An improved power adaptation for adaptive TuCM over flat Rayleigh fading channels

Adaptive turbo coded modulation (TuCM) has near-capacity performance on fading channels when the channel state is timely known at the transmitter. However, in practice, the channel state is known with an unavoidable time delay. Considering time delay, it is pointed out that adaptive TuCM is very sensitive to time delay; and that time delay is the important constraint for its application. In order to resolve this problem, an improved power adaptation is proposed in this paper. The analysis and simulation results show that the BER performance of adaptive TuCM can be ensured for various time delays with our improved power adaptation.