Convolutional soft-decision sequential decoder generic (virtual) class. This is the public interface. More...

#include <CC_SequentialDecoding.h>

Inheritance diagram for ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >:

Public Member Functions
	CC_SequentialDecoding (const std::vector< unsigned int > &constraints, const std::vector< std::vector< T_Register > > &genpoly_representations)
virtual	~CC_SequentialDecoding ()
void	set_node_limit (unsigned int _node_limit)
void	reset_node_limit ()
void	set_metric_limit (float _metric_limit)
void	reset_metric_limit ()
void	set_tail_zeros (bool _tail_zeros)
void	reset ()
CC_Encoding< T_Register, T_IOSymbol > &	get_encoding ()
float	get_score () const
float	get_score_db_sym () const
unsigned int	get_nb_nodes () const
unsigned int	get_current_depth () const
unsigned int	get_max_depth () const
void	set_edge_bias (float _edge_bias)
void	set_verbosity (unsigned int _verbosity)
virtual void	print_dot (std::ostream &os)=0
virtual void	print_stats (std::ostream &os, bool success)=0
virtual bool	decode (const CC_ReliabilityMatrix &relmat, std::vector< T_IOSymbol > &decoded_message)=0
Protected Attributes
CC_Encoding< T_Register, T_IOSymbol >	encoding
	Convolutional encoding object.
bool	use_metric_limit
	True if a give up path metric threshold is used.
float	metric_limit
	The give up path metric threshold.
bool	use_node_limit
	Stop above number of nodes threshold.
unsigned int	node_limit
	Number of nodes threshold.
float	codeword_score
	Metric of the codeword found if any.
int	cur_depth
	Current depth for the encoder.
int	max_depth
	Maximum depth reached in the graph.
unsigned int	node_count
	Count of nodes in the code tree.
bool	tail_zeros
	True if tail of m-1 zeros in the message are assumed. This is the default option.
float	edge_bias
	Edge metric bias subtracted from log2 of reliability of the edge.
unsigned int	verbosity
	Verbosity level.

Detailed Description

template<typename T_Register, typename T_IOSymbol>
class ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >

Convolutional soft-decision sequential decoder generic (virtual) class. This is the public interface.

Template Parameters:

T_Register	Type of the encoder internal registers
T_IOSymbol	Type of the input and output symbols

Constructor & Destructor Documentation

template<typename T_Register , typename T_IOSymbol >

ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::CC_SequentialDecoding	(	const std::vector< unsigned int > &	constraints,
		const std::vector< std::vector< T_Register > > &	genpoly_representations
	)		`[inline]`

Constructor

Parameters:

constraints Vector of register lengths (constraint length + 1). The number of elements determines k.

genpoly_representations Generator polynomial numeric representations. There are as many elements as there are input bits (k). Each element is itself a vector with one polynomial value per output bit. The smallest size of these vectors is retained as the number of output bits n. The input bits of a symbol are clocked simultaneously into the right hand side, or least significant position of the internal registers. Therefore the given polynomial representation of generators should follow the same convention.

                                                                              :
                encoding(constraints, genpoly_representations),
                use_metric_limit(false),
                metric_limit(0.0),
                use_node_limit(false),
                node_limit(0),
                codeword_score(0.0),
                cur_depth(-1),
                max_depth(0),
                node_count(0),
                tail_zeros(true),
                edge_bias(0.0),
                verbosity(0)
        {}

template<typename T_Register , typename T_IOSymbol >

virtual ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::~CC_SequentialDecoding ( ) [inline, virtual]

Destructor

        {
        }

Member Function Documentation

template<typename T_Register , typename T_IOSymbol >

virtual bool ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::decode	(	const CC_ReliabilityMatrix &	relmat,
		std::vector< T_IOSymbol > &	decoded_message
	)		`[pure virtual]`

Decodes given the reliability matrix

Parameters:

relmat	Reference to the reliability matrix
decoded_message	Vector of symbols of retrieved message

Implemented in ccsoft::CC_FanoDecoding< T_Register, T_IOSymbol >, and ccsoft::CC_StackDecoding< T_Register, T_IOSymbol >.

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_current_depth ( ) const [inline]

Get the current depth

    {
        return cur_depth;
    }

template<typename T_Register , typename T_IOSymbol >

CC_Encoding<T_Register, T_IOSymbol>& ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_encoding ( ) [inline]

Get encoding object reference

    {
        return encoding;
    }

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_max_depth ( ) const [inline]

Get the maximum depth reached

    {
        return max_depth;
    }

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_nb_nodes ( ) const [inline]

Get the number of nodes created minus root node

    {
        return node_count;
    }

template<typename T_Register , typename T_IOSymbol >

float ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_score ( ) const [inline]

Get the codeword score. Valid only if decode returned successfully.

    {
        return codeword_score;
    }

template<typename T_Register , typename T_IOSymbol >

float ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::get_score_db_sym ( ) const [inline]

Get the codeword score in dB/Symbol units. Valid only if decode returned successfully.

    {
        if (cur_depth > 0)
        {
            return (10.0*log(2.0)*codeword_score) / cur_depth;
        }
        else
        {
            return 0.0;
        }
    }

template<typename T_Register , typename T_IOSymbol >

virtual void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::print_dot ( std::ostream & os ) [pure virtual]

Print the dot (Graphviz) file of the current decode tree to an output stream

Parameters:

os	Output stream

Implemented in ccsoft::CC_FanoDecoding< T_Register, T_IOSymbol >, and ccsoft::CC_StackDecoding< T_Register, T_IOSymbol >.

template<typename T_Register , typename T_IOSymbol >

virtual void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::print_stats	(	std::ostream &	os,
		bool	success
	)		`[pure virtual]`

Print statistics to an output stream

Parameters:

os	Output stream
success	true if decoding was successful

Implemented in ccsoft::CC_FanoDecoding< T_Register, T_IOSymbol >, and ccsoft::CC_StackDecoding< T_Register, T_IOSymbol >.

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::reset ( ) [inline]

Reset the decoding process

Reimplemented in ccsoft::CC_FanoDecoding< T_Register, T_IOSymbol >, and ccsoft::CC_StackDecoding< T_Register, T_IOSymbol >.

    {
        node_count = 0;
        codeword_score = 0.0;
        cur_depth = -1;
        max_depth = 0;
        encoding.clear(); // clear encoder's registers
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::reset_metric_limit ( ) [inline]

Reset the metric limit threshold. The process will continue until out of memory or end of the tree.

    {
        use_metric_limit = false;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::reset_node_limit ( ) [inline]

Reset the node limit threshold. The process will continue until out of memory or end of the tree.

    {
        use_node_limit = false;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::set_edge_bias ( float _edge_bias ) [inline]

Set the edge metric bias

    {
        edge_bias = _edge_bias;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::set_metric_limit ( float _metric_limit ) [inline]

Set the metric limit threshold

    {
        metric_limit = _metric_limit;
        use_metric_limit = true;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::set_node_limit ( unsigned int _node_limit ) [inline]

Set the node limit threshold

    {
        node_limit = _node_limit;
        use_node_limit = true;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::set_tail_zeros ( bool _tail_zeros ) [inline]

Set the tail zeros option

    {
        tail_zeros = _tail_zeros;
    }

template<typename T_Register , typename T_IOSymbol >

void ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::set_verbosity ( unsigned int _verbosity ) [inline]

Set verbosity level

    {
        verbosity = _verbosity;
    }

Member Data Documentation

template<typename T_Register , typename T_IOSymbol >

float ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::codeword_score [protected]

Metric of the codeword found if any.

template<typename T_Register , typename T_IOSymbol >

int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::cur_depth [protected]

Current depth for the encoder.

template<typename T_Register , typename T_IOSymbol >

float ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::edge_bias [protected]

Edge metric bias subtracted from log2 of reliability of the edge.

template<typename T_Register , typename T_IOSymbol >

CC_Encoding<T_Register, T_IOSymbol> ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::encoding [protected]

Convolutional encoding object.

template<typename T_Register , typename T_IOSymbol >

int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::max_depth [protected]

Maximum depth reached in the graph.

template<typename T_Register , typename T_IOSymbol >

float ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::metric_limit [protected]

The give up path metric threshold.

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::node_count [protected]

Count of nodes in the code tree.

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::node_limit [protected]

Number of nodes threshold.

template<typename T_Register , typename T_IOSymbol >

bool ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::tail_zeros [protected]

True if tail of m-1 zeros in the message are assumed. This is the default option.

template<typename T_Register , typename T_IOSymbol >

bool ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::use_metric_limit [protected]

True if a give up path metric threshold is used.

template<typename T_Register , typename T_IOSymbol >

bool ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::use_node_limit [protected]

Stop above number of nodes threshold.

template<typename T_Register , typename T_IOSymbol >

unsigned int ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >::verbosity [protected]

Verbosity level.

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

/shared/development/google_code/rssoft/libccsoft/lib/CC_SequentialDecoding.h

Public Member Functions

Protected Attributes

Detailed Description

template<typename T_Register, typename T_IOSymbol> class ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<typename T_Register, typename T_IOSymbol>
class ccsoft::CC_SequentialDecoding< T_Register, T_IOSymbol >