Abstract
Exploiting channel reciprocity, time-divisionduplexing (TDD) operated massive multiple-input multipleoutput (MIMO) systems are able to acquire the channel state information with a reasonable overhead of channel estimation. However, in practical scenarios, the imperfections in channel reciprocity can significantly degrade the system performance. In this work, we propose a novel self calibration scheme for the maximum ratio transmission in TDD multi-user massive MIMO systems to compensate for the imperfect channel reciprocity, with considerations of imperfect channel estimation. The proposed scheme shows the greater robustness to a compound effect of channel reciprocity error and channel estimation error, compared with the traditional self calibration scheme that is widely used in massive MIMO systems.