Sökning: "Information distortion"

Visar resultat 1 - 5 av 241 avhandlingar innehållade orden Information distortion.

1. 1. High-End Performance with Low-End Hardware : Analysis of Massive MIMO Base Station Transceivers

   Författare :Christopher Mollén; Erik G. Larsson; A. Lee Swindlehurst; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Beamforming; distortion; massive MIMO; MIMO; nonlinear hardware; peak-to-average ratio;

   Sammanfattning : Massive MIMO (multiple-input–multiple-output) is a multi-antenna technology for cellular wireless communication, where the base station uses a large number of individually controllable antennas to multiplex users spatially.  This technology can provide a high spectral efficiency. LÄS MER

3. 2. Intermodulation Distortion in Active and Passive Components

   Författare :Martin Mattsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intermodulation distortion; hyperabrupt junction; polynomial model; passive intermodulation; nonlinear analysis; loaded-line phase shifter; varactor modeling;

   Sammanfattning : Wireless communication is growing rapidly, and the demand for higher data rate, low latency, and availability leads to a more complex infrastructure with new challenges. Multiple communication systems have to co-exist in a densely populated frequency-spectrum, where higher power levels and more sensitive receivers are required. LÄS MER

4. 3. Perceptually motivated speech recognition and mispronunciation detection

   Författare :Christos Koniaris; Olov Engwall; Martin Cooke; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; feature extraction; feature selection; auditory models; MFCCs; speech recognition; distortion measures; perturbation analysis; psychoacoustics; human perception; sensitivity matrix; pronunciation error detection; phoneme; second language; perceptual assessment;

   Sammanfattning : This doctoral thesis is the result of a research effort performed in two fields of speech technology, i.e., speech recognition and mispronunciation detection. Although the two areas are clearly distinguishable, the proposed approaches share a common hypothesis based on psychoacoustic processing of speech signals. LÄS MER

5. 4. Tree Structures in Broadcast Encryption

   Författare :Kristin Anderson; Ingemar Ingemarsson; Jacob Löfvenberg; Robert Forchheimer; Ben Smeets; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Broadcast encryption; Subset Difference; tree structure; Information technology; Informationsteknologi;

   Sammanfattning : The need for broadcast encryption arises when a sender wishes to securely distribute messages to varying subsets of receivers, using a broadcast channel, for instance in a pay-TV scenario. This is done by selecting subsets of users and giving all users in the same subset a common decryption key. LÄS MER

7. 5. Modeling and optimization of least-cost corridors

   Författare :Lindsi Seegmiller; Takeshi Shirabe; Kai-Florian Richter; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; raster data modeling; raster-based geographic information systems; route planning; optimal routing; corridor; wide path; corridor width; distortion; three-dimensional grid; rasterdatamodellering; rasterbaserade geografiska informationssystem; ruttplanering; optimal dirigering; korridor; bred väg; korridorbredd; distorsion; tredimensionellt rutnät; Geoinformatics; Geoinformatik;

   Sammanfattning : Given a grid of cells, each having a value indicating its cost per unit area, a variant of the least-cost path problem is to find a corridor of a specified width connecting two termini such that its cost-weighted area is minimized. A computationally efficient method exists for finding such corridors, but as is the case with conventional raster-based least-cost paths, their incremental orientations are limited to a fixed number of (typically eight orthogonal and diagonal) directions, and therefore, regardless of the grid resolution, they tend to deviate from those conceivable on the Euclidean plane. LÄS MER