Title :
Trellis-coded modulation on digital microwave radio systems-simulations for multipath fading channels
Author :
McKay, R.G. ; Shafi, M. ; Carlisle, C.J.
Author_Institution :
Telecom Corp. of New Zealand Ltd., Wellington, New Zealand
fDate :
28 Nov-1 Dec 1988
Abstract :
Extensive simulations have been made to examine the performance of digital microwave radio systems based on TCM (trellis-coded modulation). Two coded systems have been simulated: the coded 1024-QAM (quadrature amplitude modulation) system uses separate TCM schemes for the I and Q channels, while the coded 512-CR system treats I and Q channels together. Theoretically predicted lower bounds on error performance were approached by both systems for additive white Gaussian noise channels. With residual ISI (intersymbol interference) the coded system achieved larger coding gains than with additive white Gaussian noise alone, due to the ability of the Viterbi decoder to correct short burst errors. The coded 512-CR system performed better than the coded 1024-QAM system in all circumstances. This is attributed to the use of combined I and Q channel coding and the more complex convolutional encoder used in the coded 512-CR system. It is concluded that TMC used in conjunction with adaptive equalization can achieve significant improvements in error performance on digital microwave radio systems
Keywords :
digital communication systems; encoding; error detection codes; fading; microwave links; modulation; radiowave propagation; telecommunication channels; I channel coding; Q channel coding; Viterbi decoder; adaptive equalization; additive white Gaussian noise channels; coded 1024-QAM; coded 512-CR system; coding gains; convolutional encoder; digital microwave radio systems; error performance; intersymbol interference; lower bounds; multipath fading channels; quadrature amplitude modulation; simulations; trellis-coded modulation; Adaptive equalizers; Additive white noise; Channel coding; Convolutional codes; Decoding; Digital modulation; Error correction codes; Intersymbol interference; Quadrature amplitude modulation; Viterbi algorithm;
Conference_Titel :
Global Telecommunications Conference, 1988, and Exhibition. 'Communications for the Information Age.' Conference Record, GLOBECOM '88., IEEE
Conference_Location :
Hollywood, FL
DOI :
10.1109/GLOCOM.1988.25843