What is synchronization in 5G?

PSS stands for Primary Synchronization Signal, SSS stands for Secondary Synchronization Signal and ESS stands for Extended Synchronization Signal. Radio frame in 5G-TF is 10ms in duration. It has total 100 slots or 50 subframes. Each subframe consists of two consecutive slots.

Transmission of a synchronizing signal along with the message signal is an approach in which the transmitter simultaneously sends a clock pilot at a multiple of symbol rate along with the information data, and the receiver then employs a very narrow BPF tuned to the clock frequency.

Primary synchronization signals consist of one of three 62-symbol Zadoff-chu sequences in a cell . The Primary Synchronization Signal (PSS) is broadcast twice during every radio frame and both transmissions are identical.

Uplink Synchronization : This is the process in which UE figure out the exact timing when it should send uplink data (i.e, PUSCH / PUCCH). Usually a network (gNB) is handling multiple UEs and the network has to ensure that the uplink signal from every UE should be aligned with a common receiver timer of the network.