Improving QoS by predictive channel quality feedback for LTE

In Long Term Evolution (LTE) systems, the quality of service (QoS) heavily relies on the accurate feedback of channel quality indicator (CQI). However, the time-varying channel and transmission delay make the outdated CQI unreliable. In this work, CQI prediction schemes based on Wiener filter, cubic spline extrapolation and short-term average are studied. The effects of using prediction schemes on data throughput are compared with simulation. A simple adaptation technique is found to make the prediction effective for both high speed and low speed mobile stations.