中文摘要：

随着世界各国海洋开发步伐的加快，对水下传感器网络、水下监视系统、水声预警网络的需求愈来愈迫切，海洋水声通信网络的研究成了世界范围内的研究热点。水声通信网研究面临的主要困难是：海洋声信道的长延时、可用频带有限、严重的时变多途影响、功耗限制、网络安全性等。在分析水下无线通信的特殊环境后，针对水声通信网的多址接入技术进行了研究，选择适合的传输方式及相关协议构建基于0FDM与CDMA技术结合的水下通信网多载波CDMA系统；在matlab上实现多载波CDMA技术的水声通信网络节点对节点的数据传送，并得出了该系统的仿真结果：在帧长一定的情况下，随着信噪比的增大，系统的误码率会减小。在信噪比一定的情况下，子载波数目的进一步增大不会带来系统误码率的改善反而会使系统复杂性增加，降低系统的平均吞吐量，因此子载波数的选择应该在系统复杂性和效率之间折衷考虑。当水声信道上的信噪比一定时，可以通过控制数据帧的长度和子载波的个数来实现较高的网络平均吞吐量。

英文摘要：

Along with the exploiture of the ocean resources all over the world, it is necessary to cry for the research of the underwater sensor network, the underwater monitoring system and the underwater acoustic prewarning system. As a result, the study of the UWN becomes the hotspot in the world. The main difficulty of the UWN includes： the long time-delay of the ocean acoustic channel, the limited usable frequency band, heavy time-varying influence, power consumption limit, and network security. Aiming at the research of the multi-access technology for the UWN, this article composes the system of the UWN using the OFDM and CDMA technology with the suitable transmitting method and protocol. It completes the transmission of the data depending on the MC-CDMA technology using the matlab between the nodes in the UWN; it also shows the results of the simulation.