The receiver for pulse width modulation reconstructs the original signal from the received one. The received waveform is integrated sample by sample to form the original signal. Figure 1 shows the block diagram of a sigma delta modulation receiver.

Figure 1: Sigma delta modulation receiver

The step size at which the sigma delta modulation is done is very important. In order to recover an analog signal at the receiver that is close to the actual analog signal the step size should be the same at both the transmitter and receiver. Figure 2 shows the sigma delta demodulation.

Figure 2: Sigma delta demodulation

At the end of this experiment, students are instructed to apply sigma delta demodulation technique to different analog waveforms and observe the results with different step sizes.