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:
Sep. 14, 2004
Filed:
Jan. 26, 2001
Luke A. Tucker, Sydney, AU;
Mark Greig Wildie, Sydney, AU;
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A double-talk detector ( ) for an acoustic echo canceler ( ) of a VoIP terminal ( ) converts ( ) received far-end signals ( ) and transmitted near-end signals ( ) into the frequency domain and high-pass filters out ( ) low-frequencies representing noise to obtain a complex reference signal and a complex error signal, respectively. It then correlates ( ) the complex signals and computes ( ) the instantaneous error energy ( ) and smoothed (long-term average) error energy ( ) of the complex error signal. If the convergence value is below 0.06 ( ), the signals are converged and double-talk detection is enabled ( ). If the convergence value is above 0.09 ( ), the signals are diverged and double-talk detection is disabled ( ). If double-talk detection is not enabled, an error threshold ( ) is set ( ) to the value of the smoothed error energy. If double-talk detection is enabled ( ), presence of double-talk is indicated ( ) if the instantaneous error energy value exceeds ( ) the error threshold, and absence of double-talk is indicated ( ) if the instantaneous error energy value does not exceed ( ) the error threshold.