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.
Results
Showing 1 to 20 of 36 for “"discrete fourier transform (dft)"”.
-
Diagnosis of operational changes in microelectromechanical systems via fault detection
… Analysis of the residual was conducted using a discrete Fourier transform (DFT). Two common MEMS research devices, the lateral comb resonator and parallel plate actuator, are used to demonstrate theoretically and experimentally the ability of the fault detectors to identify induced faults in …
-
Improving Mobile SOC's Performance as an Energy Efficient DSP Platform with Heterogeneous Computing
… concepts, several implementations of both the discrete Fourier transform (DFT) and the fast Fourier transform (FFT) are tested across devices. The results show both improvement in performance and energy efficiency on many devices compared to traditional Java implementations and indicate that …
-
Mathematical methods for non-intrusive load monitoring
The calculation of the Discrete Fourier Transform (DFT) of a discrete time signal is a fundamental problem in discrete-time signal processing. This thesis presents algorithms that use methods from number theory and algebra to exploit additional constraints about a signal to aid in the calculation …
-
Resistive Companion Dynamic Phasor Networks and Phasor to Time Domain Network Coupling
… sources, modified nodal analysis (MNA), and a discrete Fourier transform (DFT) phasor estimation. A coupling device using this technique is implemented in Virtual Test Bed (VTB). The accuracy and stability of the method is verified with two test systems, including a system consisting of a …
-
PAPR reduction in OFDM communications with generalized discrete Fourier transform
The main advantage of Generalized Discrete Fourier Transform (GDFT) is its ability to design a wide selection of constant modulus orthogonal code sets, based on the desired performance metrics mimicking the engineering specs of interest. One of the main drawbacks of Orthogonal Frequency Division …
-
Generalized DFT: extensions in communications
Discrete Fourier Transform (DFT) is a restricted version of Generalized DFT (GDFT) which offers a very limited number of sets to be used in a multicarrier communication system. In contrast, as an extension on Discrete Fourier Transform (DFT) from the linear phase to non-linear phase, the proposed …
-
Analysis of Wavelet Based Alternatives for OFDM
… performance is achieved when compared to the discrete Fourier transform (DFT)-based OFDM. We analyze DFT, discrete wavelet transform (DWT), and dual tree complex wavelet transform (DT-CWT) based systems in an additive white Gaussian noise (AWGN) channel. The analysis is verified by Monte Carlo …
-
Single-carrier frequency domain equalization using subband decomposition for optical wireless communications
… subbands. As a time-to-frequency transform, subband decomposition technique can be employed to frequency domain equalization. Compared with the commonly used discrete Fourier transform (DFT), subband transform is more flexible and efficient to compensate the fading of …
-
Enabling Technologies for Joint Communication and Sensing in Aviation
… the common waveform for this kind of system discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM), is analyzed. A critical focus of this analysis lies on the influence of non-linearities introduced by the power amplifier at the transmitter. The analysis …
-
Imaging applications of the sparse FFT
The sparse Fourier transform leverages the intrinsic sparsity of the frequency spectrum in many natural applications to compute the discrete Fourier Transform (DFT) in sub-linear time. Consequently, it has the potential to enable Big Data applications. In this thesis, we focus on extending the …
-
Potential fields from cardiac strands of cylindrical geometry
… in the extracellular medium is in the form of a Fourier integral; the equation is subsequently reformulated into a more convenient computational form using a discrete Fourier transform (DFT) method. Implementation of this method using a Fast Fourier Transform (FFT) technique, results in a fast …
-
Side scan sonar image formation, restoration and modelling.
… proposed which allows the development of fast Discrete Fourier Transform (DFT) and gradient based algorithms. The second part of the thesis deals with the correction of platform motion distortion. A novel noncausal MAP formulation of the problem is proposed and the use of the ICM and SR …
-
Low-complexity approximations for discrete transforms : design, fast algorithms, image coding, and use as a tool in statistical inference
Discrete transforms play an important role in the context of signal processing. They are pivotal tools because they allow us to analyze and interpret data in the domain of transforms, which often reveal useful patterns. In particular, we can mention the discrete Fourier transform (DFT), the …
-
Fast algorithm and surface integral equations for two-dimensional materials modeling
… By scaling special functions and applying discrete Fourier transform (DFT), the multipole expansions with dense matrices can be transformed to diagonal matrices with stable accuracy. Therefore a broadband 2D FMA with high efficiency and accuracy is achieved with a multi-level scheme. Then a …
-
Algorithmic enhancements to polynomial matrix factorisations
… that better meet analyticity by operating in the discrete Fourier transform (DFT)-domain have received increasing attention.;While offering promising results in applications including broadband MIMO and beamforming, the PEVD has seen limited deployment in hardware due to its high computational …
-
Fast Fourier Transforms on Distributed Memory Parallel Machines
… of developing such algorithms to compute the Discrete Fourier Transform (DFT) of real and complex data. The implementations given in this dissertation work for a class of data distributions commonly encountered in scientific applications, known as the block scattered data distributions. The …
-
A multimodal breast cancer imaging system using coregistered dynamic diffuse optical tomography and digital breast tomosynthesis
… real-time hybrid FPGA-assisted demodulation by discrete Fourier transform (DFT). The overall DOT system integrates 96 CW-NIRS and 24 FD-NIRS source locations, as well as 32 CW-NIRS and 20 FD-NIRS detection locations into low-profile plates that mate to the DBT compression paddle and x-ray …
-
Wavelets for approximate Fourier transform and data compression
… we develop a wavelet-based fast approximate Fourier transform algorithm. The second part is devoted to the developments of several wavelet-based data compression techniques for image and seismic data. We propose an algorithm that uses the discrete wavelet transform (DWT) as a tool to compute …
-
High-Resolution Time-Synchronized Monitoring and Anomaly Detection in Modern Distribution System
… The algorithm improves upon the traditional Discrete Fourier Transform (DFT) by employing adaptive windowing to suppress spectral leakage. In addition, its harmonic estimation accuracy is enhanced through the implementation of M-point average filters that mitigate the leakage from the …
-
Prolate Spheroidal Sequence Based Transceivers for Time-Frequency Dispersive Channels
Most existing transceivers are Fourier-centric where complex sinusoids play a central role in the internals of the core building blocks. From the channel perspective, complex sinusoids constitute the fundamental effects in the wireless baseband equivalent channel model; exemplified by the …
Page 1 of 2