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Advanced Non-Uniform Sampling Techniques for Energy-Efficient Data Acquisition
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- Author / Creator
- Elmi, Mohammad
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With the growing demand for power-efficient data acquisition systems, particularly in low-power sensor applications that rely on energy harvesting or limited energy stored in small batteries, non-uniform sampling (NUS) techniques have gained attention as an effective approach to managing a restricted power budget while preserving the accuracy of the acquired data. Conventionally, signals are sampled uniformly independent of their shapes and frequency content, but NUS techniques intelligently reduce the overall collected data by selecting the most valuable data points for reconstructing sensed input signals. This approach remarkably aids data acquisition systems to reduce unnecessary power consumption in the critical system building blocks such as analog-to-digital converters (ADCs), digital signal processors (DSPs), and transceivers.This thesis addresses the key challenges in designing and implementing NUS techniques to highlight their potential in developing power-efficient data acquisition systems. The primary objective of this research is to introduce new NUS schemes to further enhance the energy efficiency of the data acquisition systems and to conduct a comprehensive review study of NUS schemes. This research presents two innovative NUS schemes: The first scheme is an ultra-low-power clock-based non-uniform sampling scheme that uses a novel derivative-based algorithm that maintains accuracy comparable with prior clock-based non-uniform sampling schemes but with reduced complexity and lower power consumption. The second proposed scheme is a clockless NUS approach that employs a derivative-dependent mechanism that provides enhanced accuracy for high-frequency content compared to other clockless NUS schemes while consuming less power. Both the proposed clock-based and clockless NUS techniques have been fabricated in CMOS technology and their performance has been characterized by experimental results when processing both real-world and ideal signals. The proposed clock-based Non-Uniform Sampling (NUS) system can operate with a clock frequency of up to 100 kHz, where power consumption scales proportionally to this frequency and is less than ∼155 nW at 1 kHz of the clock. The proposed clockless NUS scheme is presented in two versions of low- and high-speed designs where their maximum power consumption is 1.15 μW (@1 MHz) and 8.81 μW (@20 MHz), respectively. As the third contribution, this thesis provides a thorough quantitative and qualitative comparison of the prior art on NUS techniques; discussing their proposed implementations, design considerations, and/or limitations, and ultimately, evaluating their performance metrics.
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- Subjects / Keywords
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- Graduation date
- Fall 2024
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.