# Types Of Digital Modulation

Three types of digital modulation are

1. Amplitude-Shift Keying (ASK)
In ASK, modulated signal can be expressed as

As modulated signal is still an ON-OFF signal, thus ASK is also called on-off keying (OOK).
2. Frequency-Shift Keying (FSK)
In FSK, modulated signal can be expressed as

3. Phase-Shift Keying (PSK)
In PSK, modulated signal can be expressed as