Study of AGC in Real-Time All-Digital Demodulation of Fiber Laser Hydrophone Using PGC Method

Abstract:

The amplitude of the demodulated signal from a fiber laser hydrophone is influenced by fluctuations in the amplitude of the interferometric signal. In this paper, two methods of automatic gain control (AGC) based on sum of squares and on the peak to peak value were put forward to obviate this problem in real-time all-digital demodulation of fiber laser hydrophone using phase generated carrier (PGC) method. The error rates of the method based on sum of squares were analyzed, and it was proposed that the error rates would be decreased by stabilizing the amplitude C of modulation signal or improving the performance of filters. The method based on the peak to peak value can be utilized to stabilize the amplitude of the demodulated signal when C>π. The simulation results show that this method works fine, and can solve the amplitude instability problem effectively caused by fluctuations in the amplitude of the interferometric signal.

• Periodical: Applied Mechanics and Materials (Volumes 484-485)
• Pages: 535-539
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.484-485.535
• Online since: January 2014
• Authors: Yue Yue Wang, Xin Lai Chen, Yu Li, Ding Rong Guo, Jun Bin Huang
• Keywords: Automatic Gain Control (AGC), Demodulation, Fiber Laser Hydrophone, Phase Generated Carrier (PGC)

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