Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 87 for “"Electrical Engineering, Electronic Engineering, Information Engineering"”.
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Sum rules and constraints on passive systems - a general approach and applications to electromagnetic scattering
… spherical wave. They are particularly useful for electrically small scatterers. The results can be used in many fields where an understanding of the interaction between electromagnetic waves and matter is vital. One interesting application is within antenna theory, where the limitations are …
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Fault Tolerance for Real-Time Systems: Analysis and Optimization of Roll-back Recovery with Checkpointing
Increasing soft error rates in recent semiconductor technologies enforce the usage of fault tolerance. While fault tolerance enables correct operation in the presence of soft errors, it usually introduces a time overhead. The time overhead is particularly important for a group of computer systems …
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Microwave CMOS VCOs and Front-Ends - using integrated passives on-chip and on-carrier
… microwave frequencies. Traditionally, microwave electronics has used exclusive and more expensive semiconductor technologies (III-V materials). However, the rapid development of consumer electronics (e.g. video game consoles) the last decade has pushed the silicon CMOS IC technology towards even …
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Off-line Foveated Compression and Scene Perception: An Eye-Tracking Approach
… offering storage and communication of pictorial information, the need to efficiently represent this information has become increasingly important, both from an information theoretic and a perceptual point of view. There has been a recent interest to design systems for efficient representation and …
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Ultra-Wideband Wireless Channels - Estimation, Modeling and Material Characterization
This licentiate thesis is focused on the characterization of ultra-wideband wireless channels. The thesis presents results on ultra-wideband communications as well as on the ultra-wideband characterization of materials. The communications related work consisted in the measurement and modeling of …
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Microwave CMOS Beamforming Transmitters
The increase of the consumer electronics market the last couple of decades has been one of the main drivers of IC process technology development. The majority of the ICs are used in digital applications, and for these CMOS is the choice of technology. The urge to squeeze more transistors on to a …
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Design of Multi-layer Telecommunication Networks: Fairness, Resilience, and Load Balancing
Migration to Next Generation Internet architectures poses new challenges for network operators in planning core networks and calls for efficient network planning and optimization tools. Optimization models underlying such tools are developed in this thesis. We study a number of single and two-layer …
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Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications
The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. The body of revolution enables …
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Wireless Communication with Medical Implants: Antennas and Propagation
With the increased sophistication of medical implants, there is a growing need for flexible high-speed communication with the implant from outside the body. Today the communication is done by an inductive link between the implant and an external coil at a low carrier frequency. Extended range and …
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Radome Diagnostics: utilizing Source Reconstruction based on Surface Integral Representations
… surface of the radome, i.e., no a priori information of the material of the radome is requested. Moreover, both synthetic and measured data are used to verify the method. In Papers I-III, the measurement set-up is a reflector antenna covered by a monolithic radome, and the near field is …
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Iterative receivers with channel estimation for MIMO and multi-user OFDM systems
… be modeled through multi-dimensional extrinsic information transfer (EXIT) charts. Although single-input single-output EXIT charts have been well studied, the multiple input-output case has generally been overlooked in the literature. Such charts are suitable for studying multi-user systems. The …
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CMOS Transceiver Front-Ends in Mobile Communication Handsets - Architectures and Building Blocks
For mobile communication systems in the low-GHz range, CMOS has increasingly become the technology of choice, and the level of integration in mobile handsets has risen. The use of off-chip components, which increases the handset assembly time and costs, is preferably avoided. However, integrating a …
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Multiple Antenna Terminals in Realistic Environments - A Composite Channel Modeling Approach
For evaluation of specific antenna arrangements in wireless communication systems we need physical channel models that take into account also the directional domain of the propagation channel. In this thesis we investigate, validate and propose a practical approach to wireless channel modeling and, …
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Measurement Based Channel Characterization and Modeling for Vehicle-to-Vehicle Communications
… by buildings (NLOS), with the help of video information recorded during the measurements. It is found that vehicles obstructing the LOS induce an additional attenuation in the received signal power. The results from system level vehicular ad hoc network (VANET) simulations are also presented, …
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On the Design of Turbo Codes
This thesis is about Turbo codes - codes constructed via parallel concatenation of two recursive convolutional encoders linked by an interleaver. The focus of the work is on the understanding and design of Turbo codes. This includes thorough investigation of central components that influence Turbo …
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Cryptanalysis of Selected Stream Ciphers
… done in a black box fashion, without using any information on the internal structure of the primitives. Despite this, it is shown how structural information is revealed very clearly under certain circumstances. The main features here are some nice results for the well-known stream ciphers …
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Continuous-Time Delta-Sigma Modulators for Ultra-Low-Power Radios
The modern small devices of today require cheap low power radio frequency (RF) transceivers that can provide reliable connectivity at all times. In an RF transceiver, the analog-to-digital converter (ADC) is one of the most important parts and it is also one of the main power consumers. There are …
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Design Space Exploration of Digital Circuits for Ultra-low Energy Dissipation
The ever expanding market of ultra portable electronic products is compelling the designer to invest major efforts in the development of small and low energy electronic devices. The driving force and benefactors of such devices are (but not limited to) e-health system, sensor network applications, …
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