Hello Petr,
This is possible, you will need to generate a custom IQ file for this output as we don’t have the amplitude offset functionality build into the pulse gen controls.
If you look in the VSG25A installation directory you will find a number of example IQ files which follow the format you can easily load into the VSG software. You can edit them with excel or any text editor easily to create your desired waveform.
Let me know if you have additional questions.
Regards,
Andrew