Merged r4605:4612 from jcorgan/glfsr branch into trunk. Implements Galois LFSR source block of degree 1 through 32.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@4613 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 67 insertions, 0 deletions

diff --git a/gnuradio-core/src/python/gnuradio/gr/qa_glfsr_source_b.py b/gnuradio-core/src/python/gnuradio/gr/qa_glfsr_source_b.py
new file mode 100755
index 000000000..ceda6c832
--- /dev/null
+++ b/gnuradio-core/src/python/gnuradio/gr/qa_glfsr_source_b.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+#
+# Copyright 2007 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# 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 2, 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.
+# 
+
+from gnuradio import gr, gr_unittest
+
+class test_glfsr_source_b(gr_unittest.TestCase):
+
+    def setUp (self):
+        self.fg = gr.flow_graph ()
+
+    def tearDown (self):
+        self.fg = None
+
+    def test_000_make(self):
+        src = gr.glfsr_source_b(16)
+        self.assertEquals(src.mask(), 0x8016)
+        self.assertEquals(src.period(), 2**16-1)
+
+    def test_001_degree(self):
+        self.assertRaises(RuntimeError,
+                          lambda: gr.glfsr_source_b(0))
+        self.assertRaises(RuntimeError,
+                          lambda: gr.glfsr_source_b(33))
+        
+    def test_002_correlation(self):
+        for degree in range(1,11):                # Higher degrees take too long to correlate
+            src = gr.glfsr_source_b(degree, False)
+            b2f = gr.chunks_to_symbols_bf((-1.0,1.0), 1)
+            dst = gr.vector_sink_f()
+            self.fg.connect(src, b2f, dst)
+            self.fg.run()
+
+            actual_result = dst.data()
+            R = auto_correlate(actual_result)
+            self.assertEqual(R[0], float(len(R))) # Auto-correlation peak at origin
+            for i in range(len(R)-1):
+                self.assertEqual(R[i+1], -1.0)    # Auto-correlation minimum everywhere else
+
+def auto_correlate(data):
+    l = len(data)
+    R = [0,]*l
+    for lag in range(l):
+        for i in range(l):
+            R[lag] += data[i]*data[i-lag]
+    return R
+
+if __name__ == '__main__':
+    gr_unittest.main ()