Method and apparatus for reducing echo feedback in a communication system

• US 6,947,773 B2
• Filed: 04/05/2004
• Issued: 09/20/2005
• Est. Priority Date: 04/18/2000
• Status: Expired due to Fees

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Grube, Gary, Ziolko, Eric, Novorita, Robert
• Primary Examiner(s): Ferguson, Keith
• Application Number:
  US10/818,150
• Publication Number:
  US 20040192202A1
• Time in Patent Office: 533 Days
• Field of Search: 455/423, 455/424, 455/425, 455/426.1, 455/426.2, 455/10, 455/24, 455/500, 455/517, 455/63.1, 455/65, 455/67.11, 455/88, 455/569.1, 455/570, 455/422.1, 455/403, 455/569, 455/550.1, 379/569.1, 379/388.07, 379/388.01, 379/388.04, 379/406.03, 379/406.06, 379/390.01, 379/392.01, 379/406.01, 379/406.05, 379/406.6, 379/406.02, 370/286, 370/288, 370/289, 381/287, 381/318
• US Class Current: 455/570
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23

Abstract

A method and apparatus for reducing echo feedback in a wireless communication system (10) is accomplished when a receiving communication unit (24) senses a feedback signal, or echo, via an ancillary communication path. The receiving communication unit is a targeted recipient of an original audio signal generated by a transmitting communication unit (22), where the original audio signal (42) is conveyed to the receiving communication unit. Upon detecting the feedback signal and determining that it exceeds a feedback threshold, the receiving communication unit attenuates an audible output of the original signal to reduce echo to the transmitting communication unit. In addition, the receiving communication unit, and/or the transmitting communication unit include echo canceller to further minimize the echo within the digital communication system.

Claims

1. A method comprising the steps of:

processing an original audio signal to produce digitized original audio;

encoding the digitized audio signal to produce encoded original audio;

decoding the encoded original audio to produce recaptured digitized audio;

delaying the recaptured digitized audio based on a delay signal to produce delayed digitized audio;

scaling the delayed digitized audio based on a gain signal to produce scaled digitized audio; and

combining the scaled digitized audio with a subsequent original audio signal.

2. The method of claim 1, further comprising the step of receiving the delay signal as at least one of a pre-programmed delay value and an announced delay value.

3. The method of claim 1, further comprising the step of determining the gain signal based on a received echo signal.

4. A communication unit comprising:

a processing unit; and

memory operably coupled to the processing unit, wherein the memory stores programming instructions that, when read by the processing unit, cause the processing unit to process an original audio signal to produce digitized original audio;

encode the digitized audio signal to produce encoded original audio;

decode the encoded original audio to produce recaptured digitized audio;

delay the recaptured digitized audio based on a delay signal to produce delayed digitized audio;

scale the delayed digitized audio based on a gain signal to produce scaled digitized audio; and

combine the scaled digitized audio with a subsequent original audio signal.

5. The communication unit of claim 4, arranged and constructed to receive the delay signal as at least one of a pre-programmed delay value and an announced delay value.

6. The communication unit of claim 4, arranged and constructed to determine the control signal based on a received echo signal.