i am using PIN diode Receiver sensitivity is 0.875 and dark current 1 nA. signal to be detected is DWDM freqeuncy of 189.2 Thz. . sample rate is default 5 X bit rate . (appx 1.28 Thz) but Q factor received is 2.5677 and BER of order 10 ^-3 data rate chosen was 10 Gbps as well as 40 Gbps. , signal power shown by electrical power meter is of order 10^-3. nd noise is 10^-25 shot and theraml noise ony. my system is still running simulation so right now i am unable to attach results but as soon as i wud be able i will surely share the results snapshot.