DVB-T Example Modification

Hello, in the DVB-T example provided by matlab the simulation does not use pilot carriers or guard intervals is there any way to include them as i am new to simulink?

Also according to DVB-T standards the frame has 68 OFDM symbols each having 1705 carriers (2k mode) if the block is changed to have 68 symbols it shows an error anyway to get around this too?

Thanks