This thesis investigates the design and the performance of low-power microsensors that communicate directly to a satellite or a constellation of satellites. Information is spread using pseudo noise (PN) or Barker codes. The sensors use a single circular microstrip patch element with a wide beamwidth or a miniature phased array antenna that continuously scans to access the satellite(s). The array beam is controlled with a beam-forming network (BFN), which contains 3 or 4-bit phase shifters, which can be made in micro-electro-mechanical systems (MEMS) or in monolithic microwave integrated circuits (MMIC). The antennas are designed using array simulation program called 'ARRAY' and the results are used in another simulation program called Advanced Design System (ADS) to simulate the whole sensor package that uses one of the antennas. The simulation results show that a sensor as small as 2.35 cm in diameter is able to send information with data rate of 1 kbps at bit error rate less than 10?? to low-earth orbit (LEO) satellites with a transmitted power of 27.5 microwatts (-15.6 dBm). / Master of Science

In this work interception and spreading sequence estimation of Direct Sequence Spread Spectrum (DSSS) signals, in low signal to noise power ratios is discussed. For interception an approach based on autocorrelation fluctuations is employed and also symbol period is estimated from this interception process. Spreading sequence estimation is performed by using eigenanalysis of the correlation matrix and estimated symbol period. These approaches are applied on different kinds of DSSS signals including 3rd generation UMTS signal and LPI radar signals. In order to examine the channel effects such as / multipath, interference and colored noise, on the performance of applied techniques, detailed analysis results are obtained. The results are compared with the performances of alternative interception techniques.

Currently, wireless communication technologies are expected to be widely employed for in-vehicle communication where in-vehicle communication is built upon the interactions of different parts inside the vehicle. This communication is to enable a variety of applications for driver and passenger needs.  To have improved driving assistance, development of in-vehicle applications is very much needed. At present, intelligent systems inside the vehicle are mostly dominated by the wired technologies. The possibilities of wireless communication have inspired us and made an opportunity to analyse replacements for wired communication within a vehicle. In this connection, the scope of our thesis is to define the in-vehicle applications which are preferred by the wireless technologies, to define the applications using wired technologies which could be replaced by the wireless technologies and to identify those applications which are difficult to implement by the wireless technologies.   In-vehicle wired networks; and problems of these wired networks, along with several existing applications, have been discussed at the initial stage of this thesis for the purpose of having a clear understanding. After that, existing In-vehicle wireless applications and several challenging applications have also been studied. Studies have been done on the most important wireless technologies with their respective specifications. The requirement of establishing wireless communication has also been explained. Finally, an analysis has been done according to the requirements of the applications and verification of their possible reliance on the wireless technologies.   In a brief, comparable studies have been done among the wireless technologies to assess their current and future fitness for In-vehicle applications. The thesis concludes with some recommendations regarding when wireless technologies might be suitable for some in-vehicle applications to replace the wired technologies.

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Approved for public release, distribution is unlimited / Synchronization of orthogonal frequency-division multiplexed (OFDM) signals is significantly more difficult than synchronization of a single-carrier system. The recently approved IEEE Standard 802.11g specifies a packet-based OFDM system that provides a basis for the discussion of OFDM synchronization in a packet-based environment. Algorithms that synchronize the receiver carrier demodulation frequency and phase, the data frame, the OFDM symbol timing, and the data symbol timing are discussed and analyzed in an AWGN channel. System View simulation is used to implement the frame and carrier frequency synchronization algorithms, where the performance of these algorithms is analyzed and they are shown to be useful detection algorithms for Standard 802.11g signal reception. / Lieutenant Commander, United States Navy

<p>This thesis work started with an extensive literature study in several areas, ZigBee, instruments and measuring methods. The knowledge was implemented in use with the ZigBee modules from the two manufacturers ITN and Chipcon along with ZigBee Software Stack. Measuring methods were developed and software in ZigBee software Stack was developed to use in the ZigBee modules for the measurements. Developing measurement methods and performing measurements was an iterative process for the different measurements. The aim was to characterize the ZigBee modules in the most important areas during the extent of this master thesis work.</p>

This thesis work started with an extensive literature study in several areas, ZigBee, instruments and measuring methods. The knowledge was implemented in use with the ZigBee modules from the two manufacturers ITN and Chipcon along with ZigBee Software Stack. Measuring methods were developed and software in ZigBee software Stack was developed to use in the ZigBee modules for the measurements. Developing measurement methods and performing measurements was an iterative process for the different measurements. The aim was to characterize the ZigBee modules in the most important areas during the extent of this master thesis work.

Approved for public release, distribution is unlimited / Direct-Sequence Spread Spectrum (DSSS) modulation is being advanced as the physical-layer basis for Seaweb undersea acoustic networking. DSSS meets the need for channel tolerance, transmission security, and multi-user access. This thesis investigates the performance of subspace-decomposition blind-equalization algorithms as alternatives to RAKE processing of DSSS signals. This approach is tailored for superior performance in time-dispersive and frequency-dispersive channels characteristic of ocean acoustic propagation. Transmitter and receiver structures are implemented in Matlab and evaluated with a statistics-based model of a doubly spread channel with additive noise. Receiver performance is examined using Monte Carlo simulation. Biterror rates versus signal-to-noise ratio are presented for various multipath assumptions, noise assumptions, and receiver synchronization assumptions. / Lieutenant, Hellenic Navy

Title: Influence of pilates method on the stabilizing system of the spine Objectives: The main aim of this diploma thesis was to confirm or refute the claim that a six-week motion program using the pilates method positively affects the stabilizing system of the spine. The partial aims of the work were to determine whether the a six-week motion program using the pilates method had a positive effect on the posture, spinal mobility, shortened muscles and standing stabilization. Methods: As a method of research, a case study was selected involving two adult persons (males). The motion program was preceded by an initial examination. In particular, static examination of the standing position, dynamic examination of standing position (flexion, extension, lateroflexion), examination of stabilization (Véle test, stand on 1 LL, standing on 2 scales), examinations of spinal distances (Schober's, Otto's and Čepojev's distance, lateroflexion), goniometry of rotation of thoracic and lumbar spine, examination of shortened muscles according to Janda (hip flexors, knee flexors, pectoralis major and minor, m.trapezius and paravertebral muscles) examination of postural stabilization by Kolář (extension test, trunk flexion test, diaphragm test, hip flexion test). Participants then underwent a six-week motion program...