水声传感网中基于定向收发的机会传输关键技术研究

水声传感网在海洋环境监测、海洋资源勘测和海事安全等方面具有广阔的应用前景。实际应用中只有当感知的数据被正确、及时地传输到收集节点获得的信息才有意义。相较于全向天线，基于定向收发的数据传输具有扩大通信距离、节省能量消耗、提高系统容量、降低通信干扰等优点。然而，水声传感网具有带宽小、误码率高、传输速度慢且延时长等特点。这些特点决定水声传感网中基于定向收发的机会传输关键技术的研究非常具有挑战性。鉴于此，本课题拟研究：（1）水声信道模型与定向收发数据传输的理论分析，为数据传输中继节点的选择奠定研究的理论基础；（2）研究水声传感网定向收发中邻居发现机制，不增加网络开销的情况下实时发现邻居节点，为数据传输增加编码机会；（3）研究定向收发中基于网络编码的机会传输机制，提高数据传输的成功率和网络吞吐量；（4）研究基于缓存管理和预解码的机会式数据传输优化方案，缓解网络拥塞提高数据传输效率。

Underwater acoustic sensor networks can be widely used in marine environment monitoring, marine resources investigating and maritime safety, etc. In practical applications, the acquired data is only useful when the sensed data can be transmitted to a sink node correctly and timely. Compared with the omnidirectional antenna, the data transmission based on directional transmission has the advantages of expanding communication distance, saving energy consumption, increasing system capacity and reducing communication interference. However, the characteristics of underwater acoustic sensor networks, e.g., limited bandwidth, high bit error, low speed and long delivery delay of data transmission, determine that the study on Opportunistic Data Delivery Based on Directional Transmission in Underwater Acoustic Sensor Networks is very challenging. In view of this, our research is to study: (1) the theoretical analysis of underwater acoustic channel model and directional data transmission, which establishes the theoretical basis for the selection of data transmission relay nodes; (2) the research on neighbor discovery mechanism in directional transmission of underwater acoustic sensor network, which can discover neighbor nodes in real time without increasing network overhead, and increase coding opportunities for data transmission; (3) the research on the opportunistic transmission mechanism based on network coding, which improves the success rate and network throughput of data transmission; (4) the research on the opportunistic data transmission optimization scheme based on cache management and pre-decoding, which is studied to alleviate network congestion and improve data transmission efficiency.