循环移位扩频水声通信

针对常规直接序列扩频水声通信数据传输速率低及M元扩频水声通信接收机复杂度高的问题，基于扩频序列优良的相关特性，提出循环移位扩频水声通信方法.在发射端，根据输入信息对基本波形进行循环移位编码；在接收端，利用快速相关技术进行时延估计及译码.进行了中远程湖上实验研究，在15 km距离，2 kHz带宽内，总数据传输速率可达438 bit/s, 误码率为10^-2—10^-5.实验结果表明该方法具有带宽利用率高、复杂度低的特点，适用于中远程及多用户水声通信. 关键词： 水声通信 扩频 循环移位 时延估计

Cyclic shift keying spread spectrum underwater acoustic communication

Aimed at solving the problem of low data rate of direct sequence spread spectrum underwater acoustic communication and that of complexity of the receivers of M-ary spread spectrum underwater acoustic communication, cyclic shift keying spread spectrum underwater acoustic communication is proposed based on the good characteristic of spread sequences. At the transmitter, base waveform is cyclically shifted according to the input information. At the receiver, only one correlator is used to estimate the time delay and decode. Multi-code spread spectrum based on cyclic shift is presented. Lake experiments at both middle and long range were conducted for the proposed methods. Single and two code cyclic shift keying underwater acoustic communication were realized in the range of 15 km and the bandwidth of 2 kHz. The data rate was 438 bit/s with bit error ratio around 10~(-2)-10~(-5) . The result demonstrated the bandwidth efficiency and low complexity of the proposed methods and the applicability for long range underwater acoustic communication and multi-user underwater acoustic communication network.