Orientador: Celso de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-09-11T21:24:05Z (GMT). No. of bitstreams: 1 CarvajalMora_HenryRamiro_M.pdf: 10096746 bytes, checksum: 558790b8f1575c8f3b46fe6c7418920d (MD5) Previous issue date: 2014 / Resumo: Neste trabalho, é avaliado o desempenho do enlace reverso de redes celulares que utilizam a técnica de múltiplo acesso por divisão de código com multiportadoras (MC-CDMA) em termos da probabilidade de erro de bit média (BER) e da eficiência espectral média. O sistema de comunicações analisado utiliza a técnica MC-CDMA, um arranjo linear de antenas na estação rádio base, entrelaçamento em frequência, combinação de máxima razão (MRC), modulação adaptativa, controle de potência e um prefixo cíclico grande o suficiente para eliminar os efeitos da interferência intersimbólica (ISI) e da interferência entre portadoras (ICI). O cenário estudado considera a presença de interferência de múltiplo acesso (MAI) e interferência de co-canal (CCI). A caracterização do canal considera a presença de ruído aditivo gaussiano branco (AWGN), perda de propagação exponencial e desvanecimento lento e seletivo em frequência que segue a distribuição de Rayleigh. Neste contexto, expressões analíticas exatas e fechadas para a BER média tanto para a modulação BPSK, quanto para a modulação M-QAM são obtidas. A exatidão das expressões é validada através de simulações de Monte Carlo. Ademais, uma expressão para a eficiência espectral celular média é determinada, a qual é uma função do fator de reuso de canais, do incremento da largura de banda devido ao prefixo cíclico, do carregamento do sistema, do fator de espalhamento, dos raios da célula e da modulação utilizada. Os resultados indicam que utilizar um fator de reuso de canais de 1 é a maneira mais eficiente de usar o espectro. No entanto, esse fator de reuso é crítico em relação às taxas de transmissão. Ademais, evidenciando que a técnica de múltiplo acesso por divisão de frequências ortogonais (OFDMA) é um caso particular da técnica MC-CDMA, os resultados mostram que a máxima eficiência espectral média obtida com a técnica OFDMA é menor do que aquela obtida com a técnica MC-CDMA / Abstract: In this work the performance of cellular networks uplink is evaluated using the multicarrier-code division multiple access (MC-CDMA) technique in terms of the mean bit error rate (BER) and the mean spectral efficiency. The analyzed communications system is supposed to employ the MC-CDMA technique, a linear antenna array in the base station, frequency interleaving, maximal ratio combining (MRC), adaptive modulation, control power and a cyclic prefix large enough to eliminate the effects of intersymbol interference (ISI) and intercarrier interference (ICI). The studied scenario assumes the presence of multiple access interference (MAI) and co-channel interference (CCI). The channel characterizations considers the presence of additive white gaussian noise (AWGN), exponential path-loss and slow and frequency selective Rayleigh fading. In this context, exact and closed analytical expressions for the mean BER for both BPSK modulation, as for M-QAM modulation are obtained. The accuracy of the expressions is validated through Monte Carlo simulations. Also, an expression for the mean cellular spectral efficiency is determined, which is a function of the channel reuse factor, the bandwidth increases due to the cyclic prefix, the system load, the spreading factor, the cell radius and the modulation employed. The results show that using an unitary channel reuse factor of 1 is the most efficient way to use the spectrum. However, this reuse factor is critical in relation to transmission rates. Moreover, considering that the orthogonal frequency division multiple access (OFDMA) technique is a particular case of MC-CDMA, the results show that the maximum mean spectral efficiency achieved with the OFDMA technique is lower than that obtained with the MC-CDMA technique / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Ce travail de thèse a porté sur le développement de réseaux de micro- et nanocapteurs opto-électrochimiques pour la bioanalyse. Ils répondent à la demande grandissante dans le domaine de la recherche et du diagnostic pour des outils permettant de réaliser de multiples analyses simultanément avec des échantillons de faibles volumes. Ces nouvelles biopuces de haute densité sont fabriquées à partir de faisceaux cohérents de fibres optiques. Une des deux faces est micro- ou nanostructurée par une attaque chimique, puis fonctionnalisée avec une sonde biologique. La première biopuce est un réseau de nanocapteurs fluorescents à ADN où les sondes ont été immobilisées grâce aux propriétés d’électropolymérisation du pyrrole. La lecture est réalisée à distance au travers du faisceau d’imagerie. En combinant la technique d’immobilisation avec des microleviers électrochimiques, plusieurs sondes différentes ont pu être adressées sur le même réseau nanostructuré. La seconde biopuce permet d’effectuer des immunodosages multiplexés en utilisant l’imagerie électrochimiluminescente résolue à l’échelle d’une microsphère. Le développement de cette technique permet de combiner les avantages de l’électrochimiluminescence avec des immunodosages multiplexés. L’élaboration de ces réseaux allie différentes techniques physico-chimiques, notamment électrochimiques, pour obtenir des biopuces avec un fort potentiel, grâce à une densité et un degré de multiplexage importants. / This work presents the development of optoelectrochemical micro- and nanosensor arrays for bioanalytical applications. These platforms respond to the growing need in research and diagnostic for tools allowing multiple and simultaneous analysis in small-volume samples. These new high density biochips are made from coherent optical fiber bundles: one face is micro- or nanostructured by chemical etching and then functionnalized with biological probes. The first biochip is a fluorescent DNA nanosensor array where probes have been immobilized by electrodeposition of a polypyrrole thin film. The detection of the hybridization is remotely performed through the imaging fiber. Different probes were succesfully addressed onto the same nanostructured array thanks to electrochemical cantilevers. The second biochip allows multiplexed sandwich immunoassays using electrochimiluminescent imaging resolved at the single bead level. In particular, the development of this new readout mechanism allows extending electrochemiluminescent detection for multiplexed immunoassays. Design and implementations of both platforms take advantages of different physical and chemical techniques, especially electrochemical, to obtain biochips with a great potential through high density and high multiplexing level.

Les travaux développés dans ce manuscrit de thèse concernent la proposition et la mise au point d’une nouvelle architecture optique basée sur la modulation de cohérence (MC) d’une source à spectre large dédiée aux calculs arithmétiques et au traitement des signaux. La modulation de cohérence de lumière est une technique particulière de codage optique qui autorise, entre autres, le multiplexage des signaux à travers une seule porteuse. Les signaux à traiter sont codés en MC par le biais de paires modulateur de lumière/lame de phase placées en série et éclairées par un seul faisceau de lumière polarisée. Cette technique est basée sur l’introduction d’un retard optique supérieur à la longueur de cohérence de la source utilisée. La validation expérimentale de l’approche proposée pour la réalisation d’opérations arithmétiques, telles que la somme et la soustraction, a été effectuée par le biais de signaux temporels. Différentes formes et fréquences des signaux ont été testées et ont parfaitement validé l’approche. L’impact du cross-talk des signaux et de la divergence du faisceau gaussien sur la qualité des opérations effectuées a été étudié. Ces effets se traduisent par un bruit de modulation d’intensité affectant le résultat des opérations effectuées. Dans ce travail, nous avons proposé des solutions permettant de minimiser son impact. L’originalité de la technique proposée est qu’elle permet la réalisation d’opérations multiples entre plusieurs signaux. Des tests ont été réalisés sur des images à deux et plusieurs niveaux de gris. Les résultats obtenus ont été évalués par les figures de mérite incluant le rapport signal sur bruit (SNR, signal to noise ratio), le rapport signal/bruit crête à crête (PSNR, peak signal to noise ratio) et l’erreur quadratique moyenne (MSE, mean squared error). Enfin, nous avons appliqué la technique à la cryptographie par contenu. Nous avons démontré la performance et la robustesse de la technique. Comme perspectives de ce travail, nous envisageons exploiter d’avantage la technique dans le domaine de la cryptographie (ie: utilisation d’une phase aléatoire pour le codage des images). De plus, une extension de l’étude à la compression des images sera utile. Une autre perspective de ce travail de recherche est l’étude de l’impact de l’incohérence spatiale sur le codage et le décodage des signaux / In this thesis, we study and developed the use of coherence multiplexing (also called path-difference, by analogy with WDM optical communications) to achieve simultaneous coding and decoding of analogue signals. The coherence modulation of light consists in encoding a signal on a light beam as an optical path-difference larger than its coherence length. This opens the way to the use of broadband sources in systems that thought to be restricted to quasi-monochromatic light. The different signals to be processed are encoded by using an Electro-optic Modulator and a birefringent plate placed between two polarizers. First, we have shown how the coherence multiplexing process can be exploited to achieve parallel real-time all optical signal addition and subtraction. Then, we have studied the impact of the crosstalk, due to the imperfection of the opto-geometrical parameters of the elements in the architecture, in the quality of the obtained results. The second part of the work consists of the validation of the technique to image signals. Thus, we have tested both image with binary and several gray levels. Also, we have confirmed that the method can be used for simple and multiplex encoding module. After that, we have evaluated the performance of the processor as a function of the continuous optical path-difference ratio in terms of Signal to Noise Ratio (SNR), Mean Square Error (MSE) and Peak to peak Signal to Noise Ratio (PSNR). Finally, we have tested the coherence multiplexing method to the encryption method based on merging together multiple-images. Therefore, we have evaluated the performance and the robustness of the method

The rapid development of optofluidics, the combination of microfluidics and integrated optics, since its formal conception in the early 2000's has aided in the advance of single-molecule analysis. The optofluidic platform discussed in this dissertation is called the liquid core anti-resonant reflecting optical waveguide (LC-ARROW). This platform uses ARROW waveguides to orthogonally intersect a liquid core waveguide with solid core rib waveguides for the excitation of specifically labeled molecules and collection of fluorescence signal. Since conception, the LC-ARROW platform has demonstrated its effectiveness as a lab-on-a-chip fluorescence biosensor. However, until the addition of optical multiplexing excitation waveguides, the platform lacked a critical functionality for use in rapid disease diagnostics, namely the ability to simultaneously detect different types of molecules and particles. In disease diagnostics, the ability to multiplex, detect and identify multiple biomarkers simultaneously is paramount for a sensor to be used as a rapid diagnostic system. This work brings optofluidic multiplexing to the sensor through the implementation of three specific designs: (1) the Y-splitter was the first multi-spot excitation design implemented on the platform, although it did not have the ability to multiplex it served as a critical stepping stone and showed that multi-spot excitation could improve the signal-to-noise ratio of the platform by ~50,000 times; (2) a multimode interference (MMI) waveguide which took the multi-spot idea and then demonstrated spectral multiplexing capable of correctly identifying multiple diverse biomarkers simultaneously; and, (3) a Triple-Core design which incorporates excitation and collection along multiple liquid cores, enabling spatial multiplexing which increases the number of individual molecules to be identified concurrently with the MMI waveguide excitation. In addition to describing the development of optical multiplexing, this dissertation includes an investigation of another LC-ARROW based design that enables 2D bioparticle trapping, the Anti-Brownian Electrokinetic (ABEL) trap. This design demonstrates two-dimensional compensation of a particle's Brownian motion in solution. The capability to maintain a molecule suspended in solution over time enables the ability to gain a deeper understanding of cellular function and therapies based on molecular functions.

L'UWB (Ultra Wide Band) consiste à transmettre des signaux entre 3.1 et 10.6 GHz avec une puissance limitée à -41.3 dBm/MHz. Pour les communications hauts débits (100 à 500 Mbit/s) et courtes portées (1 à 10 m), les solutions de l'état de l'art reposent sur des traitements numériques complexes. Mitsubishi ITE propose une solution alternative multi-bandes (MB) impulsionnelle basée sur un récepteur non-cohérent. La démodulation OOK est effectuée par une détection d'énergie originale avec un seuillage adapté dynamiquement suivant les conditions de propagation. La parallélisation complète de ce système MB-OOK permet à la fois d'éviter les interférences inter-symboles et de récupérer la quasi totalité de l'énergie disponible. En outre, l'approche impulsionnelle limite les évanouissements du signal sur canal multi-trajets. La comparaison des systèmes MB-OOK et MB-OFDM démontre la pertinence de la solution proposée pour des applications très hauts débits, courte portée et faible consommation.

<p>The task of the project was to evaluate a differential phase shift keying demodulation technique by replacing a Mach-Zehnder interferometer receiver with an optical filter (Fiber Bragg Grating). Computer simulations were made with single optical transmission, multi channel systems and transmission with combined angle/intensity modulated optical signals. The simulations showed good results at both 10 and 40 Gbit/s. Laboratory experiments were made at 10 Gbit/s to verify the simulation results. It was found that the demodulation technique worked, but not with satisfactory experimental results. The work was performed at Eindhoven University of Technology, Holland, within the framework of the STOLAS project at the department of Electro-optical communication.</p>

Recently there is an emergence of many Internet applications such as multimedia, video conferencing, distributed interactive simulations (DIS), and high-performance scientific computations like Grid computing. These applications require huge amount of bandwidth and a viable communication paradigm to coordinate with multiple sources and destinations. Optical networks are the potential candidates for providing high bandwidth requirement. Existing communication paradigms include broadcast, and multicast. Hence supporting these paradigms over optical networks is necessary. Multicasting over optical networks has been well investigated in the literature. QoS policies implemented in IP does not apply for Wavelength division multiplexed (WDM) or optical burst switched (OBS) networks, as the optical counterpart for store-and-forward model does not exist. Hence there is a need to provision QoS over optical networks. These QoS requirements can include contention, optical signal quality, reliability and delay. To support these diverse requirements, optical networks must be able to manage the available resources effectively. Destinations participating in the multicast session are fixed (or rather static). Due to the random contention in the network, if at least one or more destination(s) is not reachable, requested multicast session cannot be established. This results in loss of multicast request with high probability of blocking. Incorporating wavelength converters (WCs) at the core nodes can decrease the contention loss, however WCs require optical-electrical-optical (O/E/O) conversion. This increases the delay incurred by optical signal. On the other hand all-optical WCs are expensive and increase the cost of the network if deployed. Goal of this thesis is, to provide hop-to-hop QoS on an existing all-optical network (AON) with no WC and optical regeneration capability. In order to minimize the request vi Abstract vii lost due to contention in AON, we propose a variation of multicasting called Quorumcasting or Manycasting. In Quorumcasting destinations can join (or leave) to (or from) the group depending on whether they are reachable or not. In other words destinations have to be determined rather than knowing them prior, as in the case of multicasting. Quorum pool is minimum number of destinations that are required to be participated in the session for successful accomplishment of the job (k be the size of quorum pool). Providing QoS for manycasting over OBS has not been addressed in the literature. Given the multicast group (with cardinality m > k) and the number of destinations required to be participated, the contribution of this work is based on providing necessary QoS. In this thesis we study the behavior of manycasting over OBS networks. In OBS networks, packets from the upper-layer (such as IP, ATM, STM) are assembled and a burst is created at the edge router. By using O/E/O conversion at the edge nodes, these optical bursts are scheduled to the core node. Control header packet or burst header packet (BHP) is sent to prior to the transmission of burst. The BHP configures the core nodes and the burst is scheduled on the channel after certain offset time. In the first part of the thesis, we explain the different distributed applications with primary focus on Grid over OBS (GoOBS). We study the loss scenario due contention and inadequate signal quality for an unicast case in OBS network. We further extend this to manycasting. We modify the BHP header fields to make the burst aware of not only contention on the next-hop link, but also bit-error rate (BER). By using recursive signal and noise power relations, we calculate the BER (or q-factor) of the link and schedule the burst only if the required BER threshold is met. Thus all the bursts that reach the next-hop node ensure that contention and BER constraint are met. This are called “Impairment-Aware (IA) Scheduling”. Burst loss in the network increases due to BER constraint. Hence we propose algorithms to decrease the burst loss and simultaneously providing the sufficient optical signal quality. We propose three algorithms called IA-shortest path tree (IA-SPT), IA-static over provisioning (IA-SOP), and IA-dynamic membership (IA-DM). In IA-SPT destination set is sorted in the non-decreasing order of the hop-distance from source. First k of them are selected and bursts are scheduled to Abstract viii these destinations along the shortest path. In IA-SOP we select additional k0(_ m − k) destinations where k0 is the over provisioning factor. Over provisioning ensures that burst at least reach k of them, decreasing the contention blocking. However as the burst has to span more destinations, the fan-out of the multicast capable switch will be more and the BER could be high. In IA-DM destinations are dynamically added or removed, depending on contention and BER. Destination is removed and new destination is added based on the two constraints. Our simulation results shows that IA-DM out performs the other two algorithms in terms of request blocking. We show that IP-based many casting has poor performance and hence there is a need for supporting many casting over OBS networks. We verify our simulation results with the proposed analytical method. In the next part, we focus on provisioning QoS in many casting. QoS parameters considered for analysis include, signal quality i.e., optical signal to noise ratio (OSNR), reliability of the link and, propagation delay. In this work we consider application based QoS provisioning. In other words, given the threshold requirements of an application, our aim is to successfully schedule the burst to the quorum pool satisfying the threshold conditions. We use a de-centralized way of the scheduling the burst, using BHP. With the help of local-network state information, the burst is scheduled only if it satisfies multiple set of constraints. Corresponding reception of burst at the node ensures that all the QoS constraints are met and burst is forwarded to the next hop. QoS attributes are either multiplicative or additive. Noise factor of the optical signal and reliability factor are multiplicative constraints, where as propagation delay is additive. We define a path information vector, which provides the QoS information of the burst at every node. Using lattice theory we define an ordering, such that noise factor and propagation delay are minimum and reliability is maximum. Using path algebra we compute the overall QoS attributes. Due to multiple set of constraints, the request blocking could be high. We propose algorithms to minimize request blocking for Multiple Constrained Many cast Problem (MCMP). We propose two algorithms MCM-SPT and MCM-DM. We consider different set of service thresholds, such as real time and data service thresholds. Real time services impose restriction on signal quality and the propagation delay. On the other hand Abstract ix data services require high reliability and signal quality. Our simulation study shows that MCM-SPT performs better than MCM-DM for real-time services and the data services can be provisioned using MCM-DM.

It is well known that communication systems employing multiple transmit and multiple receive antennas provide high data rates along with increased reliability. Some of the design criteria of the space-time block codes (STBCs) for multiple input multiple output (MIMO)communication system are that these codes should attain large transmit diversity, high data-rate, low decoding-complexity, low decoding –delay and low peak-to-average power ratio (PAPR). STBCs based on real orthogonal designs (RODs) and complex orthogonal designs (CODs) achieve full transmit diversity and in addition, these codes are single-symbol maximum-likelihood (ML) decodable. It has been observed that the data-rate (in number of information symbols per channel use) of the square CODs falls exponentially with increase in number of antennas and it has led to the construction of rectangular CODs with high rate. We have constructed a class of maximal-rate CODs for n transmit antennas with rate if n is even and if n is odd. The novelty of the above construction is that they 2n+1 are constructed from square CODs. Though these codes have a high rate, this is achieved at the expense of large decoding delay especially when the number of antennas is 5or more. Moreover the rate also converges to half as the number of transmit antennas increases. We give a construction of rate-1/2 CODs with a substantial reduction in decoding delay when compared with the maximal- rate codes. Though there is a significant improvement in the rate of the codes mentioned above when compared with square CODs for the same number of antennas, the decoding delay of these codes is still considerably high. For certain applications, it is desirable to construct codes which are balanced with respect to both rate and decoding delay. To this end, we have constructed high rate and low decoding-delay RODs and CODs from Cayley-Dickson Algebra. Apart from the rate and decoding delay of orthogonal designs, peak-to-average power ratio (PAPR) of STBC is very important from implementation point of view. The standard constructions of square complex orthogonal designs contain a large number of zeros in the matrix result in gin high PAPR. We have given a construction for square complex orthogonal designs with lesser number of zero entries than the known constructions. When a + 1 is a power of 2, we get codes with no zero entries. Further more, we get complex orthogonal designs with no zero entry for any power of 2 antennas by introducing co- ordinate interleaved variables in the design matrix. These codes have significant advantage over the existing codes in term of PAPR. The only sacrifice that is made in the construction of these codes is that the signaling complexity (of these codes) is marginally greater than the existing codes (with zero entries) for some of the entries in the matrix consist of co-ordinate interleaved variables. Also a class of maximal-rate CODs (For mathematical equations pl see the pdf file)

Wireless systems with multiple antennas at both the transmitter and receiver (MIMO systems) have been the focus of research in the recent past due to their ability to provide higher data rates and better reliability than their single antenna counterparts. Designing a communication system for MIMO frequency selective channels provides many signal processing challenges. Popular methods like MIMOOFDM and space-time precoding linearly process blocks of data at both the transmitter and the receiver. Independence between the blocks is ensured by introducing sufficient redundancy between successive blocks. This approach has many pitfalls, including the limit on achievable data rate due to redundancy requirements and the need for additional coding/processing. In this thesis, we provide a filterbank precoding framework (FBP) for communication over MIMO frequency selective channels. By viewing the channel as a polynomial matrix, we derive the minimum redundancy required for achieving FIR equalization of the precoded channel. It is shown that, for most practical channels, a nominal redundancy is enough. The results are general, and hold for channels of any dimension and order. We derive the zero-forcing and MMSE equalizers for the precoded channel. The role of equalizer delay in system performance is analyzed. We extend the minimum redundancy result to the case of space-time filterbank precoding (STFP). Introducing the time dimension allows the channel to be represented by a block pseudocirculant matrix. By using the Smith form of block pseudocirculant matrices, we show that very high data rates can be achieved with STFP. When channel information is available at the transmitter, we derive an iterative algorithm for obtaining the MMSE optimal precoder-equalizer pair. We then provide a comparison of FBP with the block processing methods. It is shown that FBP provides better BER performance than the block processing methods at a lower computational cost. The reasons for the better performance of FBP are discussed.

En les xarxes IP/MPLS sobre WDM on es transporta gran quantitat d'informacio, la capacitat de garantir que el trafic arriba al node de desti ha esdevingut un problema important, ja que la fallada d'un element de la xarxa pot resultar en una gran quantitat d'informacio perduda. Per garantir que el trafic afectat per una fallada arribi al node desti, s'han definit nous algoritmes d'encaminament que incorporen el coneixement de la proteccio en els dues capes: l'optica (WDM) i la basada en paquets (IP/MPLS). D'aquesta manera s'evita reservar recursos per protegir el trafic a les dues capes. Els nous algoritmes resulten en millor us dels recursos de la xarxa, ofereixen rapid temps de recuperacio, eviten la duplicacio de recursos i disminueixen el numero de conversions del trafic de senyal optica a electrica. / The use of optical technology in core networks combined with IP/Multi-Protocol Label Switching (MPLS) solution has been presented as a suitable choice for the next generation Internet architecture. The integration of both layers is facilitated by the development of Generalized MPLS (GMPLS). In this network architecture, a single fibre failure can result in potentially huge data losses as the effects propagate up and through the network causing disruptions in the service of many applications. This research provides and evaluates new QoSP routing schemes that consider both IP/MPLS and optical network layers to compute the paths and backup paths subject to the QoS requirements of the traffic. Although effort has been devoted in developing multi-layer routing algorithms that consider all switching layers, protection is not considered amongst them. This is considered in this thesis. Where electrical to optical signal conversions have been reduded as well as the avoidance of traffic duplications resulting in better use of the network resources.