SBIR/STTR Research Award
A NEW FAMILY OF LOW OVERHEAD ERROR REDISTRIBUTING (LOER) CODING TECHNIQUES WILL BE EXPLORED.
Award amount
$49,680Program and phase
SBIR · Phase IAward year
1984Award details
- Awarding agency
- National Aeronautics and Space Administration
- Branch
- Not reported
- Recipient company
- Time & Space Processing Inc.
- Proposal award date
- Not reported
- Contract end date
- Not reported
- UEI
- Not reported
- Solicitation number
- Not reported
- Topic code
- Not reported
Research abstract
A NEW FAMILY OF LOW OVERHEAD ERROR REDISTRIBUTING (LOER) CODING TECHNIQUES WILL BE EXPLORED. CODES IN THIS FAMILY INTRODUCE A SMALL BIT ERROR RATE BUT CONCENTRATE THE TRANSMISSION BIT ERRORS ON SOME OF THE BITS WHILE SHIELDING CERTAIN OTHER BITS. THIS LOER CODING TECHNIQUE IS COMBINED WITH A DATA QUALITY INDICATOR (DQI) SIGNAL FROM THE MODEM TO YIELD AN ALGORITHM FOR TRANSMISSION OF LINEAR PREDICTIVE CODING (LPC) SPEECH OVER FADING MOBILE SATELLITE CHANNELS. THIS ALGORITHM USES LOER CODING TO MINIMIZE THE EFFECT OF BIT ERRORS AND THE DQI SIGNAL TO TRIGGER INTER-FRAME SMOOTHING OF LPC MODEL PARAMETERS. THE LOER CODING SCHEME IS IMPLEMENTED IN A REAL TIME VOICE DIGITIZER. THE DQI SIGNAL IS IMPLEMENTED IN A MOBILE SATELLITE MODEM. THESE DEVICES ARE INTERFACED AND THE OVERALL EFFECT OF THE ERROR PROTECTION ALGORITHMS IS MEASURED IN ACTUAL LISTENING TESTS.
Technology keywords
Not reported