A Combined Filter for Synchronous Detection in Underwater Acoustic Mobile Communication System

Abstract

A scale-stretching combined filter is proposed for underwater acoustic mobile communication receivers. The combined filter consists of the sum of signals with different time stretching and shifting. Based on the matched filtering theory, Doppler stretching scales, time shift, and the order of each component of the combined filter are derived. The method proposed in this paper improves the matching degree of the filter with wideband Doppler echo signals with different moving speeds. Simulation results show that the combined filter proposed in this paper can improve the detection probability and synchronization time estimation accuracy of wideband Doppler echo. In addition, the combined filter proposed in this paper has the same calculation amount as the matched filter. This feature makes this filter suitable for the synchronous detection of underwater acoustic mobile communication with real-time operation and low power consumption requirements.