The Lincoln Low-Rate Vocoder: A 1200/2400 bps LPC-10 Voice Terminal

Abstract

The following is a description of a low data rate voice terminal. The unit uses an LPC-10 algorithm which provides a 2400 bps NATO standard compatible mode and a 1200 bps frame-fill mode. The unit has an RS-449 digital interface with MIL-STD-188-114 levels. The user operates the unit from a telephone instrument with a PTT handset. The user interface models an augmented combination of an FM transceiver and a telephone to inform the user of the state of the data communications equipment in a natural manner. These protocols cover the full and half duplex channels. The unit exhibits a DRT (intelligibility) score of 91.1% at 2400 bps and 88.7% at 1200 bps in benign acoustic environments. (Author)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 21, 1984
Accession Number
ADA141291

Entities

People

  • Douglas B. Paul

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Coding
  • Connectors
  • Data Rate
  • Data Transmission
  • Decoding
  • Digital Communications
  • Environment
  • Indicators
  • Intelligibility
  • Microphones
  • Overload
  • Speech
  • Standards
  • Terminals
  • Transmitters
  • User Interface
  • White Noise

Readers

  • Aerospace Test and Evaluation
  • Speech Processing/Speech Recognition.
  • Team-Based Human-Centered Cognitive Task Decision Making and Information Performance.