Browse Prior Art Database

UNKNOWN CODEWORD STATUS PREDICTION

IP.com Disclosure Number: IPCOM000008632D
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2002-Jun-28
Document File: 1 page(s) / 57K

Publishing Venue

Motorola

Related People

Rick Britton: AUTHOR [+4]

Abstract

The present invention relates to internal digital voice frame voting in a TACTM system. When digital voice frames are voted, the resultant frame quality will be better than or equal to the best frame that is being received.

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MOTOROLA Technical Developments

UNKNOWN CODEWORD STATUS PREDICTION

by Rick Britton, Phil Hargrave, Dave Helm and Steve VanSickle

BACKGROUND

  The present invention relates to internal digital voice frame voting in a TACTM system. When digital voice frames are voted, the resultant frame quality will be better than or equal to the best frame that is being received.

  This is accomplished by the fact that the frame is broken into smaller units called codewords. Along with the codewords, the frame contains bit error status information related to the codewords. Based off of the status information, the voter will select the best codewords to build the voted frame. Ideally, each codeword of importance will have a unique individual status associated with it. Thus, making the selection of codewords an exercise of creating a frame with the lowest combined status by performing pure codeword by codeword voting.

PROBLEM

  APCO compliant systems use an IMBE vocoder. The voice portion of the IMBE frames consist of eight codewords, UO to U7. The bit error status information presented to the voter consists of individual status information for the UO and U4 codewords as well as a combined status for the UO

to U6 codewords. Since there is not an individual codeword status for each codeword, pure codeword by codeword voting cannot be performed. Thus, the resultant signal quality will potentially be less than if pure codeword by codeword voting could have been performed.

SOLUTION

  Since...