sinnadyr
Member level 2

I am writing a thesis on using G3-PLC for power line communications, whereas the G3 standard uses D/QPSK modulation. What I have figured out so far is that both 4QAM and QPSK appearently produces the same waveform, but are they the same matematically?
In a QPSK constellation, are the mapping points at 45, 125, 225 and 315 degrees while the 4QAM is at 0, 90, 180 and 270?
I also struggle to understand the I/Q components of such a constellation diagram. What does "inphase" and "quadrature-phase" actually mean? Is it only other words for real and imaginary part for this type of usage?
Thank you.
In a QPSK constellation, are the mapping points at 45, 125, 225 and 315 degrees while the 4QAM is at 0, 90, 180 and 270?
I also struggle to understand the I/Q components of such a constellation diagram. What does "inphase" and "quadrature-phase" actually mean? Is it only other words for real and imaginary part for this type of usage?
Thank you.