a compatible QPSK modulation scheme is used to achieve a similar data rate in a 6.25-kHz channel. The phase is shifted either ±45° or ±135° to get the four symbols. A unique demodulator has ...

This demodulator is suitable for the quadrature phase-shift keying (QPSK) modulator previously published by the same author, "Novel Low-Cost QPSK Modulator Needs No Adjustments" (electronic design ...

QAM Modulator and Demodulator combine two amplitude modulation signals into a single data transfer channel: 1. Technique of modifying any one characteristic (amplitude, frequency, or phase) ... The ...