Search for dissertations about: "Vector quantization VQ"

Showing result 1 - 5 of 9 swedish dissertations containing the words Vector quantization VQ.

  2. 1. Towards Asymptotic Vector Quantization

    Author : Jonas Samuelsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EM algorithm; parametric models; expectation maximization; spectrum coding; Gaussian mixture models; fast search; bounded support; multidimensional companding; vector quantization; high rate quantization;

    Abstract : We study topics in source coding, and vector quantization (VQ) in particular. We approach VQ from two directions: a theoretical starting point based on high rate quantization theory, and a practical based on a database desription of the signal source. READ MORE

  4. 2. On Soft Decoding and Robust Vector Quantization

    Author : Mikael Skoglund; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; speech and image coding; intersymbol interference; Rayleigh fading; soft decoding; CDMA; index assignment; Hadamard transform; channel optimized VQ; robust VQ; combined source-channel coding; vector quantization VQ ; noisy channels;

    Abstract : This thesis considers vector quantization for noisy channels. Vector quantization (VQ) is an important technique for block-based source coding, with applications in, e.g., speech and image coding. READ MORE

  5. 3. Towards Low-Complexity Vector Quantization

    Author : T. Z. Shabestary; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gaussian encoder; source coding; companding; Gaussian mixture; random coding; vector quantization; spectral coding;

    Abstract : This thesis is about constructing low-complexity, yet high-performance, vector quantizers (VQs) for 'real-world' sources. Knowledge concerning the source is extracted from a finite training set. In contrast with conventional VQ design procedures, we use the training set to estimate a statistical model for the source. READ MORE

  6. 4. On Robust LPC-spectrum Coding and Vector Quantization

    Author : Roar Hagen; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; robustness against channel noise; LPC-spectrum coding; vector quantization; speech coding; linear mapping of a block code;

    Abstract : Digital speech coding is concerned with representing a discrete-time speech signal with as few bits per second as possible without introducing annoying artifacts in the coded speech. Many modern speech coders are based on Linear Predictive Coding (LPC) which employ a source-filter model for speech production. READ MORE

  7. 5. Vector Quantization in Speech Coding. Variable Rate, Memory and Lattice Quantization

    Author : Thomas Eriksson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : This dissertation focuses on different quantization methods in speech coding. Variable rate quantization has the potential to substantially reduce the bit rate requirements in speech coding. READ MORE