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wifi: Add TableBasedErrorRateModel class

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This commit is contained in:
Sébastien Deronne
2020-07-10 22:56:36 +02:00
committed by Sebastien Deronne
parent b4f88cd33d
commit 3d21933f2c
4 changed files with 308 additions and 0 deletions
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1
src/wifi/helper/wifi-helper.cc
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@@ -964,6 +964,7 @@ WifiHelper::EnableLogComponents (void)
LogComponentEnable ("SpectrumWifiPhy", LOG_LEVEL_ALL);
LogComponentEnable ("StaWifiMac", LOG_LEVEL_ALL);
LogComponentEnable ("SupportedRates", LOG_LEVEL_ALL);
LogComponentEnable ("TableBasedErrorRateModel", LOG_LEVEL_ALL);
LogComponentEnable ("ThresholdPreambleDetectionModel", LOG_LEVEL_ALL);
LogComponentEnable ("WifiMac", LOG_LEVEL_ALL);
LogComponentEnable ("WifiMacQueueItem", LOG_LEVEL_ALL);

217
src/wifi/model/table-based-error-rate-model.cc Normal file
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@@ -0,0 +1,217 @@
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2020 University of Washington
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* 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
*
* Authors: Rohan Patidar <rpatidar@uw.edu>
* Sébastien Deronne <sebastien.deronne@gmail.com>
*/
#include <cmath>
#include <algorithm>
#include "ns3/log.h"
#include "ns3/string.h"
#include "ns3/pointer.h"
#include "ns3/uinteger.h"
#include "table-based-error-rate-model.h"
#include "wifi-utils.h"
#include "wifi-tx-vector.h"
#include "dsss-error-rate-model.h"
#include "yans-error-rate-model.h"
static const double SNR_PRECISION = 2;
namespace ns3 {
NS_OBJECT_ENSURE_REGISTERED (TableBasedErrorRateModel);
NS_LOG_COMPONENT_DEFINE ("TableBasedErrorRateModel");
TypeId
TableBasedErrorRateModel::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::TableBasedErrorRateModel")
.SetParent<ErrorRateModel> ()
.SetGroupName ("Wifi")
.AddConstructor<TableBasedErrorRateModel> ()
.AddAttribute ("FallbackErrorRateModel",
"Ptr to the fallback error rate model to be used when no matching value is found in a table",
PointerValue (CreateObject<YansErrorRateModel> ()),
MakePointerAccessor (&TableBasedErrorRateModel::m_fallbackErrorModel),
MakePointerChecker <ErrorRateModel> ())
.AddAttribute ("SizeThreshold",
"Threshold in bytes over which the table for large size frames is used",
UintegerValue (400),
MakeUintegerAccessor (&TableBasedErrorRateModel::m_threshold),
MakeUintegerChecker<uint64_t> ())
;
return tid;
}
TableBasedErrorRateModel::TableBasedErrorRateModel ()
{
NS_LOG_FUNCTION (this);
}
TableBasedErrorRateModel::~TableBasedErrorRateModel ()
{
NS_LOG_FUNCTION (this);
m_fallbackErrorModel = 0;
}
double
TableBasedErrorRateModel::RoundSnr (double snr, double precision) const
{
NS_LOG_FUNCTION (this << snr);
double multiplier = std::round (std::pow (10.0, precision));
return std::floor (snr * multiplier + 0.5) / multiplier;
}
uint8_t
TableBasedErrorRateModel::GetMcsForMode (WifiMode mode)
{
uint8_t mcs = 0xff; // Initialize to invalid mcs
if (mode.GetModulationClass () == WIFI_MOD_CLASS_OFDM || mode.GetModulationClass () == WIFI_MOD_CLASS_ERP_OFDM)
{
if (mode.GetConstellationSize () == 2)
{
if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
{
mcs = 0;
}
if (mode.GetCodeRate () == WIFI_CODE_RATE_3_4)
{
mcs = 1;
}
}
else if (mode.GetConstellationSize () == 4)
{
if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
{
mcs = 2;
}
else if (mode.GetCodeRate () == WIFI_CODE_RATE_3_4)
{
mcs = 3;
}
}
else if (mode.GetConstellationSize () == 16)
{
if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
{
mcs = 4;
}
else if (mode.GetCodeRate () == WIFI_CODE_RATE_3_4)
{
mcs = 5;
}
}
else if (mode.GetConstellationSize () == 64)
{
if (mode.GetCodeRate () == WIFI_CODE_RATE_2_3)
{
mcs = 6;
}
else if (mode.GetCodeRate () == WIFI_CODE_RATE_3_4)
{
mcs = 7;
}
}
}
else if (mode.GetModulationClass () == WIFI_MOD_CLASS_HT || mode.GetModulationClass () == WIFI_MOD_CLASS_VHT || mode.GetModulationClass () == WIFI_MOD_CLASS_HE)
{
mcs = mode.GetMcsValue ();
}
NS_ABORT_MSG_IF (mcs == 0xff, "Error, MCS value for mode not found");
return mcs;
}
double
TableBasedErrorRateModel::DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txVector, double snr, uint64_t nbits) const
{
NS_LOG_FUNCTION (this << mode << txVector << snr << nbits);
uint64_t size = std::max<uint64_t> (1, (nbits / 8));
double roundedSnr = RoundSnr (RatioToDb (snr), SNR_PRECISION);
uint8_t mcs = GetMcsForMode (mode);
NS_LOG_FUNCTION (this << +mcs << roundedSnr << size);
// HT: for mcs greater than 7, use 0 - 7 curves for data rate
if (mode.GetModulationClass () == WIFI_MOD_CLASS_HT)
{
mcs = mcs % 8;
}
if (mcs > ERROR_TABLE_MAX_NUM_MCS)
{
NS_LOG_WARN ("Table missing for MCS: " << +mcs << " in TableBasedErrorRateModel: use fallback error rate model");
return m_fallbackErrorModel->GetChunkSuccessRate (mode, txVector, snr, nbits);
}
auto errorTable = size < m_threshold ? AwgnErrorTable32 : AwgnErrorTable1458;
auto itVector = errorTable[mcs];
auto itTable = std::find_if (itVector.begin(), itVector.end(),
[&roundedSnr](const std::pair<double, double>& element) {
return element.first == roundedSnr;
});
double minSnr = itVector.begin ()->first;
double maxSnr = (--itVector.end ())->first;
double per;
if (itTable == itVector.end ())
{
if (roundedSnr < minSnr)
{
per = 1.0;
}
else if (roundedSnr > maxSnr)
{
per = 0.0;
}
else
{
double a = 0.0, b = 0.0, previousSnr = 0.0, nextSnr = 0.0;
for (auto i = itVector.begin (); i != itVector.end (); ++i)
{
if (i->first < roundedSnr)
{
previousSnr = i->first;
a = i->second;
}
else
{
nextSnr = i->first;
b = i->second;
break;
}
}
per = a + (roundedSnr - previousSnr) * (b - a) / (nextSnr - previousSnr);
}
}
else
{
per = itTable->second;
}
uint16_t tableSize = size < m_threshold ? ERROR_TABLE_SMALL_FRAME_SIZE : ERROR_TABLE_LARGE_FRAME_SIZE;
if (size != tableSize)
{
// From IEEE document 11-14/0803r1 (Packet Length for Box 0 Calibration)
per = (1.0 - std::pow ((1 - per), (static_cast<double> (size) / tableSize)));
}
return 1.0 - per;
}
} //namespace ns3

88
src/wifi/model/table-based-error-rate-model.h Normal file
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@@ -0,0 +1,88 @@
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2020 University of Washington
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* 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
*
* Authors: Rohan Patidar <rpatidar@uw.edu>
* Sébastien Deronne <sebastien.deronne@gmail.com>
*/
#ifndef TABLE_BASED_ERROR_RATE_MODEL_H
#define TABLE_BASED_ERROR_RATE_MODEL_H
#include "ns3/error-rate-tables.h"
#include "error-rate-model.h"
#include "wifi-mode.h"
namespace ns3 {
class WifiTxVector;
/*
* \ingroup wifi
* \brief the interface for the table-driven OFDM error model
*
*/
class TableBasedErrorRateModel : public ErrorRateModel
{
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
TableBasedErrorRateModel ();
~TableBasedErrorRateModel ();
//Inherited from ErrorRateModel
double DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txVector, double snr, uint64_t nbits) const;
/**
* \brief Utility function to convert WifiMode to an MCS value
* \param mode the WifiMode
* \return the MCS value
*/
static uint8_t GetMcsForMode (WifiMode mode);
private:
/**
* Round SNR (in dB) to the specified precision
*
* \param snr the SNR to round (in dB)
* \param precision the precision to use
* \return the rounded SNR (in dB) to the specified precision
*/
double RoundSnr (double snr, double precision) const;
/**
* Fetch the frame success rate for a given Wi-Fi mode, TXVECTOR, SNR and frame size.
* \param mode the Wi-Fi mode
* \param txVector the TXVECTOR
* \param snr the SNR (linear scale)
* \param nbits the number of bits
* \return the frame success rate for a given Wi-Fi mode, TXVECTOR, SNR and frame size
*/
double FetchFsr (WifiMode mode, WifiTxVector txVector, double snr, uint64_t nbits) const;
Ptr<ErrorRateModel> m_fallbackErrorModel; //!< Error rate model to fallback to if no value is found in the table
uint64_t m_threshold; //!< Threshold in bytes over which the table for large size frames is used
};
} //namespace ns3
#endif /* TABLE_BASED_ERROR_RATE_MODEL_H */

2
src/wifi/wscript
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@@ -14,6 +14,7 @@ def build(bld):
'model/yans-error-rate-model.cc',
'model/nist-error-rate-model.cc',
'model/dsss-error-rate-model.cc',
'model/table-based-error-rate-model.cc',
'model/interference-helper.cc',
'model/yans-wifi-phy.cc',
'model/yans-wifi-channel.cc',
@@ -173,6 +174,7 @@ def build(bld):
'model/yans-error-rate-model.h',
'model/nist-error-rate-model.h',
'model/dsss-error-rate-model.h',
'model/table-based-error-rate-model.h',
'model/wifi-mac-queue.h',
'model/txop.h',
'model/wifi-phy-header.h',