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Model verifies design of mobile data modemIt has been proposed to use differential minimum shift keying (DMSK) modems in spacecraft-based mobile communications systems. For an employment of these modems, it is necessary that the transmitted carrier frequency be known prior to signal detection. In addition, the time needed by the receiver to lock onto the carrier frequency must be minimized. The present article is concerned with a DMSK modem developed for the Mobile Satellite Service. This device demonstrated fast acquisition time and good performance in the presence of fading. However, certain problems arose in initial attempts to study the acquisition behavior of the AFC loop through breadboard techniques. The development of a software model of the AFC loop is discussed, taking into account two cases which were plotted using the model. Attention is given to a demonstration of the viability of the modem by an approach involving modeling and analysis of the frequency synchronizer.
Document ID
19860041776
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Davarian, F.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Sumida, J.
(California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Date Acquired
August 12, 2013
Publication Date
February 1, 1986
Publication Information
Publication: Microwaves & RF
Volume: 25
ISSN: 0745-2993
Subject Category
Communications And Radar
Accession Number
86A26514
Distribution Limits
Public
Copyright
Other

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