TCMP-A Modulation and Coding Strategy for Rician Fading Channels

Abstract

Conventional digital modulation schemes provide poor performance over moderately and severely fading channels without the use of coding. The drawback of applying recently developed trellis coded modulation schemes to such channels is that they require coherent detection to achieve their full potential. This paper describes TCMP, a novel modulation strategy for Rician fading channels, which multiplexes a time domain pilot sequence with trellis coded data to permit coherent detection. This technique is shown to provide remarkably robust performance in the presence of fading. It is also shown that when choosing trellis codes for fading channels, time diversity is of greater importance than asymptotic coding gain. The motivation for studying this strategy is to find efficient signaling schemes for transmitting data at a 4.8 kbit/s rate over a mobile satellite channel, with 5 kHz channel spacing. © 1989 IEEE