Downlink channels: PDSCH, PDCCH, PBCH

Three Physical Channels for the Downlink

The 5G NR downlink relies on three physical channels that each serve a distinct purpose. The Physical Downlink Shared Channel carries user data and system information blocks using modulation from QPSK up to 256-QAM and supporting up to eight MIMO layers for peak throughput. The Physical Downlink Control Channel delivers Downlink Control Information that tells UEs their scheduling assignments, power control commands, and slot format indicators. The Physical Broadcast Channel carries the Master Information Block as part of the SSB, using QPSK modulation with a fixed 80-millisecond periodicity.