This dissertation considers three related problems in distributed transmission and reception networks. Generally speaking, these types of networks have a transmit cluster with one or more transmit nodes and a receive cluster with one or more receive nodes. Nodes within a given cluster can communicate with each other using a wired or wireless local area network (LAN/WLAN). The overarching goal in this setting is typically to increase the efficiency of communication between the transmit and receive clusters through techniques such as distributed transmit beamforming, distributed reception, or other distributed versions of multi-input multi-output (MIMO) communication. More recently, the problem of wireless power transfer has also been considered in this setting. The first problem considered by this dissertation relates to distributed reception in a setting with a single transmit node and multiple receive nodes. Since exchanging lightly quantized versions of in-phase and quadrature samples results in high throughput requirements on the receive LAN/WLAN, previous work has considered an approach where nodes exchange hard decisions, along with channel magnitudes, to facilitate combining similar to an ideal receive beamformer. It has been shown that this approach leads to a small loss in SNR performance, with large reductions in required LAN/WLAN throughput. A shortcoming of this work, however, is that all of the prior work has assumed that each receive node has a perfect estimation of its channel to the transmitter. To address this shortcoming, the first part of this dissertation investigates the effect of channel estimation error on the SNR performance of distributed reception. Analytical expressions for these effects are obtained for two different modulation schemes, M-PSK and M2-QAM. The analysis shows the somewhat surprising result that channel estimation error causes the same amount of performance degradation in ideal beamforming and pseudo-beamforming systems despite the fact that the channel estimation errors manifests themselves quite differently in both systems. The second problem considered in this dissertation is related to oscillator stability and phase noise modeling. In distributed transmission systems with multiple transmitters in the transmit cluster, synchronization requirements are typically very strict, e.g., on the order of one picosecond, to maintain radio frequency phase alignment across transmitters. Therefore, being able to accurately model the behavior of the oscillators and their phase noise responses is of high importance. Previous approaches have typically relied on a two-state model, but this model is often not sufficiently rich to model low-cost oscillators. This dissertation develops a new three-state oscillator model and a method for estimating the parameters of this model from experimental data. Experimental results show that the proposed model provides up to 3 dB improvement in mean squared error (MSE) performance with respect to a two-state model. The last part of this work is dedicated to the problem of wireless power transfer in a setting with multiple nodes in the transmit cluster and multiple nodes in the receive cluster. The problem is to align the phases of the transmitters to achieve a certain power distribution across the nodes in the receive cluster. To find optimum transmit phases, we consider a iterative approach, similar to the prior work on one-bit feedback for distributed beamforming, in which each receive node sends a one-bit feedback to the transmit cluster indicating if the received power in that time slot for that node is increased. The transmitters then update their phases based on the feedback. What makes this problem particularly interesting is that, unlike the prior work on one-bit feedback for distributed beamforming, this is a multi-objective optimization problem where not every receive node can receive maximum power from the transmit array. Three different phase update decision rules, each based on the one-bit feedback signals, are analyzed. The effect of array sparsity is also investigated in this setting.

Phased array antenna (PAA) is a key component in many of the modern military and commercial radar and communication systems requiring highly directional beams with narrow beam widths. One of the advantages that this technology offers is a physical movement-free beam steering. Radar and communication technologies also require the PAA systems to be compact, light weight, demonstrate high bandwidth and electromagnetic interference (EMI) free performance. Conventional electrical phase shifters are inherently narrowband. This calls for technologies that have a larger bandwidth and high immunity to electromagnetic interference. Optical true-time-delay (TTD) technique is an emerging technology that is capable of providing these features along with the ability to provide frequency independent beam steering. Photonic crystal fiber (PCF) based optical TTD lines are capable of providing precise and continuous time delays required for PAA systems. Photonic crystal fibers are a new class of optical fibers with a periodic arrangement of air-holes around a core that can be designed to provide extraordinary optical characteristics which are unrealizable using conventional optical fibers. In this dissertation, highly dispersive photonic crystal fiber structures based on index-guidance and bandgap-guidance were designed. Designs exhibiting dispersion coefficients as large as -9500ps/nm/km and 4000ps/nm/km at 1550nm were presented. A TTD module utilizing a fabricated highly dispersive PCF with a dispersion coefficient of -600ps/nm/km at 1550nm was formed and characterized. The module consisted of 4 delay lines employing highly dispersive PCFs connected with various lengths of non-zero dispersion shifted fibers. By employing PCFs with enhanced dispersion coefficients, the TTD module size can be proportionally reduced. A 4-element linear X-band PAA system using the PCF-TTD module was formed and characterized to provide continuous time delays to steer radiofrequency (RF) beams from -41 degrees to 46 degrees by tuning the wavelength from 1530nm to 1560nm. Using the PCF-TTD based X-Band PAA system, single and simultaneous multiple beam transmission and reception capabilities were demonstrated. Noise and distortion performance characteristics of the entire PAA system were also evaluated and device control parameters were optimized to provide maximum spurious-free-dynamic range. In order to alleviate computational and weight requirements of practical large PAA systems, a sparse array instead of a standard array needs to be used. X-Band sparse array systems using PCF and dispersive fiber TTD technique were formed and RF beam steering was demonstrated. As an important achievement during the research work, the design and fabricated structure of a PCF currently reported to have the highest dispersion coefficient of -5400ps/nm/km at 1549nm, along with its limitations was also presented. Finally, other interesting applications of highly dispersive PCFs in the areas of pulse compression and soliton propagation were explored. / text

Saving energy and increasing network lifetime are significant challenges in the field of Wireless Sensor Networks (WSNs). Energy-aware routing protocols have been introduced for WSNs to overcome limitations of WSN including limited power resources and difficulties renewing or recharging sensor nodes batteries. Furthermore, the potentially inhospitable environments of sensor locations, in some applications, such as the bottom of the ocean, or inside tornados also have to be considered. ZigBee is one of the latest communication standards designed for WSNs based on the IEEE 802.15.4 standard. The ZigBee standard supports two routing protocols, the Ad hoc On-demand Distance Vector (AODV), and the cluster-tree routing protocols. These protocols are implemented to establish the network, form clusters, and transfer data between the nodes. The AODV and the cluster-tree routing protocols are two of the most efficient routing protocols in terms of reducing the control message overhead, reducing the bandwidth usage in the network, and reducing the power consumption of wireless sensor nodes compared to other routing protocols. However, neither of these protocols considers the energy level or the energy consumption rate of the wireless sensor nodes during the establishment or routing processes.

Siegfried Kracauer a fait remarquer, déjà en 1931, que le bestseller est un « signe d’une expérience sociologique réussie ». Dans le cas des émissions littéraires à la télévision, nous assistons à une double configuration d’un succès : celui de l’émission, puis celui du livre. Au- delà de leur influence sur la consommation des livres, les programmes médiatiques sur la littérature font partie de l’ensemble de lieux communs (Robert, 2002) et, comme les écoles ou les institutions littéraires, participent à l’établissement des traditions de lecture. Ils présentent explicitement ou implicitement les titres désirables et prescrivent les normes de lecture acceptées. En présélectionnant des livres pour des milliers de gens à la fois, en invitant des auteurs à présenter leur œuvres ou en mettant en vedette des critiques littéraires, ces programmes de formats fort différents participent aux processus de légitimation culturelle. Cette thèse décrit les différentes modalités des formes de présentation du fait littéraire à la télévision et leurs évolutions. À travers une analyse d’une sélection d’émissions qui ont connu du succès à différentes époques et dans différents contextes culturels, cette recherche vise à cerner la relation médiatique qui existe entre la littérature et la télévision. Établissant ainsi les caractéristiques d’une expérience socio-médiatique réussie, cette thèse explore le dispositif de l’émission littéraire télévisuelle tel qu’il s’est développé entre 1950 et 2010, principalement en étudiant les émissions qui ont marqué la télévision nationale et le paysage littéraire en Allemagne, en Espagne et en France. En décrivant le dispositif médiatique qui fait le lien entre la conception, la production, le contenu et la portée de ces émissions, à travers une approche comparée et intermédiale, cette recherche analyse le complexe réseau de médiations qui entrent en jeu dans la construction et dans la réception de ces émissions, suivant quatre axes thématiques: le dispositif médiatique, la relation avec l’écrivain, le rôle primordial du présentateur et la mise en scène des lecteurs. / Siegfried Kracauer famously noted, in 1931, that the bestseller is the « sign of a successful sociological experience ». In the case of televised literary shows, we witness a double configuration of such a success: that of the television show and that of the book. Like the book, the literary shows depend on various factors that are sometime difficult to identify, such as the socio-historical context, the collective imaginary tied to the book and to the activity of reading, as well as the media context. Beyond their influence on the purchase of books, these literary shows constitute a part of the common spaces (Robert, 2002) and, just like the schools and literary institutions, participate in the establishment of reading traditions. They present – explicitly or implicitly – the titles considered desirable and prescribe the norms for accepted readings. By selecting books for thousands of people at a time, by inviting authors to present their works or by featuring literary critics, these shows participate in the process of cultural legitimation. This thesis describes and analyses the various ways of portraying the literary world on television and its evolutions through time and in changing cultural contexts. By analysing a selection of successful shows, it describes the existing relationship between the two media that are the book and the television. Establishing thus the characteristics of an experience that touches both media and sociology, this thesis explores the literary show’s apparatus as it developed between 1950 and 2010, mainly by studying literary programmes that marked national television and the literary field in France, Germany, and Spain. By describing the media apparatus that establishes the link between the conception, the production, the content and the impact of these shows, through a comparative and intermedial approach, this research analyses the complex network of mediations that interplay in the construction and the reception of these shows. It does so by following four key points: the media apparatus, the changing relationship with the writer, the primordial role of the presenter, and the staging of the readers.