Hi
I’m using optisym ver.7, there is a sample file called “Coherent 4 QAM.osd” under lightwave systems folder (attached)
I’m trying to plot BER vs Fiber length or versus anything (just basics). I used “sweep” to change the fiber length at different ranges as I learnt from your tutorials, but I didn’t get any curve (for example BER getting worse as we increase fiber length)
I found something wrong in the received signals after balanced detection for example the In-phase signal (I) should be (-I) and Quadrature signal should be also (-Q), so I used electrical gain of -1 after both branches, but still cannot get anything.
I attached the original sample.
Thank you
