Patent
Resisting the effects of channel noise in digital transmission of information
Reads0
Chats0
TLDR
In this article, the vector quantization technique is used to resist the effects of channel noise in the digital transmission of information by means of the technique known as vector quantisation, in which the codebook for binary index code assignment is generated by picking a vector quantized codeword with high probability and low perceptually-related distance from a required group of nearest neighbors, assigning that codewords and those neighbors binary index codes differing only in one bit, repeating the steps just outlined for assigned binary code to residual codeewords until the last assignments must be made arbitrarily.Abstract:
A method for resisting the effects of channel noise in the digital transmission of information by means of the technique known as vector quantization, in which the codebook for binary index code assignment is generated by picking a vector quantized codeword with high probability and low perceptually-related distance from a required group of nearest neighbors, assigning that codeword and those neighbors binary index codes differing only in one bit, repeating the steps just outlined for assigned binary index codes to residual codewords until the lasts assignments must be made arbitrarily. Applications include transmission of speech by coded LPC parameters and transmission of image intensity or chrominance blocks for visual images. Such systems also make possible and are attractive for memory-efficient storage of such signals.read more
Citations
More filters
Journal ArticleDOI
Side match and overlap match vector quantizers for images
TL;DR: Owing to the structure of SMVQ and OMVQ, simple variable length noiseless codes can achieve as much as 60% bit rate reduction over fixed-length noisless codes.
PatentDOI
Low-bit-rate speech coder using LPC data reduction processing
TL;DR: A speech coder employs vector quantization of LPC parameters, interpolation, and trellis coding for improved speech coding at low bit rates (400 bps).
PatentDOI
Vector quantization in a harmonic speech coding arrangement
TL;DR: A harmonic speech coding arrangement where vector quantization is used to improve speech quality is described in this article, where scaled vectors can be added into the magnitude and phase spectra for use at the synthesizer in generating speech as a sum of sinusoids.
Patent
Mapper for high data rate signalling
Yuri Goldstein,Yuri Okunev +1 more
TL;DR: In this article, a PAM mapper includes a constellation matrix memory (40) string indicating of a plurality of different constellations, which can be used individually or together to support different modem data rates.
Patent
Efficient excitation quantization in noise feedback coding with general noise shaping
Jes Thyssen,Juin-Hwey Chen +1 more
TL;DR: In this article, a zero-state filter structure with multiple filters is used to produce a zero state response error vector in a noisy feedback coding (NFC) system, where the response vector is generated by the all-zero filter, which is the only filter with a response substantially equivalent to a filter response of the zero state filter.
References
More filters
Journal Article
Vector quantization
TL;DR: During the past few years several design algorithms have been developed for a variety of vector quantizers and the performance of these codes has been studied for speech waveforms, speech linear predictive parameter vectors, images, and several simulated random processes.
Journal ArticleDOI
Product code vector quantizers for waveform and voice coding
M. J. Sabin,Robert M. Gray +1 more
TL;DR: Several algorithms are presented for the design of shape-gain vector quantizers based on a traning sequence of data or a probabilistic model, and their performance is compared to that of previously reported vector quantization systems.
Patent
Predictive coding of speech signals
TL;DR: In this article, an adaptive predictor is employed which is readjusted periodically to match the time-varying characteristics of a speech signal, which is used to reduce the channel capacity required to transmit a signal with specified fidelity.
Patent
Adaptive graylevel image compression system
TL;DR: In this paper, a method for modeling differential pulse code modulation (DPCM) input data for entropy coding is presented, in which the sign and magnitude of one piece of DPCM data after another are modelled to provide a magnitude state input and a sign state input, respectively, to an entropy encoder or decoder.
Journal ArticleDOI
Analysis of Digital Errors in Nonlinear PCM Systems
N. Rydbeck,C.-E. Sundberg +1 more
TL;DR: The technique used for the analysis leads to the conclusion that there are PCM codes less sensitive to digital errors than the standard binary folded PCM code.