A spectrum efficient speech processing method for land mobile radio systems

Author

Hong, Daehyoung ; Kotzin, Michael D. ; van den Heuvel, A.P.

Author_Institution

Motorola Inc., Schaumburg, IL, USA

fYear

1991

fDate

19-22 May 1991

Firstpage

274

Lastpage

279

Abstract

A method employing a novel combination of speech coding and channel modulation to provide improved spectrum efficiency for land mobile radio systems is described. The method employs a variant of the adaptive subband coding method and multilevel modulation which permits up to 4 TDM (time-division-multiplexed) voice channels to be carried by a single 25 kHz FM channel and more than 10 voice channels if an efficient linear modulation is employed. Details of the implementation show that the complexity required is modest. Comparison with current analog FM radio in terms of practically achievable performance in a mobile has shown that while the induced audible defects due to channel errors are quite different the overall performance is very comparable

Keywords

encoding; mobile radio systems; modulation; speech analysis and processing; telecommunication channels; 25 kHz; FM channel; TDM; VLF; adaptive subband coding; channel errors; channel modulation; land mobile radio systems; linear modulation; multilevel modulation; performance; spectrum efficiency; speech coding; speech processing; voice channels; Bandwidth; Bit rate; Channel coding; Error analysis; Land mobile radio; Modulation coding; Robustness; Speech coding; Speech enhancement; Speech processing;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1991. Gateway to the Future Technology in Motion., 41st IEEE

Conference_Location

St. Louis, MO

ISSN

1090-3038

Print_ISBN

0-87942-582-2

Type

conf

DOI

10.1109/VETEC.1991.140493

Filename

140493