A Discrete-Event Network Simulator
API
80211b.c
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2010 The Boeing Company
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  * Author: Gary Pei <guangyu.pei@boeing.com>
19  */
20 
21 /*
22  * This program is used to generate plots found in the paper
23  * G. Pei and Tom Henderson, "Validation of ns-3 802.11b PHY model",
24  * available online at http://www.nsnam.org/~pei/80211b.pdf
25  *
26  * It can be compiled as a C program and relies on a library installation of
27  * the GNU Scientific Library (gsl). To compile:
28  * gcc 80211b.c -o 80211b -lm -lgsl -lgslcblas
29  *
30  * The executable output should be redirected into a text file 80211b.txt
31  * ./80211b > 80211b.txt
32  *
33  * Then gnuplot can load the associated plot file which references 80211b.txt:
34  * gnuplot 80211b.plt
35  */
36 
37 #include <gsl/gsl_math.h>
38 #include <gsl/gsl_integration.h>
39 #include <gsl/gsl_cdf.h>
40 #include <gsl/gsl_sf_bessel.h>
41 
42 #define min(a,b) ((a) < (b) ? (a) : (b))
43 #define max(a,b) ((a) > (b) ? (a) : (b))
44 #define WLAN_SIR_perfect 10.0 // if SIR > 10dB, perfect reception
45 #define WLAN_SIR_impossible 0.1 // if SIR < -10dB, impossible to receive
46 
59 typedef struct fn_parameter_t
60 {
61  double beta;
62  double n;
64 
65 double QFunction (double x)
66 {
67  return 0.5 * erfc (x / sqrt (2.0));
68 }
69 
70 double f (double x, void * params)
71 {
72  double beta = ((fn_parameters *) params)->beta;
73  double n = ((fn_parameters *) params)->n;
74  double f = pow ( 2 * gsl_cdf_ugaussian_P (x + beta) - 1, n - 1) * exp (-x * x / 2.0) / sqrt (2.0 * M_PI);
75  return f;
76 }
77 
78 double p_e2 (double e2)
79 {
80  double sep;
81  double error;
82  fn_parameters params;
83  params.beta = sqrt (2.0 * e2);
84  params.n = 8.0;
85  gsl_integration_workspace* w = gsl_integration_workspace_alloc (1000);
86  gsl_function F;
87  F.function = &f;
88  F.params = &params;
89  gsl_integration_qagiu (&F, -params.beta, 0, 1e-7, 1000, w, &sep, &error);
90  gsl_integration_workspace_free (w);
91  if (error == 0.0)
92  {
93  sep = 1.0;
94  }
95  return 1.0 - sep;
96 }
97 
98 double p_e1 (double e1)
99 {
100  return 1.0 - pow ( 1.0 - p_e2 (e1 / 2.0), 2.0);
101 }
102 
103 double DbToNoneDb (double x)
104 {
105  return pow (10.0, x / 10.0);
106 }
107 
108 double NoneDbToDb (double x)
109 {
110  return 10.0 * log10 (x);
111 }
112 
113 double DQPSKFunction (double x)
114 {
115  double pi = acos (-1.0);
116  return ( (sqrt (2.0) + 1.0) / sqrt (8.0 * pi * sqrt (2.0))) * (1.0 / sqrt (x)) * exp ( -(2.0 - sqrt (2.0)) * x);
117 }
118 
119 double Get80211bDsssDbpskBerIeee (double EcNc)
120 {
121  double ber;
122  if (EcNc > WLAN_SIR_perfect)
123  {
124  ber = 0;
125  }
126  else if (EcNc < WLAN_SIR_impossible)
127  {
128  ber = 0.5;
129  }
130  else
131  {
132  ber = min (QFunction (sqrt (11.0 * EcNc)),0.5);
133  }
134  return ber;
135 }
136 
137 double Get80211bDsssDbpskBer (double sinr)
138 {
139  double EbN0 = sinr * 22000000.0 / 1000000.0;
140  double ber = 0.5 * exp (-EbN0);
141  return ber;
142 }
143 
144 double Get80211bDsssDqpskBerIeee (double EcNc)
145 {
146  double ber;
147  if (EcNc > WLAN_SIR_perfect)
148  {
149  ber = 0;
150  }
151  else if (EcNc < WLAN_SIR_impossible)
152  {
153  ber = 0.5;
154  }
155  else
156  {
157  ber = min (QFunction (sqrt (5.5 * EcNc)),0.5);
158  }
159  return ber;
160 }
161 
162 double Get80211bDsssDqpskBer (double sinr)
163 {
164 // 2 bits per symbol, 1 MSPS
165  double EbN0 = sinr * 22000000.0 / 1000000.0 / 2.0;
166  double ber = DQPSKFunction (EbN0);
167  return ber;
168 }
169 
171 {
172  double ber;
173  if (EcNc > WLAN_SIR_perfect)
174  {
175  ber = 0.0;
176  }
177  else if (EcNc < WLAN_SIR_impossible)
178  {
179  ber = 0.5;
180  }
181  else
182  {
183  double pew = 14.0 * QFunction (sqrt (EcNc * 8.0)) + QFunction (sqrt (EcNc * 16.0));
184  pew = min (pew, 0.99999);
185  ber = 8.0 / 15.0 * pew;
186  }
187  return ber;
188 }
189 
190 double Get80211bDsssDqpskCCK11BerIeee (double EcNc)
191 {
192  double ber;
193  if (EcNc > WLAN_SIR_perfect)
194  {
195  ber = 0.0;
196  }
197  else if (EcNc < WLAN_SIR_impossible)
198  {
199  ber = 0.5;
200  }
201  else
202  {
203  double pew = 24.0 * QFunction (sqrt (EcNc * 4.0)) + 16.0 * QFunction (sqrt (EcNc * 6.0)) + 174.0 * QFunction (sqrt (EcNc * 8.0)) + 16.0 * QFunction (sqrt (EcNc * 10.0)) + 24.0 * QFunction (sqrt (EcNc * 12.0)) + QFunction (sqrt (EcNc * 16.0));
204  pew = min (pew, 0.99999);
205  ber = 128.0 / 255.0 * pew;
206  }
207  return ber;
208 }
209 
210 int main (int argc, char * argv[])
211 {
212  double rss, sinr;
213  double totalPkt = 200.0;
214 //double noise = 1.552058; // (dB) this noise figure value corresponds to
215  // -99 dBm noise floor reported in CMU paper
216  double noise = 7; // (dB) this noise figure value corresponds to the
217  // default in YansWifiPhy, and matches CMU testbed results
218  double EcNc, EbN01, EbN02, EbN05, EbN011;
219  double ieee1,ieee2,ieee5,ieee11;
220  double numBits = (1024. + 40. + 14.) * 8.;
221  double dbpsk,dqpsk,cck16,cck256,sepcck16,sepcck256;
222  noise = DbToNoneDb (noise) * 1.3803e-23 * 290.0 * 22000000;
223  for (rss = -102.0; rss <= -80.0; rss += 0.1)
224  {
225  sinr = DbToNoneDb (rss) / 1000.0 / noise;
226  EcNc = sinr * 22000000.0 / 11000000.0; // IEEE sir
227  EbN01 = sinr * 22000000.0 / 1000000.0;
228  // 2 bits per symbol, 1 MSPS
229  EbN02 = sinr * 22000000.0 / 1000000.0 / 2.0;
230  EbN05 = sinr * 22000000.0 / 1375000.0 / 4.0;
231  EbN011 = sinr * 22000000.0 / 1375000.0 / 8.0;
232  // 1=rss, 2=EcNc, 3=EbN01, 4=EbN02, 5=EBN05, 6=EbN011
233  printf ("%g %g %g %g %g %g ", rss, NoneDbToDb (EcNc),
234  NoneDbToDb (EbN01),NoneDbToDb (EbN02),
235  NoneDbToDb (EbN05),NoneDbToDb (EbN011));
236  ieee1 = Get80211bDsssDbpskBerIeee (EcNc);
237  ieee2 = Get80211bDsssDqpskBerIeee (EcNc);
238  ieee5 = Get80211bDsssDqpskCCK5_5BerIeee (EcNc);
239  ieee11 = Get80211bDsssDqpskCCK11BerIeee (EcNc);
240  // 7=ber_ieee1, 8=ber_ieee2, 9=ber_ieee5, 10=ber_ieee11
241  printf (" %g %g %g %g ", ieee1, ieee2,ieee5,ieee11);
242  ieee1 = totalPkt * pow (1 - ieee1, numBits);
243  ieee2 = totalPkt * pow (1 - ieee2, numBits);
244  ieee5 = totalPkt * pow (1 - ieee5, numBits);
245  ieee11 = totalPkt * pow (1 - ieee11, numBits);
246  // 11=pkt_ieee1, 12=pkt_ieee2, 13=pkt_ieee5, 14=pkt_ieee11
247  printf (" %g %g %g %g ", ieee1, ieee2,ieee5,ieee11);
248  dbpsk = Get80211bDsssDbpskBer (sinr);
249  dqpsk = Get80211bDsssDqpskBer (sinr);
250  cck16 = max (0, 8.0 / 15.0 * p_e2 (4.0 * EbN05 / 2.0));
251  cck256 = max (0, 128.0 / 255.0 * p_e1 (8.0 * EbN011 / 2.0));
252  // 15=ber_dbpsk, 16=ber_dqpsk, 17=ber_cck16, 18=ber_cck256
253  printf (" %g %g %g %g ", dbpsk, dqpsk,cck16,cck256);
254  dbpsk = totalPkt * pow (1 - dbpsk,numBits);
255  dqpsk = totalPkt * pow (1 - dqpsk,numBits);
256  sepcck16 = p_e2 (4.0 * EbN05 / 2.0);
257  sepcck256 = p_e1 (8.0 * EbN011 / 2.0);
258  cck16 = totalPkt * pow (1.0 - sepcck16,numBits / 4.0);
259  cck256 = totalPkt * pow (1.0 - sepcck256,numBits / 8.0);
260  // 19=pkt_dbpsk, 20=pkt_dqpsk, 21=pkt_cck16, 22=pkt_cck256
261  printf (" %g %g %g %g ", dbpsk, dqpsk,cck16,cck256);
262  // 23=sinr
263  printf (" %g \n",NoneDbToDb (sinr));
264  }
265  return 0;
266 }
#define WLAN_SIR_perfect
Definition: 80211b.c:44
double p_e2(double e2)
Definition: 80211b.c:78
double Get80211bDsssDqpskCCK11BerIeee(double EcNc)
Definition: 80211b.c:190
#define WLAN_SIR_impossible
Definition: 80211b.c:45
double NoneDbToDb(double x)
Definition: 80211b.c:108
double Get80211bDsssDqpskCCK5_5BerIeee(double EcNc)
Definition: 80211b.c:170
double Get80211bDsssDbpskBerIeee(double EcNc)
Definition: 80211b.c:119
double p_e1(double e1)
Definition: 80211b.c:98
#define min(a, b)
Definition: 80211b.c:42
double DQPSKFunction(double x)
Definition: 80211b.c:113
double QFunction(double x)
Definition: 80211b.c:65
double Get80211bDsssDbpskBer(double sinr)
Definition: 80211b.c:137
double Get80211bDsssDqpskBerIeee(double EcNc)
Definition: 80211b.c:144
double f(double x, void *params)
Definition: 80211b.c:70
double Get80211bDsssDqpskBer(double sinr)
Definition: 80211b.c:162
double DbToNoneDb(double x)
Definition: 80211b.c:103
#define max(a, b)
Definition: 80211b.c:43
list x
Random number samples.
fn_parameter_t structure
Definition: 80211b.c:60
double beta
beta
Definition: 80211b.c:61
double n
n
Definition: 80211b.c:62