constellation

System object: comm.QPSKDemodulator
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

Plot QPSK Reference Constellation

Create a QPSK modulator.

mod = comm.QPSKModulator;

Determine the reference constellation points.

refC = constellation(mod)
refC = 4×1 complex

   0.7071 + 0.7071i
  -0.7071 + 0.7071i
  -0.7071 - 0.7071i
   0.7071 - 0.7071i

Plot the constellation.

constellation(mod)

Create a PSK demodulator having 0 phase offset.

demod = comm.QPSKDemodulator('PhaseOffset',0);

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

constellation(demod)