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:
May. 31, 1994
Filed:
Jul. 12, 1993
Motorola, Inc., Schaumburg, IL (US);
Abstract
A signal processor such as an ADPCM decoder (128b) receives an input signal. As part of the CCITT Recommendation G.726 algorithm, an inverse adaptive quantizer (41) processes the input signal to provide a quantized difference signal d.sub.q (k). When enabled, a noise detector (50) samples signal d.sub.q (k) once for each of a predetermined number of received samples. The noise detector (50) adds the absolute value of signal d.sub.q (k) to a total energy estimate. At the end of the predetermined number of samples, the noise detector (50) compares the total energy estimate to a product of a noise threshold and the predetermined number. If the total energy estimate exceeds this product, then a noise indication is provided. In another embodiment (228b) a noise detector (250) compares an existing energy estimate signal d.sub.ml (k) computed by an adaptation speed control block (48) as part of the G.726 algorithm to an energy threshold to save processing time.