Accession Number : AD0854654

Title :   Adaptive Communications Techniques.

Descriptive Note : Final rept. Oct 67-Nov 68,

Corporate Author : COMMUNICATIONS AND SYSTEMS INC PARAMUS NJ

Personal Author(s) : Franco, Albert G. ; Egstein, Marshall ; Morgan, Kenneth

Report Date : MAY 1969

Pagination or Media Count : 148

Abstract : New methods were developed that are applicable to HF that will measure in a fraction of a second multipath, Doppler, in-band noise, signal strength, and frequency selective noise. These methods, which were developed for modems employing FSK and quaternary DPSK modulation, use the transmitted data to measure the characteristics of the medium; no additional test signals are required. As an outgrowth of the Doppler sensing technique, a new way of Doppler tracking for quaternary DPSK modems was developed. The measurements devised under this program can be used to initiate adaptive responses that will improve system performance. Several of the adaptive responses examined appear attractive for this application. A simulation program for evaluating the sensing techniques and these adaptive responses is presented. (Author)

Descriptors :   *INFORMATION THEORY), (*ADAPTIVE COMMUNICATIONS, (*DATA TRANSMISSION SYSTEMS, DIGITAL SYSTEMS), HIGH FREQUENCY, MODULATORS, DEMODULATORS, MODULATION, ANOMALIES, DETECTORS, DOPPLER SYSTEMS.

Subject Categories : Cybernetics
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE