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.

Date of Patent:
Sep. 09, 2003

Filed:

Apr. 30, 1998
Applicant:
Inventors:

Michael O. Polley, Richardson, TX (US);

William J. Bright, Dallas, TX (US);

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M 1/00 ;
U.S. Cl.
CPC ...
H04M 1/00 ;
Abstract

Echo cancellation in data communication between modems utilizes analog echo cancellation to lessen reduction of usable dynamic range of the received signal at the input to the analog-to-digital converter (DAC) in the receiver. Two digital-to analog (D/A) conversions are provided in the modem's analog front end (AFE). One generates the analog signal for transmission. The other generates an analog representation of a cancellation signal that is used to electronically cancel the echo before analog-to-digital (A/D) conversion of the received signal. A preferred embodiment utilizes multiplexed DAC architecture to emulate two DACs by sharing DAC circuitry between data paths of the two D/A conversions.


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