Joint sector identity and integer part of carrier frequency offset detection by phase-difference in long term evolution cell search process

In the Long Term Evolution (LTE) system, the initial cell search needs not only to achieve the timing synchronisations of symbols, slots and frames, but also to detect the sector identity (ID), the cell ID group and the carrier frequency offset (CFO), which includes an integer part (ICFO) and a fractional part. To accomplish this cell search process, two synchronisation signals, the primary synchronisation signal (PSS) and the secondary synchronisation signal, are periodically broadcasted from base stations in the LTE system. The PSS is mainly used for sector ID detection. In this study, an innovative algorithm for detecting the sector ID and ICFO together via the PSS-matching process is presented. In the proposed scheme, the phases of the differential correlation instead of the absolute values are adopted to determine the ICFO. Furthermore, a new set of PSS is proposed in order to improve the success probability of ICFO detection. Compared with conventional schemes, the proposed scheme can detect both the sector ID and ICFO with higher accuracy and much lower complexity.