Phase-shift keying

One of the types of phase modulation, in which the phase of the carrier oscillation changes abruptly depending on the information message. Represents a family of modulations such as BPSK, 4PSK, QPSK and others.

In phase-shift keying (PSK) is a method of digital communication in which the phase of a transmitted signal is varied to convey information. The simplest PSK technique is binary phase-shift keying. This method uses two opposite signal phases broken up timewise into individual bits, or binary bits. The state of each of these bits is determined according to the state of the preceding bit. If the phase does not change, the signal state stays the same. This is sometimes called biphase modulation.