RF Blockset 2.5

Effect of Nonlinear Amplifier on 16-QAM Modulation

This model illustrates the nonlinear effect of an RF amplifier on a 16-QAM modulated signal.

Contents

Demo Model

Fig. 1 16-QAM modulation demo model:

Simulation Results

When you compare the spectrums of transmitted and received signals (Fig. 2), you can see the spectrum regrowth at the received signal. This regrowth is due to the nonlinearity of the amplifier.

Fig. 2 Spectrums of transmitted and received signals:

When you compare the constellations of transmitted and received signals (Figs. 3 and 4 respectively), you can see the signal distortion at the received signal. This distortion is due to the nonlinearity of the amplifier.

Fig. 3 Constellation of transmitted signal:

Fig. 4 Constellation of received signal:

To view the nonlinear effect, double-click the Slider Gain block and change the value of the gain while the model is running.