simthlib::ConvCodeTrellis Class Reference

#include <trellis.h>

Inheritance diagram for simthlib::ConvCodeTrellis:

[legend]List of all members.

Public Types
enum	StartingMode { FREE, ZERO, AMBIGOUS }
Public Member Functions
	ConvCodeTrellis (int states, int inbits, int outbits, StartingMode startingMode)
virtual	~ConvCodeTrellis ()
	Destructor.
void	printStateDiagram (std::ostream &os) const
virtual simth::BitSeq *	Encode (const simth::BitSeq &) const
	encodes a bit sequence
virtual void	Encode (const simth::BitSeq &bsin, simth::BitSeq *bsout) const
Protected Member Functions
virtual int	getNextState (int state, int input, size_t step, size_t path_length) const
virtual int	getNextOut (int state, int input, size_t step, size_t path_length) const
virtual int	getPrevState (int state, int index, size_t step, size_t path_length) const
virtual int	getPrevOut (int state, int index, size_t step, size_t path_length) const
virtual int	getPrevIn (int state, int index, size_t step, size_t path_length) const
virtual const Trellis::TrellisStatesArray &	getPrevTrellisArray (size_t time_step, size_t path_length) const
ConvCodeTrellis::StartingMode	startingMode () const
virtual bool	isPossibleStartingState (int state) const =0
virtual int	terminationInput (int state) const
Protected Attributes
Trellis::TrellisStatesArray	forward
	branches of the code trellis (forward)
Trellis::TrellisStatesArray	back
	branches of the code trellis (back)
simth::Array< int >	terminationInput_
Trellis::TrellisStatesArray	terminationForward
Trellis::TrellisStatesArray	terminationBack

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Detailed Description

This class provides a Trellis specialized to the use of a convolutional code. This class overwrites the pure virtual functions (getNextState(..),...) of the base class Trellis.

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Member Enumeration Documentation

enum simthlib::ConvCodeTrellis::StartingMode

Starting mode of the trellis: ZERO should be used for a conventional convolutional code, AMBIGOUS should be used for a differential code. Enumeration values: FREE  ZERO  AMBIGOUS

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Constructor & Destructor Documentation

simthlib::ConvCodeTrellis::ConvCodeTrellis (  int  states, int  inbits, int  outbits, StartingMode  startingMode )

Constructor to build a trellis with the given number of states, input and output bits and the specified starting mode. The starting mode defines, which states are allowed starting states, e.g. ZERO means that each path starts from the all-zero-state. Parameters: states  The number of states. inbits  The number of uncoded input bits per step outbits  The number of coded bits per step. startingMode  For conventional codes the starting mode should be set to 'ZERO'.

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

Destructor.

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Member Function Documentation

virtual void simthlib::ConvCodeTrellis::Encode (  const simth::BitSeq &  bsin, simth::BitSeq *  bsout )  const [virtual]

virtual simth::BitSeq* simthlib::ConvCodeTrellis::Encode (  const simth::BitSeq &   )  const [virtual]

encodes a bit sequence

int simthlib::ConvCodeTrellis::getNextOut (  int  state, int  input, size_t  step, size_t  path_length )  const [inline, protected, virtual]

Returns the coder output according to a given previous state and input for the given coding step. Implements simthlib::Trellis.

int simthlib::ConvCodeTrellis::getNextState (  int  state, int  input, size_t  step, size_t  path_length )  const [inline, protected, virtual]

Returns the next coder state according to a given previous state and input for the given coding step. The parameter step is required because of the corresponding virtual function in Trellis. However, the result is independent of step here. Implements simthlib::Trellis.

int simthlib::ConvCodeTrellis::getPrevIn (  int  state, int  index, size_t  step, size_t  path_length )  const [inline, protected, virtual]

Returns the previous coder input according to a given current state and number of the trellis branch leading to this state in the previous coding step. Implements simthlib::Trellis.

int simthlib::ConvCodeTrellis::getPrevOut (  int  state, int  index, size_t  step, size_t  path_length )  const [inline, protected, virtual]

Returns the previous coder output according to a given current state and number of the trellis branch leading to this state in the previous coding step. Implements simthlib::Trellis.

int simthlib::ConvCodeTrellis::getPrevState (  int  state, int  index, size_t  step, size_t  path_length )  const [inline, protected, virtual]

Returns the previous coder state according to a given current state and number of the trellis branch leading to this state in the previous coding step. Implements simthlib::Trellis.

const Trellis::TrellisStatesArray & simthlib::ConvCodeTrellis::getPrevTrellisArray (  size_t  time_step, size_t  path_length )  const [inline, protected, virtual]

Returns the argument to getPrevArray_state() according to the given time step and path length. Implements simthlib::Trellis.

virtual bool simthlib::ConvCodeTrellis::isPossibleStartingState (  int  state  )  const [protected, pure virtual]

Returns true if the given state is a possible starting state. The result depends on the starting mode set by the constructor argument. Implements simthlib::Trellis. Implemented in simthlib::ConvCodeTrellisShiftRegister, and simthlib::ConvCodeTrellisExplicit.

void simthlib::ConvCodeTrellis::printStateDiagram (  std::ostream &  os  )  const

Reimplemented from simthlib::Trellis.

ConvCodeTrellis::StartingMode simthlib::ConvCodeTrellis::startingMode (   )  const [inline, protected]

virtual int simthlib::ConvCodeTrellis::terminationInput (  int  state  )  const [protected, virtual]

Returns in order to a definite state of the trellis the termination input. If the recursive polynom is zero, the termination input is zero independend from the state of the trellis. Implements simthlib::Trellis.

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Member Data Documentation

Trellis::TrellisStatesArray simthlib::ConvCodeTrellis::back [protected]

branches of the code trellis (back)

Trellis::TrellisStatesArray simthlib::ConvCodeTrellis::forward [protected]

branches of the code trellis (forward)

Trellis::TrellisStatesArray simthlib::ConvCodeTrellis::terminationBack [protected]

Trellis::TrellisStatesArray simthlib::ConvCodeTrellis::terminationForward [protected]

simth::Array<int> simthlib::ConvCodeTrellis::terminationInput_ [protected]

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