- 标题
- 摘要
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- 实验方案
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Lorentzian demodulation algorithm for multimode polymer optical fiber Bragg gratings
摘要： For strain sensing applications, we develop a simple and accurate Lorentzian demodulation algorithm for fiber Bragg gratings (FBGs) inscribed in multimode optical fibers. As multimode FBG spectra generally exhibit multiple peaks, simply tracking some particular spectral peaks (i.e., maximum detection) results in measurement failure when the strain is large. Here, using an FBG inscribed in a perfluorinated graded-index multimode polymer optical fiber, we experimentally evaluate the new method by comparing its performance with those of other demodulation algorithms, such as the maximum and centroid detection methods. Finally, using this method, we demonstrate the accurate measurement of strain of up to 1.0%.
关键词： fiber Bragg gratings,FBG,Lorentzian demodulation algorithm,strain sensing,multimode polymer optical fiber Bragg gratings
更新于2025-11-28 14:24:03
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Evaluating the Effect on Demodulation With a Comprehensive Model of Distortions of Fiber Bragg Grating Sensing Signals
摘要： Spectral distortions are complex and unpredictable in fiber Bragg grating (FBG) sensing applications. An inappropriate choice of FBG demodulation algorithm will lead to unacceptable results in practice. Although many demodulation algorithms have been developed for distorted spectra, they may be limited for some types of spectral distortion. Until now, no model of FBG spectral distortion has been proposed to test different demodulation algorithms. Here, we fulfill this aim by introducing a comprehensive model with asymmetrical distortion, multi-peaks distortion, interferometric noise, background noise, and random noise. Using numerical simulations, we evaluate the performance of eight most typical demodulation algorithms with this model. We show that different algorithms should be used within specific ranges of spectral distortions. Altogether, this study provides a guide map as useful reference for selecting an appropriate FBG demodulation algorithm for practical applications. Furthermore, our proposed model paves the way for developing more reliable FBG demodulation algorithms for different spectral distortions.
关键词： spectral distortion,fiber Bragg grating,Demodulation
更新于2025-09-23 15:22:29
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[Advances in Intelligent Systems and Computing] Image Processing and Communications Challenges 10 Volume 892 (10th International Conference, IP&C’2018 Bydgoszcz, Poland, November 2018, Proceedings) || Air-Gap Data Transmission Using Backlight Modulation of Screen
摘要： Novel technique for data transmission from air–gap secured computer is considered in this paper. Backlight modulation of screen using BFSK allows data transmission that is not visible for human. The application of digital camera equipped and telescope allows data recovery during the lack of the user’s activity. Demodulation scheme with automatic selection of demodulation ?lters is presented. Di?erent con?guration of data transmission parameters and acquisition hardware were tested.
关键词： BFSK,Image processing,Air–gap transmission,Network security,Digital demodulation
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE) - Osaka, Japan (2019.10.15-2019.10.18)] 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE) - Generating Hand Contour Images with Information of the Fingers Curled using a Colored Glove
摘要： In this paper we investigate the possibilities of narrowband FSK detection using a superregenerative (SR) receiver. Previous SR FM demodulation techniques rely on detecting the amplitude variations caused by the different frequencies involved in FSK modulation. However, this requires relatively high frequency deviations because the frequency response of SR receivers is not very selective. In this paper we take a different approach, exploiting the distinct phase trajectories of FSK modulations resulting from the transmitted data. The well-known fact that the SR oscillator response preserves the phase information of the received signal is successfully exploited to allow the detection of several FSK modulations. These include the special case of MSK, opening the way to applying the SR principle to several communication standards, such as IEEE 802.15.4. The key ideas for symbol synchronization are also presented. Experimental results on a 10 kbit/s proof-of-concept MSK receiver, achieving a sensitivity better than 114 dBm in the HF band, validate the proposed approach.
关键词： narrowband FSK demodulation,Low-power communication receivers,RF receivers,MSK demodulation,superregenerative receiver
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Bombay, India (2019.3.29-2019.3.31)] 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Detection and Quantification of Milk Adulteration by Laser Induced Instumentation
摘要： In this paper we investigate the possibilities of narrowband FSK detection using a superregenerative (SR) receiver. Previous SR FM demodulation techniques rely on detecting the amplitude variations caused by the different frequencies involved in FSK modulation. However, this requires relatively high frequency deviations because the frequency response of SR receivers is not very selective. In this paper we take a different approach, exploiting the distinct phase trajectories of FSK modulations resulting from the transmitted data. The well-known fact that the SR oscillator response preserves the phase information of the received signal is successfully exploited to allow the detection of several FSK modulations. These include the special case of MSK, opening the way to applying the SR principle to several communication standards, such as IEEE 802.15.4. The key ideas for symbol synchronization are also presented. Experimental results on a 10 kbit/s proof-of-concept MSK receiver, achieving a sensitivity better than 114 dBm in the HF band, validate the proposed approach.
关键词： narrowband FSK demodulation,Low-power communication receivers,RF receivers,MSK demodulation,superregenerative receiver
更新于2025-09-23 15:21:01
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Demodulation Technique Based on Laser Interference for Weak Photo-Acoustic Signals on Water Surface
摘要： To detect underwater sound-generating targets, a water surface acoustic wave laser interference and signal demodulation technique is proposed in this paper. The underlying principle of this technique involves casting a laser beam onto the water surface disturbed by an underwater acoustic source and creating interference between lights re?ected by the surface and reference lights. A data acquisition and processing system was employed to obtain water surface acoustic wave information from the interference signals by means of demodulation, thus allowing detection of the underwater target. For the purpose of this study, an interference detection platform was set up in an optical dark chamber. High-frequency water surface ?uctuations were introduced in the reference optical path as the phase generated carriers to create laser interference signals in two different paths, which received demodulation based on an improved arc tangent demodulation algorithm and characteristic ratio algorithm, respectively, in view of their different frequencies. Water surface wave information was then derived from such low-frequency and high-frequency signals. According to test results, in the frequency range of 200 Hz–10 kHz, the frequency detection accuracy was better than 1 Hz. The amplitude measurements exhibited high repeatability, with a standard deviation lower than 2.5 nm. The theory proposed in this paper is therefore experimentally veri?ed with good results.
关键词： optical interference,phase generated carrier,water surface acoustic waves,phase demodulation
更新于2025-09-23 15:19:57
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - An improvement on the CNN-based OAM Demodulator via Conditional Generative Adversarial Networks
摘要： In the paper, an Orbital Angular Momentum (OAM) demodulation method based on Conditional Generative Adversarial Networks(CGAN) is proposed to improve the accuracy of Convolutional Neural Networks (CNN) based demodulator. We train a CGAN on a limited data set, and the discriminator in CGAN is fine-tuned as a new classifier for OAM demodulation. Our numerical simulations demonstrate that the proposed method can improve the accuracy of OAM demodulator from 93.56% to 98.36% over 400-m free-space link when the turbulence strength equals 4×10-13m-2/3.
关键词： Deep Learning,OAM demodulation,Conditional Generative Adversarial Networks
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE International Conference on Artificial Intelligence and Computer Applications (ICAICA) - Dalian, China (2019.3.29-2019.3.31)] 2019 IEEE International Conference on Artificial Intelligence and Computer Applications (ICAICA) - Design of Unequal Error Protection LDPC Code in PPM and LDPC Optical Communication System
摘要： In the space optical communication system, the link power loss is large, and the unequal error protection (UEP) scheme can effectively protect more important data in the transmission process and save transmission power. However, the performance of existing unequal error protection LDPC codes used directly in space optical communication systems is not ideal. In this paper, a design scheme of LDPC codes with multilevel unequal error protection performance is proposed for pulse position modulation (PPM) and Low-density parity- check (LDPC) codes iterative demodulation system. The scheme is aimed at maximizing the average variable node degree of each protection level to improve the unequal error protection characteristics of LDPC codes while combining the improved external in the BICM-ID system extrinsic information transfer(EXIT) method to analyze the convergence threshold of degree distribution and optimize the degree distribution of UEP-LDPC code by iterative linear programming to obtain the minimum threshold and satisfy the unequal error protection characteristics. The simulation results show that the UEP-LDPC code constructed in this paper has improved performance compared with the existing UEP-LDPC code.
关键词： EXIT,degree distribution optimization,UEP-LDPC,iterative demodulation
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 14th International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Bangkok, Thailand (2019.4.11-2019.4.14)] 2019 IEEE 14th International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Optical Fiber MEMS Micro Pressure Sensor Based On Beam-membrane Structure
摘要： In this paper, an optical fiber MEMS (Micro-Electro-Mechanical System) micro pressure sensor based on BM (beam-membrane) structure is proposed. The most important part of the sensor is composed of a sensitive silicon diaphragm and a dual fiber collimator. In the designed optic fiber micro pressure sensor, the sensitive silicon diaphragm creatively utilizes a BM structure made by MEMS manufacturing technology. By comparing other structures and performing simulations, the BM structure has better linearity while ensuring its sensitivity is concluded. The BM structure is used to reflect light(cid:712)and the dual-fiber collimator is used to transmit and receive light. The measurement range of the sensor is from 0KPa to 10KPa. The intensity demodulation makes the whole system easier to realize and ensures the performance of the sensor. By setting up the sensor experimental platform and conducting experiments, the sensitivity of the designed sensor is -0.252db/KPa.
关键词： MEMS,intensity demodulation,micro pressure,beam-membrane
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A Mathematical Expression of Bit Error Rate of PCM-FM using Non-coherent Detection
摘要： there telemetry. However, PCM/FM, also known as CPFSK, is widely used in aeronautical theoretical expression of its bit error rate in the literature. In this paper, based on the analysis of non-coherent detection of PCM/FM signal, a mathematical expression is derived. The analytical result is verified by computer simulation and compared with other modulation schemes and the proposed expression can significantly benefit the system design and evaluation of receiver performance.
关键词： bit error rate,CPFSK,telemetry,PCM/FM,demodulation
更新于2025-09-16 10:30:52