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

M元FDM-PLFM移动水声通信方法

¹ School of Marine, Northwestern Polytechnical University, Xi’an 710072, China
² Key Laboratory of Ocean Acoustics and Sensing Ministry of Industry and Information Technology, Xi’an 710072, China

Received: 6 July 2018

Abstract

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.

摘要

针对移动水声通信中的多普勒频移特性，提出M元FDM-PLFM移动水声通信方法。从理论上对分段式线性调频信号（piecewise-LFM）与传统LFM信号的互相关性进行了分析，并结合频分复用（FDM），提高了传统水声LFM通信方法的频谱利用率，并保留了在较低的多普勒频移条件下，水声LFM通信方法无需多普勒频移补偿的优势。仿真结果表明，该方法相较传统水声M元LFM通信方法，在较高的数据率条件下，有更低的误码率。