Title :
Voice control of the pan-European digital mobile radio system
Author :
Southcott, C.B. ; Freeman, D. ; Cosier, G. ; Sereno, D. ; van der Krogt, A. ; Gilloire, A. ; Braun, H.J.
Author_Institution :
British Telecom Res. Lab., Ipswich, UK
Abstract :
The DTX (discontinuous transmission) system that has been standardized by CEPT for the pan-European digital mobile radio system is described. In this mode the transmitter is switched on when a user begins to talk and switched off again when he or she stops. There are two reasons for using DTX: to increase the number of radio channels (by 100% or more) which can be accommodated in a given bandwidth and to reduce the power drain in hand portable equipment. It is noted that, while adding little degradation to the speech channel and very little additional cost, the DTX will increase considerably the capacity of the system. Particular attention is given to the voice activity detector, the comfort noise subsystem, speech frame substitution, objective and subjective testing, and complexity
Keywords :
cellular radio; digital radio systems; radiotelephony; voice communication; CEPT standardisation; DTX system; comfort noise subsystem; discontinuous transmission; pan-European digital mobile radio system; speech frame substitution; system capacity improvement; testing; voice activity detector; voice control; Bandwidth; Control systems; Costs; Degradation; Detectors; Land mobile radio; Radio control; Radio transmitters; Speech enhancement; Testing;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64122
