1 | /************************************************************************************ |
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2 | * Copyright (C) 2008 by Politehnica University of Bucharest and Rutgers University |
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3 | * All rights reserved. |
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4 | * Refer to LICENSE for terms and conditions of use. |
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5 | ***********************************************************************************/ |
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6 | package vnsim.network.propagation; |
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7 | |
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8 | |
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9 | import java.io.BufferedReader; |
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10 | import java.io.FileReader; |
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11 | import java.io.File; |
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12 | import java.util.StringTokenizer; |
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13 | import java.util.Scanner; |
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14 | import java.io.IOException; |
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15 | |
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16 | import vnsim.map.object.Globals; |
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17 | |
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18 | |
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19 | public class Ricean |
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20 | { |
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21 | //vectors containig the Gaussian components from the txt file |
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22 | double[] data1,data2; |
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23 | //number of Gaussian components |
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24 | int n; |
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25 | |
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26 | double K; |
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27 | //max velocity of nodes , used in calculating the fm Doppler frequency |
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28 | double maxVelocity; |
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29 | |
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30 | double fm0,fs,dt,fm; |
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31 | |
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32 | public Ricean(String fileName,boolean isUrban) throws IOException |
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33 | { |
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34 | this.K=Globals.RICEAN_K; |
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35 | |
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36 | if(isUrban) |
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37 | this.maxVelocity=Globals.RICEAN_MAX_VELOCITY_URBAN; |
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38 | else |
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39 | this.maxVelocity=Globals.RICEAN_MAX_VELOCITY_FREE; |
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40 | |
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41 | this.fm=this.maxVelocity/Globals.DSRC_LAMBDA; |
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42 | |
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43 | this.fm0=this.fs=this.dt=0; |
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44 | |
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45 | this.loadDataFile(fileName); |
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46 | } |
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47 | |
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48 | //reading gaussian components from file |
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49 | public void loadDataFile(String fileName) throws IOException |
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50 | { |
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51 | //Scanner s=new Scanner(new File(fileName)); |
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52 | |
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53 | BufferedReader br=new BufferedReader(new FileReader(fileName)); |
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54 | |
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55 | this.n=Integer.parseInt(br.readLine()); |
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56 | this.fm0=(double)Integer.parseInt(br.readLine()); |
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57 | this.fs=(double)Integer.parseInt(br.readLine());; |
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58 | |
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59 | this.data1=new double[this.n]; |
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60 | this.data2=new double[this.n]; |
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61 | |
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62 | StringTokenizer st; |
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63 | |
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64 | for(int i=0;i<this.n;i++) |
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65 | { |
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66 | st=new StringTokenizer(br.readLine()); |
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67 | |
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68 | this.data1[i]=Double.parseDouble(st.nextToken()); |
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69 | this.data2[i]=Double.parseDouble(st.nextToken()); |
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70 | } |
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71 | } |
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72 | |
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73 | //calculates the fading and adds it to the received power calculated by Two Ray Ground |
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74 | public double getPr(double Pt,double R,int currentTime) |
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75 | { |
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76 | double Pr, Pr_Rice=0.0, Pr_tot; |
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77 | |
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78 | Pr = TwoRay.getPr(Pt,R); |
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79 | |
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80 | double time_index; |
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81 | double envelope_fac, tmp_x1, tmp_x2, x1_interp, x2_interp; |
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82 | |
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83 | time_index=currentTime + 2*this.fs * this.fm/this.fm0; |
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84 | |
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85 | time_index-=(double)this.n * Math.floor(time_index/(double)this.n); |
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86 | |
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87 | double X0, X1, X2, X3; |
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88 | int ind0, ind1, ind2, ind3; |
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89 | |
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90 | ind1 = (int)Math.floor(time_index); |
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91 | ind0 = (ind1-1+this.n) % this.n; |
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92 | ind2 = (ind1+1) % this.n; |
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93 | ind3 = (ind1+2) % this.n; |
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94 | |
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95 | X1 = time_index - ind1; |
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96 | X0 = X1+1.0; |
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97 | X2 = X1-1.0; |
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98 | X3 = X1-2.0; |
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99 | |
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100 | x1_interp = this.data1[ind0]*X1*X2*X3/(-6.0) +this.data1[ind1]*X0*X2*X3*(0.5) +this.data1[ind2]*X0*X1*X3*(-0.5) +this.data1[ind3]*X0*X1*X2/6.0; |
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101 | |
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102 | x2_interp = this.data2[ind0]*X1*X2*X3/(-6.0) +this.data2[ind1]*X0*X2*X3*(0.5) +this.data2[ind2]*X0*X1*X3*(-0.5) +this.data2[ind3]*X0*X1*X2/6.0; |
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103 | |
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104 | /* Find the envelope multiplicative factor */ |
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105 | tmp_x1 = x1_interp + Math.sqrt(2.0 * this.K); |
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106 | tmp_x2 = x2_interp; |
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107 | |
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108 | envelope_fac = (tmp_x1*tmp_x1 + tmp_x2*tmp_x2) / |
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109 | (2.0 * (this.K+1)); |
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110 | |
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111 | Pr_Rice = envelope_fac; |
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112 | |
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113 | Pr_tot = Pr * Pr_Rice; |
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114 | |
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115 | return Pr_tot; |
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116 | } |
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117 | } |
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