Echo mitigation in the presence of variable delays due to adaptive jitter buffers

Patent metadata

Field	Value
Publication number	US-8929263-B2
Application number	US-201313905640-A
Country	US
Kind code	B2
Filing date	May 30, 2013
Priority date	Feb 25, 2010
Publication date	Jan 6, 2015
Grant date	Jan 6, 2015

Abstract

In an example embodiment, a control connection is introduced between an adaptive jitter buffer (AJB) and an adaptive bulk delay (ABD) buffer of an echo canceller (ECAN) in an Internet Protocol (IP) conference bridge. The control connection allows the AJB to control the amount of delay inserted by the ABD in the ECAN convolution processor (CP) signal path. The adjustment in ABD delay restores the time alignment of the ECAN internal echo estimate and offsets variations in echo tail delay introduced by network induced AJB delay changes. Time-invariance is preserved in the echo tail path.

First claim

The invention claimed is:

1. Logic encoded in a tangible, non-transitory computer readable medium for execution by a processor, and when executed operable to:
receive a first signal from a first interface;
receive a second signal from a second interface, the second signal comprising an echo of the first signal, the second signal passing through an adaptive jitter buffer;
generate an echo cancelation signal to eliminate the echo of the first signal;
determine an echo delay fo…

Assignees

• Cisco Tech Inc

Inventors

• Ramalho Michael A
• Skrabutenas Gary
• Frauenthal Jim

Classifications

• H04M3/002 Primary

  Electricity · mapped topic

• H04M9/082 Primary

  Electricity · mapped topic

• H04B3/23

  Electricity · mapped topic