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 20 of 39 for “"Noise Cancellation"”.
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Adaptive noise cancellation using multichannel lattice structure.
This thesis presents a multichannel adaptive noise cancellation technique (MCLS) for cancelling the noise over nonlinear transmission channel. The technique applies to the situation in which the reference signal and noisy primary signal are collected simultaneously. The coefficients of the …
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Scaling IoT-based noise cancellation to multiple noise sources
… (IoT) sensing techniques with active noise cancellation (ANC) has demonstrated certain benefits over the conventional methods for ANC, including wideband cancellation without blocking the ear and non-causal adaptive filtering. These benefits, however, can only be observed in acoustic …
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Magnetocardiography in unshielded environment based on optical magnetometry and adaptive noise cancellation
… quantum magnetometers and an adaptive noise cancellation for heart magnetic field measurement within a magnetically-unshielded environment. Optically-pumped quantum magnetometers are based on the use of the atomic-spin-dependent optical properties of an atomic medium. An …
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Optimal feedback control formulation of the active noise cancellation problem : pointwise and distributed
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.
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A feasibility analysis of single-sensor active noise cancellation in the interior of an automobile
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.
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Background Noise Reduction in Wind Tunnels using Adaptive Noise Cancellation and Cepstral Echo Removal Techniques for Microphone Array Applications
… were conducted to investigate Adaptive Noise Cancelling and Cepstrum echo removal post-processing techniques on acoustic data from a linear microphone array in an anechoic chamber. A point source speaker driven with white noise was used as the primary signal. The first experiment …
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Evaluation of several techniques for enhancing speech degraded by additive noise in mobile radio environments
… for enhancing speech degraded by additive noise in mobile cellular communications. The primary goal of this multi-stage study was to examine adaptive noise cancellation techniques in which one microphone is used to measure the speech plus noise signal and another microphone is used to form …
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Passive Cancellation of Common-Mode Electromagnetic Interference in Switching Power Converters
… regulations, it is necessary to attenuate this noise. Ordinarily this must be accomplished by using a magnetic choke on the input power lines, which can result in large penalties to the overall size, weight, and cost of the completed system. In order to lessen the requirement for this magnetic …
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Circuits for time-domain signal processing
… integer-N clock multiplier with feedforward noise cancellation is introduced to overcome the bandwidth limitation of conventional integer-N phase-locked loops (PLLs) by canceling the voltage controlled oscillator (VCO) noise in an open-loop fashion. Background calibration is presented to find …
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An Investigation on Acoustic Metamaterial Physics to Inspire the Design of Novel Aircraft Engine Liners
Attenuation of low frequency turbofan engine noise has been a challenging task in an industry that requires low weight and tightly-packed solutions. Without innovative advancements, the technology currently used will not be able to keep up with the increasingly stringent requirements on aircraft …
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Actively exploiting propagation delay for acoustic systems
… (RF), and acoustics -- to improve active noise cancellation. By ""piggybacking"" sound over RF, our proposed system is able to compute anti-noise signals more precisely, and ultimately attain better cancellation performance. (2) We develop solutions that exploit the propagation delays of …
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Motion-aircraft resistant design of photoplethysmograph ring sensor for driver monitoring
… have been eliminated using a customized Adaptive Noise Cancellation algorithm. Both the lab results and the road test results have suggested that the new Ring Sensor is indeed capable of rejecting motion artifacts in all three possible motion axes and producing considerable amount of usable …
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Demonstration of active structural acoustic control of cylinders
Active control is applied to reduce noise emission from a vibrating elastic cylinder by exerting forces on the cylinder that cancel the noise-generating vibration. This technique is called Active Structural Acoustic Control (ASAC) (Fuller, 1987). Sensors are implemented using piezoelectric film, …
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Study of substrate noise and techniques for minimization
… presents a study of the effects of substrate noise on analog circuits in mixed-signal chips and techniques for minimizing these harmful effects on sensitive analog circuits. A microchip built in a 0.25um CMOS epitaxial process was designed, fabricated, and tested for this research. Through the …
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Design of Low Power Integrated Radios
… is 3.21%. Next, a 2.3-2.5 GHz low-power low-noise 0.7 V mixer-first RF frontend for an IEEE 802.15.6 narrowband receiver is presented which uses frequency translated mutual noise cancellation based on passive coupling. Unlike traditional noise cancelling techniques we perform symmetrical …
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Longer Range Backscatter Communications for IoT
… the backscatter system is the presence of phase noise. A powerful method for phase noise cancellation is Range Correlation. To achieve maximum suppression of phase noise, it is crucial to match time delays between correlated signals. However, in backscatter communication, the transmission delays …
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Techniques for high-performance digital frequency synthesis and phase control
… architecture that leverages a recently invented noise-shaping time-to-digital converter (TDC) and an all-digital quantization noise cancellation technique to achieve excellent in-band and out-of-band phase noise, respectively. In addition, a passive digital-to-analog converter (DAC) structure is …
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Resonant Spatial Light Modulation: Optical Programming and Sensing at the Fundamental Limit
… characterization of the associated thermal noise limits in wavelength-scale microcavities, develop a new class of optical sensors operating at this fundamental limit, and analyze noise cancellation techniques to enable continued development in quantum optical measurement, precision sensing, …
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DEVELOPMENT OF QUANTUM TECHNOLOGIES FOR QUANTUM COMMUNICATION
… In collaboration with INRiM, an active phase-noise cancellation system for TF-QKD has been implemented and tested, demonstrating stable phase coherence over two 50-km fiber spools. Moreover, field measurements on underground fibers near medium-voltage lines have been conducted in the RSE test …
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Dynamically Corrected Quantum Control: A Geometrical Framework
… and suppressing the unwanted environmental noise has been one of the essential challenges in developing quantum information technologies. In the past, driving pulse sequences based on Dirac delta functions or square wave functions, such as Hahn spin echo or CPMG, have been developed to …
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