System-level performance gains of per-antenna-rate-control (S-PARC)

Currently, there is a high level of interest in MIMO antenna systems, such as per-antenna-rate-control (PARC), for enhancing the data rates for the HSDPA provision of the WCDMA standard. Recent studies have shown that PARC may be improved by adaptively selecting the number of transmitted substreams (the MIMO mode) and the antenna subset from which the substreams are transmitted to better match propagation conditions. In this paper we evaluate the system-level performance of S-PARC for HSDPA. We show that S-PARC achieves significant gains with respect to conventional (non-selective) PARC as well as receive diversity systems, even in the presence of spatially correlated fading. We demonstrate the importance of MIMO mode and antenna selection in correlated fading, and show that without it, a performance loss with respect to receive diversity can occur.