Comparison of multiantenna techniques for high-speed packet communication

We evaluate the use of multiantenna techniques as a way of achieving higher data rates in WCDMA downlink packet transmission. The evaluation is limited to different open loop transmit diversity techniques using two, three and four transmit antennas without any knowledge of the wireless channel at the transmitter. The achievable data rates through multiantenna techniques are evaluated as link level throughputs with a UTRA FDD downlink model for HSDPA, using a conventional RAKE receiver with one and two receiving antennas. The model includes H-ARQ, while the dynamic link adaptation is not modelled explicitly. The results show that most of the performance gain is achieved with additional receiving antenna, while the gain from transmit diversity is rather limited and in some cases even negative.