Digital-to-analog converters (DACs) suffer from static and dynamic nonlinearity problems, which degrade their accuracy and performance. Mismatch errors in the analog components restrict the maximum achievable linearity.
This thesis presents various techniques for correcting these errors. It describes a correction process for the nonlinear behavior of DACs, on three different...
Designing spectral efficient, high-speed wireless links that offer high quality-
of-service and range capability has been a critical research and engineering challenge. In this thesis, we mainly address the complexity and performance issues of
channel estimation and data detection in multiple-input multiple-output (MIMO)
orthogonal frequency division multiplexing (OFDM) systems over...
This thesis presents a comparison of time-domain and frequency-domain algorithms for phase noise calculation in oscillators. Floquet theory provides the mathematical foundation for these calculations and the numerical methods employ perturbation projection vectors (PPVs). The PPVs are an estimate of an oscillator's sensitivity to noise.
The in-house circuit simulator SPICE3...
Ultra-wideband (UWB) communication has emerged as a very promising
technology for short-range wireless applications, including
high-speed multimedia transmissions and sensor networks. UWB
system designs involve many different aspects covering analog and
digital processing, channel estimation and modeling, and
modulation and demodulation. Although UWB still faces many
challenges, significant progress has...
The code reuse problem is a common software engineering problem in scientific computing. As a prevailing programming language in many scientific fields, Fortran does not provide support to address this problem. One particular reason is that Fortran lacks the support for generic programming. By applying program-generation techniques, we developed two...
In this thesis, maximum likelihood Doppler frequency estimation and phase noise suppression algorithms for Orthogonal Frequency Division Multiplexing (OFDM) systems are presented. A novel handover decision algorithm for wireless systems, called predictive base station switching (PBSS), is also introduced.
The maximum Doppler Frequency is the ratio of the speed of...
The main contributions of this thesis are the development and
application of four computationally efficient solutions for
least-squares-based (LS-based) minimum variance spectral estimation
(MVSE). They are: (1) fast computational solution for the 1-D
covariance LS-based MVSE, (2) fast computational solution for the
1-D modified covariance LS-based MVSE, (3) fast computational...
Although the digital revolution can realize many of past analog components in the digital forms, our world is surrounded with analog signals such as voice, temperature, etc. The bridge between these two worlds is one of key performance limitations among overall systems and it includes analog filters and data converters....
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...
fIndoor wireless local area networks (LAN's) and personal area networks (PAN’s) have evolved very rapidly in the recent past. The indoor wireless LAN's are mainly dominated by narrow-band technologies like the IEEE 802.11a,b which are short range and provide data rates of 1 Mbps to 54 Mbps. The Bluetooth has...