Quadrature Phase-Shift Keying or QPSK is a sibling of the Phase-Shift Keying or PSK family.

QPSK is a form of modulation in which the carrier signal is sent in four phases, 45°, 135°, 225°, and 315°. The change between one phase and the next encodes 2 bits per symbol. With a total of 4 symbols at a 90° seperation, this allows for 8 bits per signal.

QPSK is seen as providing the best error rate in the presence of radio noise. It's most common in IEEE 802.11b wireless equipment and satellite equipment.


Log in or register to write something here or to contact authors.