Periodic CSI

Not all of these indicator is measured for every CSI report. Depending on the situation and configuration from network, UE perform different combination of measurement. CQI (Channel Quality Indicator) PMI (Precoding Matrix Index ) RI (Rank Indicator)

CQI is Channel Quality Indicator. PMI stands for Pre-coding Matrix Indicator, and RI is Rank Indicator . These three values are computed on the fly in LTE systems and used to try to optimize resource allocation among the various user end devices (UEs) that are requesting service.

CQI stands for Channel Quality Indicator . As the name implies, it is an indicator carrying the information on how good/bad the communication channel quality is. This CQI is for HSDPA. (LTE also has CQI for its own purpose).

LTE PMI stands for Precoding Matrix Indicators . They are applicable to closed loop transmission modes: • Transmission Mode-4:Closed Loop Spatial Multiplexing.