an implementation of DSSS error rate model More...

#include <dsss-error-rate-model.h>

Static Public Member Functions
static double	DqpskFunction (double x)

static double	GetDsssDbpskSuccessRate (double sinr, uint32_t nbits)

static double	GetDsssDqpskSuccessRate (double sinr, uint32_t nbits)

static double	GetDsssDqpskCck5_5SuccessRate (double sinr, uint32_t nbits)

static double	GetDsssDqpskCck11SuccessRate (double sinr, uint32_t nbits)

Static Protected Attributes
static const double	WLAN_SIR_PERFECT = 10.0

static const double	WLAN_SIR_IMPOSSIBLE = 0.1

Static Private Attributes
static const double	spectralEfficiency1bit = 2000000.0 / 1000000.0

static const double	spectralEfficiency2bit = 2000000.0 / 1000000.0 / 2.0

Detailed Description

an implementation of DSSS error rate model

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.

This model is designed to run with highest accuracy using the Gnu Scientific Library (GSL), but if GSL is not installed on the platform, will fall back to (slightly less accurate) Matlab-derived models for the CCK modulation types.

More detailed description and validation can be found in http://www.nsnam.org/~pei/80211b.pdf

Member Function Documentation

double inet::physicallayer::DsssErrorRateModel::DqpskFunction ( double x )

static

Referenced by GetDsssDqpskSuccessRate().

 {
     return ((sqrt(2.0) + 1.0) / sqrt(8.0 * 3.1415926 * sqrt(2.0)))
            * (1.0 / sqrt(x))
            * exp(-(2.0 - sqrt(2.0)) * x);
 }

double inet::physicallayer::DsssErrorRateModel::GetDsssDbpskSuccessRate	(	double	sinr,
		uint32_t	nbits
	)

static

Referenced by inet::physicallayer::Ieee80211NistErrorModel::getDSSSAndHrDSSSChunkSuccessRate(), and inet::physicallayer::Ieee80211YansErrorModel::getDSSSAndHrDSSSChunkSuccessRate().

 {
     double EbN0 = sinr * spectralEfficiency1bit;    // 1 bit per symbol with 1 MSPS
     double ber = 0.5 * exp(-EbN0);
     return pow((1.0 - ber), (int)nbits);
 }

double inet::physicallayer::DsssErrorRateModel::GetDsssDqpskCck11SuccessRate	(	double	sinr,
		uint32_t	nbits
	)

static

Referenced by inet::physicallayer::Ieee80211NistErrorModel::getDSSSAndHrDSSSChunkSuccessRate(), and inet::physicallayer::Ieee80211YansErrorModel::getDSSSAndHrDSSSChunkSuccessRate().

 {
 #ifdef ENABLE_GSL
     // symbol error probability
     double EbN0 = sinr * 22000000.0 / 1375000.0 / 8.0;
     double sep = SymbolErrorProb256Cck(8.0 * EbN0 / 2.0);
     return pow(1.0 - sep, nbits / 8.0);
 #else // ifdef ENABLE_GSL
     EV << "Running a 802.11b CCK Matlab model less accurate than GSL model" << endl;
     // The matlab model
     double ber;
     if (sinr > WLAN_SIR_PERFECT) {
         ber = 0.0;
     }
     else if (sinr < WLAN_SIR_IMPOSSIBLE) {
         ber = 0.5;
     }
     else {    // fitprops.coeff from matlab berfit
         double a1 = 7.9056742265333456e-003;
         double a2 = -1.8397449399176360e-001;
         double a3 = 1.0740689468707241e+000;
         double a4 = 1.0523316904502553e+000;
         double a5 = 3.0552298746496687e-001;
         double a6 = 2.2032715128698435e+000;
         ber = (a1 * sinr * sinr + a2 * sinr + a3) / (sinr * sinr * sinr + a4 * sinr * sinr + a5 * sinr + a6);
     }
     return pow((1.0 - ber), (int)nbits);
 #endif // ifdef ENABLE_GSL
 }

double inet::physicallayer::DsssErrorRateModel::GetDsssDqpskCck5_5SuccessRate	(	double	sinr,
		uint32_t	nbits
	)

static

Referenced by inet::physicallayer::Ieee80211NistErrorModel::getDSSSAndHrDSSSChunkSuccessRate(), and inet::physicallayer::Ieee80211YansErrorModel::getDSSSAndHrDSSSChunkSuccessRate().

 {
 #ifdef ENABLE_GSL
     // symbol error probability
     double EbN0 = sinr * 22000000.0 / 1375000.0 / 4.0;
     double sep = SymbolErrorProb16Cck(4.0 * EbN0 / 2.0);
     return pow(1.0 - sep, nbits / 4.0);
 #else // ifdef ENABLE_GSL
     EV << "Running a 802.11b CCK Matlab model less accurate than GSL model" << endl;
     // The matlab model
     double ber;
     if (sinr > WLAN_SIR_PERFECT) {
         ber = 0.0;
     }
     else if (sinr < WLAN_SIR_IMPOSSIBLE) {
         ber = 0.5;
     }
     else {    // fitprops.coeff from matlab berfit
         double a1 = 5.3681634344056195e-001;
         double a2 = 3.3092430025608586e-003;
         double a3 = 4.1654372361004000e-001;
         double a4 = 1.0288981434358866e+000;
         ber = a1 * exp(-(pow((sinr - a2) / a3, a4)));
     }
     return pow((1.0 - ber), (int)nbits);
 #endif // ifdef ENABLE_GSL
 }

double inet::physicallayer::DsssErrorRateModel::GetDsssDqpskSuccessRate	(	double	sinr,
		uint32_t	nbits
	)

static

Referenced by inet::physicallayer::Ieee80211NistErrorModel::getDSSSAndHrDSSSChunkSuccessRate(), and inet::physicallayer::Ieee80211YansErrorModel::getDSSSAndHrDSSSChunkSuccessRate().

 {
     double EbN0 = sinr * spectralEfficiency2bit;    // 2 bits per symbol, 1 MSPS
     double ber = DqpskFunction(EbN0);
     return pow((1.0 - ber), (int)nbits);
 }