Symmetrical triangular LFM for underwater acoustic communications

Synchronous detection acts as a key role in underwater acoustic communications. It is discovered that the Symmetrical Triangular Linear Frequency Modulation (STLFM) signal has double energy peaks in their fractional Fourier transform domain and these two peaks have symmetry in their amplitude if the STLFM signal is captured in the accurate time windows for the synchronization. In this paper, we propose a synchronization detection method based on the STLFM. To verify the effectiveness of the proposed method, we apply simulations based on the Bellhop program and sea trial data collected at Wuyuan Bay, Xiamen, China. The results show that the proposed STLFM method outperforms the LFM method