单矢量水听器OFDM水声通信技术实验

针对水声通信中信道特性复杂、低信噪比的情况,为提高水声通信质量,在理论研究OFDM与矢量信号处理技术基础上,提出并设计了一套基于DSP平台和三维同振型矢量水听器的矢量OFDM实时水声通信调制解调器.在哈尔滨市松花江水域中进行了水平方向上矢量水声通信实验.实验结果表明,系统达到实时通信的要求,在4.3 km的水平通信距离上、QPSK调制、1/2卷积码编码、通信频带4～8 kHz的条件下,通信速率达到1 873 bit/s,最终误码率低于10-4,矢量OFDM比标量OFDM水声通信误码率有明显改善.

Experimental study of OFDM underwater acoustic communication using a vector hydrophone

The purpose of this paper is to overcome the effect of a complex underwater acoustic channel and low signal-to-noise ratio and improve the quality of underwater acoustic communication(UAC).Based on the theoretical study of orthogonal frequency division multiplexing(OFDM) and vector signal processing,a vector OFDM real-time underwater acoustic communication modem based on a digital signal processing(DSP) platform and a resonant-sphere type three-dimensional vector hydrophone was presented and designed.The river trials on the Songhua river in Harbin revealed that the system achieved the real-time communication requirement.The data rate was 1 873 bit/s at a 4.3 km horizontal communication distance,under the conditions of quadri-phase shift keying(QPSK) modulation,1/2 convolutional coding,a bandwidth of 4~8 kHz,and the eventual bit error rate was less than 10-4.The bit error rate of vector OFDM was obviously better than that of a scalar OFDM communication system.