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:
Dec. 26, 2000
Filed:
Apr. 02, 1997
Luis E Caceres, Hackettstown, NJ (US);
Linda Ann Seltzer, Lawrenceville, NJ (US);
Cliff Sui, Berkeley Heights, NJ (US);
AT&T Corporation, New York, NY (US);
Abstract
A method for processing telecommunications signals to alleviate echo during a voice communication between a local talker and a remote talker comprises the application of circular buffers for near and far end signals to preserve processing time. Overlapping blocks of samples are processed and indexed by incrementing the index over time to generate an array for storing magnitude coherence versus time delay between outgoing and incoming samples. Echo is clipped based on power spectral matching. The clipped echo is replaced with noise fill of at least one of two types, white noise and tonal noise, at an appropriate level. Also, crackle which comprises high energy spikes and a residual echo effect which is low energy, bursty and non-linear may be identified and replaced with noise fill.