Sökning: "time-frequency analysis"

Visar resultat 16 - 20 av 43 avhandlingar innehållade orden time-frequency analysis.

1. 16. The Non-Linear Instantaneous Least Squares Approach to Signal Parameter Estimation

   Författare :Jakob Ängeby; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

3. 17. Modelling and Inference using Locally Stationary Processes : Biomedical applications

   Författare :Rachele Anderson; Statistical Signal Processing Group; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Modelling of Time-Varying Signals; Locally Stationary Processes; Statistical Inference; Time-frequency Estimation; Regression; EEG Signals; HRV Signals;

   Sammanfattning : This thesis considers statistical methods for non-stationary signals, specifically stochastic modelling, inference on the model parameters and optimal spectral estimation. The models are based on Silverman’s definition of Locally Stationary Processes (LSPs). LÄS MER

4. 18. Multiscale analysis of multi-channel signals

   Författare :Håkan Carlqvist; Jan-Olov Strömberg; Maria Hansson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical statistics; Matematisk statistik; Mathematical statistics; Matematisk statistik;

   Sammanfattning : I: Amplitude and phase relationship between alpha and beta oscillations in the human EEG We have studied the relation between two oscillatory patterns within EEG signals (oscillations with main frequency 10 Hz and 20 Hz), with wavelet-based methods. For better comparison, a variant of the continuous wavelet transform, was derived. LÄS MER

5. 19. Gait Event Detection in the Real World

   Författare :Siddhartha Khandelwal; Nicholas Wickström; Thorsteinn Rögnvaldsson; Brian Caulfield; Högskolan i Halmstad; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gait analysis; gait event detection; wearable sensors; accelerometers;

   Sammanfattning : Healthy gait requires a balance between various neuro-physiological systems and is considered an important indicator of a subject's physical and cognitive health status. As such, health-related applications would immensely benefit by performing long-term or continuous monitoring of subjects' gait in their natural environment and everyday lives. LÄS MER

7. 20. Smart Cooperation with Network Coding in Hierarchical Wireless Networks

   Författare :Nan Li; Lars Kildehöj Rasmussen; Daniel Lucani; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless communications; Hierarchical networks; 5G; Cognitive radio; Internet of Things; Cooperative communications; Spectrum sharing; Network coding; Optimization; Performance analysis.; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : To achieve more dynamic, efficient and intelligent use of the scarce wireless spectrum resource, the concept of cooperation has been formalized into several hierarchical network models in future mobile networks. Cooperative communications, such as relaying, can potentially increase communication efficiency and spectrum utilization due to the broadcast nature of wireless networks, and may lead to a better support for diverse communication modes with flexible spectrum sharing. LÄS MER