inet::physicallayer::Ieee80211OfdmModulator Class Reference

#include <Ieee80211OfdmModulator.h>

Inheritance diagram for inet::physicallayer::Ieee80211OfdmModulator:

Public Member Functions
	Ieee80211OfdmModulator (const Ieee80211OfdmModulation *subcarrierModulation, unsigned int polarityVectorOffset)
virtual const ITransmissionSymbolModel *	modulate (const ITransmissionBitModel *bitModel) const override
const Ieee80211OfdmModulation *	getModulation () const override
virtual std::ostream &	printToStream (std::ostream &stream, int level, int evFlags=0) const override
	Prints this object to the provided output stream. More...
Public Member Functions inherited from inet::IPrintableObject
virtual	~IPrintableObject ()
virtual std::string	printToString () const
virtual std::string	printToString (int level, int evFlags=0) const
virtual std::string	getInfoStringRepresentation (int evFlags=0) const
virtual std::string	getDetailStringRepresentation (int evFlags=0) const
virtual std::string	getDebugStringRepresentation (int evFlags=0) const
virtual std::string	getTraceStringRepresentation (int evFlags=0) const
virtual std::string	getCompleteStringRepresentation (int evFlags=0) const

Static Public Attributes
static const ApskSymbol	negativePilotSubcarrier
static const ApskSymbol	positivePilotSubcarrier

Protected Member Functions
int	getSubcarrierIndex (int ofdmSymbolIndex) const
void	insertPilotSubcarriers (Ieee80211OfdmSymbol *ofdmSymbol, int symbolID) const

Protected Attributes
const Ieee80211OfdmModulation *	subcarrierModulation
unsigned int	pilotSubcarrierPolarityVectorOffset

Static Protected Attributes
static const double	pilotSubcarrierPolarityVector [127]

Additional Inherited Members
Public Types inherited from inet::IPrintableObject
enum	PrintLevel {   PRINT_LEVEL_TRACE, PRINT_LEVEL_DEBUG, PRINT_LEVEL_DETAIL, PRINT_LEVEL_INFO,   PRINT_LEVEL_COMPLETE = INT_MIN }
enum	PrintFlag { PRINT_FLAG_FORMATTED = (1 << 0), PRINT_FLAG_MULTILINE = (1 << 1) }

Constructor & Destructor Documentation

Ieee80211OfdmModulator()

inet::physicallayer::Ieee80211OfdmModulator::Ieee80211OfdmModulator	(	const Ieee80211OfdmModulation *	subcarrierModulation,
		unsigned int	polarityVectorOffset
	)

                                                                                                                                     :
    subcarrierModulation(subcarrierModulation),
    pilotSubcarrierPolarityVectorOffset(polarityVectorOffset)
{
}

Member Function Documentation

getModulation()

const Ieee80211OfdmModulation* inet::physicallayer::Ieee80211OfdmModulator::getModulation ( ) const

inlineoverridevirtual

Implements inet::physicallayer::IModulator.

{ return subcarrierModulation; }

Referenced by inet::physicallayer::Ieee80211OfdmModulatorModule::getModulation().

getSubcarrierIndex()

int inet::physicallayer::Ieee80211OfdmModulator::getSubcarrierIndex ( int  ofdmSymbolIndex ) const

protected

{
    // This is the translated version of the M(k) function defined in 18.3.5.10 OFDM modulation: (18-23) equation.
    // We translate it by 26 since its range is [-26,26] and we use subcarrier indices as array indices.
    if (ofdmSymbolIndex >= 0 && ofdmSymbolIndex <= 4)
        return ofdmSymbolIndex;
    else if (ofdmSymbolIndex >= 5 && ofdmSymbolIndex <= 17)
        return ofdmSymbolIndex + 1;
    else if (ofdmSymbolIndex >= 18 && ofdmSymbolIndex <= 23)
        return ofdmSymbolIndex + 2;
    else if (ofdmSymbolIndex >= 24 && ofdmSymbolIndex <= 29)
        return ofdmSymbolIndex + 3;
    else if (ofdmSymbolIndex >= 30 && ofdmSymbolIndex <= 42)
        return ofdmSymbolIndex + 4;
    else if (ofdmSymbolIndex >= 43 && ofdmSymbolIndex <= 47)
        return ofdmSymbolIndex + 5;
    else
        throw cRuntimeError("The domain of the M(k) (k = %d) function is [0,47]", ofdmSymbolIndex);
}

Referenced by modulate().

insertPilotSubcarriers()

void inet::physicallayer::Ieee80211OfdmModulator::insertPilotSubcarriers ( Ieee80211OfdmSymbol *  ofdmSymbol, int  symbolID  ) const

protected

{
    ofdmSymbol->pushApskSymbol(pilotSubcarrierPolarityVector[symbolID % 127] == 1 ? &positivePilotSubcarrier : &negativePilotSubcarrier, 5);
    ofdmSymbol->pushApskSymbol(pilotSubcarrierPolarityVector[symbolID % 127] == 1 ? &positivePilotSubcarrier : &negativePilotSubcarrier, 19);
    ofdmSymbol->pushApskSymbol(pilotSubcarrierPolarityVector[symbolID % 127] == 1 ? &positivePilotSubcarrier : &negativePilotSubcarrier, 33);
    ofdmSymbol->pushApskSymbol(pilotSubcarrierPolarityVector[symbolID % 127] == 1 ? &negativePilotSubcarrier : &positivePilotSubcarrier, 47);
}

Referenced by modulate().

modulate()

const ITransmissionSymbolModel * inet::physicallayer::Ieee80211OfdmModulator::modulate ( const ITransmissionBitModel *  bitModel ) const

overridevirtual

Implements inet::physicallayer::IModulator.

{
    std::vector<const ISymbol *> *ofdmSymbols = new std::vector<const ISymbol *>();
    const ApskModulationBase *modulationScheme = subcarrierModulation->getSubcarrierModulation();
    const BitVector *bits = bitModel->getBits();
    // Divide the resulting coded and interleaved data string into groups of N_BPSC bits.
    unsigned int nBPSC = modulationScheme->getCodeWordSize();
    ShortBitVector bitGroup;
    std::vector<const ApskSymbol *> apskSymbols;
    for (unsigned int i = 0; i < bits->getSize(); i++) {
        // For each of the bit groups, convert the bit group into a complex number according
        // to the modulation encoding tables
        bitGroup.setBit(i % nBPSC, bits->getBit(i));
        if (i % nBPSC == nBPSC - 1) {
            const ApskSymbol *apskSymbol = modulationScheme->mapToConstellationDiagram(bitGroup);
            apskSymbols.push_back(apskSymbol);
        }
    }
    // Divide the complex number string into groups of 48 complex numbers.
    // Each such group is associated with one OFDM symbol.
    for (unsigned int i = 0; i < apskSymbols.size(); i += NUMBER_OF_OFDM_DATA_SUBCARRIERS) {
        Ieee80211OfdmSymbol *ofdmSymbol = new Ieee80211OfdmSymbol();
        // In each group, the complex numbers are numbered 0 to 47 and mapped hereafter into OFDM
        // subcarriers numbered -26 to -22, -20 to -8, -6 to -1, 1 to 6, 8 to 20, and 22 to 26.
        // The 0 subcarrier, associated with center frequency, is omitted and filled with the value 0.
        for (unsigned int j = 0; j < NUMBER_OF_OFDM_DATA_SUBCARRIERS; j++) {
            int subcarrierIndex = getSubcarrierIndex(j);
            ofdmSymbol->pushApskSymbol(apskSymbols.at(j + i), subcarrierIndex);
        }
        insertPilotSubcarriers(ofdmSymbol, i / NUMBER_OF_OFDM_DATA_SUBCARRIERS + pilotSubcarrierPolarityVectorOffset);
        EV_DEBUG << "Modulated OFDM symbol: " << *ofdmSymbol << endl;
        ofdmSymbols->push_back(ofdmSymbol);
    }
    return new Ieee80211OfdmTransmissionSymbolModel(1, NaN, ofdmSymbols->size() - 1, NaN, ofdmSymbols, modulationScheme, modulationScheme);
}

Referenced by inet::physicallayer::Ieee80211LayeredOfdmTransmitter::encodeAndModulate(), and inet::physicallayer::Ieee80211OfdmModulatorModule::modulate().

printToStream()

std::ostream & inet::physicallayer::Ieee80211OfdmModulator::printToStream ( std::ostream &  stream, int  level, int  evFlags = 0  ) const

overridevirtual

Prints this object to the provided output stream.

Reimplemented from inet::IPrintableObject.

{
    stream << "Ieee80211OfdmModulator";
    if (level <= PRINT_LEVEL_TRACE)
        stream << EV_FIELD(subcarrierModulation, printFieldToString(subcarrierModulation, level + 1, evFlags));
    return stream;
}

Referenced by inet::physicallayer::Ieee80211OfdmModulatorModule::printToStream().

Member Data Documentation

negativePilotSubcarrier

const ApskSymbol inet::physicallayer::Ieee80211OfdmModulator::negativePilotSubcarrier

static

Referenced by insertPilotSubcarriers().

pilotSubcarrierPolarityVector

const double inet::physicallayer::Ieee80211OfdmModulator::pilotSubcarrierPolarityVector

staticprotected

Initial value:

= {
    1, 1, 1, 1, -1, -1, -1, 1, -1, -1, -1, -1, 1, 1, -1, 1, -1, -1, 1, 1, -1, 1, 1, -1, 1, 1, 1, 1, 1, 1, -1, 1,
    1, 1, -1, 1, 1, -1, -1, 1, 1, 1, -1, 1, -1, -1, -1, 1, -1, 1, -1, -1, 1, -1, -1, 1, 1, 1, 1, 1, -1, -1, 1, 1,
    -1, -1, 1, -1, 1, -1, 1, 1, -1, -1, -1, 1, 1, -1, -1, -1, -1, 1, -1, -1, 1, -1, 1, 1, 1, 1, -1, 1, -1, 1, -1, 1,
    -1, -1, -1, -1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, 1, -1, -1, 1, -1, -1, -1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1
}

Referenced by insertPilotSubcarriers().

pilotSubcarrierPolarityVectorOffset

unsigned int inet::physicallayer::Ieee80211OfdmModulator::pilotSubcarrierPolarityVectorOffset

protected

Referenced by modulate().

positivePilotSubcarrier

const ApskSymbol inet::physicallayer::Ieee80211OfdmModulator::positivePilotSubcarrier

static

Referenced by insertPilotSubcarriers().

subcarrierModulation

const Ieee80211OfdmModulation* inet::physicallayer::Ieee80211OfdmModulator::subcarrierModulation

protected

Referenced by modulate(), and printToStream().

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

• Ieee80211OfdmModulator.h
• Ieee80211OfdmModulator.cc