Furthermore, NEC's design also supports a full sequence of Adaptive Modulation in all steps from 2048QAM down to QPSK (Quadrature Phase-Shift Keying
This article offers closed-form expressions for FOBP for classical binary phase-shift keying (BPSK), quadrature phase-shift keying
(QPSK) (including offset QPSK (OQPSK)) and minimum-shift keying (MSK) modulation.
The later presentation of the quadrature phase-shift keying
(QPSK) modulator output signal implies that any complex modulation can be generated using properly chosen amplitudes and phases of the I and Q signals.
A solid-state high power amplifier (HPA) amplifies an offset quadrature phase-shift keying
signal on the uplink, and a traveling-wave-tube amplifier (TWTA) provides the gain for the downlink.
The effect of a limiter with a L/TWTA was also examined for single-tone (with and without quadrature phase-shift keying
(QPSK) modulation), four-tone and infinite-tone (noise power ratio (NPR)) excitation.
Of course, a similar transceiver design also could be used for biphase or quadrature phase-shift keying
data transmission in the 24 GHz ISM band.
Depending on the applications, various modulation schemes are being implemented from quadrature phase-shift keying
(QPSK) to 64 quadrature amplitude modulation (QAM).
The industry continues to embrace linear modulation techniques such as quadrature phase-shift keying
(QPSK), 64-state QAM (64QAM) and multicarrier configurations.