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_calcdist >	sptr
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_complex >	map_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_complex >	points ()
	Returns the set of points in this constellation. More...
std::vector< gr_complex >	s_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_complex >	d_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

typedef std::shared_ptr<constellation_calcdist> gr::digital::constellation_calcdist::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

constell	List of constellation points (order of list matches pre_diff_code)
pre_diff_code	List of alphabet symbols (before applying any differential coding) (order of list matches constell)
rotational_symmetry	Number of rotations around unit circle that have the same representation.
dimensionality	Number of dimensions to the constellation.
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.

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

• constellation.h