Abstract
Due to the explosive growth of wireless communication, the demands for
radio spectrum are rapidly increasing. It is very di±cult to accommodate
new wireless services under the current spectrum allocation scheme. On
the other hand, the allocated spectrum is not e±ciently utilized. Cognitive
Radio is proposed as a technology to solve the imbalance between spectrum
scarcity and spectrum under-utilization. Spectrum utilization can be im-
proved by making it possible for a user who does not have the license for
spectrum (secondary user) to access the spectrum which is not occupied by
the licensed user (primary user). This secondary user has the awareness of
the spectrum and adapts its transmission accordingly on a non-interference
basis. This spectrum access and awareness scheme is referred to as Cogni-
tive Radio. The idea is also known as Dynamic Spectrum Access (DSA) or
Open Spectrum Access (OSA). Cognitive Radio is seen as the ¯nal point
of software defined radio (SDR) platform evolution. A fully °exible and
e±cient software defined radio platform will be the enabling technology for
Cognitive Radio. Cognitive Radio imposes a number of requirements on
the processing platform such as °exibility, energy e±ciency and guaranteed
throughput/latency. The trend in the implementation of SDR is moving
towards Multiprocessor System-on-Chip (MPSoC) platforms.
The work of this PhD thesis is part of the Ad-hoc Adaptive Freeband
(AAF) project. The aim of the AAF project is to design a Cognitive Radio
based wireless ad-hoc network for emergency situations. Although the AAF
project addresses Cognitive Radio in a holistic fashion from physical layer to
networking issues, the work of this thesis mainly focuses on the design of the
adaptive physical layer (baseband processing). The physical layer consid-
ered in this thesis mainly consists of two parts: transmission and spectrum
sensing. A reconfigurable MPSoC platform is used to support the adap-
tive baseband processing of Cognitive Radio. A coarse-grain recon¯gurable
processor called the Montium, developed at the University of Twente, is
considered in this thesis as a key element of the proposed MPSoC platform.
Original language | English |
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Qualification | Doctor of Philosophy |
Awarding Institution |
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Supervisors/Advisors |
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Thesis sponsors | |
Award date | 26 Feb 2009 |
Place of Publication | Enschede |
Publisher | |
Print ISBNs | 978-90-365-2797-2 |
DOIs | |
Publication status | Published - 26 Feb 2009 |