Parallel processors are classified into two classes: shared-memory multiprocessors and distributed- memory multiprocessors. In the shared-memory system, processors communicate through a common memory unit. However, in the distributed multiprocessor system, each processor has its own memory unit and the communications among the processors are performed through an interconnection network. Thus,...
As more features are being integrated into mobile platforms, the demand for
long battery life during standby mode has been increasing. Light load efficiency
becomes one of essential features in today's DC-DC converter. The most effective
method to improve light load efficiency is to operate the DC-DC converter under
pulse-frequency-modulation...
Ultra-wideband (UWB) radio has become an attractive alternative for wireless communications due to the robustness to multipath fading, low power transmission, mostly-digital implementation, and low cost. Furthermore, short-range, high data-rates applications are possible with UWB radios due to the wide spectral
allocations at 3.1 - 10.6 GHz.
This thesis presents...
The enormous success of wireless technology has recently led to an explosive demand for, and hence a shortage of, bandwidth resources. This expected shortage problem is reported to be primarily due to the inefficient, static nature of current spectrum allocation methods. As an initial step towards solving this shortage problem,...
Pulsed ultra-wideband (UWB) radio uses extremely short pulses to transmit information. Such pulses provide very fine timing information, which has led to technological advances in high-precision localization. This thesis investigates UWB localization strategies with a focus on receiver synchronization algorithms for time-difference-of-arrival localization to achieve centimeter accuracies in a 3-dimensional...
As more wind farms are connected to the grid, the variable nature of wind energy begins to influence grid stability. Energy storage could help smooth the variable nature of wind energy. Laboratory demonstration and exploration of the interaction between different energy storage devices and wind energy could help improve and...
Interconnection networks play important roles in designing high performance computers. Recently two new classes of interconnection networks based on the concept of Gaussian and Eisenstein-Jacobi integers were introduced. In this research, efficient routing and broadcasting algorithms for these networks are developed. Furthermore, constructing edge disjoint Hamiltonian cycles in Gaussian networks...
New video-conference devices based on omnidirectional multi-camera systems have been emerging in the last few years. These devices require innovative and automated video quality assessment in the earlier stages of their design in order to guarantee competitive product development and quality monitoring. Current quality assessment techniques are not adequate since...
The purpose of this thesis is to explore methods which can reduce the power dissipation of a mobile system while decoding MPEG video. MPEG decoding is a microprocessor intensive process that makes heavy use of both the L1 and L2 caches as well as main memory. The heavy load placed...
Transmission over wireless networks presents multiple technical challenges due to
noise, interference, fading, power constraints and bandwidth limitation. Different
solutions have been propposed to overcome these issues and some of them are
treated here. Cooperative diversity has been proposed as an implementation for
networks where terminals are restricted to using...