Synchronization and Doppler scale estimation with dual PN padding TDS-OFDM for underwater acoustic communication

We propose a joint synchronization and Doppler scale estimation method with time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) for underwater acoustic communication. Dual frequency-domain pseudo-random noise (PN) sequences serve as training sequences for synchronization and channel estimation. Frame synchronization, carrier frequency offset (CFO) estimation and Doppler scale estimation are obtained simultaneously by two-dimensional auto-correlations of received signals. Theoretical analyses and computer simulations show that the proposed method is suitable for synchronization and Doppler scale estimation, even in the presence of long delay spread and significant Doppler effects.