Accession Number:

AD0768999

Title:

Adaptive Data Transmission Study.

Descriptive Note:

Final rept. Sep 72-Jun 73,

Corporate Author:

SIGNATRON INC LEXINGTON MASS

Personal Author(s):

Report Date:

1973-08-01

Pagination or Media Count:

217.0

Abstract:

DATA TRANSMISSION SYSTEMS, INTERSYMBOL INTERFERENCE, VITERBI DECODING, SIGNAL PROCESSING, TROPOSPHERIC SCATTER COMMUNICATION, MAXIMUM LIKELIHOOD ESTIMATIONA study was completed of feasible techniques for transmission of up to 13 megabitssecond over a tropospheric-scatter channel. The techniques identified for this study were frequency-division-multiplexfrequency modulation, parallel processing of subchannel data, transmitter time-gating, receiver time-gating, coding techniques, maximum likelihood detection including the Viterbi algorithm, and adaptive equalization. The investigation considered a realistic channel model and terminal equipment constraints in a determination of technique performance, adaptability to a changing multipath channel, and implementability. A practical realization of a feedback equalizer was found to have superior performance relative to all other practical receivers considered. Moreover, the equalizer performance was within 1 dB of a bound for an ideal maximum likelihood decoder. Modified author abstract

Subject Categories:

  • Cybernetics
  • Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE