Hi Dhananjay,
If you are trying to simulate a passive optical network, you’d better pick the system you wish to simulate from the papers and then try to simulate that. If you want to implement an OFDM system with both OFDM transmitter and receiver on either side of the fiber, you can use a bidirectional fiber and choose the frequencies so that the uplink and downlonk wouldn’t interfere. I can help more if you give more specific information about it.
Regards