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:
Apr. 06, 2010
Filed:
Feb. 09, 2006
Yonghua Fang, Ottawa, CA;
Renee Johnston, Dunrobin, CA;
Mirjana Popovic, Ottawa, CA;
Dieter Schulz, Dunrobin, CA;
Yonghua Fang, Ottawa, CA;
Renee Johnston, Dunrobin, CA;
Mirjana Popovic, Ottawa, CA;
Dieter Schulz, Dunrobin, CA;
Mitel Networks Corporation, Ottawa, Ontario, CA;
Abstract
A method of determining residue-echo threshold for the trans-hybrid echo path of a loop start (LS) trunk line, comprising the steps of estimating the impulse response of the trans-hybrid echo path, passing a speech-like signal through the LS trunk circuit and collecting the echo signal. The collected echo signal is compared to the convolution of the speech-like signal with the estimated impulse response. The difference between the convolution result and the collected echo signal is the residue echo, which represents the effect of nonlinearity. With different levels of excitation signal, a curve of residue echo power level against input signal level is obtained, and the distortion characteristics are derived from this curve.