RF Blockset 2.5

Effect of Nonlinear Amplifier on QPSK Modulation

This model illustrates the nonlinear effect of an RF amplifier on a QPSK modulated communication system.

Contents

Demo Model

Fig. 1 QPSK modulation demo model:

Signal Compression Due to the Nonlinearity of RF Amplifier

Fig. 2 and Fig. 3 show the presence of compression and phase rotation.

Fig. 2 Constellation of transmitted signal:

Fig. 3 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.