QPSK Modulator with Continuous Phase and Fast Response Based on Phase-Locked Loop
Among M-phase shift keying (M-PSK) schemes, quadrature phase-shift keying (QPSK) is used most often because of its efficient bandwidth consumption.However, in comparison with minimum-shift keying, which has continuous phase transitions, QPSK requires a higher bandwidth to transmit a signal.This article focuses on the phase transitions in QPSK signa