Synchronization & BCH for TDD Frame in LTE
- The Primary synchronization signal (PSS): is placed at the third symbol in subframes #1 and #6.
- The secondary synchronization signal (SSS): is placed at the last symbol in subframes #0 and #5.
- The S-RACH is transmitted on the UpPTS within the special frame.
- The Primary Broadcast Channel (P-BCH) and the Dynamic Broadcast Channel (DBCH):
are located as in LTE FDD.
Random access typically uses one of the normal subframes as in FDD, allowing for a relatively long random-access preamble providing coverage and capacity also in large cells. However, in scenarios where random-access coverage is not an issue, a short random access preamble in the UpPTS can be used instead.