UWAN.c

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/************************************************************************************
* Copyright (C) 2020                                                               *
* TETCOS, Bangalore. India                                                         *
*                                                                                  *
* Tetcos owns the intellectual property rights in the Product and its content.     *
* The copying, redistribution, reselling or publication of any or all of the       *
* Product or its content without express prior written consent of Tetcos is        *
* prohibited. Ownership and / or any other right relating to the software and all  *
* intellectual property rights therein shall remain at all times with Tetcos.      *
*                                                                                  *
* Author:    Shashi Kant Suman                                                     *
*                                                                                  *
* ---------------------------------------------------------------------------------*/
#include "main.h"
#include "UWAN.h"
#include "ErrorModel.h"
 
/**
UWAN Init function initializes the UWAN parameters.
*/
_declspec (dllexport) int fn_NetSim_UWAN_Init()
{
    // return fn_NetSim_UWAN_Init_F();
    return 0;
}
 
/**
This function is called by NetworkStack.dll, whenever the event gets triggered
inside the NetworkStack.dll for the UWAN protocol
*/
_declspec (dllexport) int fn_NetSim_UWAN_Run()
{
    return 0;
}
 
/**
This function is called by NetworkStack.dll, once simulation end to free the
allocated memory for the network.
*/
_declspec(dllexport) int fn_NetSim_UWAN_Finish()
{
    // return fn_NetSim_UWAN_Finish_F();
    return 0;
}
 
/**
This function is called by NetworkStack.dll, while writing the event trace
to get the sub event as a string.
*/
_declspec (dllexport) char* fn_NetSim_UWAN_Trace(NETSIM_ID nSubEvent)
{
    nSubEvent;
    return "";
}
 
/**
This function is called by NetworkStack.dll, while configuring the device
for UWAN protocol.
*/
_declspec(dllexport) int fn_NetSim_UWAN_Configure(void** var)
{
    var;
    // return fn_NetSim_UWAN_Configure_F(var);
    return 0;
}
 
/**
This function is called by NetworkStack.dll, to free the UWAN protocol data.
*/
_declspec(dllexport) int fn_NetSim_UWAN_FreePacket(NetSim_PACKET* pstruPacket)
{
    pstruPacket;
    // return fn_NetSim_UWAN_FreePacket_F(pstruPacket);
    return 0;
}
 
/**
This function is called by NetworkStack.dll, to copy the UWAN protocol
details from source packet to destination.
*/
_declspec(dllexport) int fn_NetSim_UWAN_CopyPacket(NetSim_PACKET* pstruDestPacket, NetSim_PACKET* pstruSrcPacket)
{
    pstruSrcPacket;
    pstruDestPacket;
    // return fn_NetSim_UWAN_CopyPacket_F(pstruDestPacket, pstruSrcPacket);
    return 0;
}
 
/**
This function write the Metrics
*/
_declspec(dllexport) int fn_NetSim_UWAN_Metrics(PMETRICSWRITER metricsWriter)
{
    metricsWriter;
    return 0;
}
 
/**
This function will return the string to write packet trace heading.
*/
_declspec(dllexport) char* fn_NetSim_UWAN_ConfigPacketTrace()
{
    return "";
}
 
/**
This function will return the string to write packet trace.
*/
_declspec(dllexport) char* fn_NetSim_UWAN_WritePacketTrace(NetSim_PACKET* pstruPacket, char** ppszTrace)
{
    pstruPacket;
    ppszTrace;
    return "";
}
 
 
_declspec(dllexport) double UWAN_calculate_propagation_delay(NETSIM_ID tx,
                                                             NETSIM_ID txi,
                                                             NETSIM_ID rx,
                                                             NETSIM_ID rxi,
                                                             PPROPAGATION_INFO info)
{
    rxi;
    NetSim_LINKS* link = DEVICE_PHYLAYER(tx, txi)->pstruNetSimLinks;
    if (link->puniMedProp.pstruWirelessLink.propagation->propMedium == PROPMEDIUM_AIR)
    {
        return propagation_air_calculate_propagationDelay(tx, rx, NULL);
    }
    else if (link->puniMedProp.pstruWirelessLink.propagation->propMedium == PROPMEDIUM_ACOUSTICS)
    {
        if (!info)
        {
            fnNetSimError("Propagation handle is passed as NULL in function %s\n",
                          __FUNCTION__);
            return 0.0;
        }
        return propagation_acoutics_calculate_propagationDelay(tx, rx, &info->propagation);
    }
    else
    {
        fnNetSimError("Unknown propagation medium for link %d\n",
                      link->nConfigLinkId);
        return 0.0;
    }
}
 
static double UWAN_getConstellationSize(PHY_MODULATION modulation)
{
    switch (modulation)
    {
        case Modulation_8_QAM:
            return 8.0;
        case Modulation_16_QAM:
            return 16.0;
        case Modulation_32_QAM:
            return 32.0;
        case Modulation_64_QAM:
            return 64.0;
        case Modulation_128_QAM:
            return 128.0;
        case Modulation_256_QAM:
            return 256.0;
        default:
            fnNetSimError("Unknown modulation technique %s.\n",
                          strPHY_MODULATION[modulation]);
            return 0.0;
    }
}
 
static double UWAN_CalculateNoise(PPROPAGATION_INFO info,
                             NETSIM_ID tx,
                             NETSIM_ID rx)
{
    return propagation_acoutics_calculate_noise(info->txInfo.dCentralFrequency * 1000,
                                                info->propagation.acouticsPropVar->dShipping,
                                                info->propagation.acouticsPropVar->dWindSpeed);
}
 
static double UWAN_CalculateSNR(double power,
                                double noise)
{
    return power - noise;
}
_declspec(dllexport) double UWAN_Calculate_ber(NETSIM_ID tx,
                                               NETSIM_ID rx,
                                               PPROPAGATION_INFO info,
                                               double rxPower,
                                        PHY_MODULATION modulation,
                                        double dataRate /* In kbps */,
                                        double bandwidth /* In kHz */)
{
    if (modulation <= Modulation_Zero ||
        modulation >= Modulation_LAST)
    {
        fnNetSimError("Unknown modulation %d.\n", modulation);
        return 0.0;
    }
 
    NetSim_LINKS* link = DEVICE_PHYLAYER(tx, 1)->pstruNetSimLinks;
    if (link->puniMedProp.pstruWirelessLink.propagation->propMedium == PROPMEDIUM_AIR)
    {
        return calculate_BER(modulation,
                             rxPower, NEGATIVE_DBM,
                             bandwidth/1000);
    }
 
    double noise = UWAN_CalculateNoise(info, tx, rx);
    double snr = UWAN_CalculateSNR(rxPower, noise);
    double EbNo = pow(10.0, snr / 10.0);
    double BER = 1.0;
    
    switch (modulation)
    {
        case Modulation_BPSK:
            BER = 0.5 * erfc(sqrt(EbNo));
            break;
        case Modulation_QPSK:
            BER = 0.5 * erfc(sqrt(0.5 * EbNo));
            break;
        case Modulation_16_QAM:
        case Modulation_32_QAM:
        case Modulation_64_QAM:
        case Modulation_128_QAM:
        case Modulation_256_QAM:
        {
            // taken from Ronell B. Sicat, "Bit Error Probability Computations for M-ary Quadrature Amplitude Modulation",
            // EE 242 Digital Communications and Codings, 2009
            // generic EbNo
            EbNo *= (dataRate * 1000) / (bandwidth * 1000);
 
            double M = UWAN_getConstellationSize(modulation);
 
            // standard squared quantized QAM, even number of bits per symbol supported
            int log2sqrtM = (int)log2(sqrt(M));
 
            double log2M = log2(M);
 
            if ((int)log2M % 2)
            {
                fnNetSimError("constellation %d is not supported for QAM.", (int)M);
                return 0.0;
            }
 
            double sqrtM = sqrt(M);
 
            BER = 0.0;
 
            // Eq (75)
            for (int k = 0; k < log2sqrtM; k++)
            {
                int sum_items = (int)((1.0 - pow(2.0, (-1.0) * (double)k)) * sqrt(M) - 1.0);
                double pow2k = pow(2.0, (double)k - 1.0);
 
                double PbK = 0;
 
                // Eq (74)
                for (int j = 0; j < sum_items; ++j)
                {
                    PbK += pow(-1.0, floor((double)j * pow2k / sqrtM))
                        * (pow2k - floor((double)(j * pow2k / sqrtM) - 0.5))
                        * erfc((2.0 * (double)j + 1.0) * sqrt(3.0 * (log2M * EbNo) / (2.0 * (M - 1.0))));
 
                }
                PbK *= 1.0 / sqrtM;
 
                BER += PbK;
            }
 
            BER *= 1.0 / (double)log2sqrtM;
        }
        break;
        case Modulation_FSK:
            BER = 0.5 * erfc(sqrt(0.5 * EbNo));
            break;
        default:
            fnNetSimError("Modulation %s is not supported.",
                          strPHY_MODULATION[modulation]);
            break;
    }
    return BER;
}