Although they are very similar, there is a subtle but important difference...
Both of these digital modulation schemes map the input bit steam to
symbols, so it makes sense that they look very similar as they perform
nearly identical functions. The difference will be in the symbol
map that is sent as an input to these functions. Inside the
Modulate PAM VI there is a check to make sure that all the symbols lie
on a straight line, wheras in the QAM VI checks that the symbol map is
a valid for QAM.
To verify this, you'll have to do a litlle digging:
Go to
Modulate PAM>>mod_PAM Modulator Validate>>mod_Validate Symbol Map(PAM).
Here, a VI called mod_Verify Symbol Map Colinearity is called.
Next, go to
Modulate QAM>>mod_QAM Modulator Validate>>mod_Validate Symbol Map(QAM).
There is no check for linearity here.
Have a great day!
Travis W
