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:
Dec. 24, 1991
Filed:
Sep. 27, 1990
Herbert M Chen, Austin, TX (US);
Alan F Hendrickson, Austin, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
An apparatus for effecting echo suppression facilitating communications between an analog device and a digital device comprising a transmit circuit for processing outgoing signals, a receive circuit for processing incoming signals, and a control circuit for controlling the transmit circuit and the receive circuit. The transmit circuit includes transmit attenuators for attenuating the outgoing signals as they pass through the transmit circuit, and an analog-to-digital conversion circuit for converting analog signals to digital signals. The receive circuit includes receive attenuators for attenuating the incoming signals as they pass through the receive circuit and a digital-to-analog conversion circuit for converting digital signals to analog signals. Each of the transmit attenuators and the receive attenuators is digitally adjustable by the control circuit. The control circuit receives sensed outgoing signals from the transmit circuit and sensed incoming signals from the receive circuit and effects a comparison of the sensed outgoing and incoming signals to determine whether the apparatus is transmitting or receiving. The control circuit digitally adjusts the transmit attenuators and the receive attenuators to distribute a predetermined maximum loss among incoming signals and outgoing signals appropriately to increase signal attenuation in the receive circuit and reduce signal attenuation in the transmit circuit when the apparatus is transmitting, and to increase signal attenuation in the transmit circuit and decrease signal attenuation in the receive circuit when the apparatus is receiving.