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:
Jul. 16, 2002
Filed:
Jul. 23, 1999
Kendall G. Moore, Tempe, AZ (US);
Samuel L. Thomasson, Gilbert, AZ (US);
Acoustic Technologies, Inc., Mesa, AZ (US);
Abstract
A transmitted signal is coupled through a coarse delay and a fine delay to one input of a correlator. Another input of the correlator is coupled to a received signal. The delays are adjusted for maximum correlation and the output of the fine delay is subtracted from the received signal to reduce or eliminate an echo. The delays operate by sampling the signal and storing the samples at successive storage sites. The storage sites are read a predetermined time later, producing the delay. The read operation for the coarse echo includes three readings from separate sites and using the correlation products to indicate the magnitude and direction for changing the delay.