Channel modeling and performance analysis of directive wideband Nakagami fading channels

The use of antenna arrays is one of the promising schemes for reducing the effect of multiple-access interference in 3G systems. So, it is expected that the use of 2-D RAKE receivers will improve capacity, coverage, and quality in W-CDMA systems. However, the performance of 2-D RAKE receivers is sensitive to the spatial correlations at the antenna array elements. The goal of this thesis is to introduce the appropriate spatial models of both typical urban and bad urban channels, calculate the resulting spatial correlations and then analyze the performance of 2-D RAKE receivers in bad urban microcellular channels. Geometrically based modeling is used to derive the angle of arrival statistics and then the temporal and spatial correlations at the BS are calculated using numerical integration schemes. The results show the differences in the spatial and temporal characteristics between TU and BU areas for both LOS and N-LOS cases. The performance of 2-D RAKE receivers in spatially correlated Nakagami faded bad urban channels is investigated by deriving the theoretical BER and running Monte Carlo simulations. The results show the significant gain in capacity of 2-D RAKE receivers as compared to 1-D RAKE receivers and the effect of the existence of the LOS component on the spatial diversity gain as compared to N-LOS case.