Hello Ina,
Thanks for sharing the reference with us.
In principle, you should be able to build the block diagram shown in Fig.2 of the paper. You can use four different replicas of the channels to build it in OptiSystem. I guess it will be a very good project.
please refer to the example in the location below to expand it and build your project.
I’ll be very happy to follow up with you once you build the example. please contact me at ahmad.atieh@optiwave.com once you finish building it if you like to discuss further. You can send me the project file as a zip file.
C:\Users\xxxxxxx\Documents\OptiSystem 15.1 Samples\Optical wireless\Terrestrial link
regards,
Ahmad