Title :
Modems for emerging digital cellular-mobile radio system
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of California, Davis, CA, USA
fDate :
5/1/1991 12:00:00 AM
Abstract :
Digital 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 π/4-QPSK (π/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 π/4-QPSK modems (emerging American and Japanese digital cellular 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 π/4-QPSK and other digital modems. More spectrally efficient modem trends for future cellular mobile (land mobile) and satellite communication system applications are also highlighted
Keywords :
cellular radio; digital radio systems; minimum shift keying; modems; phase shift keying; radiotelephony; standards; π/4-QPSK; American standards; European standards; GMSK; Gaussian minimum-shift keying; Japanese standards; coherent QPSK; differential QPSK; digital cellular standards; digital cellular-mobile radio; digital channel sounding; digital modems; filtering methods; land mobile radio; pilot-aided techniques; radiotelephony; satellite communication system; spectrally efficient; Bandwidth; Bit rate; Digital modulation; Frequency modulation; Frequency shift keying; Land mobile radio; Modems; RF signals; Radio frequency; Telephony;
Journal_Title :
Vehicular Technology, IEEE Transactions on
