gr::fec::code::ldpc_H_matrix Class Reference

Parity check matrix in Richardson/Urbanke format. More...

#include <gnuradio/fec/ldpc_H_matrix.h>

Public Types
typedef std::shared_ptr< ldpc_H_matrix >	sptr

Public Member Functions
void	encode (unsigned char *outbuffer, const unsigned char *inbuffer) const override=0
	Encode inbuffer with LDPC H matrix into outbuffer. More...
void	decode (unsigned char *outbuffer, const float *inbuffer, unsigned int frame_size, unsigned int max_iterations) const override=0
	Decode inbuffer with LDPC H matrix into outbuffer. More...
unsigned int	n () const override=0
	Get the codeword length n. More...
unsigned int	k () const override=0
	Get the information word length k. More...
Public Member Functions inherited from gr::fec::code::fec_mtrx
virtual	~fec_mtrx ()
virtual void	encode (unsigned char *outbuffer, const unsigned char *inbuffer) const =0
	Encode inbuffer with LDPC H matrix into outbuffer. More...
virtual void	decode (unsigned char *outbuffer, const float *inbuffer, unsigned int frame_size, unsigned int max_iterations) const =0
	Decode inbuffer with LDPC H matrix into outbuffer. More...
virtual unsigned int	n () const =0
	Get the codeword length n. More...
virtual unsigned int	k () const =0
	Get the information word length k. More...

Static Public Member Functions
static sptr	make (const std::string filename, unsigned int gap)
	Constructor given alist file and gap. More...

Additional Inherited Members
Protected Member Functions inherited from gr::fec::code::fec_mtrx
	fec_mtrx (void)

Detailed Description

Parity check matrix in Richardson/Urbanke format.

This class stores a matrix for use with the ldpc_encoder class. It must be of the specific format described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory (ISBN 978-0-521-85229-6). The form is:

\[\left[\begin{array}{ccc} T & A & B\\ E & C & D \end{array}\right]\]

This class can be used with the ldpc_bit_flip_decoder.

To convert a parity check matrix to this format, use the python functions in: /lib/python2.7/dist-packages/gnuradio/fec/LDPC/Generate_LDPC_matrix.py.

Member Typedef Documentation

sptr

typedef std::shared_ptr<ldpc_H_matrix> gr::fec::code::ldpc_H_matrix::sptr

Member Function Documentation

decode()

void gr::fec::code::ldpc_H_matrix::decode ( unsigned char *  outbuffer, const float *  inbuffer, unsigned int  frame_size, unsigned int  max_iterations  ) const

overridepure virtual

Decode inbuffer with LDPC H matrix into outbuffer.

Implements gr::fec::code::fec_mtrx.

encode()

void gr::fec::code::ldpc_H_matrix::encode ( unsigned char *  outbuffer, const unsigned char *  inbuffer  ) const

overridepure virtual

Encode inbuffer with LDPC H matrix into outbuffer.

Implements gr::fec::code::fec_mtrx.

k()

unsigned int gr::fec::code::ldpc_H_matrix::k ( ) const

overridepure virtual

Get the information word length k.

Implements gr::fec::code::fec_mtrx.

make()

static sptr gr::fec::code::ldpc_H_matrix::make ( const std::string  filename, unsigned int  gap  )

static

Constructor given alist file and gap.

Parameters

filename	Name of an alist file to use. The alist format is described at: http://www.inference.phy.cam.ac.uk/mackay/codes/alist.html
gap	A property of the matrix being used. For alist files distributed with GNU Radio, this value is specified in the alist filename. The gap is found during the matrix preprocessing algorithm. It is equal to the number of rows in submatrices E, C and D.

n()

unsigned int gr::fec::code::ldpc_H_matrix::n ( ) const

overridepure virtual

Get the codeword length n.

Implements gr::fec::code::fec_mtrx.

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

• ldpc_H_matrix.h