A method implemented by a wireless transmit/receive unit (WTRU) having multiple antennas includes determining, by the WTRU, information that is associated with a baseband channel and that indicates any of measurement information and channel information, and transmitting, by the WTRU, a signal for requesting baseband beam tracking, on condition that any of: (1) the WTRU determines, according to the indicated information, that: (i) system performance is degraded in a hybrid beamforming transmission, and (ii) re-estimation of the baseband channel is part of a current link adaptation procedure, and (2) detailed baseband channel information was not part of a multiple-in multiple-out (MIMO) setup procedure.