A Discrete-Event Network Simulator
API
yans-error-rate-model.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2005,2006 INRIA
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation;
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
19  * Sébastien Deronne <sebastien.deronne@gmail.com>
20  */
21 
22 #include "ns3/log.h"
23 #include "yans-error-rate-model.h"
24 #include "wifi-utils.h"
25 #include "wifi-phy.h"
26 
27 namespace ns3 {
28 
29 NS_LOG_COMPONENT_DEFINE ("YansErrorRateModel");
30 
31 NS_OBJECT_ENSURE_REGISTERED (YansErrorRateModel);
32 
33 TypeId
34 YansErrorRateModel::GetTypeId (void)
35 {
36  static TypeId tid = TypeId ("ns3::YansErrorRateModel")
37  .SetParent<ErrorRateModel> ()
38  .SetGroupName ("Wifi")
39  .AddConstructor<YansErrorRateModel> ()
40  ;
41  return tid;
42 }
43 
44 YansErrorRateModel::YansErrorRateModel ()
45 {
46 }
47 
48 double
49 YansErrorRateModel::GetBpskBer (double snr, uint32_t signalSpread, uint64_t phyRate) const
50 {
51  NS_LOG_FUNCTION (this << snr << signalSpread << phyRate);
52  double EbNo = snr * signalSpread / phyRate;
53  double z = std::sqrt (EbNo);
54  double ber = 0.5 * erfc (z);
55  NS_LOG_INFO ("bpsk snr=" << snr << " ber=" << ber);
56  return ber;
57 }
58 
59 double
60 YansErrorRateModel::GetQamBer (double snr, unsigned int m, uint32_t signalSpread, uint64_t phyRate) const
61 {
62  NS_LOG_FUNCTION (this << snr << m << signalSpread << phyRate);
63  double EbNo = snr * signalSpread / phyRate;
64  double z = std::sqrt ((1.5 * log2 (m) * EbNo) / (m - 1.0));
65  double z1 = ((1.0 - 1.0 / std::sqrt (m)) * erfc (z));
66  double z2 = 1 - std::pow ((1 - z1), 2);
67  double ber = z2 / log2 (m);
68  NS_LOG_INFO ("Qam m=" << m << " rate=" << phyRate << " snr=" << snr << " ber=" << ber);
69  return ber;
70 }
71 
72 uint32_t
73 YansErrorRateModel::Factorial (uint32_t k) const
74 {
75  uint32_t fact = 1;
76  while (k > 0)
77  {
78  fact *= k;
79  k--;
80  }
81  return fact;
82 }
83 
84 double
85 YansErrorRateModel::Binomial (uint32_t k, double p, uint32_t n) const
86 {
87  double retval = Factorial (n) / (Factorial (k) * Factorial (n - k)) * std::pow (p, static_cast<double> (k)) * std::pow (1 - p, static_cast<double> (n - k));
88  return retval;
89 }
90 
91 double
92 YansErrorRateModel::CalculatePdOdd (double ber, unsigned int d) const
93 {
94  NS_ASSERT ((d % 2) == 1);
95  unsigned int dstart = (d + 1) / 2;
96  unsigned int dend = d;
97  double pd = 0;
98 
99  for (unsigned int i = dstart; i < dend; i++)
100  {
101  pd += Binomial (i, ber, d);
102  }
103  return pd;
104 }
105 
106 double
107 YansErrorRateModel::CalculatePdEven (double ber, unsigned int d) const
108 {
109  NS_ASSERT ((d % 2) == 0);
110  unsigned int dstart = d / 2 + 1;
111  unsigned int dend = d;
112  double pd = 0;
113 
114  for (unsigned int i = dstart; i < dend; i++)
115  {
116  pd += Binomial (i, ber, d);
117  }
118  pd += 0.5 * Binomial (d / 2, ber, d);
119 
120  return pd;
121 }
122 
123 double
124 YansErrorRateModel::CalculatePd (double ber, unsigned int d) const
125 {
126  NS_LOG_FUNCTION (this << ber << d);
127  double pd;
128  if ((d % 2) == 0)
129  {
130  pd = CalculatePdEven (ber, d);
131  }
132  else
133  {
134  pd = CalculatePdOdd (ber, d);
135  }
136  return pd;
137 }
138 
139 double
140 YansErrorRateModel::GetFecBpskBer (double snr, uint64_t nbits,
141  uint32_t signalSpread, uint64_t phyRate,
142  uint32_t dFree, uint32_t adFree) const
143 {
144  NS_LOG_FUNCTION (this << snr << nbits << signalSpread << phyRate << dFree << adFree);
145  double ber = GetBpskBer (snr, signalSpread, phyRate);
146  if (ber == 0.0)
147  {
148  return 1.0;
149  }
150  double pd = CalculatePd (ber, dFree);
151  double pmu = adFree * pd;
152  pmu = std::min (pmu, 1.0);
153  double pms = std::pow (1 - pmu, nbits);
154  return pms;
155 }
156 
157 double
158 YansErrorRateModel::GetFecQamBer (double snr, uint64_t nbits,
159  uint32_t signalSpread,
160  uint64_t phyRate,
161  uint32_t m, uint32_t dFree,
162  uint32_t adFree, uint32_t adFreePlusOne) const
163 {
164  NS_LOG_FUNCTION (this << snr << nbits << signalSpread << phyRate << m << dFree << adFree << adFreePlusOne);
165  double ber = GetQamBer (snr, m, signalSpread, phyRate);
166  if (ber == 0.0)
167  {
168  return 1.0;
169  }
170  /* first term */
171  double pd = CalculatePd (ber, dFree);
172  double pmu = adFree * pd;
173  /* second term */
174  pd = CalculatePd (ber, dFree + 1);
175  pmu += adFreePlusOne * pd;
176  pmu = std::min (pmu, 1.0);
177  double pms = std::pow (1 - pmu, nbits);
178  return pms;
179 }
180 
181 double
182 YansErrorRateModel::DoGetChunkSuccessRate (WifiMode mode, WifiTxVector txVector, double snr, uint64_t nbits) const
183 {
184  NS_LOG_FUNCTION (this << mode << txVector.GetMode () << snr << nbits);
185  if (mode.GetModulationClass () == WIFI_MOD_CLASS_ERP_OFDM
186  || mode.GetModulationClass () == WIFI_MOD_CLASS_OFDM
187  || mode.GetModulationClass () == WIFI_MOD_CLASS_HT
188  || mode.GetModulationClass () == WIFI_MOD_CLASS_VHT
189  || mode.GetModulationClass () == WIFI_MOD_CLASS_HE)
190  {
191  if (mode.GetConstellationSize () == 2)
192  {
193  if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
194  {
195  return GetFecBpskBer (snr,
196  nbits,
197  txVector.GetChannelWidth () * 1000000, //signal spread
198  mode.GetPhyRate (txVector), //PHY rate
199  10, //dFree
200  11); //adFree
201  }
202  else
203  {
204  return GetFecBpskBer (snr,
205  nbits,
206  txVector.GetChannelWidth () * 1000000, //signal spread
207  mode.GetPhyRate (txVector), //PHY rate
208  5, //dFree
209  8); //adFree
210  }
211  }
212  else if (mode.GetConstellationSize () == 4)
213  {
214  if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
215  {
216  return GetFecQamBer (snr,
217  nbits,
218  txVector.GetChannelWidth () * 1000000, //signal spread
219  mode.GetPhyRate (txVector), //PHY rate
220  4, //m
221  10, //dFree
222  11, //adFree
223  0); //adFreePlusOne
224  }
225  else
226  {
227  return GetFecQamBer (snr,
228  nbits,
229  txVector.GetChannelWidth () * 1000000, //signal spread
230  mode.GetPhyRate (txVector), //PHY rate
231  4, //m
232  5, //dFree
233  8, //adFree
234  31); //adFreePlusOne
235  }
236  }
237  else if (mode.GetConstellationSize () == 16)
238  {
239  if (mode.GetCodeRate () == WIFI_CODE_RATE_1_2)
240  {
241  return GetFecQamBer (snr,
242  nbits,
243  txVector.GetChannelWidth () * 1000000, //signal spread
244  mode.GetPhyRate (txVector), //PHY rate
245  16, //m
246  10, //dFree
247  11, //adFree
248  0); //adFreePlusOne
249  }
250  else
251  {
252  return GetFecQamBer (snr,
253  nbits,
254  txVector.GetChannelWidth () * 1000000, //signal spread
255  mode.GetPhyRate (txVector), //PHY rate
256  16, //m
257  5, //dFree
258  8, //adFree
259  31); //adFreePlusOne
260  }
261  }
262  else if (mode.GetConstellationSize () == 64)
263  {
264  if (mode.GetCodeRate () == WIFI_CODE_RATE_2_3)
265  {
266  return GetFecQamBer (snr,
267  nbits,
268  txVector.GetChannelWidth () * 1000000, //signal spread
269  mode.GetPhyRate (txVector), //PHY rate
270  64, //m
271  6, //dFree
272  1, //adFree
273  16); //adFreePlusOne
274  }
275  if (mode.GetCodeRate () == WIFI_CODE_RATE_5_6)
276  {
277  //Table B.32 in Pâl Frenger et al., "Multi-rate Convolutional Codes".
278  return GetFecQamBer (snr,
279  nbits,
280  txVector.GetChannelWidth () * 1000000, //signal spread
281  mode.GetPhyRate (txVector), //PHY rate
282  64, //m
283  4, //dFree
284  14, //adFree
285  69); //adFreePlusOne
286  }
287  else
288  {
289  return GetFecQamBer (snr,
290  nbits,
291  txVector.GetChannelWidth () * 1000000, //signal spread
292  mode.GetPhyRate (txVector), //PHY rate
293  64, //m
294  5, //dFree
295  8, //adFree
296  31); //adFreePlusOne
297  }
298  }
299  else if (mode.GetConstellationSize () == 256)
300  {
301  if (mode.GetCodeRate () == WIFI_CODE_RATE_5_6)
302  {
303  return GetFecQamBer (snr,
304  nbits,
305  txVector.GetChannelWidth () * 1000000, // signal spread
306  mode.GetPhyRate (txVector), //PHY rate
307  256, // m
308  4, // dFree
309  14, // adFree
310  69 // adFreePlusOne
311  );
312  }
313  else
314  {
315  return GetFecQamBer (snr,
316  nbits,
317  txVector.GetChannelWidth () * 1000000, // signal spread
318  mode.GetPhyRate (txVector), //PHY rate
319  256, // m
320  5, // dFree
321  8, // adFree
322  31 // adFreePlusOne
323  );
324  }
325  }
326  else if (mode.GetConstellationSize () == 1024)
327  {
328  if (mode.GetCodeRate () == WIFI_CODE_RATE_5_6)
329  {
330  return GetFecQamBer (snr,
331  nbits,
332  txVector.GetChannelWidth () * 1000000, // signal spread
333  mode.GetPhyRate (txVector), //PHY rate
334  1024, // m
335  4, // dFree
336  14, // adFree
337  69 // adFreePlusOne
338  );
339  }
340  else
341  {
342  return GetFecQamBer (snr,
343  nbits,
344  txVector.GetChannelWidth () * 1000000, // signal spread
345  mode.GetPhyRate (txVector), //PHY rate
346  1024, // m
347  5, // dFree
348  8, // adFree
349  31 // adFreePlusOne
350  );
351  }
352  }
353  }
354  return 0;
355 }
356 
357 } //namespace ns3
ns3::YansErrorRateModel::GetTypeId
static TypeId GetTypeId(void)
Get the type ID.
Definition: yans-error-rate-model.cc:34
NS_LOG_FUNCTION
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by "...
Definition: log-macros-enabled.h:244
ns3::WIFI_MOD_CLASS_ERP_OFDM
ERP-OFDM PHY (19.5)
Definition: wifi-mode.h:56
ns3::WifiTxVector
This class mimics the TXVECTOR which is to be passed to the PHY in order to define the parameters whi...
Definition: wifi-tx-vector.h:70
NS_OBJECT_ENSURE_REGISTERED
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:45
min
#define min(a, b)
Definition: 80211b.c:42
NS_ASSERT
#define NS_ASSERT(condition)
At runtime, in debugging builds, if this condition is not true, the program prints the source file...
Definition: assert.h:67
NS_LOG_COMPONENT_DEFINE
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
NS_LOG_INFO
#define NS_LOG_INFO(msg)
Use NS_LOG to output a message of level LOG_INFO.
Definition: log.h:281
ns3::WIFI_MOD_CLASS_VHT
VHT PHY (Clause 22)
Definition: wifi-mode.h:62
ns3::YansErrorRateModel::GetFecQamBer
double GetFecQamBer(double snr, uint64_t nbits, uint32_t signalSpread, uint64_t phyRate, uint32_t m, uint32_t dfree, uint32_t adFree, uint32_t adFreePlusOne) const
Definition: yans-error-rate-model.cc:158
ns3::WifiMode
represent a single transmission modeA WifiMode is implemented by a single integer which is used to lo...
Definition: wifi-mode.h:99
ns3::ErrorRateModel
the interface for Wifi&#39;s error models
Definition: error-rate-model.h:36
ns3::WifiTxVector::GetMode
WifiMode GetMode(uint16_t staId=SU_STA_ID) const
If this TX vector is associated with an SU PPDU, return the selected payload transmission mode...
Definition: wifi-tx-vector.cc:107
ns3::YansErrorRateModel
Model the error rate for different modulations.
Definition: yans-error-rate-model.h:53
ns3::YansErrorRateModel::CalculatePdEven
double CalculatePdEven(double ber, unsigned int d) const
Definition: yans-error-rate-model.cc:107
ns3::YansErrorRateModel::GetQamBer
double GetQamBer(double snr, unsigned int m, uint32_t signalSpread, uint64_t phyRate) const
Return BER of QAM-m with the given parameters.
Definition: yans-error-rate-model.cc:60
ns3::WIFI_MOD_CLASS_HT
HT PHY (Clause 20)
Definition: wifi-mode.h:60
ns3::WifiMode::GetModulationClass
WifiModulationClass GetModulationClass() const
Definition: wifi-mode.cc:480
ns3
Every class exported by the ns3 library is enclosed in the ns3 namespace.
ns3::WifiMode::GetConstellationSize
uint16_t GetConstellationSize(void) const
Definition: wifi-mode.cc:386
ns3::YansErrorRateModel::CalculatePdOdd
double CalculatePdOdd(double ber, unsigned int d) const
Definition: yans-error-rate-model.cc:92
ns3::YansErrorRateModel::Factorial
uint32_t Factorial(uint32_t k) const
Return k!
Definition: yans-error-rate-model.cc:73
ns3::WIFI_MOD_CLASS_OFDM
OFDM PHY (Clause 17)
Definition: wifi-mode.h:58
ns3::WifiMode::GetPhyRate
uint64_t GetPhyRate(uint16_t channelWidth, uint16_t guardInterval, uint8_t nss) const
Definition: wifi-mode.cc:73
ns3::YansErrorRateModel::Binomial
double Binomial(uint32_t k, double p, uint32_t n) const
Return Binomial distribution for a given k, p, and n.
Definition: yans-error-rate-model.cc:85
ns3::YansErrorRateModel::GetBpskBer
double GetBpskBer(double snr, uint32_t signalSpread, uint64_t phyRate) const
Return BER of BPSK with the given parameters.
Definition: yans-error-rate-model.cc:49
ns3::WifiTxVector::GetChannelWidth
uint16_t GetChannelWidth(void) const
Definition: wifi-tx-vector.cc:135
ns3::YansErrorRateModel::DoGetChunkSuccessRate
double DoGetChunkSuccessRate(WifiMode mode, WifiTxVector txVector, double snr, uint64_t nbits) const
A pure virtual method that must be implemented in the subclass.
Definition: yans-error-rate-model.cc:182
ns3::WifiMode::GetCodeRate
WifiCodeRate GetCodeRate(void) const
Definition: wifi-mode.cc:310
ns3::YansErrorRateModel::GetFecBpskBer
double GetFecBpskBer(double snr, uint64_t nbits, uint32_t signalSpread, uint64_t phyRate, uint32_t dFree, uint32_t adFree) const
Definition: yans-error-rate-model.cc:140
ns3::TypeId
a unique identifier for an interface.
Definition: type-id.h:58
ns3::TypeId::SetParent
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:923
ns3::WIFI_MOD_CLASS_HE
HE PHY (Clause 26)
Definition: wifi-mode.h:64
ns3::YansErrorRateModel::CalculatePd
double CalculatePd(double ber, unsigned int d) const
Definition: yans-error-rate-model.cc:124