LTE: What is meant by scrambling in PHY layer?

Question

What are the different type of sequencing is used and if there is any difference what is use of individual sequence or function of each sequence?

Answer 1

In short Scrambling or scrambling code is used to distinguish different transmitters.

In LTE we use PCI which is a set of 504 IDs (derived from 3 primary synch sequences and 168 secondary sequences) used to scramble certain downlink transmissions so the UE can distinguish signals from different cells.