Title :
A high speed data modem for digital cellular radio
Author :
Jacobsmeyer, Jay M.
Author_Institution :
Pericle Commun. Co., Colorado Springs, CO, USA
Abstract :
This paper describes an adaptive rate modem ideally suited for fading mobile radio channels. The modem adapts its information rate to the time-varying channel conditions by changing the code rate of a special trellis code. The modem exploits the unused capacity in the cellular radio channel and can quadruple the mean data rate of wireless modems. Because trellis coded modulation is used, the bandwidth and symbol rate are constant. A novel estimator and rate changing hardware ensure the modem can track and adjust to rapid multipath fading. The modem can be made backward compatible with existing TDMA digital cellular standards like IS-136 and GSM
Keywords :
adaptive systems; cellular radio; channel capacity; differential phase shift keying; digital radio; fading; land mobile radio; modems; time division multiple access; time-varying channels; trellis coded modulation; trellis codes; DPSK; GSM; IS-136; TCM; TDMA digital cellular standards; adaptive rate modem; bandwidth; code rate; digital cellular radio; estimator; fading mobile radio channels; high speed data modem; information rate; mean data rate; multipath fading; rate changing hardware; symbol rate; time-varying channel conditions; trellis code; trellis coded modulation; wireless modems; Bandwidth; Convolutional codes; Fading; Hardware; Information rates; Land mobile radio; Land mobile radio cellular systems; Modems; Modulation coding; Time-varying channels;
Conference_Titel :
Wireless Communications Conference, 1997., Proceedings
Conference_Location :
Boulder, CO
Print_ISBN :
0-7803-4194-5
DOI :
10.1109/WCC.1997.622244
