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1. EP0473611 - ADAPTIVE TRANSFORM CODER HAVING LONG TERM PREDICTOR

Office European Patent Office
Application Number 90906644
Application Date 09.04.1990
Publication Number 0473611
Publication Date 11.03.1992
Publication Kind A4
IPC
G01L 5/00
GPHYSICS
01MEASURING; TESTING
LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
5Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
G10L 19/08
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
LSPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
19Speech or audio signal analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
04using predictive techniques
08Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters
G10L 21/02
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
LSPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
21Processing of the speech or voice signal to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
02Speech enhancement, e.g. noise reduction or echo cancellation
G10L 25/90
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
LSPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
25Speech or voice analysis techniques not restricted to a single one of groups G10L15/-G10L21/129
90Pitch determination of speech signals
G10L 25/93
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
LSPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
25Speech or voice analysis techniques not restricted to a single one of groups G10L15/-G10L21/129
93Discriminating between voiced and unvoiced parts of speech signals
CPC
G10L 25/90
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
LSPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
25Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
90Pitch determination of speech signals
Applicants PACIFIC COMMUNICATION SCIENCES, INC.
Inventors WILSON, PHILIP, J.
CHHATWAL, HARPRIT
Designated States
Priority Data 33999189 18.04.1989 US
Title
(DE) Adaptiver Transformcodierer mit Langzeitprädiktor.
(EN) ADAPTIVE TRANSFORM CODER HAVING LONG TERM PREDICTOR
(FR) CODEUR TRANSFORMATEUR ADAPTIF A PREVISION A LONG TERME.
Abstract
(EN)
A method and apparatus for removing the periodicity from a speech signal in a transform coder prior to the quantization of the speech signal, which speech signal is a sampled time domain speech signal composed of information samples, the transform coder sequentially segregating the speech signal into blocks of information samples, is shown to include apparatus and method for determining the pitch in each of the sample blocks (64), determining a long term prediction parameter (68) for each of the blocks based on the pitch determined for each block, calculating a periodicity value for each sample in the block wherein the calculation of the periodicity value is based upon the pitch and the long term predictor parameter, generating a revised block of difference (76) samples by subtracting the periodicity value from the corresponding sample, and performing adaptive transform coding on each of the difference blocks.

(FR)
Méthode et appareillage destinés à faire passer la périodicité d'un signal vocal dans un codeur transformateur avant la quantisation du signal vocal, celui-ci étant un signal vocal exemplifié dans un certain registre de temps, composé d'échantillons d'informations. Le codeur transformateur effectue une coupure séquentielle du signal vocal en blocs d'échantillons d'informations, et il comprend un appareillage et un procédé pour déterminer la hauteur du son de chacun des blocs d'échantillons (64), déterminant ainsi un paramètre de prévision à long terme (68) pour chacun des blocs basé sur la hauteur du son déterminée pour chaque bloc; il calcule une valeur périodique par chaque échantillon du bloc, le calcul de la valeur périodique étant basé sur la hauteur du son et le paramètre de prévision à long terme. Il en résulte un bloc révisé d'échantillons de différence (76) obtenu en soustrayant la valeur périodique de l'échantillon correspondant, et en réalisnt un codage de transformation adaptive de chacun des blocs de différence.