Research of Mobile Underwater Acoustic Communication of M-Ary Combining FDM and Piecewise-LFM

Aiming at the countering doppler shift, a mobile underwater acoustic communication scheme of M-ary via FDM-PLFM is proposed. The cross-correlation between piecewise linear frequency modulation(PLFM) and traditional LFM signal is analyzed based on the cross-correlation function. Combining with frequency division multiplexing(FDM), the spectrum utilization of traditional underwater acoustic LFM communication scheme is improved. With the underwater acoustic LFM communication scheme, the new scheme does not require the doppler frequency shift compensation at the low doppler shift. The simulation results show that the present scheme has lower bit error rate than that for the traditional underwater acoustic M-ary LFM communication method under higher data rate conditions.