Sökning: "time-frequency representations"
Hittade 5 avhandlingar innehållade orden time-frequency representations.
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
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
3. Estimation and Classification of Non-Stationary Processes : Applications in Time-Frequency Analysis
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
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
5. Spectral Analysis for Signal Detection and Classification : Reducing Variance and Extracting Features
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