A 5G UE measures the signal-to-interference-and-noise ratio (SINR) at the cell-specific reference

signal (CSI-RS) to report channel quality information such as the CQI, RI, and PMI to a gNodeB. The

CSI-RS SINR is used to determine the modulation and coding scheme (MCS) index, which is then used

by the gNodeB to select the modulation and code rate for the transport block.

CQI (channel quality indicator), RI (rank indicator), and PMI (precoding matrix indicator) are all

parameters that are used to indicate the channel quality of the wireless link between a UE and a

gNodeB in a 5G network. These parameters are reported by the UE to the gNodeB and are used to

determine the optimal modulation and coding schemes for the downlink transmissions.

To report these parameters, the UE needs to measure the channel quality, the UE measures the SINR

(Signal-to-Interference-plus-Noise Ratio) of specific signals to report the channel quality information.