SYSTEM STUDY FOR SUPER MOBILE COMMUNICATIONS SATELLITE GROUND STATION.
Quarterly rept. no. 3, 1 Jan-31 Mar 64
PENNSYLVANIA UNIV PHILADELPHIA MOORE SCHOOL OF ELECTRICAL ENGINEERING
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The work included analyses of certain digital modulation systems which are potential competitors to the analog systems reviewed earlier, analysis of antenna noise, further develop ment of antenna array systems, a development of a method for field calculation of antenna pointing directions, and a survey of existing and potential low noise receiving systems. The modulation studies indicate that only scant improvement over the capability of angle modulation feedback techniques are possible with digital systems - assuming the published results on the former are correct. The conclusion is based on analyses carried out on several multistate PCM transmission systems. One of these, using a weighted pulse duration, the weighting being dependent on the significance of the information represented by the pulse does not appear to have been studied before. It gave better results than a single error coded system, a deltasigma system, and of course, an unweighted system. Author