Improved MMSE estimation of correlated MIMO channels using a structured correlation estimator

Channel estimation is an important and challenging task in MIMO communications. The minimum mean-square-error (MMSE) channel estimator is able to exploit spatial correlation of the MIMO channel but requires prior estimation of the channel correlation matrix. In this paper, we investigate pilot-based MMSE channel estimation including channel correlation estimation. We propose an MMSE channel estimator using a structured correlation estimator and demonstrate its advantages over conventional MMSE estimators. Simulation results show that the proposed channel estimator outperforms conventional channel estimators in the case of strong spatial correlation and at low SNR.