Mobile transmit diversity for base-station antenna arrays

For base-station antenna arrays operating at 1.8 GHz in urban vehicular environments, we experimentally investigate the spatial diversity provided by transmitting from the mobile terminal with two lambda / 2 dipole antennas that are separated by lambda / 2 and arranged in copolarized (CP) and cross-polarized (XP) configurations. The results show that, in both configurations, spatial signatures observed at the antenna array associated with each antenna element of the mobile change differently, especially when nonline-of-sight communication exists. The relative variation of spatial signatures is larger in an XP configuration compared to a CP configuration. (C) 2001 John Wiley & Sons, Inc.