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constellation

System object: comm.RectangularQAMDemodulator
Package: comm

Calculate or plot ideal signal constellation

Syntax

y = constellation(h)
constellation(h)

Description

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

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

Examples

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.

constellation(mod)

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.

constellation(demod)

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