Capturing mobile underwater pseudonoise synchronous signal using multi‐strategy in waveform domain

Abstract

Capturing pseudonoise (PN) synchronous signals is an important issue in spreading spectrum underwater acoustic communication. In this letter, local waveform domain information is combined with multi‐strategy to enhance the Doppler tolerance of conventional Partial Matched Filtering‐Fast Fourier Transform (PMF‐FFT) acquisition algorithm under low signal‐to‐noise ratio (SNR). First, an optimized algorithm based on partial reconstruction in waveform domain was proposed, such that the Doppler tolerance increased by 38.9% when the SNR = −15 dB. Second, a local baseband multi‐waveform compression algorithm was proposed to further enhance the Doppler parallel search ability multiply. At last, frequency offset estimation was completed after searching the multi‐waveform serially. The effectiveness of the proposed algorithm was verified through the experiment at sea.