Hi Jamal,
You have asked a good question because The positioning of the FBG along with EDFA plays an
important role in improvement of the optical systems performance.
When FBG is used at
transmitter side for dispersion compensation, it gives better
performance (minimum BER) as compare to when used for
compensation at receiver side. For 10km BER reduces from
6.73164e-319 to 1.87745e-322 with input power 4dB, for
20km BER reduces from 4.90116e-287 to 1.29445e-320 with
input power 2dB, for 40km BER reduces from 7.5984e-290 to
2.16954e-305 with input power 10 dB, for 50 km bit error
reduces from 1.10874e-102 to 4.16583e-181. Only for 30km
BER increases from 1.39294e-312 to 1.8834e-251. For 10, 20,
30, 40, 50 km to get minimum BER best FBGs length are
4mm, 14mm,10mm, 14mm, 14mm respectively. The gain of
the EDFA also plays an important role in systems
performance. For configuration (FBG at the transmitter end)
Thanks,