Adaptive resource allocation for multiuser MIMO systems with transmit group MMSE

In this paper, we propose an integrated cross-layer optimization framework for resource allocation over a multi-user MIMO system using transmit group MMSE (Tx-GMMSE) at the base station. We adopt the full-rate full-diversity orthogonal STBC in the multi-user Tx-GMMSE physical layer allowing a flexible tradeoff of spatial multiplexing (for spectral efficiency) and full rate spatial diversity (for protection against packet outage) with various number of antenna groupings. The proposed cross-layer framework, which determines the user selection, rate selection, power selection as well as mode selection (spatial diversity or spatial multiplexing) for each user, can introduce robustness to the potential packet transmission errors even at moderate to large CSIT errors.