Sökning: "time-frequency representations"

Hittade 5 avhandlingar innehållade orden time-frequency representations.

1. 1. High resolution time-frequency representations

   Författare :Isabella Reinhold; Statistical Signal Processing Group; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; time-frequency analysis; non-stationary signals; multi-component signals; IF estimation; reassignment;

   Sammanfattning : Non-stationary signals are very common in nature, e.g. sound waves such as human speech, bird song and music. It is usually meaningful to describe a signal in terms of time and frequency. LÄS MER

3. 2. Discrete Stochastic Time-Frequency Analysis and Cepstrum Estimation

   Författare :Johan Sandberg; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ambiguity domain; time-frequency analysis; time-frequency representations; covariance function; non-stationary random processes; Speaker recognition; MFCC; cepstrum;

   Sammanfattning : The theory of stochastic time-frequency analysis of non-stationary random processes has mostly been developed for processes in continuous time. In practice however, random processes are observed, processed, and interpreted at a finite set of time points. LÄS MER

4. 3. Estimation and Classification of Non-Stationary Processes : Applications in Time-Frequency Analysis

   Författare :Johan Brynolfsson; Statistical Signal Processing Group; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time-Frequency Estimation; Parameter Estimation; Reassignment method; Non-Stationary Processes; Smooth spectral estimation; Neural Networks;

   Sammanfattning : This thesis deals with estimation and classification problems of non-stationary processes in a few special cases.In paper A and paper D we make strong assumptions about the observed signal, where a specific model is assumed and the parameters of the model are estimated. LÄS MER

5. 4. The Non-Linear Instantaneous Least Squares Approach to Signal Parameter Estimation

   Författare :Jakob Ängeby; Chalmers University of Technology; []
   Nyckelord :aliasing; polynomial-phase signals; synthetic aperture radar auto-focusing; non-linear least squares; time-frequency estimation; estimation theory; non-stationary processes; non-uniform sampling;

   Sammanfattning : Estimation of parameters of non-stationary signals observed in noise is a challenging and difficult task, motivated by applications such as radar and mobile tele-communication. Here, a novel method for signal parameter estimation named the Non-linear Instantaneous Least Squares (NILS) approach is presented, which can be applied to linear and non-linear signals, and to both uniformly and non-uniformly sampled data. LÄS MER

7. 5. Spectral Analysis for Signal Detection and Classification : Reducing Variance and Extracting Features

   Författare :Isabella Reinhold; Statistical Signal Processing Group; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multifönster; Tids-frekvensanalys; Instantaneous frequency; Multitaper; Signal resolution; Reassignment method; Time-frequency analysis;

   Sammanfattning : Spectral analysis encompasses several powerful signal processing methods. The papers in this thesis present methods for finding good spectral representations, and methods both for stationary and non-stationary signals are considered. LÄS MER