thank you alistu for the information.i will follow what you said.
one more doubt is regarding the decoding. i am using direct detection in my system, using FBGs so which signal should be passed on to the photodetector? the transmission output or the reflected output? and as i am using W=3 so detection is to be done with 3 FBGs per user in series?
will be thankful if you can help me out in this.