. An LED was identified that was both electrically efficient (16%) and of appropriate wavelength (660 nm) for transmitting optical signals from the implant. Pulse period encoding was used for transmission of signals because it was robust and required less power than schemes with higher LED duty cycles. Specialized photodetector circuits were developed to receive pulse encoded data, and decoder circuits were built to reconstruct the transmitted signals. Two prototype single-channel neural waveform telemeters (approx. 10 Hz to 7 kHz bandwidth) were constructed and implanted in the visual cortex of rabbits. Both implants successfully transmitted neuroelectric signals. The first implant survived for four weeks before failing due to a flaw in the encapsulation, and the improved second prototype continues to function properly 28 months after implantation. Integrated circuits (ICs) were designed to record and transmit eight channels of neural waveforms. The first IC telemeter functioned properly, although the sensitivity was not as great as needed for the recording of neural waveforms. It required less than 50 mW of electrical power to operate. Efforts to improve this design introduced flaws in the next set of IC designs, so these problems were addressed, and a final set of designs was submitted for fabrication at the conclusion of this research project.
by Bruce C. Larson.
Ph.D.
Thom, Joseph Andrew. "An agile and stable optical system for high-fidelity coherent control of a single p88sSrp+s ion." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26528.
Повний текст джерелаAl-Dabbagh, Rasha Khalid Mohammed. "A photonic generation and transmission system for millimetre-wave futuristic communications." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16249.
Повний текст джерелаReyhanioglu, Erinc. "Selection Of Light Source And Implementation Of Data Acquisition System Of An Optical Experimental Setup." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/1044361/index.pdf.
Повний текст джерелаoutput signal is recorded on a PC based data recorder after being digitized by an analog to digital converter card.
Kaiser, Wilfried [Verfasser]. "Impact of advanced modulation formats on the system performance of high-speed optical transmission systems / Wilfried Kaiser." Aachen : Shaker, 2003. http://d-nb.info/1181600766/34.
Повний текст джерелаFazel, Sina. "ROADM node implementation in agile optical network." Thesis, Evry, Institut national des télécommunications, 2016. http://www.theses.fr/2016TELE0002.
Повний текст джерелаTraffic demand is exponentially increasing in recent years. Cisco forecast claims that by 2020, transport traffic will be 13 times of today's traffic transmission. This incremental traffic demand makes concerns about energy consumption and network scalability as well as increasing the network complexity. In this respect, to adresse the future traffic demand requirement and provide a reliable telecommunication network, precise network planning and engineering are needed. To this aim, we adress the problem of ROADM node design by presenting different architectures, components and subsystems to investigate the Broadcast and Select and Route and Select ROADM node architectures. Colored/colorless, directional/directionless and contentional/contentionless add/drop module configurations are studied. Futhermore, the problem of Intra Node Blocking is investigated by developing a node simulator in a dynamic network traffic platform. In this respect, we propose an offline contention management strategy for an ROADMnode in order to efficiently decrease the Intra Node blocking ration by more than 1.5 order of magnitude. Finally, we focus on network planning by investigating short and medium term network upgrades for metro-core optical network. To this goal, we investigate the possibility of non coherent signal transmission in metro-core segment of hierarchical layered optical network. Quality of transmission for 100 Gbit/s PDM-DQPSK-modulation format is investigated. Then, we propose the implementation of PDM-CS-DQPSK modulation format to transmit 100 Gbit/s signals in ROADM based optical transmission systems
Al-Olofi, Mohammed [Verfasser]. "Transmission of Ultra-Wideband Radio System over Optical Wireless Links using Intensity Modulation Direct Detection / Mohammed Al-Olofi." München : Verlag Dr. Hut, 2016. http://d-nb.info/1113335602/34.
Повний текст джерелаChen, Hang. "Optical Encryption Techniques for Color Image and Hyperspectral Data." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0374.
Повний текст джерелаOptical information security is one of the most important research directions in information science and technology, especially in the field of copyright protection, confidential information transmission/storage and military remote sensing. Since double random phase encoding technology (DRPE) was proposed, optical image encryption technology has become the main topic of optical information security and it has been developed and studied deeply. Optical encryption techniques offer the possibility of high-speed parallel processing of two dimension image data and hiding information in many different dimensions. In this context, much significant research and investigation on optical image encryption have been presented based on DRPE or further optical operation, such as digital holography, Fresnel transform, gyrator transform. Simultaneously, the encrypted image has been extended from single gray image to double image, color image and multi-image. However, the hyperspectral image, as a significant element in military and commercial remote sensing, has not been deeply researched in optical encryption area until now. This work extends the optical encryption technology from color image to hyperspectral image. For better comprehension of hyperspectral image encryption, this work begins with the introduction and analysis of the characteristics of hyperspectral cube. Subsequently, several kinds of encryption schemes for color image, including symmetric and asymmetric cryptosystem, are presented individually. Furthermore, the optical encryption algorithms for hyperspectral cube are designed for securing both the spatial and spectral information simultaneously. Some numerical simulations are given to validate the performance of the proposed encryption schemes. The corresponding attack experiment results demonstrate the capability and robustness of the approaches designed in this work. The research in this dissertation provides reference for the further practicality of hyperspectral image encryption
Chen, Jiajun. "Modal optical studies of multi-moded ultra-low-noise detectors in far-infrared." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270352.
Повний текст джерелаSeck, Aida. "Contribution à l’optimisation des systèmes de transmission optiques cohérents (Nx100 Gbit/s) utilisant le multiplexage en polarisation par des formats de modulation en phase et une conception de ligne limitant l’impact des effets non-linéaires." Thesis, Evry, Institut national des télécommunications, 2014. http://www.theses.fr/2014TELE0008/document.
Повний текст джерелаThe ever-increasing demand of capacity in very high bit rate coherent optical transmission systems has paved the way towards the investigation of several techniques such as the use of ultra-low loss fibers, Erbium doped fiber amplifiers, polarization and wavelength division multiplexing (WDM), coherent detection, multi-level modulation formats, spatial division multiplexing, etc. However, there are questions concerning polarization division multiplexing and a development towards some advanced modulation formats including phase modulation and polarization division multiplexing. In this thesis, in order to increase the capacity-by-distance product of future optical coherent systems using wavelength and polarization division multiplexing, we first study spectral shaping of the transmitted signals to increase the information spectral density. For this purpose, we have numerically investigated the multi-channel transmission performance of Polarization Switched Quadrature Phase Shift Keying (PSQPSK) and we have compared it to the performance of Polarization-Division-Multiplexed QPSK (PDM-QPSK), using Root Raised Cosine (RRC) spectral shaping, in the context of a flexible channel grid. In addition we have presented the advantage of PS-QPSK against PDM-QPSK as a function of the system parameters, while we have also discussed the benefit of a RRC spectral shaping against a tight filtering at the transmitter side with a 2nd order super-Gaussian-shaped filter. Furthermore, we have focused on nonlinear effects that limit the transmission distance by degrading the transmitted symbols during propagation. Analyzing and reducing the impact of nonlinear effects is essential when using technologies that increase the information spectral density such as polarization division multiplexing which causes new nonlinear effects due to additional interactions between symbols during the propagation through the fiber. Therefore a reduction of the impact of nonlinear effects is necessary for the development of future systems with higher bit rates of 400 Gbit/s and 1 Tbit/s per channel. We have established in this thesis, design rules to reduce the impact of nonlinear effects in the optical WDM transmission systems at 100 Gbit/s per channel that use polarization multiplexing
Charlet, Gabriel. "Etude des formats de modulation et des méthodes de détection pour les transmissions multiplexées en longueurs d’ondes sur fibre optique au débit de 40Gb/s et 100Gb/s." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112008/document.
Повний текст джерелаModulation and detection methods have been studied to improve the performance of optical long distance communication systems. Polarization division multiplexed modulation and multilevel phase modulation format have been evaluated. Coherent detection associated with digital signal processing has been selected at the receiver side to optimize system performance. This receiver design allows especially to compensate linear distortions induced by fiber optics propagation very efficiently. After long distance propagation, optical signal to noise ratio is a major limitation. The other main limitation comes from non linear interactions of light and fiber optics which put a limit on the maximum power to be injected within fiber optics.The first wavelength division multiplexed transmission over long distances (>1000km) using coherent detection has been demonstrated.Various strategies have been proposed to minimize the impact of non linear effect. The impact of polarisation multiplexing has been quantified in configuration where chromatic dispersion is either regularly optically compensated within the line or digitally compensated at the receiver end.The proposition to use a polarization multiplexed format using only 2 phase levels as well as the algorithms capable to detect them has been done. The performance gain obtained compared to the convention solution using 4 phase levels has been demonstrated.At 100Gb/s bit rate, the demonstration of the first transmission over trans-oceanic distance has also been done.These research work have been used to define and then develop Alcatel-Lucent products which are now commercialized, at 40Gb/s by using a polarization multiplexed and 2 phase levels modulation format, and at 100Gb/s by using a polarization multiplexed 4 phase levels format
Ringar, Octave. "Utilisation des techniques avancées d’Emission / Réception multi-antennes pour une transmission optique large bande." Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0100/document.
Повний текст джерелаFree space optical systems are potential candidates of large band spatial transmission solutions. In this thesis, FSO network architecture in the case of geo- stationary satellite to earth communication link is investigated and the influence of zenith angle on the quality of the link has been evaluated. Because of the variation of scintillation due to the complexity of the atmosphere, the optical space to earth communication link channel model has been developped. In order to overcome the main limitations of the prop- agation, optical relays with low earth orbit satellites and spatial diversity on earth could improve the link performance. To improve the link performance, an aggregated simulation model turbulence has been built based on parameters ”p” and ”1-p” introduced in the combined model a↵ecting the considered channels. The parameter ” p ” corresponds to the ratio of the distance from the earth to the relay over the total distance of 36 000Km. In the case of 1000 Km for a relay in the exosphere, p = 1/36. Simulation results show that the proposed network system architecture has outperformed the direct link performance
Amari, Abdelkerim. "Compensation des effets nonlinéaires pour les transmissions WDM longue distance à 400Gbps et au-delà." Thesis, Paris, ENST, 2016. http://www.theses.fr/2016ENST0031/document.
Повний текст джерелаOptical communication systems have evolved since their deployment to meet the growing demand for high-speed communications. Over the past decades, the global demand for communication capacity has increased exponentially and the most of the growth has occurred in the last few years when data started dominating network traffic. In order to meet the increase of traffic demands fueled by the growth of internet services, an increase of access network capacity and consequently metro and long-haul network capacities is required. Next generation of long-haul WDM transmission systems is expected to operate at 400Gbps or 1Tbps bit rate. Superchannel approaches, such as Nyquist WDM and multi-band OFDM, allow both high spectral efficiency and small guardband which makes them promising candidates to generate these high bit rates in combination with multi-level modulations formats. Such transmission systems are strongly disturbed by fiber nonlinear effects which increase with the data rate and the small guard band. Therefore, fiber nonlinearities compensation is required to get the desired performance in terms of transmission reach. DSP based approaches such as digital back propagation and third-order Volterra based nonlinear equalizer have been already proposed to deal with intra-channel or intra-band nonlinear effects. In the context of superchannel systems, we have proposed two new compensation techniques to deal with fiber nonlinear effects. The first one, called fifth-order inverse Volterra based nonlinear equalizer, compensate for intra-band nonlinear effects. The second approach, which is the interband/ subcarrier nonlinear interference canceler, is proposed to combat the nonlinear interference insuperchannel systems
Khaleghi, Hamidreza. "Influence des amplificateurs optiques à semi-conducteurs (SOA) sur la transmission cohérente de signaux optiques à format de modulation multi-porteuses (CO-OFDM)." Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00829663.
Повний текст джерелаAlmeida, Hugo Miguel Moreira de. "Planeamento de redes de transporte de dados para o SKA (Square Kilometre Array)." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13614.
Повний текст джерелаThe SKA (Square Kilometre Array) will be the world’s largest and most sensitive radio telescope with a square kilometre (one million square metres) of collecting area, expecting to be able to clarify some of the main questions about the universe. This project is currently in the preparatory phase, having already established the regions and distributions of the various antennas and the location of signal processing and storage units. In order to satisfy the scientific requirements, the SKA is comprised of thousands of radio wave receivers (antennas) that need to be connected to a processing unit and data centre storage. Transmission distances and capacity depend on the configuration and type of antennas. This dissertation intends to submit a planning and optimization of transport networks between the antennas and the central processing units, in order to present an economic and spectral efficiency solution.
O SKA (Square Kilometre Array) pretende ser o maior e mais sensível radiotelescópio do mundo com uma dimensão de um quilómetro quadrado (um milhão de metros quadrados) de área efetiva, esperando que seja capaz de esclarecer algumas das principais questões sobre o universo. Este projeto encontra-se atualmente na fase preparatória já tendo sido estabelecidas as regiões e as distribuições das várias antenas e a localização das unidades de processamento de sinal e armazenamento. Por forma a atender os requisitos científicos, o SKA é compreendido por milhares de recetores de ondas de rádio (antenas) que necessitam de ser interligados a uma unidade de processamento e armazenamento de dados central. As distâncias de transmissão e a sua capacidade dependem da configuração e do género de antenas. Esta dissertação pretende apresentar um planeamento e otimização de Redes de Transporte entre as antenas e as unidades de processamento central, por forma apresentar uma solução económica e com eficiência espectral.
Šustr, Pavel. "Optický zesilovač v laboratorní výuce." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218165.
Повний текст джерелаLee, Kil-Hoon. "Design of signal integrity enhancement circuits." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37191.
Повний текст джерелаDoubková, Veronika. "Bezpečnostní rizika podle standardu ISO 27001." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-412984.
Повний текст джерела