Modulation of data bits into complex symbols in MATLAB In communication theory, a modulator takes the input sequence and and maps it to some complex numbers. In MATLAB the following commands can do that.

data = randi([0 1],96,1);
hModulator = comm.PSKModulator(16,'BitInput',true);
modData = step(hModulator, data); 


My question, is regarding the last step. Why is a step function able to do this mapping. In particular this step function represents the step response.

Thanks for any advice.
The method step(H,X) used here has nothing to do with the step function. It modulates the input data X with the modulator object H, as described here. See also here.