The demodulation of a BPSK modulated signal, the carrier must be in phase and frequency synchronism with the carrier available at the transmitter. The carrier for the purpose of demodulation can either be transmitted along with the modulated signal or extracted from the modulated signal at the receiver. Two commonly used techniques of carrier recovery are signal squaring and Costas loop. In the FlexTrainer, we are using signal squaring method to recover the carrier from the received signal. Figure 1 shows the BPSK demodulation.

Figure 1: Binary phase shift keying demodulation

At the end of this experiment, students are encouraged to perform binary phase shift keying demodulation for different data words and baud rates.