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. 01, 1991
Filed:
Mar. 05, 1990
Eric R Schorman, Bedford, TX (US);
Kevin M Laird, Halton City, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A communication device (10) comprises an input for receiving a first audio signal (12) and an input (36) for receiving a second audio signal. The communication device (10) also includes a circular buffer (34) for storing the output digital audio signal (12) and for producing an output audio signal (20). The communication device (10) determines whether at least a portion of the output audio signal (20) is present in the second audio signal. If such a portion is present, the communication device (10) subtracts the portion of the output audio signal (20) from the second audio signal, to produce a third audio signal (26). A threshold detector, responsive to the third audio signal, produces a first control signal, when the level of the third audio signal increases to at least a first predetermined level, and a second control signal, when the level of the third audio signal decreases to a value lower than a second predetermined level, where the second predetermined level is lower than the first predetermined level. Finally, a buffer control (22 ) causes the buffer (34) to suspend production of the output audio signal in response to the first control signal, and causes the buffer (34) to resume production of the audio signal (12), in response to the second control signal.