simthlib::SoftoutDecoding Class Reference

#include <softoutdecoding.h>

Inheritance diagram for simthlib::SoftoutDecoding:

[legend]List of all members.

Public Member Functions
virtual	~SoftoutDecoding ()
virtual void	softout4InputBits (simth::LlrSeq &metr, simth::LlrSeq *softout, simth::LlrSeq *apri=NULL)=0
virtual void	softout4OutputBits (const simth::LlrSeq &metr, simth::LlrSeq *softout, simth::LlrSeq *apri=NULL)=0
virtual void	softout4InputBits (simth::LlvSeq &metr, simth::LlrSeq *softout, simth::LlrSeq *apri=NULL)=0
virtual void	softout4OutputBits (const simth::LlvSeq &metr, simth::LlrSeq *softout, simth::LlrSeq *apri=NULL)=0
virtual void	normalDecoding (const simth::LlrSeq &llr, simth::BitSeq &bsout)=0
virtual int	getDataLength (int codedLength) const =0
virtual int	getCodeLength (int rawLength) const =0
virtual void	reset ()=0
virtual void	print (std::ostream &os) const =0

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Detailed Description

This abstract class provides an interface for a soft-out decoder wich provides a soft output decoding algorithm (e.g., SOVA). This soft information can be estimated both for the data bits and coded bits (softout4OutbitsBits(), softout4InputBits()). Besides this, a soft-out decoder provides normal decoding, which can be used in the last step of an interative decoding procedure. Note, that a soft out decoder is not derived by a normal decoder (i.e. a soft out decoder is not a normal decoder and it is not a basic device defined in simthetic. Rather a Softoutput Decoding is used within several types of turbo decoders to provide extrinsic information needed by the iterative decoding process.

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Constructor & Destructor Documentation

virtual simthlib::SoftoutDecoding::~SoftoutDecoding (   )  [virtual]

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Member Function Documentation

virtual int simthlib::SoftoutDecoding::getCodeLength (  int  rawLength  )  const [pure virtual]

Returns the length of the coded bit sequence which the coder generates from a data sequence of the given length. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual int simthlib::SoftoutDecoding::getDataLength (  int  codedLength  )  const [pure virtual]

Returns the length of a data bit sequence which can be encoded into a coded bit sequence of the given length. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual void simthlib::SoftoutDecoding::normalDecoding (  const simth::LlrSeq &  llr, simth::BitSeq &  bsout )  [pure virtual]

Performs a maximum likelihood sequence estimation of the data sequence based on the log-likelihood ratios of the received modulation symbols (soft decision decoding without soft {out}put) This can be usefull in the last step of an iterative decoding procedure when no soft-out information is needed. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual void simthlib::SoftoutDecoding::print (  std::ostream &  os  )  const [pure virtual]

Implemented in simthlib::TrellisSoftoutDecoding, simthlib::ConvSoftoutDecoding, and simthlib::SoftoutDAPSKDecoding.

virtual void simthlib::SoftoutDecoding::reset (   )  [pure virtual]

In derived classes where the decoding procedures depend on data stored in previous performed decoding procedures, the implementation of this function should set the class to the initial state. Classes, which do not change their state (i.e. storing some data) by decoding procedures, can use the standard implementation given by this class. Implemented in simthlib::TrellisSoftoutDecoding, and simthlib::SoftoutDAPSKDecoding.

virtual void simthlib::SoftoutDecoding::softout4InputBits (  simth::LlvSeq &  metr, simth::LlrSeq *  softout, simth::LlrSeq *  apri = NULL )  [pure virtual]

Estimates soft output for the given coded sequence of llvValues. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual void simthlib::SoftoutDecoding::softout4InputBits (  simth::LlrSeq &  metr, simth::LlrSeq *  softout, simth::LlrSeq *  apri = NULL )  [pure virtual]

Estimates soft output for the given coded sequence of llrValues. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual void simthlib::SoftoutDecoding::softout4OutputBits (  const simth::LlvSeq &  metr, simth::LlrSeq *  softout, simth::LlrSeq *  apri = NULL )  [pure virtual]

Estimates soft output for the output sequence of the decoder (resp.\ the data sequence) due to the given input sequence of llvValues. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

virtual void simthlib::SoftoutDecoding::softout4OutputBits (  const simth::LlrSeq &  metr, simth::LlrSeq *  softout, simth::LlrSeq *  apri = NULL )  [pure virtual]

Estimates soft output for the output sequence of the decoder (resp.\ the data sequence) due to the given input sequence of llrValues. Implemented in simthlib::TrellisSoftoutDecoding, simthlib::SoftoutDAPSKDecoding, and simthlib::PunctConvSoftoutDecoding.

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