Analysis of multiple antenna transmission for HSUPA

The 3-rd generation (3G) mobile wireless systems, such as WCDMA HSPA, continue to evolve along with the LTE and LTE Advanced standards, often described as 4G. Currently, multiple antenna transmission schemes such as closed-loop beamforming transmit diversity (CL-BFTD) and MIMO spatial multiplexing are considered by the 3GPP for HSPA uplink (HSUPA) to enhance its performance. In this paper, we review the technical approaches proposed in order to introduce multiple antenna transmission modes into HSUPA. The introduction is followed by the performance analysis of HSUPA, assuming that stations are equipped with two transmit antennas. The analysis is performed using system-level simulations and considers the macrocell deployment with the ITU Pedestrian A and Vehicular A channel models. The results of the analysis demonstrate that the application of CL-BFTD can improve the average system throughput by up to 20-25%, owing to a lower mobile station transmit power and reduced inter-cell interference. The current analysis of the MIMO transmission scheme with two parallel spatial channels reveals throughput gains approximately up to 10%, observed at low user station density in the system deployment.