GNU Radio Manual and C++ API Reference 3.10.5.1
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gr::digital::constellation_rect Class Reference

Rectangular digital constellation. More...

#include <gnuradio/digital/constellation.h>

Public Types

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

Public Member Functions

 ~constellation_rect () override
 
- Public Member Functions inherited from gr::digital::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, normalization_t normalization=AMPLITUDE_NORMALIZATION)
 
 ~constellation_sector () override
 
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 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)
 

Protected Member Functions

 constellation_rect (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)
 
unsigned int get_sector (const gr_complex *sample) override
 
gr_complex calc_sector_center (unsigned int sector)
 
unsigned int calc_sector_value (unsigned int sector) override
 
- Protected Member Functions inherited from gr::digital::constellation_sector
virtual unsigned int get_sector (const gr_complex *sample)=0
 
virtual unsigned int calc_sector_value (unsigned int sector)=0
 
void find_sector_values ()
 
- 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_sector
unsigned int n_sectors
 
- 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

Rectangular digital constellation.

Only implemented for 1-(complex)dimensional constellation.

Constellation space is divided into rectangular sectors. Each sector is associated with the nearest constellation point.

Works well for square QAM.

Works for any generic constellation provided sectors are not too large.

Member Typedef Documentation

◆ sptr

Constructor & Destructor Documentation

◆ ~constellation_rect()

gr::digital::constellation_rect::~constellation_rect ( )
override

◆ constellation_rect()

gr::digital::constellation_rect::constellation_rect ( 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 
)
protected

Member Function Documentation

◆ calc_sector_center()

gr_complex gr::digital::constellation_rect::calc_sector_center ( unsigned int  sector)
protected

◆ calc_sector_value()

unsigned int gr::digital::constellation_rect::calc_sector_value ( unsigned int  sector)
overrideprotectedvirtual

◆ get_sector()

unsigned int gr::digital::constellation_rect::get_sector ( const gr_complex sample)
overrideprotectedvirtual

◆ make()

static constellation_rect::sptr gr::digital::constellation_rect::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 
)
static

Make a rectangular constellation object.

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.
real_sectorsNumber of sectors the real axis is split in to.
imag_sectorsNumber of sectors the imag axis is split in to.
width_real_sectorswidth of each real sector to calculate decision boundaries.
width_imag_sectorswidth of each imag sector to calculate decision boundaries.
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: