Algorithm Implementation of Data Acquisition System of Fiber Bragg Grating Demodulator Based on Compressive Sampling

摘要

According to the demodulation of high frequency vibration signal in the FBG (Fiber Bragg Grating) demodulator, the sampling frequency of the demodulator is high. And the high frequency sampling circuit designed in the practical application has the problem of high cost and unstable system. Therefore, the compressive sampling method is introduced into the FBG demodulator to replace the traditional Nyquist sampling for the compressive sampling of the reflection spectrum signal of FBG. This method reduces the sampling frequency requirement of data acquisition system by compressing data. In this paper, simulation experiments are used to verify the feasibility of compressive sampling. Through simulation experiments, the signal can still be reconstructed by algorithm when the data compressive ratio is 3.6:1. The MSE (mean-square error) of the reconstructed signal and the original signal is 0.0161, and the RE (relative error) near the peak value of the reconstructed signal is less than 0.009. Compared to directly reducing the sampling frequency, the reconstruction error of compressive sampling is much smaller than that of low-frequency sampling. In addition, through simulation experiments, it was found that compressive sampling can reconstruct signals under certain noise.