不同海底地形下海洋信道对水声通信的影响

The impact of the channels to underwater acoustic communications with different seabed topographies

海底反射是形成多径干扰的主要因素之一,针对由海底引起的水声通信的多径干扰问题,利用信号多径比(SMR)来描述浅海平坦海底、倾斜海底以及深海平坦海底3种不同的海底地形对水声通信的影响。利用真实测量的信道冲击响应数据分析阿拉伯海西北部典型海底地形下的SMR。最后对直接序列扩频(DSSS)系统在3种地形信道下的表现进行仿真研究。对实验信号的分析表明,平坦浅海海底信道具有最严重的多径衰落,是3种信道中最恶劣的,深海信道次之,倾斜海底信道条件较好,直扩信号在倾斜海底信道条件下误码率最低。

Seabed reflection is one of the main factors of the multipath interference in underwater acoustic communi-cation. With this problem, signal to multipath ratio （ SMR） is defined to describe the seabed reflection interference. Three kinds of seabed are mentioned in this paper：flat seabed in shallow water, sloping seabed, and flat seabed in deep sea. Signal to Multipath Ratio of the typical seabed is analyzed with the real sea acoustic channel impulse re-sponse, which are acquired from the northwest of Arabia Sea. Simulation study is in progress on the performance of direct sequence spread spectrum （ DSSS） system in the three kinds of seabed channel. The result of experiment data analysis shows that the acoustic channel of flat seabed in shallow water has the most serious multipath fading, chan-nel response in deep sea is better than the one in the shallow water and sloping seabed channel response is the best in the three seabed types. The DSSS system has the lowest bit error rate in sloping seabed channel.