Cell Identification Scheme for OFDM Cellular Systems Based on a New Preamble Structure

A cell identification scheme for OFDM cellular systems is proposed, which uses only one OFDM symbol with several identical slots as preamble. After performing OFDM timing/frequency synchronization, the UE identifies its cell ID by a novel scheme composed of cell group identification and cell index identification. Each cell group is distinguished from others by a unique subcarrier mask, which is an m-sequence. It activates or deactivates a subset of the subcarriers. Furthermore, cells with different indices in the same cell group load different differentially coded sequences on the adjacent active subcarriers. The UE recognizes the cell-group-specific mask via power detection of the received frequency domain signal. Then it identifies the cell index from differential demodulation and detection of the cell-index-specific sequence. Simulation results show that the proposed scheme is able to support a very large number of cell IDs and it works well even in bad multi-cell environment