The physical cell ID is an identification of a cell at the physical layer. It has a similar role as a primary scrambling code of UMTS cell. Physical cell ID is mainly used by UE to decode physical layer data, which is transmitted by eNodeB. There can be situations where the resource element for the reference signal is same, even when the physical cell ID detection and System Information Detection to know precisely how this physical cell is used in the process of initial cell detection.
It is used in E-ULTRA systems to identify a cell. UE uses it to decode PSS and SSS. PCI range from 0-503. PCI is used to scramble the data to help the separate mobile information from the different transmitters. A physical cell ID will determine the primary and secondary sync signal sequence.
