Capacity improvement in CDMA and FDMA cellular mobile communication systems using adaptive antennas

A simulation study of the possibility of capacity improvement in multi-cell CDMA and FDMA cellular systems by using adaptive antennas at the base stations is presented. Phased arrays that form steerable, fixed-pattern, narrow beams towards the users, have been assumed to approximate the performance of the adaptive antennas in a multipath-free environment. Simulation results for BER improvements in CDMA systems by assuming only distance-dependent path loss are given. Further improvements by considering the voice activity factor are also presented. Then, simulation results for improvements in the outage probability in CDMA and FDMA systems and degradation caused by power control errors assuming distance-dependent path loss and log-normal shadowing are presented.