Sequence hopping cell search scheme for OFDM cellular systems

Abstract

OFDM has been a widely accepted technology in high rate and multimedia data service systems, such as 3G Long Term Evolution (3G LTE) system in the 3rd Generation Partnership Project (3GPP). In this paper, we propose a new cell search scheme based on the frequency domain sequence hopping of synchronization channel symbols. The assigned hopping pattern provides frame boundary information as well as cell identification (cell ID) to a mobile station (MS). The proposed synchronization channel structure allows MS to acquire OFDM symbol/frame timing, cell ID and frequency offset estimates in the initial cell search stage. The cell search in MS is composed of 2 steps; OFDM symbol synchronization step, frequency offset correction and cell ID/frame boundary detection step. We evaluate the performance of proposed scheme under various channel environments. The impacts of multipath fading, vehicular speed and frequency offset on the performance are investigated. We also compare the performance of proposed scheme with 3G LTE cell search scheme.