Dual rate mobile data system

Author

Hansson, Ulf ; Sjöberg, Sten

Author_Institution

Eritel, Goteborg, Sweden

fYear

1992

fDate

10-13 May 1992

Firstpage

964

Abstract

A mobile data system that uses two significantly different data rates on the air interface is described. In a cellular system it is the conditions prevailing for a mobile terminal at the cell border that set the limit for a reasonable data rate. However, there are conditions in the cell, e.g., a stationary terminal close to the base station, where it is possible to use a higher data rate. A system is described that is designed for 12.5-kHz land mobile radio channels. The system uses a binary digital FM of GMSK type as the default transmission mode, but it switches to multilevel CPM when radio conditions are found to be good by the terminal. Considerations on the choice of the number of levels, and on the performance and complexity of the multilevel signaling, are given. Criteria for deciding when conditions are good enough for a rate increase are suggested

Keywords

data communication systems; frequency shift keying; minimum shift keying; mobile radio systems; pulse frequency modulation; telecommunication channels; 12.5 kHz; CPFSK; GMSK; air interface; base station; binary digital FM; cell border; cellular system; complexity; data rate; data rates; default transmission mode; dual rate system; land mobile radio channels; mobile data system; mobile terminal; multilevel CPM; multilevel signaling; number of levels; performance; radio conditions; rate increase; stationary terminal; Base stations; Bit rate; Data systems; Digital signal processing; Frequency modulation; Land mobile radio; Modems; Product development; RF signals; Switches;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1992, IEEE 42nd

Conference_Location

Denver, CO

ISSN

1090-3038

Print_ISBN

0-7803-0673-2

Type

conf

DOI

10.1109/VETEC.1992.245267

Filename

245267