| 1. | In this thesis , a multicarrier modulation high bit - rate underwater acoustic communication system was designed and constructed after analyzing those effects
本论文在分析这些因素的影响之后，设计并制作完成了一个多载波高速水声通信系统。 |
| 2. | Firstly , some useful experience about designing underwater acoustic communication systems and the properties of underwater acoustic channels are introduced
论文首先总结了前人关于海洋水声通信系统设计的经验，讨论了海洋水声信道的特点。 |
| 3. | The effect of multipath propagation commonly exists in the underwater acoustic channel and the fading which was caused by multipath propagation was the main influence factor of underwater acoustic communication system
水声信道中广泛存在着多径传播效应。由多径传播引起的信号衰落现象是影响水声通信系统性能的主要因素。 |
| 4. | As these underwater acoustic communication systems is intended for comparatively short distances , up to 10 - 30 km , problems arise when the submarine operate outside the normal areas , far from the save waters covered by national defence and communication systems
但是这些水声通信系统仅仅适用于短距离通信，最远只能到10 ~ 30千米，如果潜艇在常规水域之外工作，远离了国家防卫和通信系统所覆盖的区域，就会出现问题。 |
| 5. | In this thesis , the characteristics of underwater acoustic channel were analyzed , the mcm technique and the lfm signal which were used in the multicarrier modulation high bit - rate underwater acoustic communication system was discussed in detail , the important parts in system designing were examined
论文对水声信道特性进行了分析，就多载波高速水声通信系统中用到的多载波调制技术、线性调频信号进行了详细论述，论述了系统设计中的重要环节。 |
| 6. | Underwater acoustic communications ( uwa ) are made difficult by the combined effect of multipath propagation and high temporal and spatial variability of the channel conditions . the fading which was caused by multipath propagation was one of the main factors influencing the performance of underwater acoustic communication systems
水声信道中广泛存在的多径传播效应是水声通信所面临的主要障碍之一，由多径所产生的信号衰落效应是影响水声通信系统性能的主要因素之一。 |
