基于水声信道辨识的前导检测和信道跟踪机理研究

After going through large numbers of lake and sea data for underwater acoustic communications, we realize: to guarantee the validity of communication, first, the preamble must be successfully detected; then, the impulse response of the communication channels should be acquired accurately. An intelligent communication system needs to be treated differently according to the underwater acoustic channels, so as to ensure the robustness of the system...Take this as our goal, in this research, we conduct a thorough investigation of preamble detection in adverse underwater acoustic channels in the presence of various external interference. Bayesian channel tracking is also studied which captures the acoustic signal propagation physics. We also carry out the classification and recognition of underwater acoustic channels and underwater acoustic interference. Our analysis is based on our OFDM system...Through all the theoretical and experimental analysis, we clarify the mechanism among detection, tracking and decoding for underwater acoustic communications, and enhance the robustness of system and security of communication. The classification and recognition of underwater acoustic channels will motivate the future adaptive multi-mode underwater acoustic communications...

通过整理大量的海试水声通信数据我们发现：要保证在各类水声环境下的有效通信，首先确保前导信号被成功检测到，之后要尽可能帮助水声通信系统准确的掌握信道状态。更智能的通信系统则需要根据水声信道情况灵活调整通信体制和系统参数，才能保证系统的稳健性。鉴于此，本研究拟基于实验室现有的水声OFDM通信系统，利用对水声信道自有特征的辨识，提出适用于不同水声信道的抗干扰前导检测方法、基于声传播模型的贝叶斯多径信道跟踪方法，同时实现水声信道分类识别以及水声干扰的识别。并对不同水声信道环境下的通信可靠性进行分析。通过增强通信系统前导检测能力，以及对水声信道的认知能力，提高现有通信系统的稳健性与传输的可靠性。此外，对水声信道的分类识别将加快未来多模式自适应水声通信体制的进展。

本研究前期调研阶段总结出:要保证在各类水声环境下的有效通信，首先确保前导信号被成功检测到，之后要尽可能帮助水声通信系统准确的掌握信道状态。更智能的通信系统则需要根据水声信道情况灵活调整通信体制和系统参数，才能保证系统的稳健性。.鉴于此，本研究基于实验室现有的水声OFDM通信系统，利用对水声信道自有特征的辨识，提出了基于SLIM的抗干扰前导检测方法，以及基于前导信号的新的水声通信同步方法。此外针对于水声信道的非平稳特性，我们研究了基于路径相关性的水声通信信道跟踪研究和基于随机有限集的多路径信道跟踪。并应用于水声通信系统，对不同水声信道环境下的通信可靠性进行分析。.通过上述增强通信系统前导检测能力，以及对水声信道的认知能力，进而提高现有通信系统的稳健性与传输的可靠性。