Title :
A 64 kbps digital land mobile radio system employing M-16QAM
Author :
Birchler, Mark A. ; Jasper, Steven C.
Author_Institution :
Motorola Inc., Land Mobile Products Sector Res., Schaumburg, IL, USA
Abstract :
The authors describe a 64 kbps digital mobile radio system which has been tailored for trunked radio system applications. Using a combination of digital speech coding, time division multiple access (TDMA), and spectrally efficient linear modulation technologies, up to 6 voice links are supported per 25 kHz RF channel. A key feature of the system is a new modulation method, M-16QAM, which makes possible high speed signaling in land mobile radio channels without the use of an equalizer. After a brief description of the overall system, including the TDMA frame/slot structure and speech coder, focus is shifted to the modulation technique. The motivation behind M-16QAM, as well as its design and simulated performance, are discussed in more detail. Results of field trials of an experimental modem are also discussed
Keywords :
amplitude modulation; digital radio systems; error statistics; mobile radio systems; modems; time division multiple access; 64 kbit/s; BER; M-16QAM; TDMA; digital land mobile radio system; digital speech coding; high speed signaling; modem; spectrally efficient linear modulation technologies; time division multiple access; trunked radio system; Digital modulation; Equalizers; Fading; Frequency division multiaccess; Land mobile radio; Modems; Modulation coding; Radio frequency; Speech coding; Time division multiple access;
Conference_Titel :
Wireless Communications, 1992. Conference Proceedings., 1992 IEEE International Conference on Selected Topics in
Conference_Location :
Vancouver, BC
Print_ISBN :
0-7803-0723-2
DOI :
10.1109/ICWC.1992.200737
