GNU Radio Manual and C++ API Reference 3.10.5.1
The Free & Open Software Radio Ecosystem
gr::digital::constellation_calcdist Class Reference

Calculate Euclidean distance for any constellation. More...

#include <gnuradio/digital/constellation.h>

Public Types

typedef std::shared_ptr< constellation_calcdistsptr
 
- Public Types inherited from gr::digital::constellation
enum  normalization_t { NO_NORMALIZATION , POWER_NORMALIZATION , AMPLITUDE_NORMALIZATION }
 

Public Member Functions

unsigned int decision_maker (const gr_complex *sample) override
 Returns the constellation point that matches best. More...
 
- Public Member Functions inherited from gr::digital::constellation
 constellation (std::vector< gr_complex > constell, std::vector< int > pre_diff_code, unsigned int rotational_symmetry, unsigned int dimensionality, normalization_t normalization=AMPLITUDE_NORMALIZATION)
 
 constellation ()
 
virtual ~constellation ()
 
void map_to_points (unsigned int value, gr_complex *points)
 Returns the constellation points for a symbol value. More...
 
std::vector< gr_complexmap_to_points_v (unsigned int value)
 
virtual unsigned int decision_maker (const gr_complex *sample)=0
 Returns the constellation point that matches best. More...
 
unsigned int decision_maker_v (std::vector< gr_complex > sample)
 Takes a vector rather than a pointer. Better for SWIG wrapping. More...
 
unsigned int decision_maker_pe (const gr_complex *sample, float *phase_error)
 Also calculates the phase error. More...
 
virtual void calc_metric (const gr_complex *sample, float *metric, gr::digital::trellis_metric_type_t type)
 Calculates distance. More...
 
virtual void calc_euclidean_metric (const gr_complex *sample, float *metric)
 
virtual void calc_hard_symbol_metric (const gr_complex *sample, float *metric)
 
std::vector< gr_complexpoints ()
 Returns the set of points in this constellation. More...
 
std::vector< gr_complexs_points ()
 Returns the vector of points in this constellation. Raise error if dimensionality is not one. More...
 
std::vector< std::vector< gr_complex > > v_points ()
 Returns a vector of vectors of points. More...
 
bool apply_pre_diff_code ()
 Whether to apply an encoding before doing differential encoding. (e.g. gray coding) More...
 
void set_pre_diff_code (bool a)
 Whether to apply an encoding before doing differential encoding. (e.g. gray coding) More...
 
std::vector< int > pre_diff_code ()
 Returns the encoding to apply before differential encoding. More...
 
unsigned int rotational_symmetry ()
 Returns the order of rotational symmetry. More...
 
unsigned int dimensionality ()
 Returns the number of complex numbers in a single symbol. More...
 
unsigned int bits_per_symbol ()
 
unsigned int arity ()
 
constellation_sptr base ()
 
pmt::pmt_t as_pmt ()
 
void gen_soft_dec_lut (int precision, float npwr=1.0)
 Generates the soft decision LUT based on constellation and symbol map. More...
 
virtual std::vector< float > calc_soft_dec (gr_complex sample, float npwr=1.0)
 Calculate soft decisions for the given sample. More...
 
void set_soft_dec_lut (const std::vector< std::vector< float > > &soft_dec_lut, int precision)
 Define a soft decision look-up table. More...
 
bool has_soft_dec_lut ()
 Returns True if the soft decision LUT has been defined, False otherwise. More...
 
std::vector< std::vector< float > > soft_dec_lut ()
 
std::vector< float > soft_decision_maker (gr_complex sample)
 Returns the soft decisions for the given sample. More...
 

Static Public Member Functions

static sptr make (std::vector< gr_complex > constell, std::vector< int > pre_diff_code, unsigned int rotational_symmetry, unsigned int dimensionality, normalization_t normalization=AMPLITUDE_NORMALIZATION)
 

Protected Member Functions

 constellation_calcdist (std::vector< gr_complex > constell, std::vector< int > pre_diff_code, unsigned int rotational_symmetry, unsigned int dimensionality, normalization_t normalization=AMPLITUDE_NORMALIZATION)
 
- Protected Member Functions inherited from gr::digital::constellation
float get_distance (unsigned int index, const gr_complex *sample)
 
unsigned int get_closest_point (const gr_complex *sample)
 
void calc_arity ()
 
void max_min_axes ()
 

Additional Inherited Members

- Protected Attributes inherited from gr::digital::constellation
std::vector< gr_complexd_constellation
 
std::vector< int > d_pre_diff_code
 
bool d_apply_pre_diff_code
 
unsigned int d_rotational_symmetry
 
unsigned int d_dimensionality
 
unsigned int d_arity
 
float d_scalefactor
 The factor by which the user given constellation points were scaled by to achieve an average amplitude of 1. More...
 
float d_re_min
 
float d_re_max
 
float d_im_min
 
float d_im_max
 
std::vector< std::vector< float > > d_soft_dec_lut
 
int d_lut_precision
 
float d_lut_scale
 

Detailed Description

Calculate Euclidean distance for any constellation.

Constellation which calculates the distance to each point in the constellation for decision making. Inefficient for large constellations.

Member Typedef Documentation

◆ sptr

Constructor & Destructor Documentation

◆ constellation_calcdist()

gr::digital::constellation_calcdist::constellation_calcdist ( std::vector< gr_complex constell,
std::vector< int >  pre_diff_code,
unsigned int  rotational_symmetry,
unsigned int  dimensionality,
normalization_t  normalization = AMPLITUDE_NORMALIZATION 
)
protected

Member Function Documentation

◆ decision_maker()

unsigned int gr::digital::constellation_calcdist::decision_maker ( const gr_complex sample)
overridevirtual

Returns the constellation point that matches best.

Implements gr::digital::constellation.

◆ make()

static sptr gr::digital::constellation_calcdist::make ( std::vector< gr_complex constell,
std::vector< int >  pre_diff_code,
unsigned int  rotational_symmetry,
unsigned int  dimensionality,
normalization_t  normalization = AMPLITUDE_NORMALIZATION 
)
static

Make a general constellation object that calculates the Euclidean distance for hard decisions.

Parameters
constellList of constellation points (order of list matches pre_diff_code)
pre_diff_codeList of alphabet symbols (before applying any differential coding) (order of list matches constell)
rotational_symmetryNumber of rotations around unit circle that have the same representation.
dimensionalityNumber of dimensions to the constellation.
normalizationUse 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.

The documentation for this class was generated from the following file: