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wifi, spectrum: Replace hardcoded guard band width in wifi spectrum

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This commit is contained in:
Sébastien Deronne
2017-04-18 20:46:08 +02:00
parent c17c46f14b
commit 5a34f6d293
5 changed files with 349 additions and 190 deletions
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410
src/spectrum/model/wifi-spectrum-value-helper.cc
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@@ -54,9 +54,9 @@ operator < (const WifiSpectrumModelId& a, const WifiSpectrumModelId& b)
static std::map<WifiSpectrumModelId, Ptr<SpectrumModel> > g_wifiSpectrumModelMap;
Ptr<SpectrumModel>
WifiSpectrumValueHelper::GetSpectrumModel (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth)
WifiSpectrumValueHelper::GetSpectrumModel (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << channelWidth << bandBandwidth);
NS_LOG_FUNCTION (centerFrequency << channelWidth << bandBandwidth << guardBandwidth);
Ptr<SpectrumModel> ret;
WifiSpectrumModelId key (centerFrequency, channelWidth);
std::map<WifiSpectrumModelId, Ptr<SpectrumModel> >::iterator it = g_wifiSpectrumModelMap.find (key);
@@ -68,10 +68,9 @@ WifiSpectrumValueHelper::GetSpectrumModel (uint32_t centerFrequency, uint32_t ch
{
Bands bands;
double centerFrequencyHz = centerFrequency * 1e6;
// Overall bandwidth will be channelWidth plus 10 MHz guards on each side
double bandwidth = (channelWidth + 20) * 1e6;
double bandwidth = (channelWidth + (2 * guardBandwidth)) * 1e6;
// For OFDM, the center subcarrier is null (at center frequency)
uint32_t numBands = static_cast<uint32_t> (bandwidth / bandBandwidth + 0.5);
uint32_t numBands = static_cast<uint32_t> ((bandwidth / bandBandwidth) + 0.5);
NS_ASSERT (numBands > 0);
if (numBands % 2 == 0)
{
@@ -105,20 +104,22 @@ WifiSpectrumValueHelper::GetSpectrumModel (uint32_t centerFrequency, uint32_t ch
// Power allocated to 71 center subbands out of 135 total subbands in the band
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateDsssTxPowerSpectralDensity (uint32_t centerFrequency, double txPowerW)
WifiSpectrumValueHelper::CreateDsssTxPowerSpectralDensity (uint32_t centerFrequency, double txPowerW, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << txPowerW);
NS_LOG_FUNCTION (centerFrequency << txPowerW << guardBandwidth);
uint32_t channelWidth = 22; // DSSS channels are 22 MHz wide
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, 312500));
double bandBandwidth = 312500;
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth, guardBandwidth));
Values::iterator vit = c->ValuesBegin ();
Bands::const_iterator bit = c->ConstBandsBegin ();
double txPowerPerBand;
// Evenly spread power across 22 MHz (71 bands)
NS_ASSERT (c->GetSpectrumModel ()->GetNumBands () == 135);
txPowerPerBand = txPowerW / 71;
uint32_t nGuardBands = static_cast<uint32_t>(((2 * guardBandwidth * 1e6) / bandBandwidth) + 0.5);
uint32_t nAllocatedBands = static_cast<uint32_t>(((channelWidth * 1e6) / bandBandwidth) + 0.5);
NS_ASSERT (c->GetSpectrumModel ()->GetNumBands () == (nAllocatedBands + nGuardBands + 1));
// Evenly spread power across 22 MHz
double txPowerPerBand = txPowerW / nAllocatedBands;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if (i >= 32 && i <= 102)
if ((i >= (nGuardBands / 2)) && (i <= ((nGuardBands / 2) + nAllocatedBands - 1)))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
@@ -127,273 +128,388 @@ WifiSpectrumValueHelper::CreateDsssTxPowerSpectralDensity (uint32_t centerFreque
}
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW)
WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW);
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, 312500));
Values::iterator vit = c->ValuesBegin ();
Bands::const_iterator bit = c->ConstBandsBegin ();
double txPowerPerBand;
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW << guardBandwidth);
double bandBandwidth = 312500;
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth, guardBandwidth));
uint32_t nGuardBands = static_cast<uint32_t>(((2 * guardBandwidth * 1e6) / bandBandwidth) + 0.5);
uint32_t nAllocatedBands = static_cast<uint32_t>(((channelWidth * 1e6) / bandBandwidth) + 0.5);
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == (nAllocatedBands + nGuardBands + 1), "Unexpected number of bands");
double txPowerPerBand = 0;
uint32_t start1 = 0;
uint32_t stop1 = 0;
uint32_t start2 = 0;
uint32_t stop2 = 0;
switch (channelWidth)
{
case 20:
// 52 subcarriers (48 data + 4 pilot)
// skip 38 subbands, then place power in 26 subbands, then
// skip guard band and 6 subbands, then place power in 26 subbands, then
// skip the center subband, then place power in 26 subbands, then skip
// the final 38 subbands.
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 129, "Unexpected number of bands");
// the final 6 subbands and the guard band.
txPowerPerBand = txPowerW / 52;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 38 && i <= 63) || (i >= 65 && i <= 90))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 38-63 and 65-90");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
start1 = (nGuardBands / 2) + 6;
stop1 = start1 + 26 - 1;
start2 = stop1 + 2;
stop2 = start2 + 26 - 1;
break;
case 10:
// 28 subcarriers (24 data + 4 pilot)
// skip 34 subbands, then place power in 14 subbands, then
// skip guard band and 2 subbands, then place power in 14 subbands, then
// skip the center subband, then place power in 14 subbands, then skip
// the final 34 subbands.
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 97, "Unexpected number of bands");
// the final 2 subbands and the guard band.
txPowerPerBand = txPowerW / 28;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 34 && i <= 47) || (i >= 49 && i <= 62))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 34-47 and 49-62");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
start1 = (nGuardBands / 2) + 2;
stop1 = start1 + 14 - 1;
start2 = stop1 + 2;
stop2 = start2 + 14 - 1;
break;
case 5:
// 16 subcarriers (12 data + 4 pilot)
// skip 34 subbands, then place power in 14 subbands, then
// skip the center subband, then place power in 14 subbands, then skip
// the final 34 subbands.
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 81, "Unexpected number of bands");
// skip guard band and 2 subbands, then place power in 8 subbands, then
// skip the center subband, then place power in 8 subbands, then skip
// the final 2 subbands and the guard.
txPowerPerBand = txPowerW / 16;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 32 && i <= 39) || (i >= 41 && i <= 48))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 32-39 and 41-48");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
start1 = (nGuardBands / 2) + 2;
stop1 = start1 + 8 - 1;
start2 = stop1 + 2;
stop2 = start2 + 8 - 1;
break;
default:
NS_FATAL_ERROR ("ChannelWidth " << channelWidth << " unsupported");
break;
}
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
Values::iterator vit = c->ValuesBegin ();
Bands::const_iterator bit = c->ConstBandsBegin ();
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 << " and " << start2 << "-" << stop2);
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
return c;
}
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateHtOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW)
WifiSpectrumValueHelper::CreateHtOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW);
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, 312500));
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW << guardBandwidth);
double bandBandwidth = 312500;
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth, guardBandwidth));
Values::iterator vit = c->ValuesBegin ();
Bands::const_iterator bit = c->ConstBandsBegin ();
uint32_t nGuardBands = static_cast<uint32_t>(((2 * guardBandwidth * 1e6) / bandBandwidth) + 0.5);
uint32_t nAllocatedBands = static_cast<uint32_t>(((channelWidth * 1e6) / bandBandwidth) + 0.5);
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == (nAllocatedBands + nGuardBands + 1), "Unexpected number of bands");
double txPowerPerBand;
// skip the guard band and 4 subbands, then place power in 28 subbands, then
// skip the center subband, then place power in 28 subbands, then skip
// the final 4 subbands and the guard band.
// Repeat for each 20 MHz band.
uint32_t start1 = (nGuardBands / 2) + 4;
uint32_t stop1 = start1 + 28 - 1;
uint32_t start2 = stop1 + 2;
uint32_t stop2 = start2 + 28 - 1;
uint32_t start3 = stop2 + (2 * 4);
uint32_t stop3 = start3 + 28 - 1;
uint32_t start4 = stop3 + 2;
uint32_t stop4 = start4 + 28 - 1;
uint32_t start5 = stop4 + (2 * 4);
uint32_t stop5 = start5 + 28 - 1;
uint32_t start6 = stop5 + 2;
uint32_t stop6 = start6 + 28 - 1;
uint32_t start7 = stop6 + (2 * 4);
uint32_t stop7 = start7 + 28 - 1;
uint32_t start8 = stop7 + 2;
uint32_t stop8 = start8 + 28 - 1;
uint32_t start9 = stop8 + (2 * 4);
uint32_t stop9 = start9 + 28 - 1;
uint32_t start10 = stop9 + 2;
uint32_t stop10 = start10 + 28 - 1;
uint32_t start11 = stop10 + (2 * 4);
uint32_t stop11 = start11 + 28 - 1;
uint32_t start12 = stop11 + 2;
uint32_t stop12 = start12 + 28 - 1;
uint32_t start13 = stop12 + (2 * 4);
uint32_t stop13 = start13 + 28 - 1;
uint32_t start14 = stop13 + 2;
uint32_t stop14 = start14 + 28 - 1;
uint32_t start15 = stop14 + (2 * 4);
uint32_t stop15 = start15 + 28 - 1;
uint32_t start16 = stop15 + 2;
uint32_t stop16 = start16 + 28 - 1;
switch (channelWidth)
{
case 20:
// 56 subcarriers (52 data + 4 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 129, "Unexpected number of bands");
// skip 32 subbands, then place power in 28 of the next 32 subbands, then
// skip the center subband, then place power in 28 of the next 32
// subbands, then skip the final 32 subbands.
// 56 subcarriers (52 data + 4 pilot)
txPowerPerBand = txPowerW / 56;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
start1 = (nGuardBands / 2) + 4;
stop1 = start1 + 28 - 1;
start2 = stop1 + 2;
stop2 = start2 + 28 - 1;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 36 && i <= 63) || (i >= 65 && i <= 92))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 36-63 and 65-92");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
" and " << start2 << "-" << stop2);
break;
case 40:
// 112 subcarriers (104 data + 8 pilot)
// possible alternative: 114 subcarriers (108 data + 6 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 193, "Unexpected number of bands");
txPowerPerBand = txPowerW / 112;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 36 && i <= 63) || (i >= 65 && i <= 92) ||
(i >= 100 && i<= 127) || (i >= 129 && i <= 156))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2) ||
(i >= start3 && i <= stop3) || (i >= start4 && i <= stop4))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 36-63, 65-92, 100-127, and 129-156");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
", " << start2 << "-" << stop2 <<
", " << start3 << "-" << stop3 <<
", " << start4 << "-" << stop4);
break;
case 80:
// 224 subcarriers (208 data + 16 pilot)
// possible alternative: 242 subcarriers (234 data + 8 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 321, "Unexpected number of bands");
txPowerPerBand = txPowerW / 224;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 36 && i <= 63) || (i >= 65 && i <= 92) ||
(i >= 100 && i <= 127) || (i >= 129 && i <= 156) ||
(i >= 164 && i <= 191) || (i >= 193 && i <= 220) ||
(i >= 228 && i <= 255) || (i >= 257 && i <= 284))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2) ||
(i >= start3 && i <= stop3) || (i >= start4 && i <= stop4) ||
(i >= start5 && i <= stop5) || (i >= start6 && i <= stop6) ||
(i >= start7 && i <= stop7) || (i >= start8 && i <= stop8))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 36-63, 65-92, 100-127, 129-156, 164-191, 193-220, 228-255, 257-284");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
", " << start2 << "-" << stop2 <<
", " << start3 << "-" << stop3 <<
", " << start4 << "-" << stop4 <<
", " << start5 << "-" << stop5 <<
", " << start6 << "-" << stop6 <<
", " << start7 << "-" << stop7 <<
", " << start8 << "-" << stop8);
break;
case 160:
// 448 subcarriers (416 data + 32 pilot)
// possible alternative: 484 subcarriers (468 data + 16 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 577, "Unexpected number of bands");
txPowerPerBand = txPowerW / 448;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 36 && i <= 63) || (i >= 65 && i <= 92) ||
(i >= 100 && i <= 127) || (i >= 129 && i <= 156) ||
(i >= 164 && i <= 191) || (i >= 193 && i <= 220) ||
(i >= 228 && i <= 255) || (i >= 257 && i <= 284) ||
(i >= 292 && i <= 319) || (i >= 321 && i <= 348) ||
(i >= 356 && i <= 383) || (i >= 385 && i <= 412) ||
(i >= 420 && i <= 447) || (i >= 449 && i <= 476) ||
(i >= 484 && i <= 511) || (i >= 513 && i <= 540))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2) ||
(i >= start3 && i <= stop3) || (i >= start4 && i <= stop4) ||
(i >= start5 && i <= stop5) || (i >= start6 && i <= stop6) ||
(i >= start7 && i <= stop7) || (i >= start8 && i <= stop8) ||
(i >= start9 && i <= stop9) || (i >= start10 && i <= stop10) ||
(i >= start11 && i <= stop11) || (i >= start12 && i <= stop12) ||
(i >= start13 && i <= stop13) || (i >= start14 && i <= stop14) ||
(i >= start15 && i <= stop15) || (i >= start16 && i <= stop16))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 36-63, 65-92, 100-127, 129-156, 164-191, 193-220, 228-255, 257-284, 292-319, 321-348, 356-383, 385-412, 420-447, 449-476, 484-511, and 513-540");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
", " << start2 << "-" << stop2 <<
", " << start3 << "-" << stop3 <<
", " << start4 << "-" << stop4 <<
", " << start5 << "-" << stop5 <<
", " << start6 << "-" << stop6 <<
", " << start7 << "-" << stop7 <<
", " << start8 << "-" << stop8 <<
", " << start9 << "-" << stop9 <<
", " << start10 << "-" << stop10 <<
", " << start11 << "-" << stop11 <<
", " << start12 << "-" << stop12 <<
", " << start13 << "-" << stop13 <<
", " << start14 << "-" << stop14 <<
", " << start15 << "-" << stop15 <<
", " << start16 << "-" << stop16);
break;
default:
NS_FATAL_ERROR ("ChannelWidth " << channelWidth << " unsupported");
break;
}
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
return c;
}
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateHeOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW)
WifiSpectrumValueHelper::CreateHeOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW);
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, 78125));
NS_LOG_FUNCTION (centerFrequency << channelWidth << txPowerW << guardBandwidth);
double bandBandwidth = 78125;
Ptr<SpectrumValue> c = Create<SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth, guardBandwidth));
Values::iterator vit = c->ValuesBegin ();
Bands::const_iterator bit = c->ConstBandsBegin ();
uint32_t nGuardBands = static_cast<uint32_t>(((2 * guardBandwidth * 1e6) / bandBandwidth) + 0.5);
uint32_t nAllocatedBands = static_cast<uint32_t>(((channelWidth * 1e6) / bandBandwidth) + 0.5);
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == (nAllocatedBands + nGuardBands + 1), "Unexpected number of bands");
double txPowerPerBand;
uint32_t start1;
uint32_t stop1;
uint32_t start2;
uint32_t stop2;
uint32_t start3;
uint32_t stop3;
uint32_t start4;
uint32_t stop4;
switch (channelWidth)
{
case 20:
// 242 subcarriers (234 data + 8 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 513, "Unexpected number of bands");
// skip 133 subbands, then place power in 121 subbands, then
// skip 3 DC, then place power in 121 subbands, then skip
// the final 133 subbands.
txPowerPerBand = txPowerW / 242;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
// skip the guard band and 11 subbands, then place power in 121 subbands, then
// skip 3 DC, then place power in 121 subbands, then skip
// the final 11 subbands and the guard band.
start1 = (nGuardBands / 2) + 12;
stop1 = start1 + 121 - 1;
start2 = stop1 + 4;
stop2 = start2 + 121 - 1;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 134 && i <= 254) || (i >= 258 && i <= 378))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 134-254 and 258-378");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
" and " << start2 << "-" << stop2);
break;
case 40:
// 484 subcarriers (468 data + 16 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 769, "Unexpected number of bands");
// skip 139 subbands, then place power in 242 subbands, then
// skip 5 DC, then place power in 242 subbands, then skip
// the final 139 subbands.
txPowerPerBand = txPowerW / 484;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
// skip the guard band and 11 subbands, then place power in 242 subbands, then
// skip 5 DC, then place power in 242 subbands, then skip
// the final 11 subbands and the guard band.
start1 = (nGuardBands / 2) + 12;
stop1 = start1 + 242 - 1;
start2 = stop1 + 6;
stop2 = start2 + 242 - 1;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 140 && i <= 381) || (i >= 387 && i <= 628))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 140-381 and 387-628");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
" and " << start2 << "-" << stop2);
break;
case 80:
// 996 subcarriers (980 data + 16 pilot)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 1281, "Unexpected number of bands");
// skip 139 subbands, then place power in 498 subbands, then
// skip 5 DC, then place power in 498 subbands, then skip
// the final 139 subbands.
txPowerPerBand = txPowerW / 996;
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
// skip the guard band and 11 subbands, then place power in 498 subbands, then
// skip 5 DC, then place power in 498 subbands, then skip
// the final 11 subbands and the guard band.
start1 = (nGuardBands / 2) + 12;
stop1 = start1 + 498 - 1;
start2 = stop1 + 6;
stop2 = start2 + 498 - 1;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 140 && i <= 637) || (i >= 643 && i <= 1140))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 140-637 and 643-1140");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
" and " << start2 << "-" << stop2);
break;
case 160:
// 2 x 996 subcarriers (2 x 80 MHZ bands)
NS_ASSERT_MSG (c->GetSpectrumModel ()->GetNumBands () == 2305, "Unexpected number of bands");
txPowerPerBand = txPowerW / (2 * 996);
NS_LOG_DEBUG ("Power per band " << txPowerPerBand);
start1 = (nGuardBands / 2) + 12;
stop1 = start1 + 498 - 1;
start2 = stop1 + 6;
stop2 = start2 + 498 - 1;
start3 = stop2 + (2 * 12);
stop3 = start3 + 498 - 1;
start4 = stop3 + 6;
stop4 = start4 + 498 - 1;
for (size_t i = 0; i < c->GetSpectrumModel ()->GetNumBands (); i++, vit++, bit++)
{
if ((i >= 140 && i <= 637) || (i >= 643 && i <= 1140) ||
(i >= 1164 && i <= 1661) || (i >= 1667 && i <= 2164))
if ((i >= start1 && i <= stop1) || (i >= start2 && i <= stop2) ||
(i >= start3 && i <= stop3) || (i >= start4 && i <= stop4))
{
*vit = txPowerPerBand / (bit->fh - bit->fl);
}
else
{
*vit = 0;
}
}
NS_LOG_DEBUG ("Added signal power to subbands 140-637, 643-1140, 1164-1661 and 1667-2164");
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
NS_LOG_DEBUG ("Added signal power to subbands " << start1 << "-" << stop1 <<
", " << start2 << "-" << stop2 <<
", " << start3 << "-" << stop3 <<
", " << start4 << "-" << stop4);
break;
default:
NS_FATAL_ERROR ("ChannelWidth " << channelWidth << " unsupported");
break;
}
NS_LOG_DEBUG ("Integrated power " << Integral (*c));
NS_ASSERT_MSG (std::abs (txPowerW - Integral (*c)) < 1e-6, "Power allocation failed");
return c;
}
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateNoisePowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, double noiseFigure)
WifiSpectrumValueHelper::CreateNoisePowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, double noiseFigure, uint32_t guardBandwidth)
{
Ptr<SpectrumModel> model = GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth);
Ptr<SpectrumModel> model = GetSpectrumModel (centerFrequency, channelWidth, bandBandwidth, guardBandwidth);
return CreateNoisePowerSpectralDensity (noiseFigure, model);
}
@@ -416,10 +532,10 @@ WifiSpectrumValueHelper::CreateNoisePowerSpectralDensity (double noiseFigureDb,
}
Ptr<SpectrumValue>
WifiSpectrumValueHelper::CreateRfFilter (uint32_t centerFrequency, uint32_t channelWidth, double bandGranularity)
WifiSpectrumValueHelper::CreateRfFilter (uint32_t centerFrequency, uint32_t channelWidth, double bandGranularity, uint32_t guardBandwidth)
{
NS_LOG_FUNCTION (centerFrequency << channelWidth << bandGranularity);
Ptr<SpectrumValue> c = Create <SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandGranularity));
NS_LOG_FUNCTION (centerFrequency << channelWidth << bandGranularity << guardBandwidth);
Ptr<SpectrumValue> c = Create <SpectrumValue> (GetSpectrumModel (centerFrequency, channelWidth, bandGranularity, guardBandwidth));
size_t numBands = c->GetSpectrumModel ()->GetNumBands ();
Bands::const_iterator bit = c->ConstBandsBegin ();
Values::iterator vit = c->ValuesBegin ();

82
src/spectrum/model/wifi-spectrum-value-helper.h
View File

@@ -49,42 +49,12 @@ public:
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param bandBandwidth width of each band (Hz)
* \param guardBandwidth width of the guard band (MHz)
*
* \return the static SpectrumModel instance corresponding to the
* given carrier frequency and channel width configuration.
*/
static Ptr<SpectrumModel> GetSpectrumModel (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth);
/**
* Create a transmit power spectral density corresponding to OFDM
* High Efficiency (HE) (802.11ax). Channel width may vary between
* 20, 40, 80, and 160 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
*/
static Ptr<SpectrumValue> CreateHeOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW);
/**
* Create a transmit power spectral density corresponding to OFDM
* High Throughput (HT) (802.11n/ac). Channel width may vary between
* 20, 40, 80, and 160 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
*/
static Ptr<SpectrumValue> CreateHtOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW);
/**
* Create a transmit power spectral density corresponding to OFDM
* (802.11a/g). Channel width may vary between 20, 10, and 5 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
*/
static Ptr<SpectrumValue> CreateOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW);
static Ptr<SpectrumModel> GetSpectrumModel (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, uint32_t guardBandwidth);
/**
* Create a transmit power spectral density corresponding to DSSS
@@ -94,8 +64,44 @@ public:
*
* \param centerFrequency center frequency (MHz)
* \param txPowerW transmit power (W) to allocate
* \param guardBandwidth width of the guard band (MHz)
*/
static Ptr<SpectrumValue> CreateDsssTxPowerSpectralDensity (uint32_t centerFrequency, double txPowerW);
static Ptr<SpectrumValue> CreateDsssTxPowerSpectralDensity (uint32_t centerFrequency, double txPowerW, uint32_t guardBandwidth);
/**
* Create a transmit power spectral density corresponding to OFDM
* (802.11a/g). Channel width may vary between 20, 10, and 5 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
* \param guardBandwidth width of the guard band (MHz)
*/
static Ptr<SpectrumValue> CreateOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth);
/**
* Create a transmit power spectral density corresponding to OFDM
* High Throughput (HT) (802.11n/ac). Channel width may vary between
* 20, 40, 80, and 160 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
* \param guardBandwidth width of the guard band (MHz)
*/
static Ptr<SpectrumValue> CreateHtOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth);
/**
* Create a transmit power spectral density corresponding to OFDM
* High Efficiency (HE) (802.11ax). Channel width may vary between
* 20, 40, 80, and 160 MHz.
*
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param txPowerW transmit power (W) to allocate
* \param guardBandwidth width of the guard band (MHz)
*/
static Ptr<SpectrumValue> CreateHeOfdmTxPowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double txPowerW, uint32_t guardBandwidth);
/**
*
@@ -103,9 +109,11 @@ public:
* \param channelWidth channel width (MHz)
* \param bandBandwidth width of each band (Hz)
* \param noiseFigure the noise figure in dB w.r.t. a reference temperature of 290K
* \param guardBandwidth width of the guard band (MHz)
*
* \return a pointer to a newly allocated SpectrumValue representing the noise Power Spectral Density in W/Hz for each Band
*/
static Ptr<SpectrumValue> CreateNoisePowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, double noiseFigure);
static Ptr<SpectrumValue> CreateNoisePowerSpectralDensity (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, double noiseFigure, uint32_t guardBandwidth);
/**
* \param centerFrequency center frequency (MHz)
@@ -118,10 +126,12 @@ public:
* \param centerFrequency center frequency (MHz)
* \param channelWidth channel width (MHz)
* \param bandBandwidth width of each band (Hz)
* \param guardBandwidth width of the guard band (MHz)
*
* \return a pointer to a SpectrumValue representing the RF filter applied
* to an received power spectral density
*/
static Ptr<SpectrumValue> CreateRfFilter (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth);
static Ptr<SpectrumValue> CreateRfFilter (uint32_t centerFrequency, uint32_t channelWidth, double bandBandwidth, uint32_t guardBandwidth);
};
/**

39
src/wifi/model/spectrum-wifi-phy.cc
View File

@@ -107,7 +107,7 @@ SpectrumWifiPhy::GetRxSpectrumModel () const
else
{
NS_LOG_DEBUG ("Creating spectrum model from frequency/width pair of (" << GetFrequency () << ", " << (uint16_t)GetChannelWidth () << ")");
m_rxSpectrumModel = WifiSpectrumValueHelper::GetSpectrumModel (GetFrequency (), GetChannelWidth (), GetBandBandwidth ());
m_rxSpectrumModel = WifiSpectrumValueHelper::GetSpectrumModel (GetFrequency (), GetChannelWidth (), GetBandBandwidth (), GetGuardBandwidth ());
}
}
return m_rxSpectrumModel;
@@ -168,7 +168,7 @@ SpectrumWifiPhy::StartRx (Ptr<SpectrumSignalParameters> rxParams)
// Integrate over our receive bandwidth (i.e., all that the receive
// spectral mask representing our filtering allows) to find the
// total energy apparent to the "demodulator".
Ptr<SpectrumValue> filter = WifiSpectrumValueHelper::CreateRfFilter (GetFrequency (), GetChannelWidth (), GetBandBandwidth ());
Ptr<SpectrumValue> filter = WifiSpectrumValueHelper::CreateRfFilter (GetFrequency (), GetChannelWidth (), GetBandBandwidth (), GetGuardBandwidth ());
SpectrumValue filteredSignal = (*filter) * (*receivedSignalPsd);
// Add receiver antenna gain
NS_LOG_DEBUG ("Signal power received (watts) before antenna gain: " << Integral (filteredSignal));
@@ -239,19 +239,19 @@ SpectrumWifiPhy::GetTxPowerSpectralDensity (uint16_t centerFrequency, uint8_t ch
case WIFI_PHY_STANDARD_holland:
case WIFI_PHY_STANDARD_80211_10MHZ:
case WIFI_PHY_STANDARD_80211_5MHZ:
v = WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW);
v = WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW, GetGuardBandwidth ());
break;
case WIFI_PHY_STANDARD_80211b:
v = WifiSpectrumValueHelper::CreateDsssTxPowerSpectralDensity (centerFrequency, txPowerW);
v = WifiSpectrumValueHelper::CreateDsssTxPowerSpectralDensity (centerFrequency, txPowerW, GetGuardBandwidth ());
break;
case WIFI_PHY_STANDARD_80211n_2_4GHZ:
case WIFI_PHY_STANDARD_80211n_5GHZ:
case WIFI_PHY_STANDARD_80211ac:
v = WifiSpectrumValueHelper::CreateHtOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW);
v = WifiSpectrumValueHelper::CreateHtOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW, GetGuardBandwidth ());
break;
case WIFI_PHY_STANDARD_80211ax_2_4GHZ:
case WIFI_PHY_STANDARD_80211ax_5GHZ:
v = WifiSpectrumValueHelper::CreateHeOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW);
v = WifiSpectrumValueHelper::CreateHeOfdmTxPowerSpectralDensity (centerFrequency, channelWidth, txPowerW, GetGuardBandwidth ());
break;
default:
NS_FATAL_ERROR ("Standard unknown: " << GetStandard ());
@@ -308,4 +308,31 @@ SpectrumWifiPhy::GetBandBandwidth (void) const
return bandBandwidth;
}
uint32_t
SpectrumWifiPhy::GetGuardBandwidth (void) const
{
double guardBandwidth = 0;
switch (GetStandard ())
{
case WIFI_PHY_STANDARD_80211a:
case WIFI_PHY_STANDARD_80211g:
case WIFI_PHY_STANDARD_holland:
case WIFI_PHY_STANDARD_80211_10MHZ:
case WIFI_PHY_STANDARD_80211_5MHZ:
case WIFI_PHY_STANDARD_80211b:
case WIFI_PHY_STANDARD_80211n_2_4GHZ:
case WIFI_PHY_STANDARD_80211n_5GHZ:
case WIFI_PHY_STANDARD_80211ac:
case WIFI_PHY_STANDARD_80211ax_2_4GHZ:
case WIFI_PHY_STANDARD_80211ax_5GHZ:
// Use 10 MHZ
guardBandwidth = 10;
break;
default:
NS_FATAL_ERROR ("Standard unknown: " << GetStandard ());
break;
}
return guardBandwidth;
}
} //namespace ns3

5
src/wifi/model/spectrum-wifi-phy.h
View File

@@ -143,6 +143,11 @@ public:
*/
double GetBandBandwidth (void) const;
/**
* \return the width of the guard band (MHz)
*/
uint32_t GetGuardBandwidth (void) const;
/**
* Callback invoked when the Phy model starts to process a signal
*

3
src/wifi/test/spectrum-wifi-phy-test.cc
View File

@@ -31,6 +31,7 @@ using namespace ns3;
static const uint16_t CHANNEL_NUMBER = 36;
static const uint32_t FREQUENCY = 5180; // MHz
static const uint32_t CHANNEL_WIDTH = 20; // MHz
static const uint32_t GUARD_WIDTH = 10; // MHz
/**
* \ingroup wifi-test
@@ -114,7 +115,7 @@ SpectrumWifiPhyBasicTest::MakeSignal (double txPowerWatts)
pkt->AddTrailer (trailer);
WifiPhyTag tag (txVector, mpdutype);
pkt->AddPacketTag (tag);
Ptr<SpectrumValue> txPowerSpectrum = WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (FREQUENCY, CHANNEL_WIDTH, txPowerWatts);
Ptr<SpectrumValue> txPowerSpectrum = WifiSpectrumValueHelper::CreateOfdmTxPowerSpectralDensity (FREQUENCY, CHANNEL_WIDTH, txPowerWatts, GUARD_WIDTH);
Ptr<WifiSpectrumSignalParameters> txParams = Create<WifiSpectrumSignalParameters> ();
txParams->psd = txPowerSpectrum;
txParams->txPhy = 0;