Dear Önem,
The easiest way to save the assigned RBs is: at the LTE_sim_main.m after the scheduling calculation per eNodeB (lines 440-450) you can create e new parameter and save it as eNodeB property, e.g. saved_RB_per_eNodeB and save the assigned RB grid to this parameter like this:
eNodeBs(s_).saved_RB_per_eNodeB(:,networkClock.current_TTI) = eNodeBs(s_).scheduler.RB_grid.user_allocation;
which will save the RBs assigned to each user for each TTI.
Best regards,
Fjolla