10 files changed, 235 insertions, 0 deletions

diff --git a/3446/CH3/EX3.1/Ex3_1.sce b/3446/CH3/EX3.1/Ex3_1.sce
new file mode 100644
index 000000000..dda4a1ca1
--- /dev/null
+++ b/3446/CH3/EX3.1/Ex3_1.sce
@@ -0,0 +1,21 @@
+// Exa 3.1

+// To determine free space and reflected surface attenuations.

+

+clc;

+clear all;

+

+hb=100; //in feets(height of BS antenna)

+hm=5;  // in feets(height of mobile antenna)

+f=881.52;//in MHz

+lamda=1.116;  //in feet

+d=5000;  //in feet

+Gb=10^0.8;  //8dB(BS antenna gain)

+Gm=10^0;   // 0dB (Mobile antenna gain)

+

+//solution

+free_atten=(4*%pi*d/lamda)^2*(Gb*Gm)^-1;

+y=round(10*log10(free_atten));

+printf('Free space attenuation is %d dB \n',y);

+reflect_atten= (d^4/(hb*hm)^2)*(Gb*Gm)^-1;

+x=round(10*log10(reflect_atten));

+printf(' Reflecting surface attenuation is %d dB \n ',x);

diff --git a/3446/CH3/EX3.10/Ex3_10.sce b/3446/CH3/EX3.10/Ex3_10.sce
new file mode 100644
index 000000000..289f40d71
--- /dev/null
+++ b/3446/CH3/EX3.10/Ex3_10.sce
@@ -0,0 +1,28 @@
+//Exa 3.10

+//To find required total transmit power in Watts.

+

+clc;

+clear all;

+

+Lp=140; // path losses in dB 

+k=1.38*10^-23; // Boltzmann’s constant (W/Kelvin-Hz)

+k_db=10*log10(k);

+f=900;//in MHz

+Gt=8; //transmitting antenna gain(dB)

+Gr=0; //receiver antenna gain(dB)

+Ag=24;//gain of receiver amplifier in dB 

+Fmargin=8;//Fade margin(dB)

+Nf=6;//Noise figure(dB)

+L0=20; // other losses in dB

+Lf=12; // antenna feed line loss in dB 

+T=24.6;//Temperature expressed in dB

+R=39.8; // data rate in dB 

+M=8;  //overall link margin(dB)

+Eb_No=10;//dB

+

+//solution

+//From equation  (3.54)

+pt_db=M-Gt-Gr-Ag+ Nf + T+ k_db+ Lp+ Lf+ L0 + Fmargin+ R+ Eb_No;

+

+Pt=10^(pt_db/10);  //dB into normal number

+printf('Total transmitted power is %d Watts \n',Pt);    

diff --git a/3446/CH3/EX3.2/Ex3_2.sce b/3446/CH3/EX3.2/Ex3_2.sce
new file mode 100644
index 000000000..5dd7c5b42
--- /dev/null
+++ b/3446/CH3/EX3.2/Ex3_2.sce
@@ -0,0 +1,28 @@
+//Exa 3.2

+//To determine received signal power and SNR ratio.

+

+clc;

+clear all;

+

+d=8000; //Distance between base station and mobile station

+f=1.5*10^9;//in Hz 

+lamda=0.2;  //in metres

+Pt=10; //BS transmitted power in watts

+Lo=8;   //Total system losses in dB

+Nf=5;    //Mobile receiver noise figure in dB

+T=290;   //temperature in degree kelvin

+BW=1.25*10^6; //in Hz

+Gb=8;  //in dB

+Gm=0;   //in dB

+Hb=30;  //in metres

+Hm=3;   //in metres

+B=1.38*10^-23; //Boltzmann's constant

+

+//solution

+Free_Lp=20*log10(Hm*Hb/d^2);

+Pr=Free_Lp-Lo+Gm+Gb+Pt;  //in dBW

+Te=T*(3.162-1);

+Pn=B*(Te+T)*BW;

+printf('Received signal power is %d dBW \n',10*log10(Pn));

+SNR=Pr-10*log10(Pn);

+printf(' SNR ratio is %d dB \n',round(SNR));

diff --git a/3446/CH3/EX3.3/Ex3_3.sce b/3446/CH3/EX3.3/Ex3_3.sce
new file mode 100644
index 000000000..ff66320c4
--- /dev/null
+++ b/3446/CH3/EX3.3/Ex3_3.sce
@@ -0,0 +1,20 @@
+//Exa 3.3

+//To determine received power and allowable Path loss.

+

+clc;

+clear all;

+

+d=3*1000;//in metres

+Y=4;// path loss exponent

+Pt=4;  //Transmitted power in watts

+f=1800*10^6;//in Hz

+Shadow=10.5;  //in dB

+d0=100;//in metres

+P0=-32;   //in dBm

+

+//solution

+disp("Using equation 3.11 and including shadow effect we get")

+Pr=P0+10*Y*log10(d0/d)+Shadow;

+printf(' Received power is %.1f dBm \n',Pr);

+path_loss=10*log10(Pt*1000)-Pr;

+printf(' Allowable path loss is %.1f dB \n ',path_loss);

diff --git a/3446/CH3/EX3.4/Ex3_4.sce b/3446/CH3/EX3.4/Ex3_4.sce
new file mode 100644
index 000000000..a7b3787dd
--- /dev/null
+++ b/3446/CH3/EX3.4/Ex3_4.sce
@@ -0,0 +1,13 @@
+//Exa 3.4

+//To determine distance between transmitter and receiver.

+

+clc;

+clear all;

+

+shadow=10; //in dB

+Lp=150;  //in dB

+

+//solution

+disp(" Using equation given in Problem i.e Lp=133.2+40*log(d) we get,");

+d=10^((Lp-10-133.2)/40);

+printf("  Separation between transmitter and receiver as %.2f km',d);

diff --git a/3446/CH3/EX3.5/EX3_5.sce b/3446/CH3/EX3.5/EX3_5.sce
new file mode 100644
index 000000000..56e19180e
--- /dev/null
+++ b/3446/CH3/EX3.5/EX3_5.sce
@@ -0,0 +1,27 @@
+// Exa 3.5

+// To calculate coherence time, coherence bandwidth, type of Symbol distortion and type of fading.

+

+clc;

+clear all;

+

+v=60*0.44704;  //.. mph to mps

+fc=860*10^6;//in Hz

+td=2*10^-6; //RMS delay spread in sec

+c=3*10^8;// speed of light in m/sec

+Rs=19200; //Coded symbol rate in bps

+

+//solution

+lamda=c/fc;

+fm=v/lamda; //Maximum doppler shift

+tc=1/(2*%pi*fm);//Channel coherence time

+printf('Channel coherence time is %.4f sec \n',tc);

+ts=1/Rs; //symbol interval

+printf(' Symbol interval is %d microsec \n',ts*10^6);

+disp(" As the symbol interval is much smaller compared to the channel coherence time. So, Symbol distortion is minimal and fading is slow.");

+disp("");

+Bc=1/(2*%pi*td);

+printf('  Coherence Bandwidth is %.2f kHz \n',Bc/1000)

+

+

+

+

diff --git a/3446/CH3/EX3.6/Ex3_6.sce b/3446/CH3/EX3.6/Ex3_6.sce
new file mode 100644
index 000000000..8270bcb41
--- /dev/null
+++ b/3446/CH3/EX3.6/Ex3_6.sce
@@ -0,0 +1,20 @@
+// Exa 3.6

+// TO determine NO of fades per second, average fade duration and maximum velocity of mobile.

+

+clc;

+clear all;

+

+p=1;// reflection coefficient of ground 

+c=3*10^8;// velocity of light in free space(m/sec)

+e=2.71828;//Euler's number

+fm=20;  //in Hz

+fc=900*10^6; //carrier frequency in Hz

+

+//solution

+Nr=sqrt(2*%pi)*fm*p*e^-(p^2);

+printf('NO of fades per second are %.2f  \n',Nr);

+Afd=e^-(p^2)/(p*fm*sqrt(2*%pi));

+printf(' Average fade duration is %.4f sec \n ',Afd);

+v=fm*c/fc;

+printf('Maximum velocity of mobile is %.2f m/sec = %d Km/hour \n',v,v*18/5);

+

diff --git a/3446/CH3/EX3.7/EX3_7.sce b/3446/CH3/EX3.7/EX3_7.sce
new file mode 100644
index 000000000..a3735a94c
--- /dev/null
+++ b/3446/CH3/EX3.7/EX3_7.sce
@@ -0,0 +1,43 @@
+// Exa 3.7

+// To calculate L50 path loss for a PCS system using Okumura and COST231 models.

+

+clc;

+clear all;

+

+d=[1 2 3 4 5];  //in km

+hb=30; //Height of BS antenna in metres

+hm=2;// height of mobile antenna in matres

+fc=900;//carrier frequency in MHz

+W=15;  //street width(m)

+b=30;  // distance between building along radio path (m) 

+phi=90; // incident angle relative to the street

+hr=30; //in m

+

+//solution

+dellhm=hr-hm;

+//L50=Lf+Lrts+Lms

+// By COST 231 model

+Lf=32.4+20*log10(d)+20*log10(fc);

+L0=4-0.114*(phi-55);

+Lrts=-16.9-10*log10(W)+10*log10(fc)+20*log10(dellhm)+L0;

+Lbsh=-18*log10(11);

+ka=54-0.8*hb;

+dellhb=hb-hr;

+kd=18-15*dellhb/dellhm;

+kf=4+0.7*(fc/925-1);

+Lms=Lbsh+ka+kd*log10(d)+kf*log10(fc)-9*log10(b);

+L50=[0 0 0 0 0];

+L50=Lf+Lrts+Lms;

+//Okumura/Hata model

+ahm=(1.1*log10(fc)-0.7)*hm-(1.56*log10(fc)-0.8);

+L_50=69.55+26.16*log10(fc)+(44.9-6.55*log10(hb))*log10(d)-13.82*log10(hb)-ahm;

+xlabel("DISTANCE FROM TRANSMITTER IN KM");

+ylabel("PATH LOSS in dB");

+plot2d(d,[L50',L_50'],[1,2]);  

+legends(['Cost 231 Model';'Okumura/Hata Model'],[1,2 ],opt=2)

+xgrid();

+disp("L50 values by Cost 231 model");

+printf('%.2f  %.2f  %.2f  %.2f  %.2f \n ',L50(1),L50(2),L50(3),L50(4),L50(5));

+disp("L50 values bu Okumura/Hata model");

+printf('%.2f  %.2f  %.2f  %.2f  %.2f \n ',L_50(1),L_50(2),L_50(3),L_50(4),L_50(5));

+disp("The results from the plot of two models shows that the calculated path loss with the COST 231 model is higher than the value obtained by the Okumura/Hata model.");

diff --git a/3446/CH3/EX3.8/Ex3_8.sce b/3446/CH3/EX3.8/Ex3_8.sce
new file mode 100644
index 000000000..8290c4bd8
--- /dev/null
+++ b/3446/CH3/EX3.8/Ex3_8.sce
@@ -0,0 +1,22 @@
+// Exa 3.8

+// TO find coverage radius of an access point.

+

+clc;

+clear all;

+

+SNRmin=12;//in dB

+n=3; //No of floors

+Backgroundnoise=-115; //dBm

+pt=100  //in dBm

+

+//solution

+pt_db=10*log10(pt);

+Sr=Backgroundnoise+SNRmin; //receiver sensitivity

+Lpmax=pt_db-Sr;

+//Refering table 3.4

+Lp_d0=38;  //ref path loss at the first meter(dB)

+Lf=15+4*(n-1); //signal attenuation through n floors

+y=3; //path loss exponent

+X=10; //Shadowing effect(dB)

+d=10^((Lpmax-Lp_d0-Lf-X)/30); //max allowable path loss

+printf('Coverage radius of an access point = %d m \n',round(d));

diff --git a/3446/CH3/EX3.9/Ex3_9.sce b/3446/CH3/EX3.9/Ex3_9.sce
new file mode 100644
index 000000000..b5a26f762
--- /dev/null
+++ b/3446/CH3/EX3.9/Ex3_9.sce
@@ -0,0 +1,13 @@
+//Exa 3.9

+// To calculate probability of exceeding signal beyond the receiver sensitivity.

+

+clc;

+clear all;

+

+SSmean=-100; //signal strength(dBm)

+Sr=-110; //receiver sensitivity(dBm)

+sd=10;  //standard deviation(dB)

+

+//solution

+P_Smin=(0.5-0.5*erf((Sr-SSmean)/(sqrt(2)*sd)));

+printf('probability of exceeding signal beyond the receiver sensitivity is %.2f \n',P_Smin);