Multirate digital phase generated carrier demodulation
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摘要: 基于相位载波(PGC,Phase Generated Carrier)解调各环节的信号频率范围,提出变采样率解调方案,解决高采样频率下的实时全数字PGC解调问题.对干涉输出信号采用高采样率进行模数转换,提高解调带宽和动态范围.对混频相乘和低通滤波后的环节采用降低采样率处理,减少实时数字信号处理的运算量.设计变采样率全数字PGC解调系统,采用现场可编程门阵列(FPGA,Field Programmable Gate Arrays)并行实现混频相乘和低通滤波环节,采用数字信号处理器(DSP, Digital Signal Processor)实现后续解调环节,实现采样率高达1MHz的实时解调.实验结果表明频率为5kHz、幅度为1rad的被测信号可以被有效解调.Abstract: Based on the signal bandwidth in each phase generated carrier (PGC) demodulation procedure, a multirate demodulation scheme was proposed to solve the real time digital PGC demodulation problem at high sampling rate. The interfered output was analog-to-digital converted at high sampling rate to improve demodulation bandwidth and dynamic range. The procedures after frequency mixing and low pass filtering were down sampled and digital PGC demodulation computation was reduced. A digital PGC demodulation system was designed and implemented. The frequency mixing and low pass filtering procedures were implemented using field programmable gate arrays (FPGA) and the following procedures were implemented using digital signal processor (DSP). Real-time demodulation experiment verified that a test signal with 5kHz and 1rad was successfully demodulated at 1MHz sampling rate.
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Key words:
- interferometers /
- fiber optic sensors /
- phase modulation /
- demodulation /
- digital signal processing
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[1] Dandridge A, Tveten A B, Giallorenzi T G. Homodyne demodulation scheme for fiber optic sensors using phase generated carrier[J]. IEEE Journal of Quantum Electronics, 1982, QE-18(10):1647-1653 [2] Cranch G A, Nash P J, Kirkendall C K.Large-scale remotely interrogated arrays of fiber-optic interferometric sensors for underwater acoustic applications[J]. IEEE Sensors Journal, 2003,3(1):19-30 [3] Waagaard O H, Havsgard G B, Wang G. An investigation of the pressure-to-acceleration responsivity ratio of fiber-optic mandrel hydrophones[J]. IEEE Journal of Lightwave Technology,2001,19(7): 994-1003 [4] 曹家年,李绪友,张立昆,等.采用PGC零差检测方案的Mach-Zehnder光纤干涉仪动态范围分析[J].哈尔滨工程大学学报, 1998, 19(5): 78-84 Cao Jianian, Li Xuyou, Zhang Likun, et al. Dynamic range analysis of Mach-Zehnder fiber optic interferometer using PGC homodyne detection scheme[J]. Journal of Harbin Engineering University, 1998,19(5): 78-84 (in Chinese) [5] 熊水东,罗洪,胡永明,等.基于加速度传感的三维光纤矢量水听器实验研究[J].压电与声光, 2005, 27(5): 483-489 Xiong Shuidong, Luo Hong, Hu Yongming, et al. Experimental research on three-dimensional fiber optic vector hydrophone based on acceleration sensing[J]. Piezoelectrics & Acoustooptics, 2005, 27(5): 483-489 (in Chinese) [6] 罗洪,熊水东,胡永明,等.三分量全保偏光纤加速度传感器的研究[J].中国激光, 2005, 32(10):1382-1386 Luo Hong, Xiong Shuidong, Hu Yongming, et al. Research on three-component all polarization-maintaining fiber optic accelerometer [J]. Chinese Journal of Lasers, 2005, 32(10): 1382-1386 (in Chinese) [7] 陈宇,李平.基于FPGA的光纤水听器PGC解调算法实现[J].应用声学, 2006, 25(1): 48-54 Chen Yu, Li Ping. FPGA-based implementation of PGC demodulation algorithm for fiber optic hydrophone[J]. Applied Acoustics, 2006, 25(1):48-54 (in Chinese) [8] 柏林厚,廖延彪,张敏,等.干涉型光纤传感器相位生成载波解调方法改进与研究[J].光子学报, 2005, 34(9): 1324-1327 Bo Linhou, Liao Yanbiao, Zhang Min, et al. The improvement on PGC demodulation method based on optical fiber interferometer sensors[J]. Acta Photonica Sinica, 2005, 34(9):1324-1327 (in Chinese)
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