Performance of Practical Multiuser MIMO Networks with Limited CSI Feedback

Efficient channel state information (CSI) feedback is crucial in practical multiuser multiple-input multiple-output (MU-MIMO) networks for effective interference mitigation. In this study, a CSI feedback scheme using random scalar quantization (RSQ) for MU-MIMO networks is proposed. The analytical expression for the quantization noise variance of the RSQ CSI feedback scheme is presented. Next, the lower bound of the relative transmission rate for the MU-MIMO network with RSQ CSI feedback is derived. Using a unified transmission framework, trade-off between the relative transmission rate and energy efficiency of the MU-MIMO network with RSQ CSI feedback is depicted. In a fully loaded network, it is shown that MU-MIMO with RSQ CSI feedback outperforms that of random vector quantization and sparse compression CSI feedback schemes by as much as 38% and 19%, respectively.