Quadrature Phase Shift Keying.



[QPSK] is a digital frequency modulation technique used for sending data over networks of several media, including [802.11] wireless.



Doubling the data rate available in [BPSK], via improved efficiency in the use of the radio bandwidth, [QPSK] is used in [802.11b] networks of 2Mpbs or greater.



* (http://www.pulsewan.com/data101/802_11_b_basics.htm 802.11b Basics)



See also [PHY], [ODFM].