How to convert ofdm symbol to signal?
I think if you added more details about your signal and the specifications of your hardware, that would be helpful to help you in that issue.
What you basically need is to multiply it by carrier signal and take the real part of the resulted signal, after that you need to do the inverse at the receiver end.  You might need also to upsample and use such filter equivalent to your system specifications.
Again, I think if you added more details about your system, we can also give you more information which may guide you.
Good luck