Source code for Constellations.QAMConstellation

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# Contributors:
# Sander Wahls (TU Delft) 2018-2019

import numpy as np
from Constellations import BaseConstellation

class QAMConstellation(BaseConstellation):
    """Quadrature amplitude modulation (QAM) constellation (implements BaseConstellation)."""

    def __init__(self, m, n):
        """Constructor for a m x n QAM constellation.

        Parameters
        ----------

        m : int
            Number of rows in the constellation.
        n : int
            Number of columns in the constellation.
        """
        self._alphabet = np.zeros(m*n, dtype=complex)
        for i in range(0, m):
            for j in range(0, n):
                self.alphabet[i*n+j] = (i - (m-1)/2.0) + 1.0j*(j - (n-1)/2.0)
        self._alphabet = self.alphabet / np.max(np.abs(self.alphabet))
        self._bit_matrix = self.gray_code(m, n)
        self._name = "%d-QAM Constellation" % self.size()