伪装水声通信信号波形设计及其应用

提出伪装水声通信信号波形设计方法,将伪随机信号作为扩频数字水印与原始海豚whistles信号的复对数谱叠加,实现数字水印的嵌入;分别采用PEAQ算法与相关系数计算听觉与波形相似度,作为两种伪装效果的评价方法。提出匹配滤波与正交匹配追踪结合的自同步算法,使通信信号帧结构的设计保持原始whistles叫声的模式,提高了伪装效果。计算机仿真与海上试验验证了伪装通信方法的有效性:设计的通信信号与原始whistles信号相比,PEAQ打分结果均大于-0.5,相关系数值均大于0.98,达到了伪装的效果;试验中通信距离为5 km,单阵元接收的误码率小于10-3,32元阵接收的误码率为0且通过垂直阵虚拟时间反转均衡技术提高了通信系统的稳健性。 

Waveform design of camouflage underwater acoustic communication and its application

A camouflage underwater acoustic communication waveform is designed. The spread spectrum digital watermarking is added in the complex logarithmic spectrum of dolphin whistles to carry information. The PEAQ algorithm is used to compute the similarity in auditory aspects and the correlation coefficient is used to compute the similarity in waveform, which are as two metrics to evaluate the camouflage effect. In addition, a self-synchronization method that combines the correlation and OMP algorithm is proposed and hence the frame structure of transmitted signal could be designed as same as the origin whistles, which would improve the camouflage performance. The validity of the proposed method is verified by the computer simulation and sea experiment. The grade of PEAQ is higher than -0.5 and the correlation coefficient is higher than 0.98, which ensure good camouflage performance in waveform and auditory aspects.The communication distance in experiment is 5 km. The bit error rate with a single array element is less than 10-3 and the bit error rate with the 32 array elements is 0. Furthermore, the robustness of the communication system is improved by using the vertical time reversal equalization technique.