ANDVT Rate Conversion Algorithm (from 2400 b/s to 1200 b/s)

Abstract

The 2400-b/s linear predictive coder (LPC) is currently being widely deployed to support tactical voice communication over narrowband channels. However, lower-data-rate voice encoders are needed for special applications: improved performance in high-bit-error conditions and implementation of integrated voice/data systems. In this report, we generated a rate-conversion algorithm to compress voice data rate from 2400 b/s to 1200 b/s. Rate reduction is effected outside the Advanced Narrowband Digital Voice Terminal (ANDVT), requiring no modification to the ANDVT software and hardware. This is a cost-effective way of obtaining 1200 b/s voice data ANDVT users for special communication requirements. Speech intelligibility at 1200 b/s as measured by the Diagnostic Rhyme Test is 90.4, which is only 1.7 points below that of the 2400 b/s LPC. Thus, 1200 b/s speech will be acceptable as 2400 b/s speech. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 27, 1991
Accession Number
ADA244340

Entities

People

  • George S. Kang
  • Larry J. Fransen

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Space

DTIC Thesaurus Topics

  • Algorithms
  • Coding
  • Computations
  • Conversion
  • Data Rate
  • Databases
  • Decoding
  • Digital Data
  • Frequency
  • Human Factors Engineering
  • Intelligibility
  • Narrowband
  • Repetition Rate
  • Speech Analysis
  • Standards
  • Terminals
  • Voice Communications

Fields of Study

  • Computer science

Readers

  • Radio communications and signal processing.
  • Speech Processing/Speech Recognition.
  • Systems Analysis and Design