Search for dissertations about: "MMSE estimator"

Showing result 1 - 5 of 7 swedish dissertations containing the words MMSE estimator.

2. 1. 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. 2. Estimation of synchronization parameters

   Author : Jaap van de Beek; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

   Abstract : This thesis deals with the estimation of synchronization parameters in {Orthogonal Frequency Division Multiplexing} (OFDM) communication systems and in active ultrasonic measuring systems. Estimation methods for the timing and frequency offset and for the attenuation taps of the frequency selective channel are presented and investigated. READ MORE

5. 3. Hardware Architectures for Wireless Communication - Symbol Detection and Channel Estimation

   Author : Johan Löfgren; Institutionen för elektro- och informationsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VLSI; Digital Design; ASIC; Architecture; Symbol Detection; Channel Estimation; MIMO; OFDM;

   Abstract : In this thesis different aspects of baseband implementation of mobile communication systems is treated. The content is focused on symbol detection and channel estimation in MIMO and OFDM. The thesis deals with the complete chain from algorithm to silicon implementation within these areas. READ MORE

6. 4. Detection of signals corrupted by non-gaussian disturbances

   Author : Jan-Olov Gustavsson; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

   Abstract : The detection of signals in additive, non-Gaussian disturbances is the main theme of this thesis. The disturbances are modeled either by non-Gaussian noise or by Gaussian noise in combination with intersymbol or co-channel interference. READ MORE

7. 5. Maximum a posteriori deconvulution of ultrasonic data with applications in nondestructive testing : Multiple transducer and robustness is

   Author : Tomas Olofsson; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Ultrasonic pulse-echo testing; nondestructive testing; maximum a posteriori estimation; linear minimum mean squared error estimation; robust filtering; multivariable filtering; sparse deconvolution; Materialvetenskap; Materials science; Teknisk materialvetenskap; Signal Processing; signalbehandling;

   Abstract : In the thesis, various aspects of deconvolution of ultrasonic pulse-echo signals in nondestructive testing are treated. The deconvolution problem is formulated as estimation of a reflection sequence which is the impulse characteristic of the inspected object and the estimation is performed using either maximum a posteriori (MAP) or linear minimum mean square error (MMSE) estimators. READ MORE