【作者】 刘东；

【导师】 程刚；

【作者基本信息】 西北工业大学 ， 通信与信息系统， 2001， 硕士

【摘要】 随着遥控距离的加大（30～100Km），远程遥控水声信号的有效检测与信道特性之间的关系更加密切，检测也变得更加困难。本论文在分析远程水声信道时变特性的基础上，对水声信号的检测技术进行研究，并对其加以改进。 论文中主要进行了以下工作：1．分析水声衰落信道最突出的多径效应与时变特性，并初步研究了时间和频率分 集技术在水声遥控系统中的应用。2．从阐明信号经过DFT后在频域呈渐近正态分布入手，给出频域检测实现恒虚 警（CFAR）的理论依据，随后分析了恒虚警和双门限处理的检测性能，并提出 恒虚警的内插算法以克服频偏，提高检测概率；研究信号预处理技术及谱泄漏 产生的原因，提出了高速采样下的平滑技术以抑制高频噪声；初步研究了高阶 累积量法检测远程遥控信号的可行性，并将其检测性能与经典的周期图法进行 了比较，指出了其切片谱用于检测的缺陷；从理论上分析了水声信号的串、并 行发射对接收检测的影响。3．设计并制作了海试用计数、显示器，调试了其所用程序，保证检测结果能够由 LED显示出来。4．最后用仿真和实际采集数据，比较了高阶累积量法、周期图法的检测性能以及 串、并行发射下的检测效果，并验证了各种方法的有效性和可靠性。更多还原

【Abstract】 With the distance of remote control (30~100Km) increasing, the relation between the effectual detection of long-distance remote control and character of channel get more closely, and the signal detection becomes more difficult. In this dissertation, based on the analysis of the time-varying character of underwater acoustic channel, the technology of acoustic signal detection is investigated and improved.The follows are the main contributions in the dissertation.1.The most prominent aspects, the effect of Multipath and time-varying character of underwater acoustic fading channel are analyzed, and the preliminary study is made on the application of time-division and frequency-division collection in underwater acoustic remote control system.2.Based on the fact that the signal after DFT is asymptolic normal distributed in frequency-domain, and the foundation of Constant False-Alarm Ratio (CFAR) detection in frequency-domain is given, then the detection-performance of CFAR and bi-threshold are analyzed, presenting interpolation algorithm of CFAR to overcome the frequency-deviation as to improve detection possibility. The technology of pre-procession and cause of Spectrum Leakage are investigated, and then the method of moving-average under the high sampling is put forward to suppress the high-frequency noise. The feasibility of detecting remote control underwater acoustic signal by High-Order Cumulant is described, and its detection performance is compared with classical Periodogram’s, indicating limitation of its slice spectrum in application of detection. The effect of detection from serial and parallel transmitting acoustic signal is studied theoretically.3.Counter-display device is designed for sea test, and its program is debugged to ensure that LED can display the detection result.4.Simulated data and actual data are used to compare the performance of High-Order Cumulant with Periodogram’s, and the effect of serial transmitting with parallel’s, then effectiveness and reliability of various detection methods are testified.更多还原