From 98ec98b72ae47ea23f5750bd67e50832a6c4e415 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= Date: Sun, 1 Apr 2018 11:35:28 +0200 Subject: [PATCH] wifi: Fix double precision issues in DsssErrorRateModel --- src/wifi/model/dsss-error-rate-model.cc | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/wifi/model/dsss-error-rate-model.cc b/src/wifi/model/dsss-error-rate-model.cc index a59985404..1caea81cb 100644 --- a/src/wifi/model/dsss-error-rate-model.cc +++ b/src/wifi/model/dsss-error-rate-model.cc @@ -65,7 +65,7 @@ DsssErrorRateModel::GetDsssDqpskCck5_5SuccessRate (double sinr, uint64_t nbits) //symbol error probability double EbN0 = sinr * 22000000.0 / 1375000.0 / 4.0; double sep = SymbolErrorProb16Cck (4.0 * EbN0 / 2.0); - return std::pow (1.0 - sep, nbits / 4.0); + return std::min (1.0, std::pow (1.0 - sep, nbits / 4.0)); #else NS_LOG_WARN ("Running a 802.11b CCK Matlab model less accurate than GSL model"); //The matlab model @@ -87,7 +87,7 @@ DsssErrorRateModel::GetDsssDqpskCck5_5SuccessRate (double sinr, uint64_t nbits) double a4 = 1.0288981434358866e+000; ber = a1 * std::exp (-std::pow ((sinr - a2) / a3, a4)); } - return std::pow ((1.0 - ber), static_cast (nbits)); + return std::min (1.0, std::pow ((1.0 - ber), static_cast (nbits))); #endif } @@ -100,7 +100,7 @@ DsssErrorRateModel::GetDsssDqpskCck11SuccessRate (double sinr, uint64_t nbits) //symbol error probability double EbN0 = sinr * 22000000.0 / 1375000.0 / 8.0; double sep = SymbolErrorProb256Cck (8.0 * EbN0 / 2.0); - return std::pow (1.0 - sep, nbits / 8.0); + return std::min (1.0, std::pow (1.0 - sep, nbits / 8.0)); #else NS_LOG_WARN ("Running a 802.11b CCK Matlab model less accurate than GSL model"); //The matlab model @@ -124,7 +124,7 @@ DsssErrorRateModel::GetDsssDqpskCck11SuccessRate (double sinr, uint64_t nbits) double a6 = 2.2032715128698435e+000; ber = (a1 * sinr * sinr + a2 * sinr + a3) / (sinr * sinr * sinr + a4 * sinr * sinr + a5 * sinr + a6); } - return std::pow ((1.0 - ber), static_cast (nbits)); + return std::min (1.0, std::pow ((1.0 - ber), static_cast (nbits))); #endif }