wifi: Add error rate table for LDPC FEC encoding

2020-09-21 20:18:11 +02:00
parent 480285f6c3
commit fe7d6dd6e8
3 changed files with 89 additions and 10 deletions
--- a/src/wifi/model/reference/error-rate-tables.h
+++ b/src/wifi/model/reference/error-rate-tables.h
@@ -25,11 +25,13 @@

 namespace ns3 {

-const uint16_t ERROR_TABLE_SMALL_FRAME_SIZE = 32;
-const uint16_t ERROR_TABLE_LARGE_FRAME_SIZE = 1458;
-const uint8_t ERROR_TABLE_MAX_NUM_MCS = 9;
+const uint16_t ERROR_TABLE_BCC_SMALL_FRAME_SIZE = 32;
+const uint16_t ERROR_TABLE_BCC_LARGE_FRAME_SIZE = 1458;
+const uint16_t ERROR_TABLE_LDPC_FRAME_SIZE = 1458;
+const uint8_t ERROR_TABLE_BCC_MAX_NUM_MCS = 9;
+const uint8_t ERROR_TABLE_LDPC_MAX_NUM_MCS = 11;

-static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > AwgnErrorTable32 [ERROR_TABLE_MAX_NUM_MCS + 1] = {
+static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > AwgnErrorTableBcc32 [ERROR_TABLE_BCC_MAX_NUM_MCS + 1] = {
  // MCS-0
  {
    {-3.20000, 1.00000}, {-3.00000, 0.99751}, {-2.80000, 0.98526}, {-2.60000, 0.97805}, {-2.40000, 0.95933},
@@ -129,7 +131,7 @@ static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > Aw
  },
 };

-static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > AwgnErrorTable1458 [ERROR_TABLE_MAX_NUM_MCS + 1] = {
+static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > AwgnErrorTableBcc1458 [ERROR_TABLE_BCC_MAX_NUM_MCS + 1] = {
  // MCS-0
  {
    {-0.80000, 1.00000}, {-0.60000, 0.99751}, {-0.40000, 0.98284}, {-0.20000, 0.93473}, {0.00000, 0.77713},
@@ -216,6 +218,82 @@ static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > Aw
  },
 };

+static const std::vector<std::pair<double /* SNR (dB) */, double /* PER */> > AwgnErrorTableLdpc1458 [ERROR_TABLE_LDPC_MAX_NUM_MCS + 1] = {
+  // MCS-0
+  {
+    {-1.50000, 1.00000}, {-1.25000, 0.97950}, {-1.00000, 0.60480}, {-0.75000, 0.17050},
+    {-0.50000, 0.03320}, {-0.25000, 0.00530}, {0.00000, 0.00085}, {0.25000, 0.00022},
+    {0.50000, 0.00004}, {0.75000, 0.00000},
+  },
+  // MCS-1
+  {
+    {1.50000, 1.00000}, {1.75000, 0.97470}, {2.00000, 0.62330}, {2.25000, 0.18590},
+    {2.50000, 0.03400}, {2.75000, 0.00550}, {3.00000, 0.00083}, {3.25000, 0.00015},
+    {3.50000, 0.00003}, {3.75000, 0.00000},
+  },
+  // MCS-2
+  {
+    {4.00000, 1.00000}, {4.25000, 0.98720}, {4.50000, 0.62560}, {4.75000, 0.15800},
+    {5.00000, 0.02090}, {5.25000, 0.00250}, {5.50000, 0.00034}, {5.75000, 0.00003},
+    {6.00000, 0.00000},
+  },
+  // MCS-3
+  {
+    {6.75000, 1.00000}, {7.00000, 0.99800}, {7.25000, 0.94340}, {7.50000, 0.57890},
+    {7.75000, 0.20640}, {8.00000, 0.04840}, {8.25000, 0.00930}, {8.50000, 0.00180},
+    {8.75000, 0.00040}, {9.00000, 0.00011}, {9.25000, 0.00002}, {9.50000, 0.00000},
+  },
+  // MCS-4
+  {
+    {10.00000, 1.00000}, {10.25000, 0.99310}, {10.50000, 0.70890}, {10.75000, 0.24720},
+    {11.00000, 0.04700}, {11.25000, 0.00590}, {11.50000, 0.00091}, {11.75000, 0.00016},
+    {12.00000, 0.00003}, {12.25000, 0.00000}
+  },
+  // MCS-5
+  {
+    {14.00000, 1.00000}, {14.25000, 0.99700}, {14.50000, 0.91830}, {14.75000, 0.53790},
+    {15.00000, 0.16610}, {15.25000, 0.03690}, {15.50000, 0.00650}, {15.75000, 0.00100},
+    {16.00000, 0.00031}, {16.25000, 0.00005}, {16.50000, 0.00000},
+  },
+  // MCS-6
+  {
+    {15.50000, 1.00000}, {15.75000, 0.98140}, {16.00000, 0.73930}, {16.25000, 0.33110},
+    {16.50000, 0.08150}, {16.75000, 0.01620}, {17.00000, 0.00270}, {17.25000, 0.00052},
+    {17.50000, 0.00005}, {17.75000, 0.00003}, {18.00000, 0.00000},
+  },
+  // MCS-7
+  {
+    {17.00000, 1.00000}, {17.25000, 0.97750}, {17.50000, 0.73980}, {17.75000, 0.33190},
+    {18.00000, 0.09640}, {18.25000, 0.02180}, {18.50000, 0.00470}, {18.75000, 0.00087},
+    {19.00000, 0.00018}, {19.25000, 0.00003}, {19.50000, 0.00000},
+  },
+  // MCS-8
+  {
+    {20.50000, 1.00000}, {20.75000, 0.99500}, {21.00000, 0.89700}, {21.25000, 0.56270},
+    {21.50000, 0.20920}, {21.75000, 0.05600}, {22.00000, 0.01170}, {22.25000, 0.00250},
+    {22.50000, 0.00038}, {22.75000, 0.00013}, {23.00000, 0.00004}, {23.25000, 0.00001},
+    {23.50000, 0.00000},
+  },
+  // MCS-9
+  {
+    {22.25000, 1.00000}, {22.50000, 0.99900}, {22.75000, 0.94080}, {23.00000, 0.63600},
+    {23.25000, 0.27190}, {23.50000, 0.08700}, {23.75000, 0.02210}, {24.00000, 0.00500},
+    {24.25000, 0.00110}, {24.50000, 0.00032}, {24.75000, 0.00004}, {25.00000, 0.00000},
+  },
+  // MCS-10
+  {
+    {25.75000, 1.00000}, {26.00000, 0.94970}, {26.25000, 0.68660}, {26.50000, 0.32940},
+    {26.75000, 0.11620}, {27.00000, 0.03440}, {27.25000, 0.00880}, {27.50000, 0.00210},
+    {27.75000, 0.00054}, {28.00000, 0.00009}, {28.25000, 0.00002}, {28.50000, 0.00000},
+  },
+  // MCS-11
+  {
+    {27.75000, 1.00000}, {28.00000, 0.94880}, {28.25000, 0.75260}, {28.50000, 0.40230},
+    {28.75000, 0.16210}, {29.00000, 0.05150}, {29.25000, 0.01310}, {29.50000, 0.00360},
+    {29.75000, 0.00100}, {30.00000, 0.00022}, {30.25000, 0.00006}, {30.50000, 0.00000},
+  },
+};
+
 } //namespace ns3

 #endif /* ERROR_RATE_TABLES_H */
--- a/src/wifi/model/table-based-error-rate-model.cc
+++ b/src/wifi/model/table-based-error-rate-model.cc
@@ -146,7 +146,8 @@ TableBasedErrorRateModel::DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txV
  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);
+  bool ldpc = txVector.IsLdpc ();
+  NS_LOG_FUNCTION (this << +mcs << roundedSnr << size << ldpc);

  // HT: for mcs greater than 7, use 0 - 7 curves for data rate
  if (mode.GetModulationClass () == WIFI_MOD_CLASS_HT)
@@ -154,13 +155,13 @@ TableBasedErrorRateModel::DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txV
      mcs = mcs % 8;
    }

-  if (mcs > ERROR_TABLE_MAX_NUM_MCS)
+  if (mcs > (ldpc ? ERROR_TABLE_LDPC_MAX_NUM_MCS : ERROR_TABLE_BCC_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 errorTable = (ldpc ? AwgnErrorTableLdpc1458 : (size < m_threshold ? AwgnErrorTableBcc32 : AwgnErrorTableBcc1458));
  auto itVector = errorTable[mcs];
  auto itTable = std::find_if (itVector.begin(), itVector.end(),
      [&roundedSnr](const std::pair<double, double>& element) {
@@ -204,7 +205,7 @@ TableBasedErrorRateModel::DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txV
      per = itTable->second;
    }

-  uint16_t tableSize = size < m_threshold ? ERROR_TABLE_SMALL_FRAME_SIZE : ERROR_TABLE_LARGE_FRAME_SIZE;
+  uint16_t tableSize = (ldpc ? ERROR_TABLE_LDPC_FRAME_SIZE : (size < m_threshold ? ERROR_TABLE_BCC_SMALL_FRAME_SIZE : ERROR_TABLE_BCC_LARGE_FRAME_SIZE));
  if (size != tableSize)
    {
      // From IEEE document 11-14/0803r1 (Packet Length for Box 0 Calibration)
--- a/src/wifi/test/wifi-error-rate-models-test.cc
+++ b/src/wifi/test/wifi-error-rate-models-test.cc
@@ -1020,7 +1020,7 @@ TableBasedErrorRateTestCase::DoRun (void)
  for (double snr = -4.0; snr <= 30.0; snr += 0.5)
    {
      double expectedValue = 0;
-      if (m_mode.GetMcsValue () > ERROR_TABLE_MAX_NUM_MCS)
+      if (m_mode.GetMcsValue () > ERROR_TABLE_BCC_MAX_NUM_MCS)
        {
          Ptr<YansErrorRateModel> yans = CreateObject<YansErrorRateModel> ();
          expectedValue = 1 - yans->GetChunkSuccessRate (m_mode, txVector, std::pow (10.0, snr / 10.0), m_size * 8);