I am using Optisuite 13. Let me give you an example of DPSK-pulse generator and decoding. I am not getting the output at the DPSK sequence decoder block. The oscilloscope does not give any output. Besides other design are also not giving the output at the decoding end. The samples which I am using are from optiwave sample 11 folder. I have optisim 13.
Please find attached the screenshot.
Also in OFDM direct detection example, the BER value is always shown 0 irrespective to any change in design such as modulator parameters, fiber length, amplifier gain.