Imported Upstream version 3.2.2

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

diff --git a/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.cc b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.cc
new file mode 100644 (file)
index 0000000..a0bb99c
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.cc
@@ -0,0 +1,85 @@
+/* -*- c++ -*- */
+/*
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gr_probe_mpsk_snr_c.h>
+#include <gr_io_signature.h>
+
+gr_probe_mpsk_snr_c_sptr
+gr_make_probe_mpsk_snr_c(double alpha)
+{
+  return gr_probe_mpsk_snr_c_sptr(new gr_probe_mpsk_snr_c(alpha));
+}
+
+gr_probe_mpsk_snr_c::gr_probe_mpsk_snr_c(double alpha)
+  : gr_sync_block ("probe_mpsk_snr_c",
+                  gr_make_io_signature(1, 1, sizeof(gr_complex)),
+                  gr_make_io_signature(0, 0, 0)),
+    d_signal_mean(0.0),
+    d_noise_variance(0.0)
+{
+  set_alpha(alpha);
+}
+
+gr_probe_mpsk_snr_c::~gr_probe_mpsk_snr_c()
+{
+}
+
+int
+gr_probe_mpsk_snr_c::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];
+
+  for (int i = 0; i < noutput_items; i++){
+    // Update of signal mean estimate
+    double mag = abs(in[i]);
+    d_signal_mean = d_alpha*abs(in[i]) + d_beta*d_signal_mean;
+
+    // Update noise variance estimate
+    double noise = mag-d_signal_mean;
+    double var = noise*noise;
+    d_noise_variance = d_alpha*var + d_beta*d_noise_variance;
+  }
+
+  return noutput_items;
+}
+
+double
+gr_probe_mpsk_snr_c::snr() const
+{
+  if (d_noise_variance == 0.0)
+    return 0.0;
+  else
+    return 10*log10(d_signal_mean*d_signal_mean/d_noise_variance);
+}
+
+void
+gr_probe_mpsk_snr_c::set_alpha(double alpha)
+{
+  d_alpha = alpha;
+  d_beta = 1.0-alpha;
+}