How to model 16-QAM modulation?

Hi All,

Need some help. I am trying to model the Effects of a Non-linear Amplifier on 16-QAM Modulation. I am trying to use the example on the Mathworks website but when I run the simulation, the only thing I get for the output is noise. I am using R2018a, with the Communication Systems Toolbox, RF Blockset, and DSP System Toolbox. For the source I am using a Random Integer Generator connected to the Rectangular 16-QAM Blockset out of the Communication Systems Toolbox. In the example from Mathworks there are a couple of blocks that I can't find in the library. The signal source says it is a 50 MHz symbol rate with 16-QAM modulation so I tried to simulate that with a random integer generator and a rectangular 16_QAM block but all I am getting is noise. There is also a block that has .397 on it and a signal sink at the output. Here is a link to what I am trying to model https://www.mathworks.com/help/simrf/examples/effect-of-nonlinear-amplifier-on-16-qam-modulation.html