Channel Adaptive Techniques in the Presence of Channel Prediction Inaccuracy

Adapting transmission parameters to the future channel state is an appealing approach to improve efficiency in wireless communication. Adaptation requires predicting the channel state. Current channel-adaptive techniques assume that the prediction is perfect. In this paper, we claim that neglecting the prediction error can lead to poor performance results, possibly even worse than without prediction at all. We have simulated the behaviour of adaptive modulation and adaptive scheduling, as well as a combination of both for inaccurate channel prediction. The results show that prediction inaccuracy can degrade the performance of wireless communications when channel adaptive techniques are used. The sensitivity to inaccuracy is, however, dependent on several factors, like the adaptive technique used or the average received signal-to-noise level at the receiver.