This thesis discusses and investigates the estimation of carrier offset frequency in

orthogonal frequency division multiplexing (OFDM) mobile systems. The investigation

starts by using Mobile WiMAX wireless communication specifications described

in IEEE 802.16e as the primary system setup. Under this setup orthogonal

frequency division multiple access (OFDMA) is used as a physical layer scheme; it

also involves the use of pilots in the OFDM symbol for channel estimation.

Although OFDM is resistant to multipath fading, it requires a high degree of synchronisation

to maintain sub-carrier orthogonality. Therefore the level of performance

of the system depends first on the accuracy in estimating the carrier frequency

offset and then the estimation of the channel. Maximum likelihood estimator

is used for estimating carrier frequency offset; its performance under different conditions

for example SNR, number of virtual carriers needed for estimation etc. are

simulated and compared with theoretical results. The optimality of IEEE 802.16e

specifications was also examined during the simulations and results analysis.