Imported Upstream version 3.2.2

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

diff --git a/gnuradio-core/src/lib/general/gr_pn_correlator_cc.cc b/gnuradio-core/src/lib/general/gr_pn_correlator_cc.cc
new file mode 100644 (file)
index 0000000..2614c3a
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_pn_correlator_cc.cc
@@ -0,0 +1,77 @@
+/* -*- c++ -*- */
+/*
+ * 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 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_pn_correlator_cc.h>
+#include <gr_io_signature.h>
+
+gr_pn_correlator_cc_sptr
+gr_make_pn_correlator_cc(int degree, int mask, int seed)
+{
+  return gr_pn_correlator_cc_sptr (new gr_pn_correlator_cc(degree, mask, seed));
+}
+
+gr_pn_correlator_cc::gr_pn_correlator_cc(int degree, int mask, int seed)
+  : gr_sync_decimator ("pn_correlator_cc",
+                      gr_make_io_signature (1, 1, sizeof(gr_complex)),
+                      gr_make_io_signature (1, 1, sizeof(gr_complex)),
+                      (unsigned int)((1ULL << degree)-1)) // PN code length
+{
+  d_len = (unsigned int)((1ULL << degree)-1);
+  if (mask == 0)
+    mask = gri_glfsr::glfsr_mask(degree);
+  d_reference = new gri_glfsr(mask, seed);
+  for (int i = 0; i < d_len; i++)      // initialize to last value in sequence
+    d_pn = 2.0*d_reference->next_bit()-1.0;
+}
+
+gr_pn_correlator_cc::~gr_pn_correlator_cc()
+{
+  delete d_reference;
+}
+
+int
+gr_pn_correlator_cc::work(int noutput_items,
+                         gr_vector_const_void_star &input_items,
+                         gr_vector_void_star &output_items)
+{
+  const gr_complex *in = (const gr_complex *) input_items[0];
+  gr_complex *out = (gr_complex *) output_items[0];
+  gr_complex sum;
+
+  for (int i = 0; i < noutput_items; i++) {
+    sum = 0.0;
+
+    for (int j = 0; j < d_len; j++) {
+      if (j != 0)                          // retard PN generator one sample per period
+       d_pn = 2.0*d_reference->next_bit()-1.0; // no conditionals
+      sum += *in++ * d_pn;
+    }
+
+    *out++ = sum*gr_complex(1.0/d_len, 0.0);
+  }
+
+  return noutput_items;
+}