gr-digital: moved consetellation object into gr-digital space.

author: Tom Rondeau <trondeau@vt.edu> 2011-04-08 21:43:25 -0400
committer: Tom Rondeau <trondeau@vt.edu> 2011-04-08 21:43:25 -0400
commit: 78078fe0015fe87b15777b94858f5110e65244c5 (patch)
tree: d696a766c62e15507b4d5b2390f8c06779ced5ef /gr-digital/lib/digital_constellation.cc
parent: 2ce3ebb921bba17a11eda2253b5670b8a50684e9 (diff)
1 files changed, 368 insertions, 0 deletions
diff --git a/gr-digital/lib/digital_constellation.cc b/gr-digital/lib/digital_constellation.cc
new file mode 100644
index 0000000000..eede99ffd8
--- /dev/null
+++ b/gr-digital/lib/digital_constellation.cc
@@ -0,0 +1,368 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2010, 2011 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 <gr_io_signature.h>
+#include <gr_constellation.h>
+#include <gr_metric_type.h>
+#include <gr_math.h>
+#include <gr_complex.h>
+#include <math.h>
+#include <iostream>
+#include <stdlib.h>
+#include <float.h>
+#include <stdexcept>
+
+#define M_TWOPI (2*M_PI)
+#define SQRT_TWO 0.707107
+
+// Base Constellation Class
+
+gr_constellation::gr_constellation (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code,
+				    unsigned int rotational_symmetry, unsigned int dimensionality) :
+  d_constellation(constellation),
+  d_pre_diff_code(pre_diff_code),
+  d_rotational_symmetry(rotational_symmetry),
+  d_dimensionality(dimensionality)
+{
+  if (pre_diff_code.size() == 0)
+    d_apply_pre_diff_code = false;
+  else if (pre_diff_code.size() != constellation.size())
+    throw std::runtime_error ("The constellation and pre-diff code must be of the same length.");
+  else
+    d_apply_pre_diff_code = true;
+  calc_arity();
+}
+
+gr_constellation::gr_constellation () :
+  d_apply_pre_diff_code(false),
+  d_rotational_symmetry(0),
+  d_dimensionality(1)
+{
+  calc_arity();
+}
+
+//! Returns the constellation points for a symbol value
+void gr_constellation::map_to_points(unsigned int value, gr_complex *points) {
+  for (unsigned int i=0; i<d_dimensionality; i++)
+    points[i] = d_constellation[value*d_dimensionality + i];
+}
+
+std::vector<gr_complex> gr_constellation::map_to_points_v(unsigned int value) {
+  std::vector<gr_complex> points_v;
+  points_v.resize(d_dimensionality);
+  map_to_points(value, &(points_v[0]));
+  return points_v;
+}
+
+float gr_constellation::get_distance(unsigned int index, const gr_complex *sample) {
+  float dist = 0;
+  for (unsigned int i=0; i<d_dimensionality; i++) {
+    dist += norm(sample[i] - d_constellation[index*d_dimensionality + i]);
+  }
+  return dist;
+}
+
+unsigned int gr_constellation::get_closest_point(const gr_complex *sample) {
+
+  unsigned int min_index = 0;
+  float min_euclid_dist;
+  float euclid_dist;
+    
+  min_euclid_dist = get_distance(0, sample);
+  min_index = 0;
+  for (unsigned int j = 1; j < d_arity; j++){
+    euclid_dist = get_distance(j, sample);
+    if (euclid_dist < min_euclid_dist){
+      min_euclid_dist = euclid_dist;
+      min_index = j;
+    }
+  }
+  return min_index;
+}
+
+unsigned int gr_constellation::decision_maker_pe(const gr_complex *sample, float *phase_error)
+{
+  unsigned int index = decision_maker(sample);
+  *phase_error = 0;
+  for (unsigned int d=0; d<d_dimensionality; d++)
+    *phase_error += -arg(sample[d]*conj(d_constellation[index+d]));
+  return index;
+}
+
+/*
+unsigned int gr_constellation::decision_maker_e(const gr_complex *sample, float *error)
+{
+  unsigned int index = decision_maker(sample);
+  *error = 0;
+  for (unsigned int d=0; d<d_dimensionality; d++)
+    *error += sample[d]*conj(d_constellation[index+d]);
+  return index;
+}
+*/
+
+std::vector<gr_complex> gr_constellation::s_points () {
+  if (d_dimensionality != 1)
+    throw std::runtime_error ("s_points only works for dimensionality 1 constellations.");
+  else
+    return d_constellation;
+}
+
+std::vector<std::vector<gr_complex> > gr_constellation::v_points () {
+  std::vector<std::vector<gr_complex> > vv_const;
+  vv_const.resize(d_arity);
+  for (unsigned int p=0; p<d_arity; p++) {
+    std::vector<gr_complex> v_const;
+    v_const.resize(d_dimensionality);
+    for (unsigned int d=0; d<d_dimensionality; d++) {
+      v_const[d] = d_constellation[p*d_dimensionality+d];
+    }
+    vv_const[p] = v_const;
+  }
+  return vv_const;
+}
+
+void gr_constellation::calc_metric(const gr_complex *sample, float *metric, trellis_metric_type_t type) {
+  switch (type){
+  case TRELLIS_EUCLIDEAN:
+    calc_euclidean_metric(sample, metric);
+    break;
+  case TRELLIS_HARD_SYMBOL:
+    calc_hard_symbol_metric(sample, metric);
+    break;
+  case TRELLIS_HARD_BIT:
+    throw std::runtime_error ("Invalid metric type (not yet implemented).");
+    break;
+  default:
+    throw std::runtime_error ("Invalid metric type.");
+  }
+}
+
+void gr_constellation::calc_euclidean_metric(const gr_complex *sample, float *metric) {
+  for (unsigned int o=0; o<d_arity; o++) {
+    metric[o] = get_distance(o, sample);
+  }
+}
+
+void gr_constellation::calc_hard_symbol_metric(const gr_complex *sample, float *metric){
+  float minm = FLT_MAX;
+  unsigned int minmi = 0;
+  for (unsigned int o=0; o<d_arity; o++) {
+    float dist = get_distance(o, sample);
+    if (dist < minm) {
+      minm = dist;
+      minmi = o;
+    }
+  }
+  for(unsigned int o=0; o<d_arity; o++) {
+    metric[o] = (o==minmi?0.0:1.0);
+  }
+}
+
+void gr_constellation::calc_arity () {
+  if (d_constellation.size() % d_dimensionality != 0)
+    throw std::runtime_error ("Constellation vector size must be a multiple of the dimensionality.");    
+  d_arity = d_constellation.size()/d_dimensionality;
+}
+
+unsigned int gr_constellation::decision_maker_v (std::vector<gr_complex> sample) {
+  assert(sample.size() == d_dimensionality);
+  return decision_maker (&(sample[0]));
+}
+
+gr_constellation_calcdist_sptr 
+gr_make_constellation_calcdist(std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code,
+				unsigned int rotational_symmetry, unsigned int dimensionality)
+{
+  return gr_constellation_calcdist_sptr(new gr_constellation_calcdist (constellation, pre_diff_code, rotational_symmetry,
+								       dimensionality));
+}
+
+gr_constellation_calcdist::gr_constellation_calcdist(std::vector<gr_complex> constellation,
+						      std::vector<unsigned int> pre_diff_code,
+						      unsigned int rotational_symmetry,
+						      unsigned int dimensionality) :
+  gr_constellation(constellation, pre_diff_code, rotational_symmetry, dimensionality)
+{}
+
+// Chooses points base on shortest distance.
+// Inefficient.
+unsigned int gr_constellation_calcdist::decision_maker(const gr_complex *sample)
+{
+  return get_closest_point(sample);
+}
+
+gr_constellation_sector::gr_constellation_sector (std::vector<gr_complex> constellation,
+						  std::vector<unsigned int> pre_diff_code,
+						  unsigned int rotational_symmetry,
+						  unsigned int dimensionality,
+						  unsigned int n_sectors) :
+  gr_constellation(constellation, pre_diff_code, rotational_symmetry, dimensionality),
+  n_sectors(n_sectors)
+{
+}
+
+unsigned int gr_constellation_sector::decision_maker (const gr_complex *sample) {
+  unsigned int sector;
+  sector = get_sector(sample);
+  return sector_values[sector];
+}
+
+void gr_constellation_sector::find_sector_values () {
+  unsigned int i;
+  sector_values.clear();
+  for (i=0; i<n_sectors; i++) {
+    sector_values.push_back(calc_sector_value(i));
+  }
+}
+
+gr_constellation_rect_sptr 
+gr_make_constellation_rect(std::vector<gr_complex> constellation,
+			   std::vector<unsigned int> pre_diff_code,
+			   unsigned int rotational_symmetry,
+			   unsigned int real_sectors, unsigned int imag_sectors,
+			   float width_real_sectors, float width_imag_sectors)
+{
+  return gr_constellation_rect_sptr(new gr_constellation_rect (constellation, pre_diff_code, rotational_symmetry,
+							       real_sectors, imag_sectors, width_real_sectors,
+							       width_imag_sectors));
+  }
+
+gr_constellation_rect::gr_constellation_rect (std::vector<gr_complex> constellation,
+					      std::vector<unsigned int> pre_diff_code,
+					      unsigned int rotational_symmetry,
+					      unsigned int real_sectors, unsigned int imag_sectors,
+					      float width_real_sectors, float width_imag_sectors) :
+  gr_constellation_sector(constellation, pre_diff_code, rotational_symmetry, 1, real_sectors * imag_sectors),
+  n_real_sectors(real_sectors), n_imag_sectors(imag_sectors),
+  d_width_real_sectors(width_real_sectors), d_width_imag_sectors(width_imag_sectors)
+{
+  find_sector_values();
+}
+
+unsigned int gr_constellation_rect::get_sector (const gr_complex *sample) {
+  int real_sector, imag_sector;
+  unsigned int sector;
+  real_sector = int(real(*sample)/d_width_real_sectors + n_real_sectors/2.0);
+  if (real_sector < 0) real_sector = 0;
+  if (real_sector >= n_real_sectors) real_sector = n_real_sectors-1;
+  imag_sector = int(imag(*sample)/d_width_imag_sectors + n_imag_sectors/2.0);
+  if (imag_sector < 0) imag_sector = 0;
+  if (imag_sector >= n_imag_sectors) imag_sector = n_imag_sectors-1;
+  sector = real_sector * n_imag_sectors + imag_sector;
+  return sector;
+}
+  
+unsigned int gr_constellation_rect::calc_sector_value (unsigned int sector) {
+  unsigned int real_sector, imag_sector;
+  gr_complex sector_center;
+  unsigned int closest_point;
+  real_sector = float(sector)/n_imag_sectors;
+  imag_sector = sector - real_sector * n_imag_sectors;
+  sector_center = gr_complex((real_sector + 0.5 - n_real_sectors/2.0) * d_width_real_sectors,
+			     (imag_sector + 0.5 - n_imag_sectors/2.0) * d_width_imag_sectors);
+  closest_point = get_closest_point(&sector_center);
+  return closest_point;
+}
+
+
+gr_constellation_psk_sptr 
+gr_make_constellation_psk(std::vector<gr_complex> constellation, 
+			  std::vector<unsigned int> pre_diff_code,
+			  unsigned int n_sectors)
+{
+  return gr_constellation_psk_sptr(new gr_constellation_psk (constellation, pre_diff_code,
+							     n_sectors));
+}
+
+gr_constellation_psk::gr_constellation_psk (std::vector<gr_complex> constellation,
+					    std::vector<unsigned int> pre_diff_code,
+					    unsigned int n_sectors) :
+  gr_constellation_sector(constellation, pre_diff_code, constellation.size(), 1, n_sectors)
+{
+  find_sector_values();
+}
+
+unsigned int gr_constellation_psk::get_sector (const gr_complex *sample) {
+  float phase = arg(*sample);
+  float width = M_TWOPI / n_sectors;
+  int sector = floor(phase/width + 0.5);
+  unsigned int u_sector;
+  if (sector < 0) sector += n_sectors;
+  u_sector = sector;
+  return sector;
+}
+  
+unsigned int gr_constellation_psk::calc_sector_value (unsigned int sector) {
+  float phase = sector * M_TWOPI / n_sectors;
+  gr_complex sector_center = gr_complex(cos(phase), sin(phase));
+  unsigned int closest_point = get_closest_point(&sector_center);
+  return closest_point;
+}
+
+
+gr_constellation_bpsk_sptr 
+gr_make_constellation_bpsk()
+{
+  return gr_constellation_bpsk_sptr(new gr_constellation_bpsk ());
+}
+
+gr_constellation_bpsk::gr_constellation_bpsk ()
+{
+  d_constellation.resize(2);
+  d_constellation[0] = gr_complex(-1, 0);
+  d_constellation[1] = gr_complex(1, 0);
+  d_rotational_symmetry = 2;
+  d_dimensionality = 1;
+  calc_arity();
+}
+
+unsigned int gr_constellation_bpsk::decision_maker(const gr_complex *sample)
+{
+  return (real(*sample) > 0);
+}
+
+
+gr_constellation_qpsk_sptr 
+gr_make_constellation_qpsk()
+{
+  return gr_constellation_qpsk_sptr(new gr_constellation_qpsk ());
+}
+
+gr_constellation_qpsk::gr_constellation_qpsk ()
+{
+  d_constellation.resize(4);
+  // Gray-coded
+  d_constellation[0] = gr_complex(-SQRT_TWO, -SQRT_TWO);
+  d_constellation[1] = gr_complex(SQRT_TWO, -SQRT_TWO);
+  d_constellation[2] = gr_complex(-SQRT_TWO, SQRT_TWO);
+  d_constellation[3] = gr_complex(SQRT_TWO, SQRT_TWO);
+  d_rotational_symmetry = 4;
+  d_dimensionality = 1;
+  calc_arity();
+}
+
+unsigned int gr_constellation_qpsk::decision_maker(const gr_complex *sample)
+{
+  // Real component determines small bit.
+  // Imag component determines big bit.
+  return 2*(imag(*sample)>0) + (real(*sample)>0);
+}
author	Tom Rondeau <trondeau@vt.edu>	2011-04-08 21:43:25 -0400
committer	Tom Rondeau <trondeau@vt.edu>	2011-04-08 21:43:25 -0400
commit	78078fe0015fe87b15777b94858f5110e65244c5 (patch)
tree	d696a766c62e15507b4d5b2390f8c06779ced5ef /gr-digital/lib/digital_constellation.cc
parent	2ce3ebb921bba17a11eda2253b5670b8a50684e9 (diff)