الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
With the increasing broadband communication demands, the shortage of
spectrum is becoming a Great challenge. The Cognitive Radio (CR)
technology is proposed in order to promote the efficient use of the spectrum and
revive the lack of spectral resource. CRs use signal detection to sense spectral
occupancy. Without guaranteed signal detection, a CR cannot reliably perform
its role so Spectrum Sensing (SS) technique is the key of the Cognitive Radio
Network (CRN). Wireless signal detection can be performed using many
different techniques. One of them is Cyclostationary Feature Detectors (CFD).
Among these techniques, CFD can be viewed as a compromise technique, as it
has better detection performance at a low Signal-to-Noise Ratio (SNR) than ED
and less strict resources than Matched Filter Detection (MFD).
The cyclostationarity of Orthogonal Frequency-Division Multiplexed
(OFDM) signals offer some statistics that will determine the status of the
spectrum and differentiate about different signals; therefore, it gives reliability at
low S/N ratio. It is demonstrated that by avoiding resource consuming operations
such as Fast Fourier Transform (FFT) and matrix inversion, and by using
algorithms, such as CORDIC, that are well suited for hardware implementations,
it is possible to achieve a reduction of an order of magnitude in power dissipation
without compromising the performance and using Altera high-speed kit like
Arria V.
Abstract
III
The detection performance of the algorithms is evaluated in an additive
white Gaussian noise (AWGN) channel with an OFDM signal that has a similar
symbol structure to be used in the Digital Video Broadcasting Terrestrial (DVBT)
system. The detection algorithm will be implemented in FPGA digital logic
in order to demonstrate the methods ability to be employed in a commercial radio
chipset with minimum resource requirements.