What is DPSK (Differential Phase-Shift Keying)?

Differential phase-shift keying is the one sort of phase modulation utilized to send information by changing the carrier wave’s phase. In Differential Phase Shift Keying the phase of the modulated signal is moved comparative with the previous signal component. No reference signal is considered. The signal phase follows the high or low state of the previous component. This DPSK method doesn’t require a reference oscillator.