الفهرس 
OFDM AND COMMUNICATIONOnly 14 pages are availabe for public view
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Abstract
Orthogonal frequency division multiplexing (OFDM) is a multicarrier
transmission technique that has been recently recognized as an
excellent method for high speed bi-directional wireless
communications. It provides a good performance against the most
severe multi-path propagation conditions.
OFDM is sensitive to frequency synchronization errors, which
results in inter-carrier interference (lCI) and degrades system’s
performance.
This research work aims to investigate the combined effects of
carrier frequency offset (CFO) and fading conditions on system’s
performance. Nakagarni-m fading channel is used as a multi-path
propagation model for its ability to emulate fading channels whose
conditions are either less severe than, the same as, or more severe
than the Rayleigh fading model.
Closed form expressions of BERISER for OFDM system subjected
to CFO over Nakagami-m fading channel are developed. The impact
of CFO and severe fading conditions on performance is revealed.
CFO mitigation techniques are introduced to improve system’s
performance when subjected to CFO. Closed form BERISER
expressions are developed for polynomial cancelation coding (PCC)OFDM
and the ameliorated ICI cancelation OFDM when subjected to
CFO in Nakagami-m fading channel, and system improvement is
emphasized.
To combat the severe fading conditions, diversity reception is
applied. Space diversity reception is employed at the receiver and
maximum ratio combining (MRC) is used. The effect of correlation
among diversity branches is considered. Expressions of BERISER for
PCC-OFDM subjected to CFO with diversity reception over
Nakagami-m fading channel are developed, and in some cases
expressions result in a closed form