Analysis of CDMA cellular radio systems employing adaptive antennas in multipath environments

This paper presents an analysis of code division multiple access (CDMA) cellular radio systems employing adaptive antennas in multipath environments. The results of simulations are described which illustrate the capacity improvements that can be achieved on the reverse link of a biphase asynchronous CDMA system using adaptive antenna arrays and switched beam systems at the base station. The effects of varying channel parameters are investigated for both correlated and uncorrelated multipath environments and the impact of imperfect power control is considered. Results are presented using both a geometrically based channel model and channels generated using ray tracing with a three dimensional building data base. These results indicate that the multipath structure significantly impacts the performance improvements that can be achieved by spatial filter systems