Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"signal demodulation"”.
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Design and prototype of an all digital system for baseband FM multiplex signal demodulation
… analog circuits is in the modulation and demodulation of baseband frequency modulated (FM) radio signals. In this project, an all digital system for demodulating baseband FM Multiplex (MPX) signals is simulated, designed, and prototyped on a Xilinx Spartan-3AN FPGA. The design architecture …
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Integrated Signal Demodulation, Data Conversion, and Packaging Strategies for a Wireless, Fully Implantable, Bidirectional Neural Interface
… which are typically controlled through EMG signals and therefore provide limited and unnatural control with no sensory feedback, neural prostheses aim to overcome these limitations by using the same implanted electrodes both for motor control and for restoring a sense of touch. This thesis …
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Extrinsic Fabry-Perot Interferometer System Using Wavelength Modulated Source
… but they suffer from limitations in signal demodulation caused by phase ambiguity and complex fringe counting when the output phase difference exceeds one fringe period. Various signal demodulation methods have been developed to overcome some of the these drawbacks with limited …
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Electronic Signal Processing in an Optical Fiber-Based Magnetometer
… of sensor head, laser source, opto-electronics, signal demodulation circuitry and display is designed, fabricated and tested. Various electronic signal demodulation schemes are discussed. The Quadrature Phase Shifted EFPI signal demodulation scheme, used in the system, is studied in detail. The …
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High Speed Fiber Optic Spectrometer
… maintained. The bottle neck then emerged in the signal demodulation part of the sensor system. The quadrature phase detection could achieve high demodulation speed but with small dynamic range, medium accuracy and measurement ambiguity. The white light interferometry could provide a solution for …
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Digital Signal Processing and Machine Learning Applied to Power Line Communications
… communication data alongside the electric power signals. Due to the ubiquitous nature of pre-existing power grid infrastructure, PLC has a huge networking potential, especially in the implementation of smart grid technologies. However, the electrical architecture and function of distribution grid …
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Dynamic pixel selection in free-space photon-counting optical communication systems for the exploitation of excess channel capacity
… in free-space optical communications turns signal demodulation and decoding into a multimode problem as wavefronts of the transmitting laser beams are warped spatially past the desired form of a diffraction-limited spot at the receiver end of a free-space optical receiver. Adaptive optics, a …
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The split-cavity cross-coupled extrinsic fiber interferometer
… point. The spectrum analysis scheme, devised for signal demodulation of the SCEFI output allows a linear readout of the phase shift. Both dynamic and static phase shifts are considered. The spectrum analysis scheme developed in this thesis, also allows independent measurements of the phase shift …
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Neural Networks For Phase Demodulation In Optical Interferometry
… evenly spaced wavenumbers. Traditional phase demodulation algorithms for WSI fail to reach the theoretical OPL sensitivity limit set by the CRB. We have designed NNs which are capable of achieving this bound across a wide range of OPL differences. The NNs are trained on simulated data, and …
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3D Camera Based on Gain-Modulated CMOS Avalanche Photodiodes
… of pixel size, higher modulation frequencies and demodulation contrast to allow a higher distance precision. In this thesis we propose a new concept of range camera exploiting linear-mode avalanche photodiodes as in-pixel demodulating detectors. Due to photocurrent gain modulation, avalanche …
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Optical Fiber Fabry-Perot Interferometer based Sensor Instrumentation System for Low Magnetic Field Measurement
… the performance of the interferometer. The signal fading in the interferometric sensors at the peak or bottom of a fringe is reduced by using a quadrature signal demodulation method. The system has been shown to have a resolution better than 100 nT over a measurement range from 100 to 40,000 …
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Hall Potential Mapping of Conducting Ferroelectric Domain Walls
… by p-type carriers. By calibration of the AFM signal, an estimate of ~ 1x10<sup>16</sup> cm<sup>−3</sup> is calculated for the mobile carrier density in the wall, around four orders of magnitude below that required for complete screening of the polar discontinuity. A carrier mobility of ∼ …
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Sapphire Fiber Optic Sensor for High Temperature Measurement
… radiation, fiber optic F-P sensors, and F-P signal demodulation. The research goal is highlighted. In Chapter 2, a temperature sensing system is introduced. The environmental thermal radiation was used as the broadband light source. A sapphire wafer F-P temperature sensor head was fabricated, …
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High Temperature High Bandwidth Fiber Optic Pressure Sensors
… was used to calibrate the sensor. Several sensor signal demodulation schemes were used for different testing purposes including a white-light interferometry system, a tunable laser based component test system (CTS), and a self-calibrated interferometric-intensity based (SCIIB) system. All of these …
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Optical Frequency Domain Reflectometry Based Quasi-distributed High Temperature Sensor
… to a multi-mode fused silica fiber for quality signal transmission in lower temperature areas. One of the challenges encountered by this approach is the shear force to the sapphire fiber, which is caused by the differential thermal expansion between the inner and outer layers of the gasifier …
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Interaction of additive and quantization noises in digital PLLs
… to retrieve the information content from remote signals. As such, they are capable of signal demodulation, phase and carrier recovery, frequency synthesis, and clock synchronization. Continuous-time PLLs are a mature area of study, and have been covered in the literature since the early classical …
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System Design, Noise Reduction, and Improved Dimension Reconstruction for High Performance Ellipsometry
… noise induced errors are studied, including signal strength, the signal sampling frequency, and the first-order coefficient between the signal variance and mean. This thesis then proposes a signal demodulation method in spectroscopic ellipsometry based on maximum likelihood, in order to …