Future-generation wireless and mobile networks are expected to
support a panoply of multimedia services, ranging from voice to
video data. There is also a de facto "anytime anywhere"
mentality that reliable communications should be ubiquitously
guaranteed, irrespective of temporal or geographical
constraints. However, the implicit catch is that these
specifications should be achieved with only minimal
infrastructure expansion or cost increases. In this thesis,
various signal processing methodologies conducive to attaining
these goals are presented.
First, a system model that takes into account the time-varying
nature of the mobile environment is developed. To this end, a
mathematically tractable basis-expansion model (BEM) of the
communication channel, augmented with multiple-state
characterization, is proposed. In the context of the developed
system model, strategies for enhancing the quality of service
(QoS), while maintaining resource efficiency, are then studied.
Specifically, dynamic channel tracking, adaptive modulation and
coding, interpolation and random sampling, and spatiotemporal
processing are examined as enabling solutions. Next, the
question of how to appropriately aggregate these disparate
methods is recast as a nonlinear constrained optimization
problem. This enables the construction of a flexible framework
that can accommodate a wide range of applications, to deliver
practical network designs. In particular, the developed methods
are well-suited for multi-user communication systems,
implemented using spread-spectrum and multi-carrier solutions,
such as code division multiple access (CDMA) and orthogonal
frequency division multiplexing (OFDM).
Moreover, privacy and security requirements are increasingly
becoming essential aspects of the QoS paradigm in
communications. Combined with the advent of novel security
technologies, such as biometrics, the conventional
communication infrastructure is expected to undergo fundamental
modifications to support these new system components and
modalities. Therefore, within the same framework for maximizing
resource efficiency, several unique signal processing
applications in network security using biometrics are also
investigated in this thesis. It is shown that a resource
allocation approach is equally appropriate, and productive, in
delivering efficient and practical key distribution and
biometric encryption solutions for secure communications.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/17455 |
| Date | 15 July 2009 |
| Creators | Bui, Francis Minhthang |
| Contributors | Hatzinakos, Dimitrios |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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