Comparative Study on Noise Reduction Effect of Fiber Optic Hydrophone Based on LMS and NLMS Algorithm

• Published in: Sensors (Basel, Switzerland) Vol. 20; no. 1; p. 301
• Main Authors: Yu, Zhihua, Cai, Yunfei, Mo, Daili
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.01.2020; MDPI
• Subjects: 3 × 3 coupler; adaptive filtering; Algorithms; Expected values; fiber optic hydrophone; Fiber optics; least mean square (lms); Noise; normalized least mean square (nlms); Signal processing; 3 × 3 coupler; fiber optic hydrophone; adaptive filtering; least mean square (LMS); normalized least mean square (NLMS)
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s20010301

Adaptive filtering has the advantages of real-time processing, small computational complexity, and good adaptability and robustness. It has been widely used in communication, navigation, signal processing, optical fiber sensing, and other fields. In this paper, by adding an interferometer with the same parameters as the signal interferometer as the reference channel, the sensing signal of the interferometric fiber-optic hydrophone is denoised by two adaptive filtering schemes based on the least mean square (LMS) algorithm and the normalized least mean square (NLMS) algorithm respectively. The results show that the LMS algorithm is superior to the NLMS algorithm in reducing total harmonic distortion, improving the signal-to-noise ratio and filtering effect.