Title: Frame synchronization for underwater acoustic communication based on maximum likelihood estimation

Author: GUO Zheng; YAN Shefeng; XU Lijun; QIN Ye

Affiliation: 1. Institute of Acoustics, Chinese Academy of Sciences; 2. University of Chinese Academy of Sciences

Abstract: Traditional frame synchronization methods for underwater acoustic communication (UWAC) merely depend on correlation coefficient when synchronization signal detection is concerned and, hence, false triggering and missed synchronization can hardly be avoided in complex UWAC channels. In order to solve this problem, firstly, we analyze the effects of interference from noise, multipath and Doppler on frame synchronization; then we propose a new frame synchronization scheme based on parameter estimation. By exploiting the parameter estimation technique, we detect the synchronization signal according to the estimated parameters, thus the false triggering rate and missed synchronization rate can be reduced. We also simplify the maximum likelihood estimation to reduce computational cost. Simulation results indicate that this new scheme outperforms the traditional method in terms of delay resolution and correlation coefficient. Both static and mobile communication experimental results show that the correlation coefficient of the new scheme is higher than that of the traditional one. Moreover, the detection ability of the receiver is improved, which helps to avoid false triggering and missed synchronization.