SS/PBCH Block (SSB) — the 5G beacon

Anatomy of the SSB

The Synchronization Signal and PBCH Block is the fundamental beacon that every 5G cell transmits for initial access. Each SSB occupies exactly 20 Resource Blocks in frequency and 4 OFDM symbols in time, containing the Primary Synchronization Signal in the first symbol, the Secondary Synchronization Signal in the third symbol, and the PBCH with its associated DMRS in the second and fourth symbols. The PSS provides symbol timing and identifies the physical cell identity group, while the SSS narrows the identity to one of 1008 possible cell IDs.