Adding a band-edge based frequency lock loop.

5 files changed, 277 insertions, 0 deletions

diff --git a/gnuradio-core/src/lib/general/Makefile.am b/gnuradio-core/src/lib/general/Makefile.am
index cf6ff1e65..ecef7d6e3 100644
--- a/gnuradio-core/src/lib/general/Makefile.am
+++ b/gnuradio-core/src/lib/general/Makefile.am
@@ -76,6 +76,7 @@ libgeneral_la_SOURCES = 		\
 	gr_fft_vcc_fftw.cc		\
 	gr_fft_vfc.cc			\
 	gr_firdes.cc			\
+	gr_fll_band_edge_cc.cc		\
 	gr_float_to_char.cc		\
 	gr_float_to_complex.cc		\
 	gr_float_to_short.cc		\
@@ -229,6 +230,7 @@ grinclude_HEADERS = 			\
 	gr_fft_vcc_fftw.h		\
 	gr_fft_vfc.h			\
 	gr_firdes.h			\
+	gr_fll_band_edge_cc.h		\
 	gr_float_to_char.h		\
 	gr_float_to_complex.h		\
 	gr_float_to_short.h		\
@@ -396,6 +398,7 @@ swiginclude_HEADERS =			\
 	gr_fft_vcc.i			\
 	gr_fft_vfc.i			\
 	gr_firdes.i			\
+	gr_fll_band_edge_cc.i		\
 	gr_float_to_char.i		\
 	gr_float_to_complex.i		\
 	gr_float_to_short.i		\
diff --git a/gnuradio-core/src/lib/general/general.i b/gnuradio-core/src/lib/general/general.i
index e1161c8eb..2c26b59cd 100644
--- a/gnuradio-core/src/lib/general/general.i
+++ b/gnuradio-core/src/lib/general/general.i
@@ -140,6 +140,7 @@
 #include <gr_wavelet_ff.h>
 #include <gr_wvps_ff.h>
 #include <gr_copy.h>
+#include <gr_fll_band_edge_cc.h>
 %}
 
 %include "gr_nop.i"
@@ -260,3 +261,4 @@
 %include "gr_wavelet_ff.i"
 %include "gr_wvps_ff.i"
 %include "gr_copy.i"
+%include "gr_fll_band_edge_cc.i"
diff --git a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc
new file mode 100644
index 000000000..946fc1e85
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.cc
@@ -0,0 +1,146 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 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_fll_band_edge_cc.h>
+#include <gr_fir_ccc.h>
+#include <gr_fir_util.h>
+#include <gri_fft.h>
+#include <gr_io_signature.h>
+#include <gr_expj.h>
+#include <gr_math.h>
+#include <cstdio>
+
+#define M_TWOPI (2*M_PI)
+
+gr_fll_band_edge_cc_sptr gr_make_fll_band_edge_cc (const std::vector<gr_complex> &taps)
+{
+  return gr_fll_band_edge_cc_sptr (new gr_fll_band_edge_cc (taps));
+}
+
+
+gr_fll_band_edge_cc::gr_fll_band_edge_cc (const std::vector<gr_complex> &taps)
+  : gr_sync_block ("fll_band_edge_cc",
+		   gr_make_io_signature (1, 1, sizeof(gr_complex)),
+		   gr_make_io_signature (1, 1, sizeof(gr_complex))),
+    d_updated (false)
+{
+  d_alpha = 0.01;
+  d_beta = 0.25*d_alpha*d_alpha;
+  d_max_freq = M_TWOPI * 0.25;
+  d_min_freq = M_TWOPI * -0.5;
+
+  d_freq = 0;
+  d_phase = 0;
+
+  std::vector<gr_complex> vtaps(0, taps.size());
+  d_filter_upper = gr_fir_util::create_gr_fir_ccc(vtaps);
+  d_filter_lower = gr_fir_util::create_gr_fir_ccc(vtaps);
+
+  set_taps(taps);
+}
+
+gr_fll_band_edge_cc::~gr_fll_band_edge_cc ()
+{
+}
+
+void
+gr_fll_band_edge_cc::set_taps (const std::vector<gr_complex> &taps)
+{
+  unsigned int i;
+
+  for(i = 0; i < taps.size(); i++) {
+    d_taps_upper.push_back(taps[i]);
+    d_taps_lower.push_back(conj(taps[i]));
+  }
+
+  d_filter_upper->set_taps(d_taps_upper);
+  d_filter_lower->set_taps(d_taps_lower);
+
+  // Set the history to ensure enough input items for each filter
+  set_history(d_taps_upper.size()+1);
+
+  d_updated = true;
+}
+
+void
+gr_fll_band_edge_cc::print_taps()
+{
+  unsigned int i;
+  printf("Upper Band-edge: [");
+  for(i = 0; i < d_taps_upper.size(); i++) {
+    printf(" %.4e + j%.4e,", d_taps_upper[i].real(), d_taps_upper[i].imag());
+  }
+  printf("]\n\n");
+
+  printf("Lower Band-edge: [");
+  for(i = 0; i < d_taps_lower.size(); i++) {
+    printf(" %.4e + j%.4e,", d_taps_lower[i].real(), d_taps_lower[i].imag());
+  }
+  printf("]\n\n");
+}
+
+int
+gr_fll_band_edge_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];
+
+  if (d_updated) {
+    d_updated = false;
+    return 0;		     // history requirements may have changed.
+  }
+
+  int i;
+  gr_complex nco_out;
+  float out_upper, out_lower;
+  float error;
+  for(i = 0; i < noutput_items; i++) {
+    nco_out = gr_expj(d_phase);
+    out[i] = in[i] * nco_out;
+
+    out_upper = norm(d_filter_upper->filter(&out[i]));
+    out_lower = norm(d_filter_lower->filter(&out[i]));
+    error = 0.1*(out_lower - out_upper);
+    printf("error: %f\n", out_upper);
+
+    d_freq = d_freq + d_beta * error;
+    d_phase = d_phase + d_freq + d_alpha * error;
+
+    if(d_phase > M_PI)
+      d_phase -= M_TWOPI;
+    else if(d_phase < -M_PI)
+      d_phase += M_TWOPI;
+    
+    if (d_freq > d_max_freq)
+      d_freq = d_max_freq;
+    else if (d_freq < d_min_freq)
+      d_freq = d_min_freq;
+  }
+
+  return noutput_items;
+}
diff --git a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
new file mode 100644
index 000000000..1c47167f8
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
@@ -0,0 +1,90 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 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_FLL_BAND_EDGE_CC_H
+#define	INCLUDED_GR_FLL_BAND_EDGE_CC_H
+
+#include <gr_sync_block.h>
+
+class gr_fll_band_edge_cc;
+typedef boost::shared_ptr<gr_fll_band_edge_cc> gr_fll_band_edge_cc_sptr;
+gr_fll_band_edge_cc_sptr gr_make_fll_band_edge_cc (const std::vector<gr_complex> &taps);
+
+class gr_fir_ccc;
+class gri_fft_complex;
+
+/*!
+ * \class gr_fll_band_edge_cc
+ * \brief Frequency Lock Loop using band-edge filters
+ *
+ * \ingroup general
+ */
+
+class gr_fll_band_edge_cc : public gr_sync_block
+{
+ private:
+  /*!
+   * Build the FLL
+   * \param taps    (vector/list of gr_complex) The taps of the band-edge filter
+   */
+  friend gr_fll_band_edge_cc_sptr gr_make_fll_band_edge_cc (const std::vector<gr_complex> &taps);
+
+  float                   d_alpha;
+  float                   d_beta;
+  float                   d_max_freq;
+  float                   d_min_freq;
+
+  gr_fir_ccc*             d_filter_upper;
+  gr_fir_ccc*             d_filter_lower;
+  std::vector<gr_complex> d_taps_upper;
+  std::vector<gr_complex> d_taps_lower;
+  bool			  d_updated;
+  float                   d_freq;
+  float                   d_phase;
+
+  /*!
+   * Build the FLL
+   * \param taps    (vector/list of gr_complex) The taps of the band-edge filter
+   */
+  gr_fll_band_edge_cc(const std::vector<gr_complex> &taps);
+
+public:
+  ~gr_fll_band_edge_cc ();
+  
+  /*!
+   * Resets the filter taps with the new prototype filter
+   * \param taps    (vector/list of gr_complex) The band-edge filter
+   */
+   void set_taps (const std::vector<gr_complex> &taps);
+
+  /*!
+   * Print the taps to screen.
+   */
+  void print_taps();
+   
+  int work (int noutput_items,
+	    gr_vector_const_void_star &input_items,
+	    gr_vector_void_star &output_items);
+};
+
+#endif
diff --git a/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.i b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.i
new file mode 100644
index 000000000..a550bec4e
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_fll_band_edge_cc.i
@@ -0,0 +1,36 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 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,fll_band_edge_cc);
+
+gr_fll_band_edge_cc_sptr gr_make_fll_band_edge_cc (const std::vector<gr_complex> &taps);
+
+class gr_fll_band_edge_cc : public gr_sync_block
+{
+ private:
+  gr_fll_band_edge_cc (const std::vector<gr_complex> &taps);
+
+ public:
+  ~gr_fll_band_edge_cc ();
+
+  void set_taps (const std::vector<gr_complex> &taps);
+};