QAM (Quadrature Amplitude Modulation) yana nufin hanyoyin modulation wanda yake iya zama na biyan da fasaha da amplitude modulation ta fadada shi a kan wasu carrier wave zuwa fili. Duk da haka, QAM yana bayyana bayanai da sauran fasaha da amplitude ta fadada carrier wave, don haka yana duba effective bandwidth. QAM tana cikin “quadrature carrier multiplexing”.
A QAM signal, yana gudanar da direct modulation ta carrier wave a quadrature. Sunan “quadrature” yana nuna cewa farko da za suka dace a kan wasu carriers shine 90 degrees amma saboda ma ake da frequency sama.
Wata signal ana kiranta in-phase “I” signal, kuma wata ta ita ce quadrature “Q” signal. Mathematically, wata ta carrier signals ita zai iya bayyana da sine wave (i.e.
) kuma wata ta ita zai iya bayyana da cosine wave (i.e.