Browse Prior Art Database

IMPROVED SIGNAL QUALITY METRIC

IP.com Disclosure Number: IPCOM000008804D
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2002-Jul-15
Document File: 1 page(s) / 63K

Publishing Venue

Motorola

Related People

Kevin Good: AUTHOR [+2]

Abstract

This invention provides an improved signal quality metric algorithm over the existing method(s). The signal quality metric can be used in any application incorporating a Trellis decoding algorithm. This metric can be and is used as an indi- cation of the quality of the Trellis encoded data. As an example, in a Motorola Astro-TAC voting sys- tem, this metric is used to determine which received signal gets voted as the best signal. DESCRIPTION A Trellis decoder does not, unfortunately, pro- vide one with information as to how many bits were in error in a given transmitted Trellis encoded block of data. It can provide a final Viterbi metric if the Viterbi decoding algorithm is used, but this metric does not provide a good signal quality metric by itself. Other experimental algorithms utilizing aver- age energy in the Trellis encoded block or algo- rithms using the number of common distances in the distance metric table work quite well under static conditions, but are rather poor performers under faded conditions.

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MOTOROLA Technical Developments

IMPROVED SIGNAL QUALITY METRIC

by Kevin Good and Alan Wilson

INTRODUCTION

   This invention provides an improved signal quality metric algorithm over the existing method(s). The signal quality metric can be used in any application incorporating a Trellis decoding algorithm. This metric can be and is used as an indi- cation of the quality of the Trellis encoded data. As an example, in a Motorola Astro-TAC voting sys- tem, this metric is used to determine which received signal gets voted as the best signal. DESCRIPTION

  A Trellis decoder does not, unfortunately, pro- vide one with information as to how many bits were in error in a given transmitted Trellis encoded block of data. It can provide a final Viterbi metric if the Viterbi decoding algorithm is used, but this metric does not provide a good signal quality metric by itself. Other experimental algorithms utilizing aver- age energy in the Trellis encoded block or algo- rithms using the number of common distances in the distance metric table work quite well under static conditions, but are rather poor performers under faded conditions.

  This algorithm works as well as the other algo- rithms described above in static conditions and is vastly superior in providing an accurate signal quali- ty metric under faded conditions.

  This invention utilizes the energy associated with each symbol which is used in calculating the distance metric and produces a signal quality metric

based upon a weigh...