change the phase (PSK) is a modulation method, digital data that will change or the phase of one signal (the carrier wave) sends.

each modulation method digital number limit of the signal, a distinct advantage does digital data offer. PSK also from a limited phase, each for a particular pattern of bits defined interest. Usually each phase, the number of parity bit encryption. Each pattern of bits in a symbol form that is by the phase of their special offer. which to set the symbols used by the modulator is specially designed phase of the signal received, the diagnosis, and gives it to the special symbol, their assigns, and such original data are retrieved. This act to a receiver requires that the phase of the signal received with a reference signal, the comparison that such a system the coherent call. ( Introduced with the name of the CPSK )

Also, instead of working out compared to a reference signal, the fixed device can be compared to herself. Changes the phase of a wave has on the player can be used as items obvious in mind. In such a system, instead of the phase difference relative to a reference signal, detect the modulator changes the phase of the signal received, the diagnosis, and not their phase. Since this plan to the difference between the phases of successive depends on. change the differential phase ( differential phase-shift keying ) or DPSK is called. DPSK can be much easier than PSK typical implementation, there are other need to have a sample of a reference signal to detect the exact phase of the signal has been received does not need. (Non-coherent) instead, this style of error probability more will be.