Amplitude Shift Keying

Calculations & Observations


A binary amplitude shift keying signal can be defined by



Where A is a binary constant, m (t) = 1 or 0, fc is the carrier frequency, and T is the bit duration. It has a power P = A2 / 2, so that A = √2P.

Thus equation can be written as


Where E = PT is the energy contained in a bit duration.


Fig.1 Showing ASK modulated signal.

In the above Fig.1, the waveforms obtained represents that when the digital signal is HIGH then the ASK signal has logic ‘1’ i.e. the logic high will show higher frequency of signal with some amplitude but when the digital signal has logic LOW i.e. ‘0’ then the ASK signal will have lower amplitude (0 V).



Fig.2 Showing ASK modulated signal.




Fig.3 Showing ASK modulated signal.