High-Stability PGC-EKF Demodulation Algorithm Integrated with a Phase Delay Compensation Module
To effectively eliminate the nonlinear distortion caused by the modulation depth (<i>C</i> value) drift and carrier phase delay (<i>θ</i>) in the phase-generated carrier (PGC) demodulation scheme, the PGC-PDC-EKF joint algorithm is presented, which combines phase delay compen...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Photonics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-6732/12/1/44 |
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| Summary: | To effectively eliminate the nonlinear distortion caused by the modulation depth (<i>C</i> value) drift and carrier phase delay (<i>θ</i>) in the phase-generated carrier (PGC) demodulation scheme, the PGC-PDC-EKF joint algorithm is presented, which combines phase delay compensation (PDC) with an extended Kalman filter (EKF). The <i>θ</i> is accurately extracted and compensated by the PDC module. Furthermore, with the EKF algorithm, the harmonic distortion of the demodulated signal due to the fluctuation of <i>C</i> value is suppressed. The experimental results indicate that <i>θ</i> is compensated accurately with a resolution of 0.01745 rad. The signal-to-noise and distortion ratio (SINAD) of the improved scheme reaches 54.01 dB, which is 18.03 dB higher than the PGC-Arctan algorithm on average. The total harmonic distortion (THD) is as low as −62.28 dB, which is 26.04 dB lower than the PGC-Arctan algorithm. The linearity of the demodulation system exceeds 99.99%. The proposed method provides a significant reference for demodulation schemes of interferometric fiber optic sensing systems in practical applications. |
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| ISSN: | 2304-6732 |