Mobile transmit diversity and TDD downlink performance for smart antennas in fast fading scenarios

In wireless communications, smart antenna systems employing an antenna array at the base station along with advanced space-time signal processing capabilities can increase capacity, extend range and mitigate interference. We study the transmit diversity configuration at the mobile, which may possibly be used to alleviate the fast fading effect on the received signal vector at the smart antenna base station. For the downlink analysis, we evaluate the performance of spatial signature based beamforming algorithms in fast moving mobile scenarios in typical suburban and urban environments. Measurements were performed using the real-time smart antenna testbed developed at the University of Texas at Austin with a 7-element circular array at the base station.