The modulation-alphabet follows the definition of CQI values for LTE. The current CQI value follows from the current SINR. During the simulation, for each TTI,
with link adaptation and feedback, the modulation and coding scheme (MCS) or CQI is adapted to the channel conditions. With increasing SNR, higher CQIs are employed to reach higher spectral efficiency and throughput. Once the highest modulation and coding scheme (CQI15) is reached, no more increase in spectral efficiency is possible and the throughput saturates at its maximum.
The reported CQI is saved in feedback property of the UE object (UEs.feedback.CQI).