Dear Wael,
to avoid any misunderstandings: peak, average and edge do not refer to the position of the individual UEs, but to the throughput cdf (peak = average of the best 5%, edge = average of the worst 5%).
To identify the users falling in this range on a TTI basis might not be feasible, since the ecdf is already based on the indiviual average UE throughput (averaging over the whole simulation length).
Best regards,
Martin