Model the error rate for different modulations. More...

#include <Ieee80211YansErrorModel.h>

Inheritance diagram for inet::physicallayer::Ieee80211YansErrorModel:

Public Member Functions
virtual std::ostream &	printToStream (std::ostream &stream, int level) const override
	Prints this object to the provided output stream. More...

Public Member Functions inherited from inet::physicallayer::Ieee80211ErrorModelBase
	Ieee80211ErrorModelBase ()

virtual double	computePacketErrorRate (const ISNIR *snir, IRadioSignal::SignalPart part) const override
	Returns the packet error rate based on SNIR, modulation, FEC encoding and any other physical layer characteristics. More...

virtual double	computeBitErrorRate (const ISNIR *snir, IRadioSignal::SignalPart part) const override
	Returns the bit error rate based on SNIR, modulation, FEC encoding and any other physical layer characteristics. More...

virtual double	computeSymbolErrorRate (const ISNIR *snir, IRadioSignal::SignalPart part) const override
	Returns the symbol error rate based on SNIR, modulation, and any other physical layer characteristics. More...

Public Member Functions inherited from inet::physicallayer::IPrintableObject
virtual	~IPrintableObject ()

virtual std::string	getInfoStringRepresentation () const

virtual std::string	getDetailStringRepresentation () const

virtual std::string	getDebugStringRepresentation () const

virtual std::string	getTraceStringRepresentation () const

virtual std::string	getCompleteStringRepresentation () const

Protected Member Functions
double	getBpskBer (double snr, Hz signalSpread, bps phyRate) const

double	getQamBer (double snr, unsigned int m, Hz signalSpread, bps phyRate) const

uint32_t	factorial (uint32_t k) const

double	binomialCoefficient (uint32_t k, double p, uint32_t n) const

double	calculatePdOdd (double ber, unsigned int d) const

double	calculatePdEven (double ber, unsigned int d) const

double	calculatePd (double ber, unsigned int d) const

double	getFecBpskBer (double snr, double nbits, Hz signalSpread, bps phyRate, uint32_t dFree, uint32_t adFree) const

double	getFecQamBer (double snr, uint32_t nbits, Hz signalSpread, bps phyRate, uint32_t m, uint32_t dfree, uint32_t adFree, uint32_t adFreePlusOne) const

virtual double	getOFDMAndERPOFDMChunkSuccessRate (const APSKModulationBase subcarrierModulation, const ConvolutionalCode convolutionalCode, unsigned int bitLength, bps gorssBitrate, Hz bandwidth, double snr) const

virtual double	getDSSSAndHrDSSSChunkSuccessRate (bps bitrate, unsigned int bitLength, double snr) const

virtual double	getHeaderSuccessRate (const IIeee80211Mode *mode, unsigned int bitLength, double snr) const override

virtual double	getDataSuccessRate (const IIeee80211Mode *mode, unsigned int bitLength, double snr) const override

Additional Inherited Members
Public Types inherited from inet::physicallayer::IPrintableObject
enum	PrintLevel { PRINT_LEVEL_TRACE, PRINT_LEVEL_DEBUG, PRINT_LEVEL_DETAIL, PRINT_LEVEL_INFO, PRINT_LEVEL_COMPLETE = INT_MIN }

Detailed Description

Model the error rate for different modulations.

A packet of interest (e.g., a packet can potentially be received by the MAC) is divided into chunks. Each chunk is related to an start/end receiving event. For each chunk, it calculates the ratio (SINR) between received power of packet of interest and summation of noise and interfering power of all the other incoming packets. Then, it will calculate the success rate of the chunk based on BER of the modulation. The success reception rate of the packet is derived from the success rate of all chunks.

The 802.11b modulations:

1 Mbps mode is based on DBPSK. BER is from equation 5.2-69 from John G. Proakis Digitial Communications, 2001 edition
2 Mbps model is based on DQPSK. Equation 8 from "Tight bounds and accurate approximations for dqpsk transmission bit error rate", G. Ferrari and G.E. Corazza ELECTRONICS LETTERS, 40(20):1284-1285, September 2004
5.5 Mbps and 11 Mbps are based on equations (18) and (17) from "Properties and performance of the ieee 802.11b complementarycode-key signal sets", Michael B. Pursley and Thomas C. Royster. IEEE TRANSACTIONS ON COMMUNICATIONS, 57(2):440-449, February 2009.
More detailed description and validation can be found in http://www.nsnam.org/~pei/80211b.pdf

Member Function Documentation

double inet::physicallayer::Ieee80211YansErrorModel::binomialCoefficient	(	uint32_t	k,
		double	p,
		uint32_t	n
	)		const

protected

Referenced by calculatePdEven(), and calculatePdOdd().

 {
     double retval = factorial(n) / (factorial(k) * factorial(n - k)) * pow(p, (int)k) * pow(1 - p, (int)(n - k));
     return retval;
 }

double inet::physicallayer::Ieee80211YansErrorModel::calculatePd	(	double	ber,
		unsigned int	d
	)		const

protected

Referenced by getFecBpskBer(), and getFecQamBer().

 {
     double pd;
     if ((d % 2) == 0) {
         pd = calculatePdEven(ber, d);
     }
     else {
         pd = calculatePdOdd(ber, d);
     }
     return pd;
 }

double inet::physicallayer::Ieee80211YansErrorModel::calculatePdEven	(	double	ber,
		unsigned int	d
	)		const

protected

Referenced by calculatePd().

 {
     ASSERT((d % 2) == 0);
     unsigned int dstart = d / 2 + 1;
     unsigned int dend = d;
     double pd = 0;
 
     for (unsigned int i = dstart; i < dend; i++) {
         pd += binomialCoefficient(i, ber, d);
     }
     pd += 0.5 * binomialCoefficient(d / 2, ber, d);
 
     return pd;
 }

double inet::physicallayer::Ieee80211YansErrorModel::calculatePdOdd	(	double	ber,
		unsigned int	d
	)		const

protected

Referenced by calculatePd().

 {
     ASSERT((d % 2) == 1);
     unsigned int dstart = (d + 1) / 2;
     unsigned int dend = d;
     double pd = 0;
 
     for (unsigned int i = dstart; i < dend; i++) {
         pd += binomialCoefficient(i, ber, d);
     }
     return pd;
 }

uint32_t inet::physicallayer::Ieee80211YansErrorModel::factorial ( uint32_t k ) const

protected

Referenced by binomialCoefficient().

 {
     uint32_t fact = 1;
     while (k > 0) {
         fact *= k;
         k--;
     }
     return fact;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getBpskBer	(	double	snr,
		Hz	signalSpread,
		bps	phyRate
	)		const

protected

Referenced by getFecBpskBer().

 {
     double EbNo = snr * signalSpread.get() / phyRate.get();
     double z = sqrt(EbNo);
     double ber = 0.5 * erfc(z);
     EV << "bpsk snr=" << snr << " ber=" << ber << endl;
     return ber;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getDataSuccessRate	(	const IIeee80211Mode *	mode,
		unsigned int	bitLength,
		double	snr
	)		const

overrideprotectedvirtual

Implements inet::physicallayer::Ieee80211ErrorModelBase.

 {
     double successRate = 0;
     if (auto ofdmMode = dynamic_cast<const Ieee80211OFDMMode *>(mode))
         successRate = getOFDMAndERPOFDMChunkSuccessRate(ofdmMode->getDataMode()->getModulation()->getSubcarrierModulation(),
                                                         ofdmMode->getDataMode()->getCode()->getConvolutionalCode(),
                                                         bitLength,
                                                         ofdmMode->getDataMode()->getGrossBitrate(),
                                                         ofdmMode->getHeaderMode()->getBandwidth(),
                                                         snr);
     else if (auto dsssMode = dynamic_cast<const Ieee80211DsssMode *>(mode))
         successRate = getDSSSAndHrDSSSChunkSuccessRate(dsssMode->getDataMode()->getNetBitrate(), bitLength, snr);
     else if (auto hrDsssMode = dynamic_cast<const Ieee80211HrDsssMode *>(mode))
         successRate = getDSSSAndHrDSSSChunkSuccessRate(hrDsssMode->getDataMode()->getNetBitrate(), bitLength, snr);
     else
         throw cRuntimeError("Unsupported 802.11 mode");
     EV_DEBUG << "Min SNIR = " << snr << ", data bit length = " << bitLength << ", data error rate = " << 1 - successRate << endl;
     if (successRate >= 1)
         successRate = 1;
     return successRate;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getDSSSAndHrDSSSChunkSuccessRate	(	bps	bitrate,
		unsigned int	bitLength,
		double	snr
	)		const

protectedvirtual

Referenced by getDataSuccessRate(), and getHeaderSuccessRate().

 {
     switch ((int)bitrate.get()) {
         case 1000000:
             return DsssErrorRateModel::GetDsssDbpskSuccessRate(snr, bitLength);
         case 2000000:
             return DsssErrorRateModel::GetDsssDqpskSuccessRate(snr, bitLength);
         case 5500000:
             return DsssErrorRateModel::GetDsssDqpskCck5_5SuccessRate(snr, bitLength);
         case 11000000:
             return DsssErrorRateModel::GetDsssDqpskCck11SuccessRate(snr, bitLength);
     }
     throw cRuntimeError("Unsupported bitrate");
 }

double inet::physicallayer::Ieee80211YansErrorModel::getFecBpskBer	(	double	snr,
		double	nbits,
		Hz	signalSpread,
		bps	phyRate,
		uint32_t	dFree,
		uint32_t	adFree
	)		const

protected

Referenced by getOFDMAndERPOFDMChunkSuccessRate().

 {
     double ber = getBpskBer(snr, signalSpread, phyRate);
     if (ber == 0.0) {
         return 1.0;
     }
     double pd = calculatePd(ber, dFree);
     double pmu = adFree * pd;
     pmu = std::min(pmu, 1.0);
     double pms = pow(1 - pmu, nbits);
     return pms;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getFecQamBer	(	double	snr,
		uint32_t	nbits,
		Hz	signalSpread,
		bps	phyRate,
		uint32_t	m,
		uint32_t	dfree,
		uint32_t	adFree,
		uint32_t	adFreePlusOne
	)		const

protected

Referenced by getOFDMAndERPOFDMChunkSuccessRate().

 {
     double ber = getQamBer(snr, m, signalSpread, phyRate);
     if (ber == 0.0) {
         return 1.0;
     }
     /* first term */
     double pd = calculatePd(ber, dFree);
     double pmu = adFree * pd;
     /* second term */
     pd = calculatePd(ber, dFree + 1);
     pmu += adFreePlusOne * pd;
     pmu = std::min(pmu, 1.0);
     double pms = pow(1 - pmu, (int)nbits);
     return pms;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getHeaderSuccessRate	(	const IIeee80211Mode *	mode,
		unsigned int	bitLength,
		double	snr
	)		const

overrideprotectedvirtual

Implements inet::physicallayer::Ieee80211ErrorModelBase.

 {
     double successRate = 0;
     if (auto ofdmMode = dynamic_cast<const Ieee80211OFDMMode *>(mode))
         successRate = getOFDMAndERPOFDMChunkSuccessRate(ofdmMode->getHeaderMode()->getModulation()->getSubcarrierModulation(),
                                                         ofdmMode->getHeaderMode()->getCode()->getConvolutionalCode(),
                                                         bitLength,
                                                         ofdmMode->getHeaderMode()->getGrossBitrate(),
                                                         ofdmMode->getHeaderMode()->getBandwidth(),
                                                         snr);
     else if (auto dsssMode = dynamic_cast<const Ieee80211DsssMode *>(mode))
         successRate = getDSSSAndHrDSSSChunkSuccessRate(dsssMode->getHeaderMode()->getNetBitrate(), bitLength, snr);
     else if (auto hrDsssMode = dynamic_cast<const Ieee80211HrDsssMode *>(mode))
         successRate = getDSSSAndHrDSSSChunkSuccessRate(hrDsssMode->getHeaderMode()->getNetBitrate(), bitLength, snr);
     else
         throw cRuntimeError("Unsupported 802.11 mode");
     EV_DEBUG << "Min SNIR = " << snr << ", header bit length = " << bitLength << ", header error rate = " << 1 - successRate << endl;
     if (successRate >= 1)
         successRate = 1;
     return successRate;
 }

double inet::physicallayer::Ieee80211YansErrorModel::getOFDMAndERPOFDMChunkSuccessRate	(	const APSKModulationBase *	subcarrierModulation,
		const ConvolutionalCode *	convolutionalCode,
		unsigned int	bitLength,
		bps	gorssBitrate,
		Hz	bandwidth,
		double	snr
	)		const

protectedvirtual

Referenced by getDataSuccessRate(), and getHeaderSuccessRate().

 {
     if (subcarrierModulation == &BPSKModulation::singleton) {
         if (convolutionalCode->getCodeRatePuncturingK() == 1 && convolutionalCode->getCodeRatePuncturingN() == 2)
             return getFecBpskBer(snr, bitLength, bandwidth, grossBitrate, 10, 11);
         else
             return getFecBpskBer(snr, bitLength, bandwidth, grossBitrate, 5, 8 );
     }
     else if (subcarrierModulation == &QPSKModulation::singleton) {
         if (convolutionalCode->getCodeRatePuncturingK() == 1 && convolutionalCode->getCodeRatePuncturingN() == 2)
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 4, 10, 11, 0 );
         else
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 4, 5, 8, 31);
     }
     else if (subcarrierModulation == &QAM16Modulation::singleton) {
         if (convolutionalCode->getCodeRatePuncturingK() == 1 && convolutionalCode->getCodeRatePuncturingN() == 2)
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 16, 10, 11, 0);
         else
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 16, 5, 8, 31);
     }
     else if (subcarrierModulation == &QAM64Modulation::singleton) {
         if (convolutionalCode->getCodeRatePuncturingK() == 2 && convolutionalCode->getCodeRatePuncturingN() == 3)
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 64, 6, 1, 16);
         else
             return getFecQamBer(snr, bitLength, bandwidth, grossBitrate, 64, 5, 8, 31);
     }
     else
         throw cRuntimeError("Unknown modulation");
 }

double inet::physicallayer::Ieee80211YansErrorModel::getQamBer	(	double	snr,
		unsigned int	m,
		Hz	signalSpread,
		bps	phyRate
	)		const

protected

Referenced by getFecQamBer().

 {
     double EbNo = snr * signalSpread.get() / phyRate.get();
     double z = sqrt((1.5 * log2(m) * EbNo) / (m - 1.0));
     double z1 = ((1.0 - 1.0 / sqrt((double)m)) * erfc(z));
     double z2 = 1 - pow((1 - z1), 2.0);
     double ber = z2 / log2(m);
     EV << "Qam m=" << m << " rate=" << phyRate << " snr=" << snr << " ber=" << ber << endl;
     return ber;
 }

virtual std::ostream& inet::physicallayer::Ieee80211YansErrorModel::printToStream	(	std::ostream &	stream,
		int	level
	)		const

inlineoverridevirtual

Prints this object to the provided output stream.

Function calls to operator<< with pointers or references either const or not are all forwarded to this function.

Reimplemented from inet::physicallayer::IPrintableObject.

75 { return stream << "Ieee80211YansErrorModel"; }

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

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation