This quantity for a modulated signal differs by a fixed amount for the two streams in I/Q data, which is derived from the narrowband assumption. For 10 points each:
[10h] Name this quantity whose “keying” is plotted on “constellation diagrams” in digital modulation. This quantity names a class of time-invariant vectors that are generalized by analytic signal representations.
ANSWER: phase [accept phasors or phase-shift keying] (The I/Q data of a signal is its decomposition into in-phase and quadrature components.)
[10e] Phasors are representations of functions with this shape, since they encode the amplitude and phase of a signal. Functions with this shape are the usual terms in a Fourier series.
ANSWER: sinusoidal [accept sine or cosine; prompt on periodic]
[10m] In circuit analysis, the ratio of two phasors corresponds to this complex quantity. A generalization of Ohm’s law for inductors and capacitors in AC circuits states that voltage equals current times this quantity.
ANSWER: impedance [prompt on Z]
<CWRU A, Physics>