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Patent Searching and Data


Title:
APPARATUS FOR AND METHOD OF SPEECH DIGITIZING
Document Type and Number:
WIPO Patent Application WO1995008241
Kind Code:
A3
Abstract:
A speech encoder converts analog speech signals into a stream of binary coded speech samples. A circuit for performing analog to digital conversion compares an input speech signal with a signal from a digital integrator. Based on the comparison a series of decisions are registered which indicate a step sign of the input signal. A syllabic filter generates a step magnitude according to the registered decisions. The step sign and step magnitude are combined providing a sign/magnitude representation of the input signal. When the sign/magnitude representation is integrated digitally in a decimation filter a digital representation of the analog signal is formed. A speech decoder, the antithesis of the encoder, converts binary coded speech samples into an analog waveform in a manner opposite to the A/D conversion method.

Inventors:
DENT PAUL W
Application Number:
PCT/US1994/010274
Publication Date:
April 13, 1995
Filing Date:
September 13, 1994
Export Citation:
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Assignee:
ERICSSON GE MOBILE COMMUNICAT (US)
International Classes:
H04L27/18; G10L19/00; H03C1/54; H03H1/02; H03M1/00; H03M1/38; H03M3/02; H03M3/04; H04B1/26; H04B1/40; H04B7/26; H04B14/06; H04L25/03; H04L27/00; H04L27/20; (IPC1-7): H04N5/225
Foreign References:
US4123709A1978-10-31
US4411002A1983-10-18
US4783644A1988-11-08
US4541103A1985-09-10
Other References:
See also references of EP 0673576A4
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