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:
Mar. 26, 1996
Filed:
Aug. 01, 1994
Sangil Park, Austin, TX (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
Echo time cancellation may be determined in a full duplex system 300 by providing an echo time determiner 302 which samples signals on either the transmit path 105 or the receive path 106. Once sampled, the signals are then filtered via smoothing filter 402 at a first smoothing parameter. Each filtered signal sample 403 is then compared with a first threshold and this comparison is sequentially done until a filtered signal sample is favorable with the first predetermined threshold. When the first signal sample is favorable to the first predetermined threshold, the beginning echo time is determined and the smoothing parameter is adjusted to a second smoothing parameter and the threshold is adjusted to a second predetermined threshold. Upon making these adjustments, the signal samples are again filtered over this time with the second smoothing parameter. The second filtered signals are then compared with the second threshold until a second filtered signal is favorable with the second predetermined threshold. When this occurs, the end of the echo is determined.