Hi Gulkaran,
Can you please elaborate more on the different coding schemes you want to adopt? NGPON2 makes use of WDM for downstream and TDM for upstream. This is an essential part of the architecture of its physical layer, so unless you want to do exactly as the standard (for example with the same large number of users at each node and so on) I think you can make use of OS TDM and WDM examples to do the implementation.
Regards