UNIVERSITY OF CARTAGENA
In this paper, the authors propose a reduced-complexity two-stage time and frequency synchronization approach for OFDM systems, operating in multipath channels. The proposed approach exploits a single-symbol preamble with a repetitive structure, composed of two identical m-sequences. The first coarse stage, based on a sliding correlation, finds out the reduced uncertainty interval over which the second fine stage, based on a differential correlation, is performed. The combined use of the sliding correlation, characterized by its low complexity, and the differential correlation, which is much more complex, carried for a limited number of times results in an overall reduced complexity approach.