Study on delay of proportional fair algorithm with controlled channel quality feedback

The delay of a modified proportional fair algorithm (PFA) is computed. The modified PFA uses a dynamic threshold to filter the feedbacks of channel quality (CQ) based on which the users priorities are calculated for scheduling. Only those in good CQs (relative to their own average CQ) can be the candidates for scheduling. The results show that the modified PFA with a low CQ threshold can not only reduce some feedback overhead but also maintain delay performance of the traditional PFA. Two methods of calculating priority, one based on signal to noise ratio, and the other on information rate, are considered. Their performances of delay have slight difference when fast fading components are distributed differently among users.