Performance improvement by post-amplifying upstream/downstream signal in WDM passive optical network

We simulated the wavelength division multiplexing passive optical network (WDM-PON) prototype with 16 pair of wavelengths. 16 downstream wavelength multiplexed to down streaming 40Gb/s data from optical line terminal (OLT) to optical network unit (ONU) via 1∶16 splitter at the remote node (RN). 16 upstream wavelength are combined at RN from ONU's and forwarded to the OLT. Amplifier section is placed only at the OLT side hence it pre-amplifying downstream signal and post-amplifying upstream signal. Upstream and downstream results are investigated and analyzed using simulated analyzer and it is found that upstream has better bit error rate (BER) and quality factor (Q-Factor) than the downstream signal.