PSS Role and Synchronization:
- Primary Synchronization Signal (PSS) aids User Equipment (UE) in:
- Determining physical-layer identity NID(2).
- Achieving synchronization up to PSS periodicity.
- PSS created using BPSK-modulated m-sequence of length 127.
- LTE uses Zadoff-Chu sequence to generate PSS.
- NID(2) identification requires three distinct m-sequences due to PSS variations.
PSS Sequence Variation:
- PSS m-sequence of length 127 cyclically shifted by 0, 43, or 86 steps.
- Shifting depends on the Physical Cell Identity (PCI) used in the cell.
- Mapping on 127 subcarriers sequentially from subcarrier 56 to 182.
Transmission and Timing:
- PSS transmitted periodically at the same rate as Synchronization Signal Blocks (SSBs).
- Occurs at Specific Subcarrier Spacing (SSB periodicity).
Decoding and PCI Derivation:
- Decoding PSS reveals one of three identities for NID(2).
- To derive PCI, decoding Secondary Synchronization Signal (SSS) is necessary.
- PCI group number NID(1) obtained from decoded SSS.