Ieee80211aRadioModel.cc

/src/linklayer/radio/Ieee80211aRadioModel.cc

https://github.com/Sorouri/inetmanet
C++ | 455 lines | 293 code | 85 blank | 77 comment | 85 complexity | 2040f5604c654cb035c60ee47201f2bf MD5 | raw file
Possible License(s): GPL-2.0

//

// Copyright (C) 2006 Andras Varga, Levente Meszaros

// Based on the Mobility Framework's SnrEval by Marc Loebbers

//

// This program is free software; you can redistribute it and/or

// modify it under the terms of the GNU General Public License

// as published by the Free Software Foundation; either version 2

// of the License, or (at your option) any later version.

//

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with this program; if not, write to the Free Software

// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

//



#define IEEE80211A

#include "Ieee80211aRadioModel.h"

#include "Ieee80211aConsts.h"



#include "FWMath.h"



#include "Modulation.h"





/* added by Sorin Cocorada sorin.cocorada@gmail.com*/

static const unsigned short comb_calc[15][15]=

{

{    1,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0 },

{    2,    1,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0 },

{    3,    3,    1,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0 },

{    4,    6,    4,    1,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0 },

{    5,   10,   10,    5,    1,    0,    0,    0,    0,    0,    0,    0,    0,    0 },

{    6,   15,   20,   15,    6,    1,    0,    0,    0,    0,    0,    0,    0,    0 },

{    7,   21,   35,   35,   21,    7,    1,    0,    0,    0,    0,    0,    0,    0 },

{    8,   28,   56,   70,   56,   28,    8,    1,    0,    0,    0,    0,    0,    0 },

{    9,   36,   84,  126,  126,   84,   36,    9,    1,    0,    0,    0,    0,    0 },

{   10,   45,  120,  210,  252,  210,  120,   45,   10,    1,    0,    0,    0,    0 },

{   11,   55,  165,  330,  462,  462,  330,  165,   55,   11,    1,    0,    0,    0 },

{   12,   66,  220,  495,  792,  924,  792,  495,  220,   66,   12,    1,    0,    0 },

{   13,   78,  286,  715, 1287, 1716, 1716, 1287,  715,  286,   78,   13,    1,    0 },

{   14,   91,  364, 1001, 2002, 3003, 3432, 3003, 2002, 1001,  364,   91,   14,    1 }

};



/*

int comb(int n,int k){

    int p1=1, p2=1,i;

    for(i=0; i<=k-1; i++)

        p1=p1*(n-i);

    for(i=2; i<=k; i++)

        p2=p2*i;

    return p1/p2;

}

*/



static unsigned short comb(int n,int k)

{

//    ASSERT((n>=1) && (n<=14) (k>=1) && (k<=14));

    return comb_calc[n-1][k-1];

}





static double Pd(int d, double Pb)

{

    long double sum=0.0;

    int k;

    if(d%2 == 1){

        for(k=(d+1)/2; k<=d; k++)

            sum+=comb(d,k)*pow(Pb,k)*pow(1.0-Pb, d-k);

    }

    else{

        sum=0.5*comb(d,d/2)*pow(Pb, d/2)*pow(1.0-Pb,d/2);

        for(k=d/2+1; k<=d; k++)

             sum+=comb(d,k)*pow(Pb,k)*pow(1.0-Pb, d-k);

    }

    //printf("prob=%f d=%d sum=%f \n",Pb,d, sum);

    return sum;



    //return pow(4*Pb*(1-Pb), d/2);

}





static double Pb(int rate, double prob)

{

    long double probc;

    switch(rate){



    case 1:

    //11, 0, 38, 0, 193, 0, 1331, 0, 7275, 0, 40406, 0, 234969, 0, 1337714, 0, 7594819, 0, 433775588, 0,

    probc=11*Pd(10,prob) + 38*Pd(12,prob) + 193*Pd(14,prob);//+1331*Pd(16,prob);

    break;



    case 2:

    //1, 16, 48, 158, 642, 2435, 9174, 34701, 131533, 499312,

    probc=Pd(6,prob)+16*Pd(7,prob)+48*Pd(8,prob);//+158*Pd(9,prob)+642*Pd(10,prob)

    //+2435*Pd(11,prob)+ 9174*Pd(12,prob)+34701*Pd(13,prob)+131533*Pd(14,prob)+499312*Pd(15,prob);

    break;



    case 3:

    //(8, 31, 160, 892, 4512, 23297, 120976, 624304, 3229885, 16721329,

    probc=8*Pd(5,prob)+31*Pd(6,prob)+150*Pd(7,prob);//+892*Pd(8,prob)+4512*Pd(9,prob)

    //+23297*Pd(10,prob)+120976*Pd(11,prob)+624304*Pd(12,prob)+ 3229885*Pd(13,prob)+ 16721329*Pd(14,prob);

    break;

    default:

    ;

    }



    return probc;

}





static double ber_bpsk(double snir, double bandwidth, double bitrate, char channelModel)

{

    double y=snir*bandwidth/bitrate;



    if(channelModel=='r')//Rayleigh

        return 0.5*(1.0-sqrt(y/(1.0+y)));



    return 0.5*erfc(sqrt(y));//awgn

}



static double ber_qpsk(double snir, double bandwidth, double bitrate, char channelModel)

{

    double y=snir*bandwidth/bitrate;



    if(channelModel=='r')//Rayleigh

        return 0.5*(1.0-sqrt(y/(1.0+y)));

    return 0.5*erfc(sqrt(y));//awgn

}



static double ber_16qam(double snir, double bandwidth, double bitrate, char channelModel)

{

    double y=snir*bandwidth/bitrate;



    if(channelModel=='r')//Rayleigh

    return ( 5.0/8.0-3.0/8.0*sqrt(2.0*y/(5.0+2.0*y))-1.0/4.0*sqrt(18.0*y/(5.0+18.0*y)) );

    return ( 0.375*erfc(sqrt(0.4*y))+0.25*erfc(3.0*sqrt(0.4*y)) );//awgn



}



static double ber_64qam(double snir, double bandwidth, double bitrate, char channelModel)

{

    double y=snir*bandwidth/bitrate;



    if(channelModel=='r')//Rayleigh

        return ( 13.0/24.0-7.0/24.0*sqrt(y/(7.0+y))-1.0/4.0*sqrt(9.0*y/(7.0+9.0*y)) );

        return 7.0/24.0*erfc(sqrt(y/7.0))+0.25*erfc(3.0*sqrt(y/7.0));//awgn

}





/* end added by Sorin Cocorada sorin.cocorada@gmail.com*/





Register_Class(Ieee80211aRadioModel);



Ieee80211aRadioModel::~Ieee80211aRadioModel()

{

    if(phyOpMode=='a')

    {

        for (ModesCI j = modes.begin (); j != modes.end (); j++) {

            delete (*j);

        }

        modes.erase (modes.begin (), modes.end ());



        if (IS_ERROR_MASK_GENERATED)

            fclose(error_masks);

    }

}



void Ieee80211aRadioModel::initializeFrom(cModule *radioModule)

{

    snirThreshold = dB2fraction(radioModule->par("snirThreshold"));

	//snirThreshold = dB2fraction(4);



    phyOpMode = radioModule->hasPar("phyOpMode") ? radioModule->par("phyOpMode") : 'b';

    if (phyOpMode==1)

          phyOpMode='b';

    else if (phyOpMode==2)

          phyOpMode='g';

    else if (phyOpMode==3)

          phyOpMode='a';

   else

         phyOpMode='b';



    channelModel = radioModule->hasPar("channelModel") ? radioModule->par("channelModel") : 'r';



    if (channelModel==1)

          channelModel='r';

    else if (channelModel==2)

          channelModel='a';

    else

          channelModel='r';





    snirVector.setName("snirVector");

    perVector.setName("PER");



	i=0;



    if(phyOpMode=='a')

    {

        configure80211a();

        error_masks = 0;



        if (IS_ERROR_MASK_GENERATED)

        {

	        char str[80];

	        sprintf(str,"%s%i%s","error_masks",(int)radioModule->par("ID"),".dat");

			error_masks= fopen(str, "w+");

			EV<<"Generation mask file : "<<str<<endl;

        }

    }

}



double Ieee80211aRadioModel::calculateDuration(AirFrame *airframe)

{

    double duration = 0;



    if(phyOpMode=='a')

        duration= (16+airframe->getBitLength()*8+6)/airframe->getBitrate()+PLCP_PREAMBLE_DELAY+PLCP_SIGNAL_DELAY+T_SYM/2;

    else if(phyOpMode=='g')

        duration=4*ceil((16+airframe->getBitLength()+6)/(airframe->getBitrate()/1e6*4))*1e-6 + 26e-6;

    else

    // The physical layer header is sent with 1Mbit/s and the rest with the frame's bitrate

        duration=airframe->getBitLength()/airframe->getBitrate() + 192/BITRATE_HEADER;

    EV<<"Radio:frameDuration="<<duration*1e6<<"us("<<airframe->getBitLength()<<"bits)"<<endl;

    return duration;

}



bool Ieee80211aRadioModel::isReceivedCorrectly(AirFrame *airframe, const SnrList& receivedList)

{



//    unsigned char packet_ok;

//    unsigned long length;

    unsigned char *buffer=NULL;



//	buffer=(unsigned char*)malloc(airframe->getBitLength()*sizeof(unsigned char));

    if (buffer)

    for(int j=0;j<airframe->getBitLength();j++)

 	//	buffer[i] = airframe->getBuffer(i);

	    buffer[j] = 0;///Error, there is no getBuffer() to airframe ;





//   length = airframe->getBitLength()+PHY_HEADER_LENGTH_A+2;



//    length = length/8;

//    printf("\n  length = %d length sans phy=%d",length,airframe->getBitLength());



	// calculate snirMin

    double snirMin = receivedList.begin()->snr;

    for (SnrList::const_iterator iter = receivedList.begin(); iter != receivedList.end(); iter++)

        if (iter->snr < snirMin)

            snirMin = iter->snr;



    cPacket *frame = airframe->getEncapsulatedMsg();

    EV << "packet (" << frame->getClassName() << ")" << frame->getName() << " (" << frame->info() << ") snrMin=" << snirMin << endl;



    if(i%1000==0){

        snirVector.record(10*log10(snirMin));

        i=0;

    }

    i++;



    if (snirMin <= snirThreshold)

    {

        // if snir is too low for the packet to be recognized

        EV << "COLLISION! Packet got lost. Noise only\n";

        return false;

    }

    else if (isPacketOK(buffer,snirMin, airframe->getBitLength(), airframe->getBitrate()))

    {

        EV << "packet was received correctly, it is now handed to upper layer...\n";

	   // for(int i=0;i<airframe->getBitLength();i++)

	//	    airframe->setBuffer(i,buffer[i]);

        return true;

    }

    else

    {

        EV << "Packet has BIT ERRORS! It is lost!\n";

        return false;

    }

    if (buffer)

	free(buffer);

}





//static unsigned char phy_header[PHY_HEADER_LENGTH_A];



bool Ieee80211aRadioModel::isPacketOK(unsigned char *buffer, double snirMin, int length, double bitrate)

{

    double berHeader, berMPDU;



    if(phyOpMode=='b')

    {

        berHeader = 0.5 * exp(-snirMin * BANDWIDTH / BITRATE_HEADER);



        // if PSK modulation

        if (bitrate == 1E+6 || bitrate == 2E+6)

            berMPDU = 0.5 * exp(-snirMin * BANDWIDTH / bitrate);

        // if CCK modulation (modeled with 16-QAM)

       else if (bitrate == 5.5E+6)

          berMPDU = 0.5 * (1 - 1 / sqrt(pow(2.0, 4))) * erfc(snirMin * BANDWIDTH / bitrate);

    else if(bitrate == 11E+6)                        // CCK, modelled with 256-QAM

        berMPDU = 0.25 * (1 - 1 / sqrt(pow(2.0, 8))) * erfc(snirMin * BANDWIDTH / bitrate);



    }

#if 0

    else if(phyOpMode=='a')

    {

        double per, psr = 1;

		unsigned char packet_ok=1;



        if (IS_ERROR_MASK_GENERATED) fprintf(error_masks,"]\n");

        psr = 1;

        EV<<"PHY_HEADER_LENGTH"<<PHY_HEADER_LENGTH_A<<endl;

        //psr *= getMode(bitrate)->getChunkSuccessRate (snirMin, PHY_HEADER_LENGTH_A, error_masks, HEADER_BITRATE);

        //psr *= getMode(bitrate)->getChunkSuccessRate (snirMin, length, error_masks, bitrate);

		psr *= getMode(bitrate)->getChunkSuccessRate (snirMin, length, buffer, bitrate);

        per = 1- psr;



        if(i%100==0) perVector.record(per);



	    for(int i=0;i<PHY_HEADER_LENGTH_A;i++)

	       if(phy_header[i]!=0)

		       return(false);



        /*double rand = dblrand();

        if (rand > per)

            return (true);

        //if no error

        else

            return (false);

		*/

	    return (true);

    }

    else if (phyOpMode=='g')

#endif

    else if ((phyOpMode=='g') || (phyOpMode=='a'))

    {

    //802.11g rates

    //PLCP Header 24bits, BPSK, r=1/2, 6Mbps

    berHeader=ber_bpsk(snirMin, BANDWIDTH , 6E+6, channelModel);

    berHeader=Pb(1, berHeader);





    switch((int)bitrate){//added by Sorin Cocorada



        case (int)(6E+6)://6Mbps, r=1/2, BPSK

            berMPDU=ber_bpsk(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(1, berMPDU);

        break;



        case (int)(9E+6)://9Mbps, r=3/4, BPSK

            berMPDU=ber_bpsk(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(3, berMPDU);

        break;



        case (int)(12E+6)://12Mbps, r=1/2, QPSK

            berMPDU=ber_qpsk(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(1, berMPDU);

        break;



        case (int)(18E+6)://18Mbps, r=3/4, QPSK

            berMPDU=ber_qpsk(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(3, berMPDU);

        break;



        case (int)(24E+6)://24Mbps, r=1/2, 16QAM

            berMPDU=ber_16qam(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(1, berMPDU);

        break;



        case (int)(36E+6)://36Mbps, r=3/4, 16QAM

            berMPDU=ber_16qam(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(3, berMPDU);

        break;



        case (int)(48E+6)://48Mbps, r=2/3, 64QAM

            berMPDU=ber_64qam(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(2, berMPDU);

        break;



        case (int)(54E+6)://54Mbps, r=3/4, 64QAM

            berMPDU=ber_64qam(snirMin, BANDWIDTH , bitrate, channelModel);

            berMPDU=Pb(3, berMPDU);

        break;



        default:

            berMPDU=0;

        }



    }



    // probability of no bit error in the PLCP header

    double headerNoError;

    // if(phyOpMode=='g')//added by Sorin Cocorada

    if ((phyOpMode=='g') || (phyOpMode=='a'))//added by Sorin Cocorada

        headerNoError = pow(1.0 - berHeader, 24);//PLCP Header 24bit(without SERVICE), 6Mbps

    else

    headerNoError = pow(1.0 - berHeader, HEADER_WITHOUT_PREAMBLE);



    // probability of no bit error in the MPDU

    double MpduNoError = pow(1.0 - berMPDU, length);

    EV << "berHeader: " << berHeader << " berMPDU: " <<berMPDU <<" length: "<<length<<" PER: "<<1-MpduNoError<<endl;

    double rand = dblrand();



    if (rand > headerNoError)

        return false; // error in header

    else if (dblrand() > MpduNoError)

        return false;  // error in MPDU

    else

        return true; // no error

}



double Ieee80211aRadioModel::dB2fraction(double dB)

{

    return pow(10.0, (dB / 10));

}



void Ieee80211aRadioModel::addTransmissionMode (TransmissionMode *mode)

{

    modes.push_back (mode);

}



TransmissionMode * Ieee80211aRadioModel::getMode (double rate) const

{

    //EV<<" getMode "<< rate<<endl;

    int mode;

    if (rate == 6E+6)       mode = 0;

    else if (rate == 9E+6)  mode = 1;

    else if (rate == 12E+6) mode = 2;

    else if (rate == 18E+6) mode = 3;

    else if (rate == 24E+6) mode = 4;

    else if (rate == 36E+6) mode = 5;

    else if (rate == 48E+6) mode = 6;

    else if (rate == 54E+6) mode = 7;

    return modes[mode];

}



void Ieee80211aRadioModel::configure80211a (void)

{

   // addTransmissionMode (new FecBpskMode (20e6,  6000000, 0.5 ));

//    addTransmissionMode (new FecBpskMode (20e6,  9000000, 0.75));

 //   addTransmissionMode (new FecQamMode  (20e6, 12000000, 0.5,   4));

  //  addTransmissionMode (new FecQamMode  (20e6, 18000000, 0.75,  4));

   // addTransmissionMode (new FecQamMode  (20e6, 24000000, 0.5,   16));

   // addTransmissionMode (new FecQamMode  (20e6, 36000000, 0.75,  16));

   // addTransmissionMode (new FecQamMode  (20e6, 48000000, 0.666, 64));

   // addTransmissionMode (new FecQamMode  (20e6, 54000000, 0.75,  64));

}