The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 13, 1992
Filed:
Jan. 09, 1992
Gordon M Jacobs, Oakland, CA (US);
Nuance DesignWorks, Inc., Oakland, CA (US);
Abstract
A decoder for recovering an analog signal from its digital representation produced by an encoder employing adaptive-delta-modulation first decodes audio bit-stream (17) in the digital domain with digital delta demodulation (15), to a pulse-code-modulation (PCM) format digital signal. Post-processing (35), complementary to encoder processing is performed digitally on the PCM signal. The output from post-processor (35) is up-sampled, and using delta modulation, a noise shaped single-bit highly oversampled output is produced by converter (14). Applying the single-bit output to lowpass filter (11) re-constructs the decoded analog signal, which is audio output (12). By fully exploiting digital signal processing techniques, the decoder can be manufactured at low cost and exceed the performance of existing analog implementations.