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 8 of 8 for “"fractional Fourier transform"”.
-
COMPARISON ON DIFFERENT DISCRETE FRACTIONAL FOURIER TRANSFORM (DFRFT) APPROACHES
As an extension of conventional Fourier transform and a time-frequency signal analysis tool, the fractional Fourier transforms (FRFT) are suitable for dealing with various types of non-stationary signals. Taking advantage of the properties and non-stationary features of linear chirp signals in the …
-
Acoustic Seabed and Target Classification using Fractional Fourier Transform and Time-Frequency Transform Techniques
… classification. The technique is based on the Fractional Fourier Transform (FrFT), which is better suited for sonar applications because FrFT uses linear chirps as basis functions. In the first stage of the algorithm, FrFT requires finding the optimum order of the transform that can be …
-
Advanced MIMO-OFDM technique for future high speed braodband wireless communications. A study of OFDM design, using wavelet transform, fractional fourier transform, fast fourier transform, doppler effect, space-time coding for multiple input, multiple output wireless communications systems
… sought. They include the comparisons of discrete Fourier transform (DFT), fractional Fourier transform (FrFT) and wavelet transform (WT) multicarrier kernels. Different wavelet types, including the raised-cosine spectrum wavelets are implemented, evaluated and compared. From different wavelet …
-
Time-frequency domain modelling for ultrasonic nondestructive testing
… thesis, work focusses on the exploration of the fractional Fourier transform and coded excitations. The fractional Fourier transform allows for retention of both time and frequency domain information simultaneously and permits the in homogeneous wave equation (with a forcing function prescribed …
-
Bi-fractional transforms in phase space
… parity operator through a two dimensional Fourier transform. Both operators are important operators in phase space and the trace of both with respect to the density operator gives the Wigner functions (displaced parity operator) and Weyl functions (displacement operator). The generalisation …
-
Estimation of Spacecraft Attitude Motion and Vibrational Modes Using Simultaneous Dual-Latitude Ground-Based Data
… quickly estimate the attitude of an RSO. The Fractional Fourier Transform shows promise as a non-model-based approach to the detection of input vibrational frequencies from the degree of linear polarization. The main results are that dual-site observation geometry is conducive to slight …
-
Advanced signal processing solutions for ATR and spectrum sharing in distributed radar systems
… chirpsub-carriers generated through the Fractional Fourier Transform (FrFT),with the aim of preserving the radar performance of a typical Linear Frequency Modulated (LFM) pulse while embedding data to be sent to acooperative system. Techniques aimed at optimise the design parameters and …
-
Remote Vibration Estimation Using Displaced Phase Center Antenna SAR in a Strong Clutter Environment
Synthetic aperture radar (SAR) is a ubiquitous remote sensing platform that is used for numerous applications. In its most common con\ufb01guration, SAR produces a high resolution, two-dimensional image of a scene of interest. An underlying assumption when creating this high resolution image is …