[31] | 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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