Introduction - If you have any usage issues, please Google them yourself
QAM is a modulation vector, the first mapping the input bits (Gray code commonly used) to a complex plane (constellation), the formation of complex modulation symbols, then symbols I, Q components (corresponding to the complex plane of the real and imaginary parts , that is, horizontal and vertical) using amplitude modulation, corresponding to the modulation in the orthogonal (orthogonal time-domain) of the two carriers (cos wt and sin wt) on