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System object: comm.RectangularQAMDemodulator
Package: comm

Calculate or plot ideal signal constellation


y = constellation(h)


y = constellation(h) returns the numerical values of the constellation.

constellation(h) generates a constellation plot for the object.


expand all

Create a rectangular QAM modulator.

mod = comm.RectangularQAMModulator;

Determine the reference constellation points.

refC = constellation(mod)
refC = 
  -3.0000 + 3.0000i
  -3.0000 + 1.0000i
  -3.0000 - 1.0000i
  -3.0000 - 3.0000i
  -1.0000 + 3.0000i
  -1.0000 + 1.0000i
  -1.0000 - 1.0000i
  -1.0000 - 3.0000i
   1.0000 + 3.0000i
   1.0000 + 1.0000i
   1.0000 - 1.0000i
   1.0000 - 3.0000i
   3.0000 + 3.0000i
   3.0000 + 1.0000i
   3.0000 - 1.0000i
   3.0000 - 3.0000i

Plot the constellation.


Create a QAM demodulator having a modulation order of 64.

demod = comm.RectangularQAMDemodulator(64);

Plot its reference constellation. The constellation method works for both modulator and demodulator objects.


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