Free-space experiments with MIMO UMTS high speed downlink packet access

The HSDPA (high speed downlink packet access) mode of UMTS provides high data rates to the user. In this contribution comparisons, based on free space measurements, between SISO (single input single output) HSDPA and MIMO (multiple input multiple output) HSDPA are shown. For two transmit antennas the STTD (space-time transmit diversity) mode of UMTS is used to increase the diversity order of the transmission. Measurements with four transmit antennas are carried out incorporating the DSTTD-SGRC (double space-time transmit diversity with sub-group rate control) proposal of MERL (Mitsubishi Electric Research Laboratories). Besides the comparison of the various HSDPA schemes, this paper focuses on the setup of the radio frequency frontend and its requirements for MIMO transmissions.