itpp::Modulator_ND Class Reference
[Digital Modulation]

Base class for an N-dimensional (ND) vector ("MIMO") modulator. See ND_UPAM for examples. More...

#include <itpp/comm/modulator_nd.h>

Inheritance diagram for itpp::Modulator_ND:


Public Member Functions
	Modulator_ND (LLR_calc_unit llrcalc_in=LLR_calc_unit())
	Constructor.
	~Modulator_ND ()
	Destructor.
int	get_dim ()
	Get number of dimensions.
LLR_calc_unit	get_llrcalc () const
	Get LLR calculation unit.
ivec	get_k ()
	Get number of bits per modulation symbol.
ivec	get_M ()
	Get number of modulation symbols per dimension.
Protected Member Functions
QLLRvec	probabilities (QLLR l)
	Convert LLR to log-probabilities.
Vec< QLLRvec >	probabilities (QLLRvec &l)
	Convert LLR to log-probabilities, vector version.
void	update_LLR (Vec< QLLRvec > &logP_apriori, QLLRvec &numerator, QLLRvec &denominator, ivec &s, QLLR x)
	Update LLR (for internal use).
void	update_LLR (Vec< QLLRvec > &logP_apriori, QLLRvec &numerator, QLLRvec &denominator, int s, QLLR scaled_norm, int j)
	Update LLR, for scalar channel (for internal use).
Protected Attributes
int	nt
	Number of dimensions.
LLR_calc_unit	llrcalc
	LLR calculation unit.
ivec	k
	Number of bits per modulation symbol.
ivec	M
	Number of modulation symbols along each dimension.
Vec< bmat >	bitmap
	Bit mapping table (one table per dimension).
Vec< ivec >	bits2symbols
	Bit pattern in decimal form ordered and the corresponding symbols (one pattern per dimension).

Detailed Description

Base class for an N-dimensional (ND) vector ("MIMO") modulator. See ND_UPAM for examples.

Definition at line 49 of file modulator_nd.h.

Constructor & Destructor Documentation

itpp::Modulator_ND::Modulator_ND ( LLR_calc_unit llrcalc_in = LLR_calc_unit() ) [inline]

Constructor.

Definition at line 52 of file modulator_nd.h.

References llrcalc.

itpp::Modulator_ND::~Modulator_ND ( ) [inline]

Destructor.

Definition at line 54 of file modulator_nd.h.

Member Function Documentation

int itpp::Modulator_ND::get_dim ( ) [inline]

Get number of dimensions.

Definition at line 57 of file modulator_nd.h.

References nt.

LLR_calc_unit itpp::Modulator_ND::get_llrcalc ( ) const [inline]

Get LLR calculation unit.

Definition at line 60 of file modulator_nd.h.

References llrcalc.

ivec itpp::Modulator_ND::get_k ( ) [inline]

Get number of bits per modulation symbol.

Definition at line 63 of file modulator_nd.h.

References k.

ivec itpp::Modulator_ND::get_M ( ) [inline]

Get number of modulation symbols per dimension.

Definition at line 66 of file modulator_nd.h.

References M.

QLLRvec itpp::Modulator_ND::probabilities ( QLLR l ) [protected]

Convert LLR to log-probabilities.

Definition at line 44 of file modulator_nd.cpp.

References itpp::LLR_calc_unit::jaclog(), and llrcalc.

Referenced by itpp::Modulator_NCD::map_demod(), itpp::Modulator_NRD::map_demod(), and probabilities().

Vec< QLLRvec > itpp::Modulator_ND::probabilities ( QLLRvec & l ) [protected]

Convert LLR to log-probabilities, vector version.

Definition at line 58 of file modulator_nd.cpp.

References itpp::length(), and probabilities().

void itpp::Modulator_ND::update_LLR	(	Vec< QLLRvec > &	logP_apriori,
		QLLRvec &	numerator,
		QLLRvec &	denominator,
		ivec &	s,
		QLLR	x
	)			`[protected]`

Update LLR (for internal use).

This function updates the numerator and denominator in the expression

$\log \left( \frac{ \sum_{s: b_k=0} \exp (-x^2) P(s) }{ \sum_{s: b_k=1} \exp (-x^2) P(s) } \right)$

Parameters:

	logP_apriori	vector of a priori probabilities per bit
	numerator	the logarithm of the numerator in the above expression
	denominator	the logarithm of the denominator in the above expression
	s	the symbol vector

Definition at line 87 of file modulator_nd.cpp.

References bitmap, itpp::LLR_calc_unit::jaclog(), k, llrcalc, and nt.

Referenced by itpp::Modulator_NCD::map_demod(), and itpp::Modulator_NRD::map_demod().

void itpp::Modulator_ND::update_LLR	(	Vec< QLLRvec > &	logP_apriori,
		QLLRvec &	numerator,
		QLLRvec &	denominator,
		int	s,
		QLLR	scaled_norm,
		int	j
	)			`[protected]`

Update LLR, for scalar channel (for internal use).

This function updates the numerator and denominator in the expression

$\log \left( \frac{ \sum_{s: b_k=0} \exp (-x^2) P(s) }{ \sum_{s: b_k=1} \exp (-x^2) P(s) } \right)$

Parameters:

	logP_apriori	vector of a priori probabilities per bit
	numerator	the logarithm of the numerator in the above expression
	denominator	the logarithm of the denominator in the above expression
	s	the symbol vector