Understanding Simulink's QPSK Transmitter and Receiver

I do not understand portions of this Simulink model provided by Matlab. https://www.mathworks.com/help/comm/ug/qpsk-transmitter-and-receiver-in-simulink.html

Most importantly:

1) How does the reciever print the descrambled message to Simulink Diagnostic Viewer at the end of the simulation? I do not see any block or way it does this

Answer 1

[akshatsood]

Hi Uddhav,

I understand that you are facing difficulty in comprehending certain portions of the Simulink model "QPSK Transmitter and Receiver". Yet it would be more convenient if you could be more specific in listing down the portions so that I can provide a concise explanation for that.

In response to your question regarding the descrambled message being printed on the Diagnostic Viewer at the end of simulation, the model utilises Model Callbacks which can be seen as a set of commands that get executed at specified action points during the execution phase of the model.

To view Model Callbacks and review the implementation code in StopFcn, refer to the following steps

• In the Simulink Toolstrip, redirect to the Modelling Tab
• Click on Model Settings and then on Model Properties
• An interface will open where various callbacks are defined under the Callbacks header.
• Click on StopFcn to view the implementation code responsible for the descrambled message which was being printed onto the Diagnostic Viewer once the simulation ended.

Please go through Model Callbacks documentation page for better understanding.

I hope this helps.