Coarse symbol synchronization algorithms for OFDM systems in multipath channels

A maximum-likelihood (ML) coarse symbol synchronization algorithm for OFDM systems in multipath channels is derived. Several simplifying assumptions reduce the rather impractical ML algorithm to more practical forms of minimum mean-squared-error and maximum correlation algorithms. All of the derived algorithms exploit the cyclic prefix and thus do not require a known training sequence. Estimating the position of the first arriving path, the algorithms allow maximum utilization of the guard interval thus minimizing intersymbol interference.