ptolemy.actor.lib.comm
Class HammingCoder

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.lib.Transformer
                              ptolemy.actor.lib.comm.HammingCoder

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class HammingCoder
extends Transformer

Encode the information symbols into Hamming code. Let k denotes parameter uncodedRate and n denotes parameter codedRate. During each firing, the actor consumes k bits and encode them into a block of code with length n. The rate of the code is k/n.

For a Hamming code, k and n must satisfy the following: n = 2^m - 1 k = 2^m - 1 - m; where m is any positive integer. Note m = n - k. It is called the order of the Hamming code. The lowest order is m = 2, and (n, k) = (3, 1).

The generator matrix G is defined as: G_k*n = [I_k | P_k*(n-k) ] where P is called the parity matrix. The subscript of a matrix indicates its dimension.

The parity check matrix H is defined as: H_(n-k)*n = [P^T | I_n-k ] Each column of H must be one of the non-zero n = 2^m - 1 combinations of m bits.

To generate a Hamming code, the k information bits is considered as a row vector X. Its Hamming code is Y = X * G. Hence Y is a row vector of length n. The result is then sent to the output port in sequence.

For more information on Hamming codes, see Proakis, Digital Communications, Fourth Edition, McGraw-Hill, 2001, pp. 416-424.

Since:

Ptolemy II 3.0

Version:

$Id: HammingCoder.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Ye Zhou

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (eal)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.Entity

Entity.ContainedObjectsIterator

Field Summary

private int	_codeSizeValue
private Parameter	_inputRate
private int	_order
private Parameter	_outputRate
private boolean	_parameterInvalid
private int[][]	_parityMatrix
private int	_uncodeSizeValue
Parameter	codedRate Integer defining the Hamming code block size.
Parameter	uncodedRate Integer defining the uncode block size.

Fields inherited from class ptolemy.actor.lib.Transformer

input, output

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

HammingCoder(CompositeEntity container, java.lang.String name)
Construct an actor with the given container and name.

Method Summary

void	attributeChanged(Attribute attribute) If the attribute being changed is uncodedRate or uncodedRate, then verify that it is a positive integer.
java.lang.Object	clone(Workspace workspace) Clone the actor into the specified workspace.
void	fire() If the attributes has changed, check the validity of uncodedRate and codedRate.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, initialize, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, prefire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup

Methods inherited from class ptolemy.kernel.ComponentEntity

_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

isFireFunctional, isStrict, iterate, postfire, prefire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, initialize, preinitialize, removeInitializable, wrapup

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

uncodedRate

public Parameter uncodedRate

Integer defining the uncode block size. It should be a positive integer. Its default value is the integer 4.

codedRate

public Parameter codedRate

Integer defining the Hamming code block size. This parameter should be a non-negative integer. Its default value is the integer 7.

_inputRate

private Parameter _inputRate

_outputRate

private Parameter _outputRate

_uncodeSizeValue

private int _uncodeSizeValue

_codeSizeValue

private int _codeSizeValue

_order

private int _order

_parityMatrix

private int[][] _parityMatrix

_parameterInvalid

private transient boolean _parameterInvalid

Constructor Detail

HammingCoder

public HammingCoder(CompositeEntity container,
                    java.lang.String name)
             throws NameDuplicationException,
                    IllegalActionException

Construct an actor with the given container and name. The output and trigger ports are also constructed.

Parameters:

container - The container.

name - The name of this actor.

Throws:

IllegalActionException - If the entity cannot be contained by the proposed container.

NameDuplicationException - If the container already has an actor with this name.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

If the attribute being changed is uncodedRate or uncodedRate, then verify that it is a positive integer. Set the tokenConsumptionRate and tokenProductionRate.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If codedRate or uncodedRate is not positive.

clone

public java.lang.Object clone(Workspace workspace)
                       throws java.lang.CloneNotSupportedException

Clone the actor into the specified workspace.

Overrides:

clone in class AtomicActor

Parameters:

workspace - The workspace for the new object.

Returns:

A new actor.

Throws:

java.lang.CloneNotSupportedException - If a derived class contains an attribute that cannot be cloned.

See Also:

NamedObj.exportMoML(Writer, int, String), NamedObj.setDeferringChangeRequests(boolean)

fire

public void fire()
          throws IllegalActionException

If the attributes has changed, check the validity of uncodedRate and codedRate. Generate the parity matrix. Read "uncodedRate" number of tokens from the input port and compute the parities. Send the parities in sequence to the output port.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - Not thrown in this base class.