Thank you for you reply!
So I am trying to make a OFDM system with and without codification (CC code)... for this I am using these flowgraphs (simpleOFDM.png and CodeOFDM.png)
The problem that I saw is: If I use just codification without modulation (just to try), the output scope is the same as the input (in this case, I am using a square waveform).
And when I use just OFDM modulation, the output signal looks stay with a time delay and also looks not be constant during the whole simulation (see pics OFDMscope and OFDM2.png).
And when I use CC code + OFDM, I also have a delayed time signal and sometimes with a lot of wrong peaks but I don't insert on the simulation any noise signal or use some USRP to transmit and receive through the air. (see pics OFDM+CC_1 and OFDM+CC_2.png).
after it, I am trying to transmit a CSV or TXT file with both situation (just OFDM and OFDM+CC code) to compare the results... but as I can check for now, the situation with OFDM+CC code get a lot of wrong information as without code... It should be the other way, isn't it?
I hope I made it clear