L’architecture actuelle des réseaux d’accès radio n’est pas adaptée en terme de capacité à supporter l’accroissement continu du trafic dans les systèmes cellulaires 4G et au-delà. L’objectif de cette thèse est de proposer une architecture réseau générique, GeRoFAN (Generic Radio over Fiber Access Network) pour la fédération des stations de base des systèmes cellulaires de nouvelle génération (WiMAX, 4G LTE). Deux innovations technologiques majeures sont utilisées pour l’implémentation de l’architecture GeRoFAN: la radio-sur-fibre (RoF) et les modulateurs réflexifs éléctro-absorbants. La thèse vise aussi à concevoir pour l’architecture GeRoFAN un plan contrôle et un canal de signalisation adapté permettant le basculement des ressources radio, selon la fluctuation du trafic, entre un grand nombre de cellules réparties à l’échelle métropolitaine. Cependant, il a été bien avéré que la transmission optique de plusieurs canaux radios en utilisant la RoF analogique est assujettie à des multiples facteurs de dégradation physique altérant la qualité du signal de ces canaux et induisant une perte dans leur capacité de Shannon. L’originalité du plan de contrôle de GeRoFAN est de réaliser une affectation optimisée des canaux radios sur les porteuses optiques, grace au multiplexage par sous-porteuse (SCM), afin d’ajuster la capacité de Shannon dans chaque cellule radio à la charge de trafic à laquelle elle est soumise. A cet effet, une connaissance fine des contraintes physiques de la transmission RoF est requise pour le plan de contrôle. Cette connaissance est acquise par l’élaboration d’un modèle analytique des divers bruits de transmission du système GeRoFAN. Contrairement à des propositions comparables, le plan contrôle de GeRoFAN se doit d’être le plus transparent que possible à la technologie des systèmes radio concernés. Sa nature " MAC radio agnostique " vise à permettre, grâce au multiplexage en longueur d’onde et au routage optique WDM, la fédération de plusieurs opérateurs utilisant différentes technologies radio sur la même infrastructure. Plus généralement, avec la mutualisation de l’architecture GeRoFAN, le plan de contrôle permet de virtualiser les ressources radiofréquences et de promouvoir de nouveaux modèles économiques pour les opérateurs Télécoms. Le dernier volet de la thèse se focalise sur la valeur "business" du paradigme GeRoFAN. Les contours du nouveau éco-system d’affaire promu par GeRoFAN sont définis. Les motivations/attentes des différentes parties prenantes dans cet éco-system sont esquissées, les contraintes réglementaires et organisationnelles soulevées sont adressées afin d’assurer un déploiement sans heurts de GeRoFAN. Bien qu’exigeant un nouveau modèle réglementaire, il s’agit de mettre en évidence l’intérêt économique de la solution GeRoFAN, tout particulièrement en comparaison à la RoF digitale, à travers des études technico-économiques chiffrant les couts d’investissement (CapEx), les couts opérationnels (OpEx) et les possibles retours sur investissement. A cet effet, deux modèles économiques sont proposés mettant en évidence la valeur ajoutée de GeRoFAN tout au long de la chaine de valeur. / Current radio access networks architectures are not suited in terms of capacity and backhauling capabilities to fit the continuing traffic increase of 4G cellular systems. The objective of the thesis is to propose an innovative and generic mobile backhauling network architecture, called GeRoFAN (Generic Radio-over-Fiber Access Network), for next generation mobile systems (WiMAX, 4G LTE). Two major technological innovations are used to implement GeRo-FAN: analog Radio-over-Fiber (RoF) and reflective amplified absorption modulators. The aim of this thesis is to design for such an architecture an original Control Plane (CP) and a signaling channel enabling to balance radio resources between a set of neighboring cells at the access/metropolitan scale according to traffic fluctuations. The transmission of several radio frequencies by means of an analog RoF link suffers from several impairments that may degrade the capacity of the radio system. The originality of the GeRoFAN-CP consists in mapping radio frequencies with optical carriers by means of Sub-Carrier Multiplexing (SCM) in order to optimize the Shannon’s capacity within the various cells covered by the system according to the current traffic load. For that purpose, a deep analysis and modeling of the various physical layer impairments impacting the quality of the radio signal is carried out. Unlike comparable approaches, the GeRoFAN-CP is as independent as possible from the radio layer protocols. Thus, the "radio MAC-agnostic" nature of the GeRoFAN-CP enables to federate multiple operators using different radio technologies onto the same backhauling optical infrastructure. Subcarrier and wavelength division multiplexing (SCM/WDM) as well as WDM optical routing capabilities are exploited onto the GeRoFAN transparent architecture. More globally, the GeRoFAN-CP enables a form of "radio frequency virtualization" while promoting new business models for Telecom service providers. The last part of the thesis focuses on the business value of the GeRoFAN paradigm. The expectations of the different stake-holders and main regulatory/organizational entities that could be involved in the deployment of GeRoFAN infrastructures should be addressed in order to achieve a smooth deployment of this new type of mobile backhauling. Economics of the GeRoFAN architecture are investigated in terms of OpEx/CapEx valuation and investment profitability, especially in reference to digitized RoF. Two business models are then proposed to study how GeRoFAN contributes to enriching the cellular backhauling service value chain.

An abstract of the thesis of Bosi Chen for the Master of Science in Electrical and Computer Engineering presented Aug 1st, 2012. Title: Spectrum Regrowth for OFDM-based LTE and WiMAX Systems. In OFDM-based (Orthogonal Frequency Dimension Multiplexing) LTE (Long Term Evolution) and WiMAX (Worldwide Interoperability for Microwave Access) Systems, one of the critical components is the RF power amplifier. With current technologies, RF power amplifiers are not perfectly linear. The nonlinearity of an RF power amplifier is one of the main concerns in RF power amplifier design. The nonlinearity control is described by the out-of-band power emission levels, and the nonlinearity of an RF power amplifier is usually described by IP3 (the third-order intercept point). However, there is need of a clear relationship or expression between the out-of-band power emission level and IP3 for LTE and WiMAX Systems, which helps the RF designers to choose components. This thesis presents the analysis of the nonlinear effect of an RF amplifier in LTE and WiMAX Systems, and the derivation of the expressions for the estimated out-of-band emission levels for LTE and WiMAX signals in terms of IP3 and the power level of the signal. The result will be helpful for RF engineers in the design and test of RF power amplifiers in LTE and WiMAX Systems.

Les forts besoins en matière d'économie de carburant, de réduction des coûts de maintenance et de diminution des accidents routiers, ont conduit à la conception et à la commercialisation d'une gamme de systèmes embarqués sans fil, installés dans les véhicules roulants terrestres. Or, il faudra surmonter plusieurs défis techniques pour que les divers bénéfices de ses systèmes se réalisent. Ce mémoire de thèse s'est déroulé au sein de l'entreprise Continental Automotive Systems et les laboratoires LAAS et LAPLACE de Centre National de la Recherche Scientifique. Les travaux ont porté sur le canal de propagation radiofréquence dans l'environnement du véhicule pour le système de surveillance de pression des pneumatiques (TPMS) et le système d'accès sans fil (PASE). Ils se sont répartis entre les expérimentations et des études théoriques visant à présenter des modèles efficaces de l'environnement de propagation, d'évaluer la qualité de communication et de proposer des solutions adaptées aux systèmes embarqués sans fil étudiés. Les résultats de simulation et de mesure montrent que nous pouvons bien cerner les mécanismes de propagation mis en jeu dans l'environnement véhicule, et d'adapter en conséquence les solutions protocolaires et antennaires. / The high potential of accident prevention by using an intelligent tire system can be clearly seen through the different accident analysis. It has been shown that adverse road conditions, tire defects or their combination play an important role in road accidents. Moreover the decrease in the number of fatalities, provided that the entire car fleet is equipped with intelligent tire systems, could be significantly improved by preventing at least 10 % of accidents. This would mean that over 4 000 life’s could be saved every year in European countries. The first part of this thesis presents is the TPM (Tire Pressure Monitoring) System, which corresponds to a wireless radiofrequency transmission between a transmitter module (TX) in each tire of the car and a fixed central receiver (RX). The transmitter, next called "Wheel Unit", is composed with different electronic sensors (temperature, pressure, acceleration...) for the detection of the tire inflation status. The data are collected by the receiver where the different wheel unit frames from each tire is decoded by the control unit. Then a graphical display informs the driver with the required pressure and temperature variations. The second investigated system is the wireless car access, which operate the bilateral link LF /RF, by sending the different commands at 315 MHz or 434 MHz. The signals are related to an electronic code featuring the key to control the vehicle (lock/unlock of doors and the trunk release, start of the engine,…). The automotive PAssive Start and Entry system (PASE) module generates a low frequency wake-up message (at 125 kHz) from the car towards the badge, and a RF challenge signal communicates back from the badge to the car at triggering event. The free radio license frequency of 434MHz is chosen for this study. The RF radio-link budget is a keystone of the overall system reliability: the carrier propagation between the wheel unit and the receiver must be effective whatever the ground composition, whatever the angular position or speed of the wheel unit, for each of the four wheel units. Moreover, the system must be insensitive to RF interferences. The transmission between the wheel units and the receiver is tricky because of the many parameters involved. These environment and operating considerations increase the radio-link budget complexity, and contribute to degrade the global transmission quality of the TPM system. The major parameters that impact the TPMS efficiency: System parameters: the system design affects the transmission performances. The frame structure, the modulation schemes and code lines contribute directly or indirectly to increase the BEP (Bit Error Probability), thus the choice of an efficient system strategy is indispensable for the TPMS. Radiofrequency channel: The car body affects considerably the wave propagation, because the data link is not a line-of-sight, and the channel varies rapidly according to the wheel unit positions and the wave trajectories. So, due to the complex and variable environment, the main characteristics of emitted waves also change in phase and power and it produces both destructive and constructive behaviors. Receiver: generally it can be posed near the metallic structure of the car, so the antenna pattern can be corrupted. RF Source effects. To ensure the good reception of the data transmitted from the sensors, a good knowledge of our wireless radio-link channel is mandatory. Thus, the transmitter part of the system must be properly described: the RF source characterization for TPMS –Tire Pressure Monitoring System- is discussed in this thesis. We proposed in the first part an original approach to characterize the source, from the transmitter antenna to the whole wheel system: thus the influence of each element (lumped antenna + rim + tire) is quantified once embedded in the antenna. Several experimental studies are performed in far and near field conditions for a complete characterization.

Thesis: S.M. in Oceanographic Engineering, Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2017. / Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science; and the Woods Hole Oceanographic Institution), 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 885-86). / A newly discovered double ducted acoustic environment present throughout much of the Beaufort Sea in the Arctic has a major effect on active acoustic transmissions. This work performs an in depth analysis of how the lower duct impacts the propagation of various active signals used commonly for acoustic communications or active sonar. First, this thesis performs a thorough modal analysis of the effect of the double ducted environment on long range propagation of a 300 Hz and 3500 Hz pulse. Signal excess is determined for the two different source pulses to quantify the effect of the lower duct on noise and SNR. Finally, channel capacity is calculated for the two frequency bands to evaluate operational impacts of the lower duct on acoustic communication systems in the Arctic. / by Scott Adams Carper / S.M. in Oceanographic Engineering / S.M.

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<p>Passive chipless wireless sensors have gained great attention in Radio Frequency Identification (RFID) applications, inventory tracking, and structural health monitoring, as they offer a prospective low-cost, scalable alternative to the state-of-the-art active sensors. While the popularity and demand for chipless sensors are on the rise, their applications are limited to low-noise environments and their caliber as low-cost, scalable devices has not been explored to a successful degree in challenging domains, such as precision agriculture, healthcare, and food packaging. Size, cost of materials, and complexity of the manufacturing process are the main obstacles to progress in the large-scale production of chipless sensors for practical applications. </p> <p><br></p> <p>Conventional manufacturing processes, such as photolithography, are costly, cumbersome, and time intensive. While additive manufacturing techniques, such as printing technologies, have circumvented some of these challenges, printing techniques require costly inks and complex post-processing steps, such as drying and sintering, which limit their large-scale utilization. To overcome these challenges, this dissertation focuses on investigating the possibility of utilizing laser processing of conventional metalized films and polymers to develop cost-effective chipless sensors. This Scalable Laser Assisted Manufacturing (SLAM) process offers a platform for large-scale roll-to-roll production of high-resolution sensors for precision agriculture, healthcare, and food packaging applications. </p> <p><br></p> <p>In this pursuit, the first study explores combining the SLAM process with 3D printing to develop a miniaturized, biodegradable, chipless sensor for soil moisture monitoring. In the second study, the SLAM process is further explored in the development of metalized stickers for healthcare applications focusing on urine bag management and early risk detection of urinary tract infections. In the third study, the capability of the SLAM process to form moisture-sensitive metal nanoparticles as a co-product of metal patterning is harnessed to develop a chipless humidity sensor. The SLAM process is further expanded in the fourth study by functionalizing metalized films with stimuli-responsive polymers to achieve specificity in detecting unique biomarkers of food spoilage. The SLAM platform described in this work opens up new avenues toward processing metalized fabric for the future of wearable electronics and implementing multi-functional sensors for precision agriculture.</p> <p>  </p>

The construction industry is vital in meeting humanity's infrastructure and essential building needs. However, its current practices contribute significantly to environmental challenges such as global warming, deforestation, and biodiversity loss. The current study points out the need for a more sustainable approach in the construction sector. The reason this study focuses on RFID-tags is both because of the academic gap regarding implementation of new standardizations and the project Lumi that this study has as its case study of the thesis.    The goal of this thesis is to analyze the Swedish construction industry’s attitude toward the implementation of RFID-tags as a standardization and fill the academic gap that has been identified in the literature review. The goal is to determine the attitude of each stakeholder type within the industry through the lens of socio-technical transition theory, to determine specific barriers and drivers for the concept. Furthermore, the aim is to determine if RFID-tags can be implemented to promote circularity and enhance sustainable development.   The research methods incorporate a literature review and a case study with semi-structured interviews conducted with eight participants. The sample consisted of actors within the construction industry, such as customers, distribution companies, entrepreneurs, manufacturers, service companies, and workers.  The thesis identified the conservative nature of the industry as an obstacle, along with the fear of failure within the construction industry. The attitude towards the standardization of RFID-tags is positive, where beneficial factors were identified, such as saving time, reducing environmental impact, and improving the structure for recycling.

Radio frequency interference has become a large problem to radio astronomers. This thesis proposes the idea that radio frequency interference can be mitigated using a phased array feed in conjunction with a large reflector. A phased array feed would allow radio astronomers to observe fainter signals than is currently possible, while at the same time enabling rapid sky surveys. A phased array feed was designed and simulated, and sensitivity optimization was performed on the array feed. It was shown that higher sensitivity can be achieved using a 7-element phased array feed than with a conventional waveguide feed. Simulations were ran using RFI mitigation algorithms on the array to show that interference cancellation can, in principle, be performed using a phased array feed. In addition to these simulations, improvements were made to a previously designed RF receiver so that radio astronomy observations could be made and interference mitigation algorithms tested on a receiver platform.

The purpose of this study is to investigate RF or Radio Frequency energy as a viable alternative to traditional heating methods for the purpose of curing resins used in resin infusion molding, a molding system for polymeric composites. Traditional heating/curing methods include technologies such as room temperature, oven, microwave, infrared, and ultraviolet. Although RF curing provides far more advantages than disadvantages, its implementation into a manufacturing process can be challenging. Specifically, three critical elements must be present in order for RF to function in a manner that is profitable to the manufacturer. Those elements are: (1) the proper generator (voltage and frequency), (2) the correct electrode configuration, and (3) the appropriate material sensitizer (amount and type). There is also the consideration of initial capital investment; which is by no means insignificant. However, if all 3 elements are present, the benefits can be immediate and numerous. Potential advantages include the following: improved part quality through penetrating and uniform heating; competitive, if not superior, material physical properties; and drastically reduced curing times. Other potential advantages include floor space savings, high energy efficiency, and increased operational flexibility. For the purpose of this thesis, experimentation will be conducted to first confirm and then, if successful, quantitatively capture the reduction in curing time. Physical properties will also be measured using tensile testing to determine whether or not RF curing can facilitate minimal loses in the material's physical properties.