Uplink performance of MMSE receivers in multi-cell MU-MIMO systems

This paper investigates the uplink performance of multiple-input multiple-output (MIMO) wireless systems employing linear minimum mean-squared error (MMSE) receivers. We focus on multi-cell MU-MIMO systems with pilot contamination over i.i.d Rayleigh fading channels. The MMSE estimator is adopted to get the CSI and we build the equivalent model of estimated channel for MU-MIMO system with pilot contamination. Then we give the relationship between the achievable sum rate with MMSE receivers and the ergodic mutual information achieved with optimal receivers. We further study the achievable ergodic sum rate of MMSE receiver and get the closed-form approximations of the lower bound with the relationship we achieved and existing results on the ergodic mutual information for optimal receivers.