OOPS ,By observing your file with a great care i found htat you have implemented WDM -PON not TDM for downstream.Shaid your system is not correct from the view of WDm PON,but correct in terms of ey diagram.You have used 2 different wavelengths for downstream and another 2 for upstream.But you havent demultiplex any wavelength at receiver side of both the cases.So how would you come to know which wavelength you are observing.It is not oblivious that your first wavelength signal go to the first port of power splitter.Same in the case of upstream.You have to choose the correct demultiplexing technique for each certain wavelength.Mow you are receiving combined signal at each eye diagram.