QPSK

Quadrature PSK (Phase Shift Keying) - a phase quadrature radio modulation technique. QPSK (quadrature PSK) delivers two bits per symbol since the four phase shift values represent 00, 01, 10 and 11.

QPSK

Quadrature Phase Shift Keying

Qpsk

QPSK is an abbreviation for Quadriphase Shift Key
Found on http://www.probertencyclopaedia.com/N17.HTM
No exact match found