中文摘要：

为解决长距离高速水声数据传输问题,采用接力式水声数据转发传输是一个很好的解决方案。结合正交频分复用技术的特点设计实现了一个数字式的水下转发器系统。系统功耗低、结构简单,可以很好地解决水声通信中存在的多途干扰和窄带宽问题,实现高速、可靠的水下数据转发的目的。湖试中,在6000m的距离内,3kHz带宽下,转发速率为4.32kb/s,误码率低于10-3。湖试结果表明,基于正交频分复用的水下转发器可以达到较高的转发速率和较低的误码率。

英文摘要：

In order to solve the problems of long-distance high-speed underwater acoustic data transmission,a good method is to transmit the data by using repeaters.In the paper,an underwater repeater system based on orthogonal frequency division multiplexing is designed.The structure of the repeater is very simple and it has the characteristic of low power.The repeater can overcome the problems due to multi-path propagation and limited bandwidth in underwater acoustic communication to achieve reliable high-speed transmitting communication.According to lake testing,the bit rate reaches 4.32kb/s for the bandwidth of 3kHz within 6000m with the bit error rate（BER） lower than 10-3.The experi-ments show that the repeater can reach high data rate with low BER.