Cell Search for 3GPP LTE System Using Interference Cancellation

Long Term Evolution (LTE) system of the third generation partnership project (3GPP) has primary and secondary synchronization channels to help the terminal search cell. Primary synchronization channel (P-SCH) is used to acquire slot timing and cell group. Secondary synchronization channel (S-SCH) is used to obtain frame boundary and cell identity (Cell ID). Not only in time division duplex (TDD) network but also in frequency division duplex (FDD) network, cells are deployed with time aligned to provide Multimedia Broadcast and Multicast Service (MBMS) efficiently as well as to improve the successful handover rate. Cell search plays important role to find a cell and handover to neighbor cell smoothly. Cell search has usually two modes, which are initial cell search and tracking mode. The former usually has large computational complexity while the latter can be designed to have rather small computational complexity to provide increased transmission and reception capacity. This paper proposes interference cancelling (IC) technique in both initial cell search and tracking mode. Cancelling the pre-detected SCH from the received signal results in the improved search performance for the next target cell. Simulation results show that the proposed scheme can achieve the improved cell search performance over non-IC scheme in synchronous network environment.