1 files changed, 69 insertions, 0 deletions
diff --git a/gr-fec/python/fec/polar/common.py b/gr-fec/python/fec/polar/common.py
new file mode 100644
index 0000000000..b4b152de61
--- /dev/null
+++ b/gr-fec/python/fec/polar/common.py
@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 Free Software Foundation, Inc.
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+
+import numpy as np
+from helper_functions import *
+
+'''
+PolarCommon holds value checks and common initializer code for both Encoder and Decoder.
+'''
+
+
+class PolarCommon:
+    def __init__(self, n, k, frozen_bit_position, frozenbits=None):
+        if not is_power_of_two(n):
+            raise ValueError("n={0} is not a power of 2!".format(n))
+        if frozenbits is None:
+            frozenbits = np.zeros(n - k, dtype=np.int)
+        if not len(frozenbits) == n - k:
+            raise ValueError("len(frozenbits)={0} is not equal to n-k={1}!".format(len(frozenbits), n - k))
+        if not frozenbits.dtype == np.int:
+            frozenbits = frozenbits.astype(dtype=int)
+        if not len(frozen_bit_position) == (n - k):
+            raise ValueError("len(frozen_bit_position)={0} is not equal to n-k={1}!".format(len(frozen_bit_position), n - k))
+        if not frozen_bit_position.dtype == np.int:
+            frozen_bit_position = frozen_bit_position.astype(dtype=int)
+
+        self.bit_reverse_positions = self._vector_bit_reversed(np.arange(n, dtype=int), int(np.log2(n)))
+        self.N = n
+        self.power = int(np.log2(self.N))
+        self.K = k
+        self.frozenbits = frozenbits
+        self.frozen_bit_position = frozen_bit_position
+        self.info_bit_position = np.delete(np.arange(self.N), self.frozen_bit_position)
+
+    def _insert_frozen_bits(self, u):
+        prototype = np.empty(self.N, dtype=int)
+        prototype[self.frozen_bit_position] = self.frozenbits
+        prototype[self.info_bit_position] = u
+        return prototype
+
+    def _extract_info_bits(self, y):
+        return y[self.info_bit_position]
+
+    def _reverse_bits(self, vec):
+        return vec[self.bit_reverse_positions]
+
+    def _vector_bit_reversed(self, vec, n):
+        return bit_reverse_vector(vec, n)
+
+    def info_print(self):
+        print "POLAR code ({0}, {1})".format(self.N, self.K)