Getting Started

Running a Simulation

To run a simulation, select the Simulation menu from the top of the model window and then select Start (or, on Microsoft Windows, click the Start button on the toolbar). The simulation stops automatically at the Stop time, which is specified in the Simulation parameters dialog box. You can stop the simulation at any time by selecting Stop from the Simulation menu at the top of the model window (or, on Microsoft Windows, by clicking the Stop button on the toolbar).

When you run the model, a new window appears displaying a scatter plot of the modulated signal with added noise, as shown in the following figure.

Scatter Plot of Signal Plus Noise

The points in the scatter plot do not lie exactly on the constellation shown in the figure Constellation for 256-ary QAM, because of the added noise. The radial pattern of points is due to the addition of phase noise, which alters the angle of the complex modulated signal.

Quadrature Amplitude Modulation

Displaying the Error Rate