Optimal thresholds for discrete power levels using adaptive modulation in presence of imperfect channel state information

The continuous power scheme was the choice of many researchers towards power allocation. However, continuous power application is not very suitable following hardware complexity. For this discrete power is efficient, especially in cellular systems as it could reduce the feedback rate. On the other hand, receiver mobility implies transmission thresholds and power level alternation determination which leads to reduction in system's spectral efficiency (SE). Consequently, a method based on adaptive modulation (AM) has been introduced and some power discrete levels while all information of channel state wasn't considered. Computer results highlight that the proposed scheme provides better efficiency in comparison to other adaptation schemes but with less feedback rate.