Merged r9564:9568 from jcorgan/bert into trunk. Adds BPSK bit error testing examples and support blocks.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9569 221aa14e-8319-0410-a670-987f0aec2ac5

8 files changed, 395 insertions, 4 deletions

diff --git a/gnuradio-core/src/lib/general/Makefile.am b/gnuradio-core/src/lib/general/Makefile.am
index 024363253..b46590070 100644
--- a/gnuradio-core/src/lib/general/Makefile.am
+++ b/gnuradio-core/src/lib/general/Makefile.am
@@ -165,7 +165,9 @@ libgeneral_la_SOURCES = 		\
 	malloc16.c			\
 	gr_unpack_k_bits_bb.cc		\
 	gr_descrambler_bb.cc		\
-	gr_scrambler_bb.cc
+	gr_scrambler_bb.cc		\
+	gr_probe_mpsk_snr_c.cc		\
+	gr_probe_density_b.cc
 
 libgeneral_qa_la_SOURCES = 		\
 	qa_general.cc			\
@@ -324,8 +326,9 @@ grinclude_HEADERS = 			\
 	random.h			\
 	gr_unpack_k_bits_bb.h		\
 	gr_descrambler_bb.h		\
-	gr_scrambler_bb.h
-
+	gr_scrambler_bb.h		\
+	gr_probe_mpsk_snr_c.h		\
+	gr_probe_density_b.h
 
 noinst_HEADERS = 			\
 	qa_general.h			\
@@ -454,7 +457,9 @@ swiginclude_HEADERS =			\
 	gri_agc2_cc.i			\
 	gri_agc2_ff.i			\
 	gr_descrambler_bb.i		\
-	gr_scrambler_bb.i
+	gr_scrambler_bb.i		\
+	gr_probe_mpsk_snr_c.i		\
+	gr_probe_density_b.i
 
 
 CLEANFILES = $(BUILT_SOURCES) *.pyc
diff --git a/gnuradio-core/src/lib/general/general.i b/gnuradio-core/src/lib/general/general.i
index 8326b27b0..542bf6064 100644
--- a/gnuradio-core/src/lib/general/general.i
+++ b/gnuradio-core/src/lib/general/general.i
@@ -131,6 +131,8 @@
 #include <gr_decode_ccsds_27_fb.h>
 #include <gr_descrambler_bb.h>
 #include <gr_scrambler_bb.h>
+#include <gr_probe_mpsk_snr_c.h>
+#include <gr_probe_density_b.h>
 %}
 
 %include "gr_nop.i"
@@ -242,3 +244,5 @@
 %include "gr_decode_ccsds_27_fb.i"
 %include "gr_descrambler_bb.i"
 %include "gr_scrambler_bb.i"
+%include "gr_probe_mpsk_snr_c.i"
+%include "gr_probe_density_b.i"
diff --git a/gnuradio-core/src/lib/general/gr_probe_density_b.cc b/gnuradio-core/src/lib/general/gr_probe_density_b.cc
new file mode 100644
index 000000000..dae4eec74
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_density_b.cc
@@ -0,0 +1,68 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gr_probe_density_b.h>
+#include <gr_io_signature.h>
+#include <stdexcept>
+#include <iostream>
+
+gr_probe_density_b_sptr 
+gr_make_probe_density_b(double alpha)
+{
+  return gr_probe_density_b_sptr(new gr_probe_density_b(alpha));
+}
+
+gr_probe_density_b::gr_probe_density_b(double alpha)
+  : gr_sync_block("density_b",
+		  gr_make_io_signature(1, 1, sizeof(char)),
+		  gr_make_io_signature(0, 0, 0))
+{
+  set_alpha(alpha);
+  d_density = 1.0;
+}
+
+gr_probe_density_b::~gr_probe_density_b()
+{
+}
+
+int 
+gr_probe_density_b::work(int noutput_items,
+			 gr_vector_const_void_star &input_items,
+			 gr_vector_void_star &output_items)
+{
+  const char *in = (const char *)input_items[0];
+
+  for (int i = 0; i < noutput_items; i++)
+    d_density = d_alpha*(double)in[i] + d_beta*d_density;
+
+  return noutput_items;
+}
+
+void
+gr_probe_density_b::set_alpha(double alpha)
+{
+  d_alpha = alpha;
+  d_beta = 1.0-d_alpha;
+}
+
diff --git a/gnuradio-core/src/lib/general/gr_probe_density_b.h b/gnuradio-core/src/lib/general/gr_probe_density_b.h
new file mode 100644
index 000000000..92b98d193
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_density_b.h
@@ -0,0 +1,72 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 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.
+ */
+#ifndef INCLUDED_GR_PROBE_DENSITY_B_H
+#define INCLUDED_GR_PROBE_DENSITY_B_H
+
+#include <gr_sync_block.h>
+
+class gr_probe_density_b;
+
+typedef boost::shared_ptr<gr_probe_density_b> gr_probe_density_b_sptr;
+
+gr_probe_density_b_sptr gr_make_probe_density_b(double alpha);
+
+/*!
+ * This block maintains a running average of the input stream and
+ * makes it available as an accessor function.  The input stream
+ * is type unsigned char.
+ *
+ * If you send this block a stream of unpacked bytes, it will tell
+ * you what the bit density is.
+ *
+ * \param alpha     Average filter constant
+ *
+ */
+
+class gr_probe_density_b : public gr_sync_block
+{
+private:
+  friend gr_probe_density_b_sptr gr_make_probe_density_b(double alpha);
+
+  double d_alpha;
+  double d_beta;
+  double d_density;
+
+  gr_probe_density_b(double alpha);
+
+public:
+  ~gr_probe_density_b();
+  
+  /*!
+   * \brief Returns the current density value
+   */
+  double density() const { return d_density; }
+
+  /*!
+   * \brief Set the average filter constant
+   */
+  void set_alpha(double alpha);
+
+  int work(int noutput_items,
+	   gr_vector_const_void_star &input_items,
+	   gr_vector_void_star &output_items);
+};
+
+#endif /* INCLUDED_GR_PROBE_DENSITY_B_H */
diff --git a/gnuradio-core/src/lib/general/gr_probe_density_b.i b/gnuradio-core/src/lib/general/gr_probe_density_b.i
new file mode 100644
index 000000000..54ed07cf5
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_density_b.i
@@ -0,0 +1,36 @@
+/* -*- 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.
+ */
+
+GR_SWIG_BLOCK_MAGIC(gr,probe_density_b);
+
+gr_probe_density_b_sptr gr_make_probe_density_b(double alpha);
+
+class gr_probe_density_b : public gr_sync_block
+{
+public:
+  double density() const;
+
+  void set_alpha(double alpha);
+
+private:
+  gr_probe_density_b();
+};
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
index 000000000..a0bb99ce1
--- /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;
+}
diff --git a/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.h b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.h
new file mode 100644
index 000000000..67492f686
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.h
@@ -0,0 +1,82 @@
+/* -*- 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.
+ */
+#ifndef INCLUDED_GR_PROBE_MPSK_SNR_C_H
+#define INCLUDED_GR_PROBE_MPSK_SNR_C_H
+
+#include <gr_sync_block.h>
+
+class gr_probe_mpsk_snr_c;
+typedef boost::shared_ptr<gr_probe_mpsk_snr_c> gr_probe_mpsk_snr_c_sptr;
+
+gr_probe_mpsk_snr_c_sptr
+gr_make_probe_mpsk_snr_c(double alpha = 0.0001);
+
+/*!
+ * Compute the estimate SNR of an MPSK signal using the Squared Signal
+ * to Noise Variance (SNV) technique.
+ *
+ * This technique assumes an AWGN channel.
+ *
+ * \param alpha  Mean and variance smoothing filter constant
+ * \ingroup sink
+ *
+ * Compute the running average of the signal mean and noise variance.
+ * The estimated signal mean, noise variance, and SNR are available
+ * via accessors.
+ *
+ * This SNR estimator is inaccurate below about 7dB SNR.
+ *
+ */
+class gr_probe_mpsk_snr_c : public gr_sync_block
+{
+  double d_alpha;
+  double d_beta;
+  double d_signal_mean;
+  double d_noise_variance;
+
+  // Factory function returning shared pointer of this class
+  friend gr_probe_mpsk_snr_c_sptr
+  gr_make_probe_mpsk_snr_c(double alpha);
+
+  // Private constructor
+  gr_probe_mpsk_snr_c(double alpha);
+
+public:
+  ~gr_probe_mpsk_snr_c();
+
+  int work (int noutput_items,
+	    gr_vector_const_void_star &input_items,
+	    gr_vector_void_star &output_items);
+
+  // Return the estimated signal mean
+  double signal_mean() const { return d_signal_mean; }
+
+  // Return the estimated noise variance
+  double noise_variance() const { return d_noise_variance; }
+
+  // Return the estimated signal-to-noise ratio in decibels
+  double snr() const;
+
+  void set_alpha(double alpha);
+};
+
+#endif /* INCLUDED_GR_PROBE_MPSK_SNR_C_H */
diff --git a/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.i b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.i
new file mode 100644
index 000000000..37a86b23d
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_probe_mpsk_snr_c.i
@@ -0,0 +1,39 @@
+/* -*- 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.
+ */
+
+GR_SWIG_BLOCK_MAGIC(gr,probe_mpsk_snr_c);
+
+gr_probe_mpsk_snr_c_sptr
+gr_make_probe_mpsk_snr_c(double alpha = 0.0001);
+
+class gr_probe_mpsk_snr_c : public gr_sync_block
+{
+private:
+  void gr_probe_mpsk_snr_c(double alpha);
+
+public:
+  double signal_mean();
+  double noise_variance();
+  double snr();
+
+  void set_alpha (double alpha);
+};