Hello,
All of these issues are directly addressed by the new OFDM Modulation and Demodulation, I cannot recommend them enough. You’ll notice that most of the topics on this forum I will probably mention using the new OFDM components and it is for a reason! Now that you have upgraded to 13.0.3 please take a look at the example file “Direct Detection OFDM 4QAM” if for whatever reason after your upgrade the new samples were not installed you can find the installer in the Optiwave Software directory.
1) Electrical signals are given arbitrary units and the component that uses the signal assigns its own units for its internal calculation. For example, the FP Cavity Laser would assign a current value to any electrical input.
2) Yes, in the new components you can set the average output power of the electrical signal.
3)The BER Test Set will give you an empirical solution to the BER, whereas the new OFDM Demodulation will display the Constellation diagram and give you the SER and EVM. After the calculation look at the Project Browser and find the graphs section of the OFDM Demodulation.