Search for dissertations about: "Gaussian noise"

Showing result 16 - 20 of 146 swedish dissertations containing the words Gaussian noise.

2. 16. Speech Enhancement Using Nonnegative MatrixFactorization and Hidden Markov Models

   Author : Nasser Mohammadiha; Arne Leijon; W. Bastiaan Kleijn; Cédric Févotte; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speech enhancement; noise reduction; nonnegative matrix factorization; hidden Markov model; probabilistic latent component analysis; online dictionary learning; super-Gaussian distribution; MMSE estimator; temporal dependencies; dynamic NMF;

   Abstract : Reducing interference noise in a noisy speech recording has been a challenging task for many years yet has a variety of applications, for example, in handsfree mobile communications, in speech recognition, and in hearing aids. Traditional single-channel noise reduction schemes, such as Wiener filtering, do not work satisfactorily in the presence of non-stationary background noise. READ MORE

4. 17. On Deterministic Models for Gaussian Networks

   Author : Nicolas Schrammar; Mikael Skoglund; Petar Popovski; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : In this thesis we study wireless networks modeled by the additive white Gaussian noise (AWGN) model. The AWGN capacity region of most network topologies is unknown, which means that the optimal transmission scheme is unknown as well. This motivates the search for capacity approximations and for approximately optimal schemes. READ MORE

5. 18. THz Vector Beam Measurement System for APEX Instrument SHeFI and Microwave Cryogenic Low Noise Amplifier Design

   Author : Olle Nyström; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vector measurements; mm- and submm-wave optics; LNA; radio astronomy; cryogenic amplifier; APEX; InP HEMT; Gaussian beam;

   Abstract : This licentiate thesis describes results of the author’s work on development of THz vector beam measurement system and microwave cryogenic low-noise amplifier.The first part, and the main focus, of the thesis covers the vector beam measurement system for frequency range 210-500 GHz developed to characterize/verify the cold opticsof the APEX instrument SHeFI. READ MORE

6. 19. Probabilistic Sequence Models with Speech and Language Applications

   Author : Gustav Eje Henter; W. Bastiaan Kleijn; Arne Leijon; Gernot Kubin; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time series; acoustic modelling; speech synthesis; stochastic processes; causal-state splitting reconstruction; robust causal states; pattern discovery; Markov models; HMMs; nonparametric models; Gaussian processes; Gaussian process dynamical models; nonlinear Kalman filters; information theory; minimum entropy rate simplification; kernel density estimation; time-series bootstrap;

   Abstract : Series data, sequences of measured values, are ubiquitous. Whenever observations are made along a path in space or time, a data sequence results. To comprehend nature and shape it to our will, or to make informed decisions based on what we know, we need methods to make sense of such data. READ MORE

7. 20. Resource Allocation in Flexible-Grid Optical Networks with Nonlinear Interference

   Author : Li Yan; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gaussian noise model; nonlinear interference; elastic optical networks; resource allocation; physical layer impairment; Flexible-grid optical network;

   Abstract : As the backbone of modern communications, the optical networks are anticipated to provide higher data rate and flexibility to support the exponentially growing volume and heterogeneity of traffic requirements. Flexible-grid optical networks have been proposed to improve the utilization of spectrum resources. READ MORE