基于光纤水听器的水声通信关键技术研究

Research on key technologies of underwater acoustic communication based on optical fiber hydrophone

闫良俊

11930428

硕士

材料工程

宋章启

2021-05-19

2021-06-07

南方科技大学

深圳

水声通信是目前唯一一种能够在水下中远距离通信的方式。本文开展基于光纤水听器的正交频分复用（OFDM）水声通信技术研究，利用Sagnac光纤水听器的低成本、高可靠性和非通信带宽内的水声噪声抑制特性来改善基于传统压电水听器水声通信的不足，同时OFDM具有较高的宽带利用率以及具有良好的抗频率选择性衰落的性能。本文的主要工作内容可以分为以下几个部分： 开展了基于差分相移键控调制的OFDM水声通信技术研究，采用基于Chirp导频的信号同步的算法，从而确定信号的起始位置，创新性地提出一种基于随机抖动循环前缀的峰均功率比抑制算法。模拟研究表明该算法极大地降低了运算的复杂度，接收端不需要额外信息就可以实现解调，并通过实验验证了该技术的可行性。 开展了Sagnac光纤水听器的研制与实验测试，通过利用标准压电水听器进行标定，测试光纤水听器的声压相位灵敏度级，以及光纤水听器的采样率和本征频率，并且对光纤水听器与标准压电水听器同时进行水声通信实验，对比分析光纤水听器与压电水听器的信噪比及误码率。通过实验测试发现光纤水听器具有很好的低频抑制效果，其频率响应特性与声波在水下传输损耗特性相适应，更加适合用于水下通信。 开展了基于光纤水听器系统的水声通信系统湖上试验，利用行波法测量了光纤水听器的频率响应特性，并获得了光纤水听器的水声通信试验初步结果。

Acoustic communication is the only way to communicate over long distances under water. This paper adopts orthogonal frequency division multiplexing (OFDM) communication technology based on optical fiber hydrophone. The Sagnac optical fiber hydrophone has low cost, high reliability and the characteristics of underwater acoustic noise suppression in non-communication bandwidth to overcome the shortcoming of underwater acoustic communication based on traditional piezoelectric hydrophone. At the same time, OFDM has high bandwidth utilization and good anti-frequency selective fading performance. The main work content of this paper can be divided into the following parts: This paper studies the underwater acoustic communication technology of OFDM based on differential phase-shift keying modulation. This paper uses chirp signal as synchronization signal, and a peak to average power ratio (PAPR) suppression algorithm based on the cyclic prefix of random dithering is proposed innovatively. Simulation results show that the algorithm can greatly reduce the complexity of operation and the receiver can realize demodulation without additional information, and the experiments verify the feasibility of the technique. The development and experimental test of Sagnac fiber optic hydrophone were carried out. By using standard piezoelectric hydrophone for calibration, the phase sensitivity level of sound pressure, sampling rate and intrinsic frequency of the fiber optic hydrophone were tested, and the underwater acoustic communication experiment was carried out simultaneously on the fiber optic hydrophone and standard piezoelectric hydrophone. The SNR and BER of optical fiber hydrophone and piezoelectric hydrophone are compared and analyzed. The experimental results show that the optical fiber hydrophone has an excellent low frequency suppression effect, and its frequency response characteristics adapt to the characteristics of acoustic transmission loss under water, so it is more suitable for underwater communication. This paper carried out experiments about the underwater acoustic communication system based on the fiber optic hydrophone system in the lake. The frequency response characteristics of the fiber optic hydrophone were measured by the traveling wave method, and the preliminary results of the underwater acoustic communication test of the fiber optic hydrophone were obtained.

水声通信 正交频分复用 Sagnac光纤水听器 峰均比抑制

Underwater acoustic communication OFDM Sagnac fiber optic hydrophone Peak-to-average ratio

中文

独立培养

南方科技大学

闫良俊. 基于光纤水听器的水声通信关键技术研究[D]. 深圳. 南方科技大学,2021.