The ever increasing demand for mobility calls for new mobile communication systems that deal more efficiently with the very limited bandwidth available. While such systems do exist and work well in computer simulations, little is known about their performance under real world conditions. Little is also known about how to best determine and compare the…
Interaction between the Medium Access Control (MAC)-layer and the physical-layer routines is one of the basic concepts of modern wireless networks. Physical-layer dependent resource allocation and scheduling guarantee efficient network utilization. Accordingly, classical link-level analyses, focusing only on the physical-layer are not sufficient anymore for optimum transceiver structure and algorithm development. This thesis presents the…
In this work, a realistic physical layer performance evaluation of High Speed Downlink Packet Access (HSDPA) as well as IEEE 802.16-2004, commonly referred to as Worldwide Inter-operability for Microwave Access (WiMAX is provided. The performance evaluation is carried out in two measurement campaigns that took place in an alpine and an urban environment. Both, WiMAX…
Bayesian filtering is a framework for the computation of an optimal state estimate fusing different types of measurements, both current and past. Positioning, especially in urban and indoor environments, is one example of an application where the powerful mathematical framework is needed to compute as a good position estimate as possible from all kinds of…
The work of this thesis can be seen as a first step towards the characterization and quality evaluation of the class of local geometric distortions. A first step to solve the problems with geometric attacks is the characterization of the class of perceptually admissible distortions. This requires the development of models to treat the distortions…
The thesis takes into account steganography and steganalysis in the pixel domain. The contribution of this thesis is threefold . From a steganalysis point of view we introduce a new steganalysis method called Amplitude of Local Extrema (ALE) which outperforms previously proposed pixel domain methods. As a second contribution we introduce a comparative methodology for…
This thesis deals with several open problems in acoustic echo cancellation and acoustic feedback control. Our main goal has been to develop solutions that provide a high performance and sound quality, and behave in a robust way in realistic conditions. This can be achieved by departing from the traditional ad-hoc methods, and instead deriving theoretically…
The analysis and design of new non-centralized learning algorithms for potential application in distributed adaptive estimation is the focus of this thesis. Such algorithms should be designed to have low processing requirement and to need minimal communication between the nodes which would form a distributed network. They ought, moreover, to have acceptable performance when the…
Air traffic control (ATC) voice radio communication between aircraft pilots and controllers is subject to technical and functional constraints owing to the legacy radio system currently in use worldwide. This thesis investigates the embedding of digital side information, so called watermarks, into speech signals. Applied to the ATC voice radio, a watermarking system could overcome…
Dynamic textures are common in natural scenes. Examples of dynamic textures in video include fire, smoke, clouds, volatile organic compound (VOC) plumes in infra-red (IR) videos, trees in the wind, sea and ocean waves, etc. Researchers extensively studied 2-D textures and related problems in the fields of image processing and computer vision. On the other…
