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Modems for emerging digital cellular-mobile radio systemDigital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Feher, Kamilo
(California, University Davis, United States)
Date Acquired
August 15, 2013
Publication Date
May 1, 1991
Publication Information
Publication: IEEE Transactions on Vehicular Technology
Volume: 40
ISSN: 0018-9545
Subject Category
Communications And Radar
Accession Number
Distribution Limits

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