Layer 1

1/ CSI-RS (Channel State Information Reference Signal ) provides mobile devices the knowledge about different characteristics of the radio channel, on which signal is transmitted. The knowledge includes radio-channel path loss, time and frequency oscillations, interference, beam-forming, and so on. 5G NR CSI-RS

Codebook-based beamforming using CSI-RS

References are TS 38.221, 38.214, 38.331

2/ Measurements are carried out on the configured set of resources (single or multiple sets), which can be CSI-RS or SS blocks. Measurements are reported to the higher layers of the protocol stack (in the device) or base stations. Measurement reports can be periodic, semi-persistent, or aperiodic depending on the functionalities. 5G NR Radio Measurements

References are TS 38.331, 38.133, 38.221, 38.214

3/ OFDM is selected for 5G NR even though there are many promising modulation schemes, such as FBMC. 5G NR Waveform

4/ Synchronization Signal Block is important for mobile devices to perform beam tracking and management, which are fundamental for random access and mobility management. 5G NR SSB

5/ TCI-State and Quasi-Colocation concept in reference signal design: 5G NR TCI-State & QCL

Example of TCI-State configuration including CSI-RS and SSB parameters