Time and Frequency Synchronization in the Presence of Large Frequency Offset

Conventional cross-correlation based time synchronization methods have sharp correlation peaks, which make it easy to get the exact time delay point. But their performances are vulnerable to the frequency offset between the transmitter and the receiver. By taking the constant amplitude zero auto corelation (CAZAC) sequences as the training sequences, a cross-correlation based time and frequency synchronization method is proposed, which can work with a large frequency offset. Compared with the conventional methods, no extra computational complexity is introduced in the process of searching the correlation peak. The estimation of the large frequency offset is also performed by sliding cross-correlation and is independent of the frequency offset. Simulations show the method is applicable to both AWGN channel and fading channel.