<p>This thesis discusses and investigates the estimation of carrier offset frequency in</p><p>orthogonal frequency division multiplexing (OFDM) mobile systems. The investigation</p><p>starts by using Mobile WiMAX wireless communication specifications described</p><p>in IEEE 802.16e as the primary system setup. Under this setup orthogonal</p><p>frequency division multiple access (OFDMA) is used as a physical layer scheme; it</p><p>also involves the use of pilots in the OFDM symbol for channel estimation.</p><p>Although OFDM is resistant to multipath fading, it requires a high degree of synchronisation</p><p>to maintain sub-carrier orthogonality. Therefore the level of performance</p><p>of the system depends first on the accuracy in estimating the carrier frequency</p><p>offset and then the estimation of the channel. Maximum likelihood estimator</p><p>is used for estimating carrier frequency offset; its performance under different conditions</p><p>for example SNR, number of virtual carriers needed for estimation etc. are</p><p>simulated and compared with theoretical results. The optimality of IEEE 802.16e</p><p>specifications was also examined during the simulations and results analysis.</p>

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.