Allow to choose whether to normalize constellation average magnitude, average power or to not normalize at all.

Signed-off-by: Eduardo Sánchez Muñoz <esm@eduardosm.net>
author: Eduardo Sánchez Muñoz <esm@eduardosm.net> 2020-12-18 12:30:26 +0100
committer: Marcus Müller <marcus@hostalia.de> 2020-12-18 13:54:10 +0100
commit: 947800c52f2fcb2b149cfd2809148afcfdb8b79a (patch)
tree: ffc11b527f2f95606da621185a8e4c8c5d048ff7 /gr-digital
parent: 00fd051dff4a73081c40f4ccfc3b4ac8c62d74f1 (diff)
4 files changed, 92 insertions, 36 deletions
diff --git a/gr-digital/grc/digital_constellation.block.yml b/gr-digital/grc/digital_constellation.block.yml
index 7a1f4654c0..943b578d80 100644
--- a/gr-digital/grc/digital_constellation.block.yml
+++ b/gr-digital/grc/digital_constellation.block.yml
@@ -29,6 +29,13 @@ parameters:
     dtype: int
     default: '1'
     hide: ${ ( 'none' if str(type) == "calcdist" else 'all') }
+-   id: normalization
+    label: Normalization Type
+    dtype: int
+    default: digital.constellation.AMPLITUDE_NORMALIZATION
+    options: [digital.constellation.NO_NORMALIZATION, digital.constellation.POWER_NORMALIZATION, digital.constellation.AMPLITUDE_NORMALIZATION]
+    option_labels: [None, Power, Amplitude]
+    hide: ${ ( 'none' if str(type) == "calcdist" else 'all') }
 -   id: precision
     label: Soft Decisions Precision
     dtype: int
@@ -39,7 +46,7 @@ parameters:
     dtype: raw
     default: None
     hide: ${ ('part' if str(soft_dec_lut) == 'None' else 'none') }
-value: ${ digital.constellation_calcdist(const_points, sym_map, rot_sym, dims) if (str(type) == "calcdist") else getattr(digital,'constellation_'+str(type))()  }
+value: ${ digital.constellation_calcdist(const_points, sym_map, rot_sym, dims, normalization) if (str(type) == "calcdist") else getattr(digital,'constellation_'+str(type))()  }
 
 
 templates:
diff --git a/gr-digital/include/gnuradio/digital/constellation.h b/gr-digital/include/gnuradio/digital/constellation.h
index a8fffe111e..ebe37088b7 100644
--- a/gr-digital/include/gnuradio/digital/constellation.h
+++ b/gr-digital/include/gnuradio/digital/constellation.h
@@ -49,11 +49,17 @@ typedef std::shared_ptr<constellation> constellation_sptr;
 class DIGITAL_API constellation : public std::enable_shared_from_this<constellation>
 {
 public:
+    enum normalization_t {
+        NO_NORMALIZATION,
+        POWER_NORMALIZATION,
+        AMPLITUDE_NORMALIZATION,
+    };
+
     constellation(std::vector<gr_complex> constell,
                   std::vector<int> pre_diff_code,
                   unsigned int rotational_symmetry,
                   unsigned int dimensionality,
-                  bool normalize_points = true);
+                  normalization_t normalization = AMPLITUDE_NORMALIZATION);
     constellation();
     virtual ~constellation();
 
@@ -233,15 +239,17 @@ public:
      * \param pre_diff_code List of alphabet symbols (before applying any differential
      *                      coding) (order of list matches constell)
      * \param rotational_symmetry Number of rotations around unit circle that have the
-     * same representation. \param dimensionality Number of dimensions to the
-     * constellation. \param normalize_points Normalize constellation points to
-     * mean(abs(points))=1 (default is true)
+     * same representation.
+     * \param dimensionality Number of dimensions to the constellation.
+     * \param normalization Use AMPLITUDE_NORMALIZATION to normalize points to
+     * mean(abs(points))=1 (default), POWER_NORMALIZATION to normalize points
+     * to mean(abs(points)^2)=1 or NO_NORMALIZATION to keep the original amplitude.
      */
     static sptr make(std::vector<gr_complex> constell,
                      std::vector<int> pre_diff_code,
                      unsigned int rotational_symmetry,
                      unsigned int dimensionality,
-                     bool normalize_points = true);
+                     normalization_t normalization = AMPLITUDE_NORMALIZATION);
 
     unsigned int decision_maker(const gr_complex* sample) override;
     // void calc_metric(gr_complex *sample, float *metric, trellis_metric_type_t type);
@@ -253,7 +261,7 @@ protected:
                            std::vector<int> pre_diff_code,
                            unsigned int rotational_symmetry,
                            unsigned int dimensionality,
-                           bool nomalize_points = true);
+                           normalization_t normalization = AMPLITUDE_NORMALIZATION);
 };
 
 
@@ -286,7 +294,8 @@ public:
                          std::vector<int> pre_diff_code,
                          unsigned int rotational_symmetry,
                          unsigned int dimensionality,
-                         unsigned int n_sectors);
+                         unsigned int n_sectors,
+                         normalization_t normalization = AMPLITUDE_NORMALIZATION);
 
     ~constellation_sector() override;
 
@@ -339,13 +348,15 @@ public:
      * \param width_imag_sectors width of each imag sector to calculate decision
      * boundaries.
      */
-    static constellation_rect::sptr make(std::vector<gr_complex> constell,
-                                         std::vector<int> pre_diff_code,
-                                         unsigned int rotational_symmetry,
-                                         unsigned int real_sectors,
-                                         unsigned int imag_sectors,
-                                         float width_real_sectors,
-                                         float width_imag_sectors);
+    static constellation_rect::sptr
+    make(std::vector<gr_complex> constell,
+         std::vector<int> pre_diff_code,
+         unsigned int rotational_symmetry,
+         unsigned int real_sectors,
+         unsigned int imag_sectors,
+         float width_real_sectors,
+         float width_imag_sectors,
+         normalization_t normalization = AMPLITUDE_NORMALIZATION);
     ~constellation_rect() override;
 
 protected:
@@ -355,7 +366,8 @@ protected:
                        unsigned int real_sectors,
                        unsigned int imag_sectors,
                        float width_real_sectors,
-                       float width_imag_sectors);
+                       float width_imag_sectors,
+                       normalization_t normalization = AMPLITUDE_NORMALIZATION);
 
     unsigned int get_sector(const gr_complex* sample) override;
     gr_complex calc_sector_center(unsigned int sector);
diff --git a/gr-digital/lib/constellation.cc b/gr-digital/lib/constellation.cc
index 0aff0aaecc..e9d3239503 100644
--- a/gr-digital/lib/constellation.cc
+++ b/gr-digital/lib/constellation.cc
@@ -32,7 +32,7 @@ constellation::constellation(std::vector<gr_complex> constell,
                              std::vector<int> pre_diff_code,
                              unsigned int rotational_symmetry,
                              unsigned int dimensionality,
-                             bool normalize_points)
+                             normalization_t normalization)
     : d_constellation(constell),
       d_pre_diff_code(pre_diff_code),
       d_rotational_symmetry(rotational_symmetry),
@@ -46,18 +46,39 @@ constellation::constellation(std::vector<gr_complex> constell,
       d_lut_scale(0)
 {
     unsigned int constsize = d_constellation.size();
-    if (normalize_points) {
+    float summed_mag = 0;
+    switch (normalization) {
+    case NO_NORMALIZATION:
+        break;
+
+    case POWER_NORMALIZATION:
+        // Scale constellation points so that average power is 1.
+        for (unsigned int i = 0; i < constsize; i++) {
+            gr_complex c = d_constellation[i];
+            summed_mag += std::norm(c);
+        }
+        d_scalefactor = constsize / sqrt(summed_mag);
+        for (unsigned int i = 0; i < constsize; i++) {
+            d_constellation[i] = d_constellation[i] * d_scalefactor;
+        }
+        break;
+
+    case AMPLITUDE_NORMALIZATION:
         // Scale constellation points so that average magnitude is 1.
-        float summed_mag = 0;
         for (unsigned int i = 0; i < constsize; i++) {
             gr_complex c = d_constellation[i];
-            summed_mag += sqrt(c.real() * c.real() + c.imag() * c.imag());
+            summed_mag += std::abs(c);
         }
         d_scalefactor = constsize / summed_mag;
         for (unsigned int i = 0; i < constsize; i++) {
             d_constellation[i] = d_constellation[i] * d_scalefactor;
         }
+        break;
+
+    default:
+        throw std::runtime_error("Invalid constellation normalization type.");
     }
+
     if (pre_diff_code.empty())
         d_apply_pre_diff_code = false;
     else if (pre_diff_code.size() != constsize)
@@ -370,19 +391,19 @@ constellation_calcdist::make(std::vector<gr_complex> constell,
                              std::vector<int> pre_diff_code,
                              unsigned int rotational_symmetry,
                              unsigned int dimensionality,
-                             bool normalize_points)
+                             normalization_t normalization)
 {
     return constellation_calcdist::sptr(new constellation_calcdist(
-        constell, pre_diff_code, rotational_symmetry, dimensionality, normalize_points));
+        constell, pre_diff_code, rotational_symmetry, dimensionality, normalization));
 }
 
 constellation_calcdist::constellation_calcdist(std::vector<gr_complex> constell,
                                                std::vector<int> pre_diff_code,
                                                unsigned int rotational_symmetry,
                                                unsigned int dimensionality,
-                                               bool normalize_points)
+                                               normalization_t normalization)
     : constellation(
-          constell, pre_diff_code, rotational_symmetry, dimensionality, normalize_points)
+          constell, pre_diff_code, rotational_symmetry, dimensionality, normalization)
 {
 }
 
@@ -401,8 +422,10 @@ constellation_sector::constellation_sector(std::vector<gr_complex> constell,
                                            std::vector<int> pre_diff_code,
                                            unsigned int rotational_symmetry,
                                            unsigned int dimensionality,
-                                           unsigned int n_sectors)
-    : constellation(constell, pre_diff_code, rotational_symmetry, dimensionality),
+                                           unsigned int n_sectors,
+                                           normalization_t normalization)
+    : constellation(
+          constell, pre_diff_code, rotational_symmetry, dimensionality, normalization),
       n_sectors(n_sectors)
 {
 }
@@ -435,7 +458,8 @@ constellation_rect::sptr constellation_rect::make(std::vector<gr_complex> conste
                                                   unsigned int real_sectors,
                                                   unsigned int imag_sectors,
                                                   float width_real_sectors,
-                                                  float width_imag_sectors)
+                                                  float width_imag_sectors,
+                                                  normalization_t normalization)
 {
     return constellation_rect::sptr(new constellation_rect(constell,
                                                            pre_diff_code,
@@ -443,7 +467,8 @@ constellation_rect::sptr constellation_rect::make(std::vector<gr_complex> conste
                                                            real_sectors,
                                                            imag_sectors,
                                                            width_real_sectors,
-                                                           width_imag_sectors));
+                                                           width_imag_sectors,
+                                                           normalization));
 }
 
 constellation_rect::constellation_rect(std::vector<gr_complex> constell,
@@ -452,9 +477,14 @@ constellation_rect::constellation_rect(std::vector<gr_complex> constell,
                                        unsigned int real_sectors,
                                        unsigned int imag_sectors,
                                        float width_real_sectors,
-                                       float width_imag_sectors)
-    : constellation_sector(
-          constell, pre_diff_code, rotational_symmetry, 1, real_sectors * imag_sectors),
+                                       float width_imag_sectors,
+                                       normalization_t normalization)
+    : constellation_sector(constell,
+                           pre_diff_code,
+                           rotational_symmetry,
+                           1,
+                           real_sectors * imag_sectors,
+                           normalization),
       n_real_sectors(real_sectors),
       n_imag_sectors(imag_sectors),
       d_width_real_sectors(width_real_sectors),
diff --git a/gr-digital/python/digital/bindings/constellation_python.cc b/gr-digital/python/digital/bindings/constellation_python.cc
index 77a252c42c..8944e666c9 100644
--- a/gr-digital/python/digital/bindings/constellation_python.cc
+++ b/gr-digital/python/digital/bindings/constellation_python.cc
@@ -14,7 +14,7 @@
 /* BINDTOOL_GEN_AUTOMATIC(0)                                                       */
 /* BINDTOOL_USE_PYGCCXML(0)                                                        */
 /* BINDTOOL_HEADER_FILE(constellation.h)                                           */
-/* BINDTOOL_HEADER_FILE_HASH(5f7cb544c3d7104e228f713f28b385ee)                     */
+/* BINDTOOL_HEADER_FILE_HASH(7830b0b770b8e3ae0fa213f34ead29b7)                     */
 /***********************************************************************************/
 
 #include <pybind11/complex.h>
@@ -43,17 +43,23 @@ void bind_constellation(py::module& m)
     using constellation_8psk_natural = ::gr::digital::constellation_8psk_natural;
     using constellation_16qam = ::gr::digital::constellation_16qam;
 
+    py::class_<constellation, std::shared_ptr<constellation>> constellation_class(
+        m, "constellation", D(constellation));
 
-    py::class_<constellation, std::shared_ptr<constellation>>(
-        m, "constellation", D(constellation))
+    py::enum_<constellation::normalization_t>(constellation_class, "normalization")
+        .value("NO_NORMALIZATION", constellation::NO_NORMALIZATION)
+        .value("POWER_NORMALIZATION", constellation::POWER_NORMALIZATION)
+        .value("AMPLITUDE_NORMALIZATION", constellation::AMPLITUDE_NORMALIZATION)
+        .export_values();
 
+    constellation_class
         // .def(py::init<std::vector<std::complex<float>,
         // std::allocator<std::complex<float> > >,std::vector<int, std::allocator<int>
         // >,unsigned int,unsigned int,bool>(),           py::arg("constell"),
         //    py::arg("pre_diff_code"),
         //    py::arg("rotational_symmetry"),
         //    py::arg("dimensionality"),
-        //    py::arg("normalize_points") = true,
+        //    py::arg("normalization") = constellation::AMPLITUDE_NORMALIZATION,
         //    D(constellation,constellation,0)
         // )
         // .def(py::init<>(),D(constellation,constellation,1))
@@ -212,7 +218,7 @@ void bind_constellation(py::module& m)
              py::arg("pre_diff_code"),
              py::arg("rotational_symmetry"),
              py::arg("dimensionality"),
-             py::arg("normalize_points") = true,
+             py::arg("normalization") = constellation::AMPLITUDE_NORMALIZATION,
              D(constellation_calcdist, make))
 
 
@@ -264,6 +270,7 @@ void bind_constellation(py::module& m)
              py::arg("imag_sectors"),
              py::arg("width_real_sectors"),
              py::arg("width_imag_sectors"),
+             py::arg("normalization") = constellation::AMPLITUDE_NORMALIZATION,
              D(constellation_rect, make))
author	Eduardo Sánchez Muñoz <esm@eduardosm.net>	2020-12-18 12:30:26 +0100
committer	Marcus Müller <marcus@hostalia.de>	2020-12-18 13:54:10 +0100
commit	947800c52f2fcb2b149cfd2809148afcfdb8b79a (patch)
tree	ffc11b527f2f95606da621185a8e4c8c5d048ff7 /gr-digital
parent	00fd051dff4a73081c40f4ccfc3b4ac8c62d74f1 (diff)