Symbol time offset synchronization based on training sequence

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation structure of digital multi- carriers that spreads the idea of a single subcarrier modulation within the same single channel by using multiple subcarriers. OFDM utilizes numerous carefully diverged orthogonal subcarriers, which are parallel transmitted. However, OFDM systems are very sensitive to synchronization errors that reduces orthogonality between sub-carriers, thereby degrading performance significantly. The synchronization problem can lead to two other problems: Carrier Frequency Offset (CFO), which leads to inter-carrier interference (ICI), and Symbol Time Offset (STO), which results in inter-symbol interference (ISI). In this research, a modified method is proposed for STO estimation using a training sequence (TS). The comparison shows that it was better than previously used methods, such as cyclic prefix (CP) by autocorrelation, CP by square difference, and ordinary TS.