Frame synchronization for underwater acoustic communication based on maximum likelihood estimation

Traditional frame synchronization methods for underwater acoustic communication (UWAC) merely depend on correlation coefficient where synchronization signal detection is concerned, false triggering and missed synchronization can hardly be avoided in complex UWAC channels. In order to solve the problem, we first analyze the interference on frame synchronization from noise, Doppler and multipath; then a new frame synchronization scheme based on parameter estimation is proposed. By applying the parameter estimation technique, we detect the synchronization signal according to the estimated parameters, so as to reduce the false triggering rate and missed synchronization rate. 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. By applying this new method, the detection capacity of the receiver is improved, thus false triggering rate and missed synchronization rate can be reduced.