说明：  该M文件为水声信道仿真，必出的图形，是一个基础图形，有注释，可以帮助初学者很好的理解整体思路，框架结构！
(The M file for underwater acoustic channel simulation, will be out of the graphics, is a basic graphics, there are comments that can help beginners a good understanding of the whole idea, framework!)