Demodulation of Amplitude Shift Keying Signal


To study Demodulation of Amplitude Shift Keying Signal (ASK) signal using Rectifier & Tuneable LPF..


As ASK is really just AM with a digital message instead of speech or music, it can be recovered using any of the AM demodulation schemes. The next part of the experiment lets you do so using an envelope detector. We needs a modulator to modulate the data to a high carrier frequency, so that the signal can be transmitted effectively. Therefore, for receiver, we must convert the digital signal back to the modulating signal. There are two methods to design the ASK demodulator, which are asynchronous detector and synchronous detector. We will discuss Asynchronous Detection of ASK demodulator in this experiment.

The ASK generation and demodulation parts of the set-up can be represented by the block diagram in Fig.1. The rectifier on the Utilities module and the Tuneable Low-pass filter module are used to implement an envelope detector to recover the digital data from the ASK signal.

Fig.1 Block diagram of setup of this experiment.