In suppressed carrier amplitude modulation carrier is generated at the receiver for the purpose of synchronous demodulation. Any discrepancy in the carrier phase and frequency will give rise to distortions in the detector output.

Two very famous methods of carrier acquisition are

• Signal Squaring Method and
• Costas Loop

In the FlexTrainer, we have used Signal Squaring Method for carrier acquisition. An outline of this scheme is shown in the figure 1.

Figure 1: Signal squaring approach of Carrier Acquisition

Synchronously demodulated speech signal is shown in figure 2.

Figure 2: Synchronously demodulated speech signal

At the end of this experiment, students are encouraged to investigate the AM-SC demodulation and to observe the effects of adding frequency offset and phase offset on the AM-SC demodulated signal.