A cyclostationary blind Doppler estimation method for underwater acoustic communications using direct-sequence spread spectrum signals

A new method for blind (non-data aided) Doppler shift estimation caused by relative motion assumed to be the same on each hydrophone receiver in a SIMO context is presented. The proposed method is based on the second order stationary statistics and it was applied to estimate the average and instantaneous Doppler shift for a single carrier underwater acoustic communications. Past experimental data collected at sea are used to determine the average and instantaneous Doppler shift within a direct sequence spread spectrum signal containing 52 repeated m-sequences.