Comtech EF Data DMD-2050E - Manual (Page 332)

DMD2050E Universal Satellite Modem ITA Operation
MN-DMD2050E Revision 2 J–30
Figure J-19 –DMD2050E I/Q for 16APSK 7/8
At this point changing the noise source level will dynamically change the selected waveforms.
You can simulate fades by attenuating the receive signal to the system.