Imported Upstream version 3.2.2

[debian/gnuradio] / gnuradio-core / src / lib / general / qa_gri_lfsr.cc

diff --git a/gnuradio-core/src/lib/general/qa_gri_lfsr.cc b/gnuradio-core/src/lib/general/qa_gri_lfsr.cc
new file mode 100644 (file)
index 0000000..9f8b62d
--- /dev/null
+++ b/gnuradio-core/src/lib/general/qa_gri_lfsr.cc
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2008 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 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.
+ */
+
+#include <gri_lfsr.h>
+#include <qa_gri_lfsr.h>
+#include <cppunit/TestAssert.h>
+#include <stdio.h>
+#include <string.h>
+
+void
+qa_gri_lfsr::test_lfsr ()
+{
+  int mask = 0x19;
+  int seed = 0x01;
+  int length = 5;
+
+  gri_lfsr lfsr1(mask,seed,length);
+  gri_lfsr lfsr2(mask,seed,length);
+  
+  unsigned char expected[] = {1, 0, 1, 1, 0, 1, 0, 1, 0, 0};
+
+  for(unsigned int i=0; i<31; i++){
+    lfsr1.next_bit();
+  }
+
+  // test that after one lfsr cycle we still match out uncycled lfsr
+  for (unsigned int i = 0; i < 41; i++) {
+    CPPUNIT_ASSERT_EQUAL((int) lfsr1.next_bit(), (int) lfsr2.next_bit());
+  }
+
+  // test the known correct values at the given shift offset
+  for(unsigned int i=0; i<10; i++){
+    CPPUNIT_ASSERT_EQUAL((int) lfsr1.next_bit(), (int) expected[i]);
+  }
+
+  // test for register length too long
+  CPPUNIT_ASSERT_THROW(gri_lfsr(mask, seed, 32), std::invalid_argument);
+}
+
+void
+qa_gri_lfsr::test_scrambler()
+{
+  // CCSDS 7-bit scrambler
+  int mask = 0x8A;
+  int seed = 0x7F;
+  int length = 7;
+
+  gri_lfsr scrambler(mask, seed, length);
+
+  // Impulse (1 and 126 more zeroes)
+  unsigned char src[] = 
+    { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0 }; // flush bits
+  
+  // Impulse response (including leading bits)
+  unsigned char expected[] =
+    { 1, 1, 1, 1, 1, 1, 1, 
+      0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 
+      0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 
+      0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 
+      0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 
+      1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 
+      0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 
+      1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 
+      1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, };
+
+  int len = sizeof(src);
+  unsigned char actual[len];
+
+  for (int i = 0; i < len; i++)
+    actual[i] = scrambler.next_bit_scramble(src[i]);
+
+  CPPUNIT_ASSERT(memcmp(expected, actual, len) == 0);
+}
+
+void
+qa_gri_lfsr::test_descrambler()
+{
+  // CCSDS 7-bit scrambler
+  int mask = 0x8A;
+  int seed = 0x7F;
+  int length = 7;
+
+  gri_lfsr descrambler(mask, seed, length);
+
+  // Scrambled sequence (impulse response)
+  unsigned char src[] =
+    { 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 
+      0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 
+      0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 
+      0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 
+      1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 
+      0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 
+      1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 
+      1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0 }; 
+
+  // Original (garbage while synchronizing, them impulse)
+  unsigned char expected[] = 
+    { 0, 1, 0, 0, 1, 0,
+      1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0 };
+  
+  int len = sizeof(src);
+  unsigned char actual[len];
+
+  for (int i = 0; i < len; i++)
+    actual[i] = descrambler.next_bit_descramble(src[i]);
+
+  CPPUNIT_ASSERT(memcmp(expected, actual, len) == 0);
+}