针对宽范围信号的光纤水听器的研究

发布时间：2018-05-08 21:49

本文选题：干涉型光纤水听器 + PGC解调　；参考：《哈尔滨工程大学》2014年硕士论文

【摘要】：光纤水听器是一种探测海洋声场信号的传感系统。鉴于其具有巨大的军用和民用价值而被研究和开发。光纤水听器具有频带宽、灵敏度高、抗电磁干扰、水下无繁琐的设备以及易形成阵列等优点。综合以上的特点,光纤水听器的研究和开发受到各国的高度重视。根据水声信号的宽带性和水下声场的复杂性,光纤水听器单元不能获取探测目标的全部信息。所以对基于宽范围信号的光纤水听器的研究具有十分重要的意义。第一,详细介绍了干涉型光纤水听器的结构和工作原理,对光的偏振态进行描述,及抗偏振衰落和随机相位衰落现象进行分析。第二,对基于内调制的相位生成载波(PGC)检测方案进行改进。对影响其动态范围上限的因素,载波的大小进行仿真;分别对影响解调效果的因素,包括信号的幅度、频率、带宽及载波信号频率的大小进行仿真,并对仿真结果进行分析。得出载波频率越大,系统的动态范围上限越大,同时,随着载波频率的减小,信号频率的增大、以及信号幅度的增大,系统解调效果恶化。第三,对其宽频带信号采用分段探测的方法,用三个探头来分别探测固定频段的信号,再分别解调出探头探测出的信号,相加得到完整的信号。通过对噪声信号和确定性宽带信号的解调,通过计算机matlab软件仿真,分析出其输入输出信号的相关系数及幅度误差,得出分段检测的好处。分段检测使待测信号的频带变宽,动态范围变大,相关系数变大,对宽带信号的解调提供一种新的思想。最后,介绍了光纤水听器的多路复用技术并对其进行分析,说明了本文所采用的时分复用技术给出了整体框图。为今后光纤水听器阵列的研究与开发提供了参考。
[Abstract]:Fiber optic hydrophone is a sensing system for detecting ocean acoustic field signals. Because of its great military and civilian value, it has been researched and developed. Fiber optic hydrophone has the advantages of high frequency bandwidth, high sensitivity, anti-electromagnetic interference, no tedious underwater equipment and easy to form arrays. Based on the above characteristics, the research and development of fiber-optic hydrophone have been paid more and more attention. According to the wideband of underwater acoustic signal and the complexity of underwater acoustic field, the fiber optic hydrophone unit can not obtain all the information of target detection. Therefore, the study of fiber optic hydrophone based on wide range signal is of great significance. Firstly, the structure and working principle of interferometric fiber-optic hydrophone are introduced in detail, the polarization state of light is described, and the phenomena of anti-polarization fading and random phase fading are analyzed. Secondly, the phase generation carrier generation (PGC) detection scheme based on internal modulation is improved. The factors affecting the upper bound of the dynamic range are simulated, and the factors affecting the demodulation effect, including the amplitude, frequency, bandwidth and frequency of the carrier signal, are simulated, and the simulation results are analyzed. It is concluded that the larger the carrier frequency, the larger the upper limit of the dynamic range of the system. At the same time, with the decrease of the carrier frequency, the increase of the signal frequency and the increase of the signal amplitude, the demodulation effect of the system deteriorates. Thirdly, the method of segmental detection is used to detect the wide-band signal. Three probes are used to detect the signals of fixed frequency band respectively, and the signals detected by the probe are demodulated respectively, and the complete signal can be obtained by adding them together. By demodulation of noise signal and deterministic wideband signal, the correlation coefficient and amplitude error of the input and output signal are analyzed by computer matlab software simulation, and the advantage of subsection detection is obtained. Piecewise detection widens the frequency band, widens the dynamic range, and increases the correlation coefficient, which provides a new idea for the demodulation of wideband signals. Finally, the multiplexing technology of fiber optic hydrophone is introduced and analyzed, and the overall block diagram of the time division multiplexing technique used in this paper is explained. It provides a reference for the research and development of fiber optic hydrophone array in the future.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB565.1

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