I understand the concept of DL MU MIMO in the sense that a number of users are served in the same time and frequency resources but they are separated in the spatial domain by precoding at the base station.
However what does it mean to have UL MU-MIMO? Since the users are distributed and precoding is at different UE I am not sure what is meant by UL MU MIMO. Does it mean we allow users to transmit in same subband? And does 5G NR support UL MU MIMO?