initial commit / add all books

94 files changed, 2988 insertions, 0 deletions

diff --git a/881/CH1/EX1.1/exa1_1.sce b/881/CH1/EX1.1/exa1_1.sce
new file mode 100755
index 000000000..eea8c0740
--- /dev/null
+++ b/881/CH1/EX1.1/exa1_1.sce
@@ -0,0 +1,20 @@
+clc
+//Example 1.1
+//Page no 6
+
+//Solution
+
+disp("Substituting into Eq 1.3 (ref pg no 4) yeilds,");
+
+ap=10*log10(200);   //absolute power ratio in dB
+
+disp('dB',ap,"The absolute power ratio is:");
+
+//absolute ratio: 200 = 100 X 2"
+
+disp("Applying the product rule for logarithms, the power gain in dB is:");
+
+Ap=10*log10(100)+10*log10(2);  //power gain in dB
+
+//Result
+disp('dB',Ap,"The power gain is, ")  
diff --git a/881/CH1/EX1.10/exa1_10.sce b/881/CH1/EX1.10/exa1_10.sce
new file mode 100755
index 000000000..5c940c122
--- /dev/null
+++ b/881/CH1/EX1.10/exa1_10.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 1.10
+//Page no 22
+
+//Solution 
+
+disp("The formula T = C+273 is used to convert degree C into Kelvin. ");
+
+T1=100+273;
+T2=0+273;
+T3=-10+273;
+
+disp('K',T1,"(a) ");
+disp('K',T2,"(b) ");
+disp('K',T3,"(c) ");
diff --git a/881/CH1/EX1.11/exa1_11.sce b/881/CH1/EX1.11/exa1_11.sce
new file mode 100755
index 000000000..89a7faee8
--- /dev/null
+++ b/881/CH1/EX1.11/exa1_11.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 1.11
+//Page no 24
+
+//Solution
+
+R=100;
+
+T=17+273;
+
+N=([1.38*(10^-23)]*[T]*[1*(10^4)]);
+
+disp('W',N,"N = "); 
+
+disp("Substituting in equation 1-16 (refer pgno 23) give the noise power in dBm: ");
+
+N1=-174+[10*log10(10000)];
+
+disp('dBm',N1,"N = ");
+
+//(b)
+
+disp("(b)The rms noise voltage is found by substituting into equation 1-17 (refer pgno 23): ");
+
+V=sqrt(4*R*N);
+
+disp('V',V,"Vn = ");  
diff --git a/881/CH1/EX1.12/exa1_12.sce b/881/CH1/EX1.12/exa1_12.sce
new file mode 100755
index 000000000..412ec2e7e
--- /dev/null
+++ b/881/CH1/EX1.12/exa1_12.sce
@@ -0,0 +1,43 @@
+clc;
+//Example 1.12
+//Page no 25
+
+
+//Solution
+
+V1=8;
+V2=0.2;
+V3=0.1;
+
+//(a)
+
+
+h1=2*1;
+
+disp('kHz',h1,"2nd harmonic = ");
+
+h2=3*1;
+
+disp('kHz',h2,"3rd harmonic = ");
+
+h3=12*1;
+
+disp('kHz',h3,"12th harmonic = ");
+
+//(b)
+
+disp("(b) ")
+
+p1=(V2/V1)*100;
+
+disp('%',p1,"%2nd order = ");
+
+p2=(V3/V1)*100;
+
+disp('%',p2,"%3nd order = ");
+
+THD=([sqrt((0.2^2)+(0.1^2)) ]/8)*100;
+
+disp('%',THD," Total harmonic distortion = ");
+
+
diff --git a/881/CH1/EX1.13/exa1_13.sce b/881/CH1/EX1.13/exa1_13.sce
new file mode 100755
index 000000000..affd43f36
--- /dev/null
+++ b/881/CH1/EX1.13/exa1_13.sce
@@ -0,0 +1,6 @@
+clc;
+//Example 1.13
+//Page no 26
+
+//Theory
+ 
diff --git a/881/CH1/EX1.14/exa1_14.sce b/881/CH1/EX1.14/exa1_14.sce
new file mode 100755
index 000000000..bac9edc78
--- /dev/null
+++ b/881/CH1/EX1.14/exa1_14.sce
@@ -0,0 +1,30 @@
+clc;
+//Example 1.14
+//Page no 27
+
+
+//solution:
+
+//(a)
+disp("Given B=100MHZ, S/N= 30dB = 1000");
+
+
+
+B=(100*(10^6));
+Sn=1000;
+
+I=3.32*B*log10(Sn+1);
+
+disp('bps',I,"I = ");
+
+//(b)
+
+disp("(b)If the SNR is increased by 4 times, the new")
+
+SNR=Sn*4;
+
+disp(SNR,"SNR = ");
+
+i=3.32*B*log10(SNR+1);
+
+disp('bps',i,"Therefore, the new information carrying capactiy is ")
diff --git a/881/CH1/EX1.15/exa1_15.sce b/881/CH1/EX1.15/exa1_15.sce
new file mode 100755
index 000000000..b5562ecfa
--- /dev/null
+++ b/881/CH1/EX1.15/exa1_15.sce
@@ -0,0 +1,16 @@
+clc; 
+//Example 1.15
+//Page no 28
+
+
+//solution
+
+v1=4;
+
+v2=0.005;
+
+
+
+sn=20*log10(v1/v2);
+
+disp('dB',sn,"S/N = ");
diff --git a/881/CH1/EX1.16/exa1_16.sce b/881/CH1/EX1.16/exa1_16.sce
new file mode 100755
index 000000000..24351d77b
--- /dev/null
+++ b/881/CH1/EX1.16/exa1_16.sce
@@ -0,0 +1,66 @@
+clc;
+//Example 1.16
+//Page no 30
+
+
+disp("Given: For a non ideal amplifier and the following parameters ");
+disp("Input signal power = 2 x 10^-10 W");
+disp("Input noise power = 2 x 10^-18 W");
+disp("Power Gain = 1 x 10^6");
+disp("Internal noise = 6 x 10^-12 W");
+
+//Solution
+
+ip=2*(10^-10);
+
+in=2*(10^-18);
+
+G=1*(10^6);
+
+Nd= 6*(10^-12);
+
+//(a)
+
+
+sn=(ip/in);
+
+SN=10*log10(round(sn));
+
+disp('dB',round(SN),"S/N = ");
+
+//(b)
+
+disp("(b)The output noise power is the sum of the internal noise and the amplified input noise, therefore ");
+
+No=(G*in)+Nd;
+
+disp('W',No,"Nout = ");
+
+disp("The output power is simply the product of the input power and the power gain. ");
+
+Po=G*ip;
+
+disp('W',Po,"Pout = ");
+
+disp("For the output signal and noise power levels calculated and substituting in equation 1-22, the output S/N is ");
+
+sn1=(Po/No);
+
+SN1=10*log10(round(sn1));
+
+disp('dB',round(SN1),"S/N = ");
+
+//(C)
+
+disp("(c)The noise factor is found by substituting the result from step (a) and (b) into equation 1-25  ");
+
+F=([round(sn)]/[round(sn1)]);
+
+disp(F,"F = ");
+
+disp("and the noise figure is calculated from equation 1-26(refer pgno 25) ");
+
+NF=10*log10(round(F));
+
+disp('dB',round(NF),"NF = ");
+
diff --git a/881/CH1/EX1.17/exa1_17.sce b/881/CH1/EX1.17/exa1_17.sce
new file mode 100755
index 000000000..4d647e1f6
--- /dev/null
+++ b/881/CH1/EX1.17/exa1_17.sce
@@ -0,0 +1,19 @@
+clc;
+//Example 1.17
+//Page no 31
+
+
+
+//solution
+
+
+
+ft=2+((2-1)/10)+([2-1]/100);//Noise factor
+
+disp(ft,"Ft = ")
+
+disp("Thus, the total noise figure is");
+
+nft=10*log10(ft);
+
+disp('dB',nft,"NFt = ")
diff --git a/881/CH1/EX1.18/exa1_18.sce b/881/CH1/EX1.18/exa1_18.sce
new file mode 100755
index 000000000..3a738dffb
--- /dev/null
+++ b/881/CH1/EX1.18/exa1_18.sce
@@ -0,0 +1,36 @@
+clc;
+//Example 1.18
+//Page no 33
+
+//solution
+
+//(a)
+
+Te=75;
+
+T=290;
+
+
+
+f=1+(Te/T);//Noise factor
+
+disp(f,"F = ");
+
+nf=10*log10(f);
+
+disp('dB',round(nf),"NF = ");
+
+//(b)
+
+disp("(b)Noise factor is found by rearranging equation 1-26 ");
+
+F=10^0.6;
+
+disp(round(F),"F = ");
+
+disp("substituting into equation 1-31 gives, ")
+
+te=T*(round(F)-1);
+
+disp('K',round(te),"Te = ");
+
diff --git a/881/CH1/EX1.3/exa1_3.sce b/881/CH1/EX1.3/exa1_3.sce
new file mode 100755
index 000000000..fe7a43343
--- /dev/null
+++ b/881/CH1/EX1.3/exa1_3.sce
@@ -0,0 +1,23 @@
+clc;
+//Example 1.3
+//Page no 8
+
+//Solution
+
+//(a)
+
+dBm1=10*log10([500*(10^-3)]/[1*(10^-3)]);
+
+disp('dBm',dBm1,"(a) 500 mW in dbm = ");
+
+//(b)
+
+dBm2=10*log10([10*(10^-9)]/[1*(10^-3)]);
+
+disp('dBm',dBm2,"(b) 10 nW in dbm = ");
+
+//(c)
+
+dBm3=10*log10([100*(10^-6)]/[1*(10^-3)]);
+
+disp('dBm',dBm3,"(c) 100 uW in dbm = ");
diff --git a/881/CH1/EX1.4/exa1_4.sce b/881/CH1/EX1.4/exa1_4.sce
new file mode 100755
index 000000000..1c6c89326
--- /dev/null
+++ b/881/CH1/EX1.4/exa1_4.sce
@@ -0,0 +1,29 @@
+clc;

+//Example 1.4

+//Page no 8

+

+//Solution

+

+//(a)

+

+p1=(10^-2.7)*(10^-3);

+

+disp('W', p1,"-27dBm in absolute power is, ");

+

+//(b)

+

+p2=(10^1.3)*(10^-3);

+

+disp('W', p2,"13dBm in absolute power is, ");

+

+//(c)

+

+p3=(10^4)*(10^-3);

+

+disp('W', p3,"40dBm in absolute power is, ");

+

+//(d)

+

+p4=(10^-5.3)*(10^-3);

+

+disp('W', p4,"-53dBm in absolute power is, ");

diff --git a/881/CH1/EX1.5/exa1_5.sce b/881/CH1/EX1.5/exa1_5.sce
new file mode 100755
index 000000000..242f27182
--- /dev/null
+++ b/881/CH1/EX1.5/exa1_5.sce
@@ -0,0 +1,60 @@
+clc;
+//Example 1.5
+//Page no 9
+
+
+
+pin=0.1*(10^-3);
+ap1=100;
+ap2=40;
+ap3=0.25;
+
+//Solution
+
+//(a)
+
+disp("(a)The input power in dBm ");
+
+Pin=10*log10(pin/0.001);
+
+disp('dBm',Pin,"The input power in dBm is, ");
+
+//(b)
+
+disp("(b)The output power is simply the input power multiplied by the three power gains: ");
+
+Pout=(pin)*ap1*ap2*ap3;
+
+Pout1=10*log10(Pout/0.001);
+
+disp('dBm',Pout1,'W',Pout,"The output power in watts and dBm is,");
+
+//(c)
+
+disp("(c)The decibel value for the three gains are determined by substituting into equation 1-3 (Pgno 4)");
+
+Ap1=10*log10(ap1);
+
+disp('dB',Ap1,"Ap1 = ");
+
+Ap2=10*log10(ap2);
+
+disp('dB',Ap2,"Ap2 = ");
+
+Ap3=10*log10(ap3);
+
+disp('dB',Ap3,"Ap3 = ");
+
+//(d)
+
+disp("(d)The overall power gain in dB (Apr) can be determined by simply adding the individual dB power gains, ");
+
+Apr=Ap1+Ap2+Ap3;
+
+disp('dB',Apr,"Apr = ");
+
+disp("The output power in dBm is the input power in dBm plus the sum of the gains of the three stages: ");
+
+Pout2=Pin+Apr;
+
+disp('dBm',Pout2,"Pout = ");
diff --git a/881/CH1/EX1.6/exa1_6.sce b/881/CH1/EX1.6/exa1_6.sce
new file mode 100755
index 000000000..2bd3863ba
--- /dev/null
+++ b/881/CH1/EX1.6/exa1_6.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 1.6
+//Page no 10
+
+
+
+//Solution
+
+//(a)
+
+a=100*5
+
+disp(a,"(a)Overall gain of the system is the product of the individual gain, that is ");
+
+ap=10*log10(a);
+
+disp('dB',ap,"Thus, the overall gain in dB is,")
+
+//(b)
+
+b=[100*(10^-6)]*500;
+
+disp('W',b,"(b)Output power  = Input power to the system X Overall power gain, that is ")
+
+bp=10*log10(b/[1*(10^-3)]);
+
+disp('dBm', bp,"Therefore, Output power expressed in dB is, ");
diff --git a/881/CH1/EX1.7/exa1_7.sce b/881/CH1/EX1.7/exa1_7.sce
new file mode 100755
index 000000000..a8743455f
--- /dev/null
+++ b/881/CH1/EX1.7/exa1_7.sce
@@ -0,0 +1,8 @@
+clc;
+//Example 1.7
+//Page no 11
+//Solution
+
+a=21+2.5;
+
+disp('dBm',a,"The difference in the two power levels is 1 dB. Therefore, from table 1-5 , the combining term is 2.5 dB and the total power is, ");
diff --git a/881/CH1/EX1.8/exa1_8.sce b/881/CH1/EX1.8/exa1_8.sce
new file mode 100755
index 000000000..c0c2e8736
--- /dev/null
+++ b/881/CH1/EX1.8/exa1_8.sce
@@ -0,0 +1,38 @@
+clc;

+//Example 1.8

+//Page no 17

+

+//Solution

+

+//Refer to figure 1-5 on page no 17

+

+//(a)

+

+disp("(a)Medium Frequencies as per ITU-T range between 0.3MHz and 3MHz.");

+

+lm1=([3*(10^8)]/[0.3*(10^6)]);

+

+lm2=([3*(10^8)]/[3*(10^6)]);

+ 

+disp('m',lm2,'and','m',lm1,"Therefore, wavelengths range for MF are between ");

+

+//(b)

+

+disp("(b)Ultra High Frequencies as per ITU-T range between 300MHz and 3GHz.");

+

+lm3=([3*(10^8)]/[300*(10^6)]);

+

+lm4=([3*(10^8)]/[3*(10^9)]);

+

+disp('m',lm4,'and','m',lm3,"Therefore, wavelengths range for UHF are between ");

+

+//(c)

+

+disp("(c)Very High Frequencies as per ITU-T range between 30MHz and 300Mz.");

+

+lm5=([3*(10^8)]/[30*(10^6)]);

+

+lm6=([3*(10^8)]/[300*(10^6)]);

+ 

+disp('m',lm6,'and','m',lm5,"Therefore, wavelengths range for VHF are between ");

+

diff --git a/881/CH1/EX1.9/exa1_9.sce b/881/CH1/EX1.9/exa1_9.sce
new file mode 100755
index 000000000..315f304f7
--- /dev/null
+++ b/881/CH1/EX1.9/exa1_9.sce
@@ -0,0 +1,16 @@
+clc;
+//Example 1.9
+//Page no 20
+
+
+
+//Solution
+
+disp("The Shannon limit for capacity is determined by substituting into equation 1-12b");
+
+I=(3.32)*(2700)*log10(1+1000);
+
+disp('bps',I);
+
+
+
diff --git a/881/CH10/EX10.1/exa10_1.sce b/881/CH10/EX10.1/exa10_1.sce
new file mode 100755
index 000000000..0fba87c94
--- /dev/null
+++ b/881/CH10/EX10.1/exa10_1.sce
@@ -0,0 +1,31 @@
+clc;
+//Example 10.1
+//Page No 395
+
+
+
+//Solution
+
+i=10*10^-4;
+dt=10*10^-9;
+dv=10;
+
+disp("The expression for the current through a capacitor is ");
+
+disp("i = C dv/dt");
+
+disp("Rearranging and solving for c yields, "); 
+
+c=i*dt/dv;
+
+disp('F',c,"C = ");
+
+disp("t = RC","The charge time constant for C when Q1 in on is ");
+
+disp("Therefore, rearranging the above equation and substituting the value of chaging time yields");
+
+C=dt/(4.6*20);
+
+disp('F',C/100,"C = ");
+
+
diff --git a/881/CH10/EX10.3/exa10_3.sce b/881/CH10/EX10.3/exa10_3.sce
new file mode 100755
index 000000000..c301f6014
--- /dev/null
+++ b/881/CH10/EX10.3/exa10_3.sce
@@ -0,0 +1,21 @@
+clc;
+//Example 10.3
+//Page No 400
+
+disp("Given: For figure, Analog sample voltage of +1.07 V. ;");
+
+//solution
+
+
+
+a=1.07/1
+
+disp(round(a));
+
+disp("The quantization error is the difference between the original sample voltage and the quantized level, or");
+
+q=1.07-1;
+
+disp(q,"Qe = ");
+
+disp("From Table 10-2, the PCM code for 1 is 101");
diff --git a/881/CH10/EX10.4/exa10_4.sce b/881/CH10/EX10.4/exa10_4.sce
new file mode 100755
index 000000000..62bf76361
--- /dev/null
+++ b/881/CH10/EX10.4/exa10_4.sce
@@ -0,0 +1,48 @@
+clc;

+//Example 10.4

+//Page No 403

+

+disp("Given: For minimum line speed with an 8-bit PCM for speech signal ranging upto 1 V. ");

+

+//solution

+

+v=1;

+n=8;

+

+

+disp("Minimum line speed with an 8-bit PCM is 64Kbps.");

+

+//(a)

+

+r=v/(2^n-1);

+

+disp('V',r,"(a)Resolution = ");

+

+q=r;

+

+disp('V',q,"Therefore, Resolution = quantization, q=");

+

+qe=q/2;

+

+disp('V',qe,"Quantization error = ");

+

+//(b)

+

+disp("(b)Dynamic range DR for 0.001 V resolution ");

+

+dr=20*log10(v/0.01);

+

+disp('db',dr,"DR = ");

+

+disp("Minimum number of bits n required to achieve the dynamic range is given by ");

+

+N=((log(100+1))/(log(2)));

+

+disp(N,"n = ");

+

+c=(N/n)*100;

+

+disp('%',c,"Therefore, coding efficiency = ");

+

+

+

diff --git a/881/CH10/EX10.8/exa10_8.sce b/881/CH10/EX10.8/exa10_8.sce
new file mode 100755
index 000000000..f7cd02d3a
--- /dev/null
+++ b/881/CH10/EX10.8/exa10_8.sce
@@ -0,0 +1,32 @@
+clc;
+//Example 10.8
+//Page No 418
+
+//solution
+
+
+
+s=8;
+
+//(a)
+
+disp("(a)With the 7 bit PCM,");
+
+b=7;
+
+r=s*b;
+
+disp('kbps',r,"line speed = ");
+
+//(b)
+
+disp("(b)With the 8 bit PCM, ");
+
+b1=8;
+
+r1=s*b1;
+
+disp('kbps',r1,"line speed = ");
+
+
+
diff --git a/881/CH12/EX12.1/exa12_1.sce b/881/CH12/EX12.1/exa12_1.sce
new file mode 100755
index 000000000..f50148991
--- /dev/null
+++ b/881/CH12/EX12.1/exa12_1.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 12.1
+//Page No 505
+
+disp("Given: A D/r ratio of 12.22");
+
+//solution
+
+dr=12.22;
+
+disp("Susbstituting into equation 12-14(refer pgno 505), we obtain ");
+
+Z0=276*log10(dr);
+
+disp('Ohm',round(Z0),"Z0 = ");
diff --git a/881/CH12/EX12.2/exa12_2.sce b/881/CH12/EX12.2/exa12_2.sce
new file mode 100755
index 000000000..df7656fa7
--- /dev/null
+++ b/881/CH12/EX12.2/exa12_2.sce
@@ -0,0 +1,17 @@
+clc;
+//Example 12.2
+//Page No 506
+
+
+//Solution
+
+d=0.025;
+D=0.15;
+e=2.23;
+
+disp("Substituting into Equation 12-15(refer pgno506) give us, ");
+
+Z0=-((138/sqrt(e))*(log10(d/D)));
+
+disp('Ohms',Z0,"Z0 = ");
+
diff --git a/881/CH12/EX12.3/exa12_3.sce b/881/CH12/EX12.3/exa12_3.sce
new file mode 100755
index 000000000..0a89b256a
--- /dev/null
+++ b/881/CH12/EX12.3/exa12_3.sce
@@ -0,0 +1,16 @@
+clc;
+//Example 12.3
+//Page No 506
+
+disp("Given: An RG-59A coaxial cable, with L=0.118uH/ft and C=21pF/ft");
+
+//Solution
+
+L=0.118*10^-6;
+C=21*10^-12;
+
+disp("Substituting into Equation 12-15(refer pgno506) give us,"); 
+
+Z0=sqrt((L/C));
+
+disp('ohm',round(Z0),"Z0 = ");
diff --git a/881/CH12/EX12.4/exa12_4.sce b/881/CH12/EX12.4/exa12_4.sce
new file mode 100755
index 000000000..fbc688aac
--- /dev/null
+++ b/881/CH12/EX12.4/exa12_4.sce
@@ -0,0 +1,30 @@
+clc;
+//Example 12.4
+//Page No 509
+
+
+
+//solution
+
+C=96.6*10^-12;
+L=241.56*10^-9;
+ep=2.3;
+c=3*10^8;
+
+disp("From equation 12-16 ");
+
+Vp=(1/sqrt(C*L));
+
+disp('m/s',Vp,"Vp = ");
+
+disp("From equation 12-24 ");
+
+Vf=(Vp/c);
+
+disp(Vf,"Vf = ");
+
+disp("From equation 12-26 ");
+
+vf=(1/sqrt(e));
+
+disp(vf,"Vf = ");
diff --git a/881/CH12/EX12.5/exa12_5.sce b/881/CH12/EX12.5/exa12_5.sce
new file mode 100755
index 000000000..523493127
--- /dev/null
+++ b/881/CH12/EX12.5/exa12_5.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 12.5
+//Page No 514
+
+
+//solution
+
+Ei=5;
+Er=3;
+
+disp("Substituting into equation 12-33 yield");
+
+r=Er/Ei;
+
+disp(r,"r = ");
+
+disp("Substituting into equation 12-37 yield");
+
+swr=(Ei+Er)/(Ei-Er);
+
+disp(swr,"SWR = ");
+
+disp("Substituting into equation 12-45 yield");
+
+r1=(swr-1)/(swr+1);
+
+disp(r1,"r = ");
diff --git a/881/CH12/EX12.6/exa12_6.sce b/881/CH12/EX12.6/exa12_6.sce
new file mode 100755
index 000000000..8eb042ce3
--- /dev/null
+++ b/881/CH12/EX12.6/exa12_6.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 12.6
+//Page No 524
+
+
+//solution
+
+f=150*10^6;
+c=3*10^8;
+z0=50;
+zl=150;
+
+disp("The Physical length of the transformer depends on the wavelength of the signal. Substituting into equation 12-3 yields, ");
+
+l=(c/f);
+
+disp('m',l,'l = ');
+
+l=l/4;
+
+disp('m',l,'l = ');
+
+disp("The characteristic impedance of the 0.5m transformer is determined from the equation 12-47 ");
+
+Z0=sqrt(z0*zl);
+
+disp('Ohm',Z0,"Z0 = ")
diff --git a/881/CH12/EX12.7/exa12_7.sce b/881/CH12/EX12.7/exa12_7.sce
new file mode 100755
index 000000000..9ea2e9296
--- /dev/null
+++ b/881/CH12/EX12.7/exa12_7.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 12.7
+//Page No 526
+
+
+
+//Solution
+
+c=3*10^8;
+
+disp("Substituting into equation 12-48");
+
+d=((0.8)*c*(1*10^-6))/2;
+
+disp('m',d,'d = ');
diff --git a/881/CH12/EX12.8/exa12_8.sce b/881/CH12/EX12.8/exa12_8.sce
new file mode 100755
index 000000000..bb429a815
--- /dev/null
+++ b/881/CH12/EX12.8/exa12_8.sce
@@ -0,0 +1,17 @@
+clc;
+//Example 12.8
+//Page No 527
+
+
+
+//solution
+
+c=3*10^8;
+d=3000;
+k=0.9;
+
+disp("Rearranging Equation 12-48 ");
+
+t=((2*d)/(k*c));
+
+disp('s',t,"t = ")
diff --git a/881/CH13/EX13.1/exa13_1.sce b/881/CH13/EX13.1/exa13_1.sce
new file mode 100755
index 000000000..4ac2e7e2b
--- /dev/null
+++ b/881/CH13/EX13.1/exa13_1.sce
@@ -0,0 +1,29 @@
+clc;
+//Example 13.1
+//Page No 545
+
+
+
+//solution
+
+n1=1.5;
+n2=1.36;
+t1=30;
+
+disp("From Table, ")
+
+disp(n1,"n1(glass) = ");
+
+disp(n2,"n2(alcohol) = ");
+
+disp("Rearranging equation 13-9 and substituting, we get ");
+
+t=((n1/n2)*sin(%pi/6));
+
+disp(t,"t2 = ");
+
+t3=asin(t);
+
+t2=t3*(180/%pi);
+
+disp(t2,"t2 = ");
diff --git a/881/CH13/EX13.2/exa13_2.sce b/881/CH13/EX13.2/exa13_2.sce
new file mode 100755
index 000000000..0be8784cd
--- /dev/null
+++ b/881/CH13/EX13.2/exa13_2.sce
@@ -0,0 +1,20 @@
+clc;
+//Example 13.2
+//Page No 554
+
+
+
+//solution
+
+n1=1.485;
+a=50*10^-6; 
+N=320; 
+l=0.850*10^-6;
+
+disp("Number of modes in a step-index fibre, N is given by equation 13-13, ");
+
+r=(sqrt(320)*((l)/(%pi*2*a)));
+
+n2=n1-r;
+
+disp(n2,"n2 = ");
diff --git a/881/CH13/EX13.3/exa13_3.sce b/881/CH13/EX13.3/exa13_3.sce
new file mode 100755
index 000000000..3eca1eea4
--- /dev/null
+++ b/881/CH13/EX13.3/exa13_3.sce
@@ -0,0 +1,20 @@
+clc;
+//Example 13.3
+//Page No
+
+
+
+//solution
+
+al=0.25*100;
+Pt=1*10^-4;
+
+disp("Substituting in equation 13-15, ");
+
+p=Pt*(10^(al/10));
+
+disp('uW',p*10,"P = ");
+
+P=10*log10(p*10^-5/0.001);
+
+disp('uW',P,"P(dB) = ");
diff --git a/881/CH13/EX13.4/exa13_4.sce b/881/CH13/EX13.4/exa13_4.sce
new file mode 100755
index 000000000..95919a0d4
--- /dev/null
+++ b/881/CH13/EX13.4/exa13_4.sce
@@ -0,0 +1,26 @@
+clc;
+//Example 13.4
+//Page No 558
+
+
+//solution
+
+n1=1.48;
+n2=1.46;
+L=6000;
+
+d=((n1-n2)/n1);
+
+disp(d,"d = ");
+
+t=((d*L)/(3*10^8));
+
+T=0.03996;
+
+disp('ns',T,"Intermodal delay t = ");
+
+disp("Therefore, the maximum data rate Fmax is given by, ");
+
+F=(1/(2*T));
+
+disp('MHz',F,"Fmax = ");
diff --git a/881/CH13/EX13.5/exa13_5.sce b/881/CH13/EX13.5/exa13_5.sce
new file mode 100755
index 000000000..adb459985
--- /dev/null
+++ b/881/CH13/EX13.5/exa13_5.sce
@@ -0,0 +1,23 @@
+clc;
+//Example 13.5
+//Page No 561
+
+
+//solution
+
+L=10000;
+dt=5*10^-6;
+
+disp("Substituting into equation 13-18 yields ");
+
+fb=(1/(dt*L));
+
+disp('Mbps',fb,"fb = ");
+
+disp("Substituting into equation 13-19 yields ");
+
+Fb=(1/((2*dt)*L));
+
+disp('Mbps',Fb,"fb = ");
+
+
diff --git a/881/CH13/EX13.6/exa13_6.sce b/881/CH13/EX13.6/exa13_6.sce
new file mode 100755
index 000000000..9f5d35625
--- /dev/null
+++ b/881/CH13/EX13.6/exa13_6.sce
@@ -0,0 +1,45 @@
+clc;
+//Example 13.8
+//Page No 575
+
+
+
+//solution
+
+P=30*10^-3;
+cl=0.5;
+conl=2;
+ltc=1.9;
+ctd=2.1;
+
+
+
+disp("The LED output power is converted to dBm using equation 13-6");
+
+Po=10*log10(P/0.001);
+
+disp('dBm',Po,"Po = ");
+
+
+
+t=20*cl;
+
+disp('dB',t,"total cable loss = ");
+
+
+
+c=3*conl;
+
+disp('dB',c,"total connector loss = ");
+
+//light source to cable and cable to light detector losses
+
+tl=t+c+ltc+ctd;
+
+disp('dB',tl,"total loss = ");
+
+disp("The receive power is determined by substituting into equation 13-22 ");
+
+Pr=Po-tl;
+
+disp('dBm',Pr,"Pr = ");
diff --git a/881/CH14/EX14.1/exa14_1.sce b/881/CH14/EX14.1/exa14_1.sce
new file mode 100755
index 000000000..8383fc6f7
--- /dev/null
+++ b/881/CH14/EX14.1/exa14_1.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 14.1
+//Page No. 584
+
+
+
+//Solution
+
+Prad=100;
+r1=1000;
+r2=2000;
+
+//(a)
+
+disp("(a)Substituting into equation 14-7 yields, ");
+
+p1=((Prad)/(4*%pi*(r1^2)));
+
+disp('uW/m^2',p1*10^6,"P1 = ");
+
+//(b)
+
+disp("(b)Substituting into equation 14-7 yields, ");
+
+p2=((Prad)/(4*%pi*(r2^2)));
+
+disp('uW/m^2',p2*10^6,"P2 = ");
diff --git a/881/CH14/EX14.2/exa14_2.sce b/881/CH14/EX14.2/exa14_2.sce
new file mode 100755
index 000000000..2120722a6
--- /dev/null
+++ b/881/CH14/EX14.2/exa14_2.sce
@@ -0,0 +1,29 @@
+clc;
+//Example 14.2
+//Page No 597
+
+
+
+//Solution
+
+//(a)
+
+d=48.7;
+ht=40;
+
+disp("(a)As per equation 14-23, ");
+
+hr=(((d-sqrt(17*ht))^2)/17);
+
+hr=round(hr);
+
+disp('m',hr,"hr = ");
+
+//(b)
+
+Ht=2*ht;
+Hr=2*hr;
+
+D=((sqrt(17*Ht))+(sqrt(17*Hr)));
+
+disp('km',D,"(b)Dmax = ");
diff --git a/881/CH14/EX14.3/exa14_3.sce b/881/CH14/EX14.3/exa14_3.sce
new file mode 100755
index 000000000..4ae94f8bf
--- /dev/null
+++ b/881/CH14/EX14.3/exa14_3.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 14.3
+//Page No 603
+
+//Solution
+
+D=40;
+f=1.8;
+o=0.9999;
+
+disp("Substituting into equation 14-34, ");
+
+Fm=([30*log10(D)]+[10*log10([6*4*0.5*f])]-[10*log10(1-o)]-70);
+
+disp('dB',Fm,"Fm = ")
diff --git a/881/CH15/EX15.1/exa15_1.sce b/881/CH15/EX15.1/exa15_1.sce
new file mode 100755
index 000000000..3bc11889d
--- /dev/null
+++ b/881/CH15/EX15.1/exa15_1.sce
@@ -0,0 +1,64 @@
+clc;
+//Example 15.1
+//Page No 616
+
+
+
+//solution
+
+Rr=72;
+Re=8;
+D=20;
+Pin=100;
+
+//(a)
+
+disp("(a)Antenna efficiency is found by substituting into equation 15-3 ");
+
+n=(Rr/[Rr+Re])*100;
+
+disp('%',n,"n = ");
+
+//(b)
+
+disp("(b)Antenna gain ");
+
+A=(n/100)*(D);
+
+disp('and','dB',A,"A = ");
+
+A1=10*log10(A);
+
+disp('dB',A1,"A = ");
+
+//(c)
+
+disp("(c)Radiated power");
+
+Prad=(n/100)*Pin;
+
+disp('W',Prad,"Prad = ");
+
+prad=10*log10(Prad/0.001);
+
+disp('dBm',prad,"Prad(dBm) = ");
+
+pRad=10*log10(Prad);
+
+disp('dBW',pRad,"Prad(dBW) = ");
+
+//(c)
+
+disp("(d)EIRP is found by substituting into equations 15-7d,e and f");
+
+EIRP=Pin*A;
+
+disp('W',EIRP,"EIRP = ");
+
+EIRP1=10*log10(EIRP/0.001);
+
+disp('dBm',EIRP1,"EIRP(dBm) = ");
+
+EIRP2=10*log10(EIRP)
+
+disp('dBW',EIRP2,"EIRP(dBW) = ");
diff --git a/881/CH15/EX15.2/exa15_2.sce b/881/CH15/EX15.2/exa15_2.sce
new file mode 100755
index 000000000..e6af4a93e
--- /dev/null
+++ b/881/CH15/EX15.2/exa15_2.sce
@@ -0,0 +1,90 @@
+clc;
+//Example 15.2
+//Page No 616
+
+
+
+//solution
+
+Dt1=1;
+Dt2=10;
+n1=1;
+n2=0.5;
+At=5;
+Lp=50;
+Lf=3;
+Pout=40;
+
+//(a)
+
+disp("(a)The antenna input power in dBm is ")
+
+Pin=Pout-Lf;    
+
+disp('dBm',Pin,"Pin = ");
+
+disp("Radiated power in dBm is ");
+
+N1=10*log10(n1);
+
+Prad=Pin+N1;
+
+disp('dBm',Prad,"Prad = ");
+
+At1=Dt1*n1;
+
+EIRP1=Prad+(10*log10(At1));
+
+disp('dBm',EIRP1,"EIRP = ");
+
+P1=EIRP1-Lp;
+
+disp('dBm',P1,"P = ");
+
+//(b)
+
+disp("(b)The antenna input power in dBm is ")
+
+Pin=Pout-Lf;    
+
+disp('dBm',Pin,"Pin = ");
+
+disp("Radiated power in dBm is ");
+
+N2=10*log10(n2);
+
+Prad=Pin+N2;
+
+disp('dBm',round(Prad),"Prad = ");
+
+EIRP2=Prad+(10*log10(Dt2));
+
+disp('dBm',round(EIRP2),"EIRP = ");
+
+P2=EIRP2-Lp;
+
+disp('dBm',round(P2),"P = ");
+
+//(c)
+
+disp("(c)The antenna input power in dBm is ")
+
+Pin=Pout-Lf;    
+
+disp('dBm',Pin,"Pin = ");
+
+disp("Radiated power in dBm is ");
+
+N3=10*log10(n2);
+
+Prad=Pin+N3;
+
+disp('dBm',round(Prad),"Prad = ");
+
+EIRP3=Prad+(10*log10(At));
+
+disp('dBm',round(EIRP3),"EIRP = ");
+
+P3=EIRP3-Lp;
+
+disp('dBm',round(P3),"P = ");
diff --git a/881/CH15/EX15.3/exa15_3.sce b/881/CH15/EX15.3/exa15_3.sce
new file mode 100755
index 000000000..e1c9ba3cb
--- /dev/null
+++ b/881/CH15/EX15.3/exa15_3.sce
@@ -0,0 +1,19 @@
+clc;
+//Example 15.3
+//Page No620
+
+
+//solution
+
+P=10;
+Ac=0.2;
+
+disp("Substituting into equation 15-12 yields ");
+
+Pcap=P*Ac;
+
+disp('uW',Pcap,"Pcap = ");
+
+pcap=10*log10(Pcap*10^-6/0.001);
+
+disp('dBm',round(pcap),"Pcap(dBm)");
diff --git a/881/CH15/EX15.4/exa15_4.sce b/881/CH15/EX15.4/exa15_4.sce
new file mode 100755
index 000000000..a407efa8e
--- /dev/null
+++ b/881/CH15/EX15.4/exa15_4.sce
@@ -0,0 +1,39 @@
+clc;
+//Example 15.4
+//Page No 643
+
+
+//solution
+
+D=2;
+c=3*10^8;
+f=6;
+Pt=10;
+
+disp("(a)The beam width is found by substituting into equation 15-29 ");
+
+O=([70*c]/[(f*10^9)*D]);
+
+disp(O,"T = ");
+
+disp("(b)The transmit power gain is found by substituting into equation 15-31c, ");
+
+A=([20*log10(f*10^3)]+[20*log10(2)]-42.2);
+
+disp('dB',A,"Ap(dB) = ");
+
+disp("(c)The receive power gain is found by substituting into equation 15-33c, ");
+
+l=(c/(f*10^9));
+
+disp('m/cycle',l,"l = ");
+
+Ap=10*log10(5.4*[(D/l)^2]);
+
+disp('dB',Ap,"Ap(dB) = ");
+
+disp("(d)The EIRP is the product of the radiated power times the transmit antenna gain, ");
+
+EIRP=Ap+(10*log10(Pt/0.001));
+
+disp('dB',EIRP,"EIRP = ");
diff --git a/881/CH15/EX15.5/exa15_5.sce b/881/CH15/EX15.5/exa15_5.sce
new file mode 100755
index 000000000..546732b06
--- /dev/null
+++ b/881/CH15/EX15.5/exa15_5.sce
@@ -0,0 +1,37 @@
+clc;
+//Example 15.5
+//Page No 651
+
+
+
+//solution
+
+f=6;
+a=0.03;
+c=3*10^8;
+
+disp("(a)The cutoff frequency is determined by substituting into equation 15-41, ");
+
+fc=(c/(2*a));
+
+fc=fc/10^9;
+
+disp('GHz',fc,"fc = ");
+
+disp("(b)The cutoff wavelength is determined by substituting into equation 15-42, ");
+
+lc=2*(a);
+
+disp('m',lc,"lc = ")
+
+disp("(c)The phase velocity is found using equation 15-41, ");
+
+vph=(c/[sqrt(1-({fc/f}^2))]);
+
+disp('m/s',vph,"vph = ");
+
+disp("(d)The group velocity is found by rearranging equation 15-36, ");
+
+vg=([c^2]/vph);
+
+disp('m/s',vg,"vg = ");
diff --git a/881/CH15/EX15.6/exa15_6.sce b/881/CH15/EX15.6/exa15_6.sce
new file mode 100755
index 000000000..01d7c65f3
--- /dev/null
+++ b/881/CH15/EX15.6/exa15_6.sce
@@ -0,0 +1,25 @@
+clc;
+//Example 15.6
+//Page No 652
+
+
+//solution
+
+a=9;
+b=4.5;
+f=4; 
+c=3*10^10;
+
+disp("(a)Cutoff frequency, ");
+
+fc=(c/(2*a));
+
+fc=fc/10^9;
+
+disp('GHz',fc,"fc = ");
+
+disp("(b)Characteristic impedence, ");
+
+Zte=(377/[sqrt(1-({fc/f}^2))]);
+
+disp('ohm',Zte,"Zte = ");
diff --git a/881/CH17/EX17.1/exa17_1.sce b/881/CH17/EX17.1/exa17_1.sce
new file mode 100755
index 000000000..c781a77bc
--- /dev/null
+++ b/881/CH17/EX17.1/exa17_1.sce
@@ -0,0 +1,28 @@
+clc;
+//Example 17.1
+//Page No 690
+
+
+
+//solution
+
+p1=10*10^-3;
+p2=0.5*10^-3;
+
+disp("(a)The power levels, ");
+
+P1=10*log10(p1/0.001);
+
+disp('dBm',P1,"P = ");
+
+P2=10*log10(p2/0.001)
+
+disp('dBm',round(P2),"P = ");
+
+disp("(b)The difference  ");
+
+P=10*log10(p1/p2);
+
+disp('dBm',round(P),"diff = ");
+
+disp("The 10mW power level is 13dB higher than 0.5W power level. ");
diff --git a/881/CH19/EX19.1/exa19_1.sce b/881/CH19/EX19.1/exa19_1.sce
new file mode 100755
index 000000000..83c5ea76c
--- /dev/null
+++ b/881/CH19/EX19.1/exa19_1.sce
@@ -0,0 +1,17 @@
+clc;
+//Example 19.1
+//Page No 749
+
+//solution
+
+disp("The total number of full-duplex channels is, ");
+
+F=10*7
+
+disp("channel per cluster",F,"F = ");
+
+disp("The total channel capacity is,")
+
+C=10*7*10;
+
+disp("channel total",C,"C = ");
diff --git a/881/CH19/EX19.2/exa19_2.sce b/881/CH19/EX19.2/exa19_2.sce
new file mode 100755
index 000000000..fc4f6cf73
--- /dev/null
+++ b/881/CH19/EX19.2/exa19_2.sce
@@ -0,0 +1,53 @@
+clc;
+//Example 19.2
+//Page No 752
+
+
+//solution
+
+Asys=1520;
+Acell=4;
+n=1140;
+j=2;
+i=3;
+
+//(a)
+
+disp("(a)Number of cells in a cluster, N ");
+
+N=(i^2)+(i*j)+(j^2);
+
+disp(N,"N = ");
+
+//(b)
+
+disp("(b)Number of clusters in the systems = area of the system / area of each cluster");
+
+ac=N*Acell;
+
+N1=(Asys/ac);
+
+disp(N1,"Number of clusters = ");
+
+//(c)
+
+disp('Km^2',ac,"(c)Area of each celler cluster  = ");
+
+//(d)
+
+sc=N1*n;
+
+disp('channels',sc,"(d)System capacity with frequency reuse = number of cluster X number of channels without frequency reuse, i.e.");
+
+//(e)
+
+disp("(e)Number of channels allocated to each cell, ");
+
+c=(Asys/Acell);
+
+disp(c,"(i)without frequency reuse = ");
+
+C=(n/N);
+
+disp(C,"(ii)With frequency reuse = ");
+
diff --git a/881/CH19/EX19.3/exa19_3.sce b/881/CH19/EX19.3/exa19_3.sce
new file mode 100755
index 000000000..d05b628b2
--- /dev/null
+++ b/881/CH19/EX19.3/exa19_3.sce
@@ -0,0 +1,29 @@
+clc;
+//Example 19.3
+//Page No 755
+
+
+//solution
+
+//(a)
+
+c=10*7;
+
+disp('channel/area',c,"(a)Channel capacity = ");
+
+//(b)
+
+disp("(b)Splitting each macrocell");
+
+c1=10*28
+
+disp('channel/area',c1,"Channel capacity = ");
+
+//(c)
+
+disp("(c)Further splitting minicell into four microcells ");
+
+c2=10*112
+
+disp('channel/area',c2,"Channel capacity = ");
+
diff --git a/881/CH2/EX2.3/exa2_3.sce b/881/CH2/EX2.3/exa2_3.sce
new file mode 100755
index 000000000..31adf4f6e
--- /dev/null
+++ b/881/CH2/EX2.3/exa2_3.sce
@@ -0,0 +1,17 @@
+clc;
+//Example 2.3
+//Page no 50
+
+disp("For the pulse waveform shown in figure 2.12 (refer pgno 50)");
+
+//Solution
+
+//(a)
+
+disp("(a)From Equation 2-16 (refer pgno 49), the dc component is ");
+
+v=([1*{0.4*(10^-3)}/{2*(10^-3)}]);
+
+disp('V',v,"V0 = ");
+
+
diff --git a/881/CH20/EX20.1/exa20_1.sce b/881/CH20/EX20.1/exa20_1.sce
new file mode 100755
index 000000000..c090bc5a5
--- /dev/null
+++ b/881/CH20/EX20.1/exa20_1.sce
@@ -0,0 +1,32 @@
+clc;
+//Example 20.1
+//Page No 768
+
+//solution
+
+N1=3;
+N2=991;
+
+//(a)
+
+disp("(a)The transmit and receive carrier frequencies");
+
+ft=((0.03*N1)+825);
+
+disp('MHz',ft,"transmit ft = ");
+
+fr=ft+45;
+
+disp('MHz',fr,"receive fr = ");
+
+//(b)
+
+disp("(b)The transmit and receive carrier frequencies for channel 991 ");
+
+Ft=((0.03*(N2-1023))+825);
+
+disp('MHz',Ft,"transmit ft = ");
+
+Fr=Ft+45;
+
+disp('MHz',Fr,"receive fr = ");
diff --git a/881/CH20/EX20.2/exa20_2.sce b/881/CH20/EX20.2/exa20_2.sce
new file mode 100755
index 000000000..6483a92bf
--- /dev/null
+++ b/881/CH20/EX20.2/exa20_2.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 20.2
+//Page No 792
+
+
+
+//solution 
+
+Pr=-100;
+
+disp("Substituing into equation 20-4, ");
+
+Pt=-76-(Pr);
+
+disp('dBm',Pt,"Pt = ")
diff --git a/881/CH24/EX24.1/exa24_1.sce b/881/CH24/EX24.1/exa24_1.sce
new file mode 100755
index 000000000..3ae33f252
--- /dev/null
+++ b/881/CH24/EX24.1/exa24_1.sce
@@ -0,0 +1,21 @@
+clc;
+//Example 24.1
+//Page No 981
+
+
+
+//soution
+
+f=18*10^9;
+D=16*10^3;
+c=3*10^8
+
+disp("free space path loss based on inverse square law, which yields, ");
+
+lp=((4*%pi*D*f)/c)^2;
+
+disp(lp,"Lp = ");
+
+Lp=10*log10(lp);
+
+disp('db',Lp,"Lp(dB) = ");
diff --git a/881/CH24/EX24.2/exa24_2.sce b/881/CH24/EX24.2/exa24_2.sce
new file mode 100755
index 000000000..8c15152a6
--- /dev/null
+++ b/881/CH24/EX24.2/exa24_2.sce
@@ -0,0 +1,27 @@
+clc;

+//Example 24.2

+//Page No 988

+

+disp("Given: d1=18.6Km, d=14.4Km, Hn=H1=200meters, n=1");

+

+//solution

+

+d1=18.6; 

+d=14.4; 

+H1=0.2;

+n=1;

+c=3*10^8;

+

+disp("From equation 24-10, the height of the nth fresnel zone Hn is, ");

+

+l=(((H1^2)*d)/(n*d1*(d1-d)));

+

+l=l*10^3;

+

+disp('m',l,"l = ")

+

+f=(c/l);

+

+f=f/10^6;

+

+disp('MHz',f,"f = ");

diff --git a/881/CH24/EX24.3/exa24_3.sce b/881/CH24/EX24.3/exa24_3.sce
new file mode 100755
index 000000000..26691996f
--- /dev/null
+++ b/881/CH24/EX24.3/exa24_3.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 24.3
+//Page No 988
+
+disp("Given: Noise bandwidth is 10MHz");
+
+//solution
+
+f=10*10^6;
+
+disp("Substituting in equation 24-16 yields, ");
+
+N=-174+(10*log10(f));
+
+disp('dBm',N,"N = ");
+
+disp("If the minimum C/N requirement for a receiver ");
+
+Cmin=24+N;
+
+disp('dBm',Cmin,"N = ");
+
+disp("For a system gain of 113.35dB, it would require a minimum transmit carrier power(Pt) of ")
+
+Pt=113.35+Cmin;
+
+disp('dBm',Pt,"N = ");
diff --git a/881/CH24/EX24.4/exa24_4.sce b/881/CH24/EX24.4/exa24_4.sce
new file mode 100755
index 000000000..dbfaa4c17
--- /dev/null
+++ b/881/CH24/EX24.4/exa24_4.sce
@@ -0,0 +1,21 @@
+clc;

+//Example 24.4

+//Page No 990

+

+disp("Given: Refer to figure");

+

+//solution

+

+disp("To achieve a S/N ratio of 32dB out of the FM demodulator, an input C/N of 15dB is required. Solving the receiver input carrier to noise ratios give, ");

+

+Cmin=15+6.5

+

+disp('dB',Cmin,"Cmin/N = ");

+

+cmin=Cmin+(-104);

+

+disp('dBm',cmin,"Cmin = ");

+

+Pt=112+cmin;

+

+disp('dBm',Pt,"Pt = ");

diff --git a/881/CH24/EX24.5/exa24_5.sce b/881/CH24/EX24.5/exa24_5.sce
new file mode 100755
index 000000000..cf835511d
--- /dev/null
+++ b/881/CH24/EX24.5/exa24_5.sce
@@ -0,0 +1,42 @@
+clc;
+//Example 24.5
+//Page No 990
+
+disp("Given: The system is shown in figure.");
+
+//solution
+
+cn=23;
+NF=4.42;
+B=68;
+
+disp("The minimum C/N at the input to the FM receiver is 23dB, ");
+
+cmin=cn+NF;
+
+disp('dB',cmin,"CMin/N = ");
+
+disp("Substituting into equation 24-16 yields, ");
+
+N=-174+B;
+
+disp('dBm',N,"N = ");
+
+Cmin=cmin+N;
+
+disp('dBm',Cmin,"Cmin = ");
+
+disp("Substituting into equation 24-14 yields, ");
+
+Fm=((30*log10(50))+10*(log10(6*0.25*0.125*8))-(10*log10(1-0.99999))-70);
+
+disp('dB',Fm,"Fm = ");
+
+disp("Substituting into equation 24-8 yields, ");
+
+Lp=92.4+(20*log10(8))+(20*log10(50));
+
+disp('dB',Lp,"Lp = ");
+
+disp("          At=Ar= 37.8 dB","          Lf = 4.875","          Lb = 4 dB","From Table 24-3");
+    
diff --git a/881/CH25/EX25.2/exa25_2.sce b/881/CH25/EX25.2/exa25_2.sce
new file mode 100755
index 000000000..9e494a490
--- /dev/null
+++ b/881/CH25/EX25.2/exa25_2.sce
@@ -0,0 +1,32 @@
+clc;
+//Example 25.2
+//Page No 1018
+
+
+
+//solution
+
+Pt=1000;
+fb=50*10^6;
+
+Tb=(1/fb);
+
+disp('s',Tb*10^1,"Tb = ");
+
+Eb=Pt*Tb;
+
+disp('J',Eb,"Eb = ");
+
+disp("Expressed as a log with 1 Joule as the reference, ");
+
+eb=10*log10(Eb);
+
+disp('dBJ',eb,"Eb = ")
+
+disp("It is common to express Pt in dBW and Eb in dBW/bps. Thus, ");
+
+pt=10*log10(Pt);
+
+disp('dBW',pt,"Pt = ");
+
+disp('dBW/bps',round(eb),"Eb = ");
diff --git a/881/CH25/EX25.5/exa25_5.sce b/881/CH25/EX25.5/exa25_5.sce
new file mode 100755
index 000000000..3bfc318c6
--- /dev/null
+++ b/881/CH25/EX25.5/exa25_5.sce
@@ -0,0 +1,27 @@
+clc;
+//Example 25.5
+//Page No 1022
+
+
+
+//solution:
+
+B=10*10^6;
+N=276*10^-16;
+K=1.38*10^-23;
+
+disp("Substituting into equation 25-12, we have");
+
+N0=(N/B);
+
+disp('W/Hz',N0,"N0 = ");
+
+n0=10*log10(N0);
+
+disp('dBW/Hz',n0,"N0 = ");
+
+disp("Rearranging equation 25-12 and solving we get, ");
+
+Te=(N0/K);
+
+disp('K/cycle',Te,"Te = ");
diff --git a/881/CH3/EX3.1/exa3_1.sce b/881/CH3/EX3.1/exa3_1.sce
new file mode 100755
index 000000000..9fe7c11d6
--- /dev/null
+++ b/881/CH3/EX3.1/exa3_1.sce
@@ -0,0 +1,36 @@
+clc;
+//Example 3.1
+//Page no 75
+
+
+
+//Solution
+
+fn=10*(10^6);
+k=10;
+c1=10;
+c2=-5;
+
+//(a)
+
+disp("(a)Substituting into equation 3-6 and 3-7 (refer pgno 75) give us ");
+
+df=k*(10*c1);
+
+disp('Hz',round(df),"dF = ");
+
+fo=fn+(round(df));
+
+disp('MHz',fo/(10^6),"F0 = ");
+
+//(b)
+
+disp("(b)Again, substituting into equation 3-6 and 3-7 yields ");
+
+dF=k*(10*c2);
+
+disp('Hz',round(dF),"dF = ");
+
+f1=fn+(round(dF));
+
+disp('MHz',f1/(10^6),"F0 = ");
diff --git a/881/CH3/EX3.2/exa3_2.sce b/881/CH3/EX3.2/exa3_2.sce
new file mode 100755
index 000000000..4107a58ef
--- /dev/null
+++ b/881/CH3/EX3.2/exa3_2.sce
@@ -0,0 +1,55 @@
+clc;
+//Example 3.2
+//Page no 96
+
+
+//Solution
+
+fn=200*(10^3);
+fi=210*(10^3);
+Kd=0.2;
+Kf=1;
+Ka=5;
+Ko=20;
+
+//(a)
+
+disp("(a)From equation 3-20 and 3-21 (refer pgno 95), we get ");
+
+Kl=Kd*Kf*Ka*Ko;
+
+disp('kHz/rad',Kl,"Kl = ");
+
+Kv=2*(%pi)*(Kl*(10^3));
+
+disp('rad/s',Kv,"Kv = ");
+
+KV=20*log10(Kv);
+
+disp('dB',round(KV),"Kv(dB) = ");
+
+//(b)
+
+dF=fi-fn;
+
+disp('kHz',(dF/(10^3)),"(b)dF = ");
+
+//(c)
+
+disp("(c)Rearranging equation 3-15 (refer pgno 89) gives us ");
+
+Vo=((dF/(10^3))/Ko);
+
+disp('V',Vo,"Vout = ");
+
+Vd=(Vo/(Kf*Ka));
+
+disp('V',Vd,"Vd = ");
+
+//(d)
+
+disp("(d)Rearranging equation 3-18 (refer pgno 94) gives us ");
+
+the=(Vd/Kd);
+
+disp('rad',the,"THe = ");
diff --git a/881/CH4/EX4.1/exa4_1.sce b/881/CH4/EX4.1/exa4_1.sce
new file mode 100755
index 000000000..cb497c803
--- /dev/null
+++ b/881/CH4/EX4.1/exa4_1.sce
@@ -0,0 +1,51 @@
+clc;
+//Example 4.1
+//Page no 118
+
+disp("Given: For and AM DSBFC modulator with a carrier frequency Fc=100kHz and a maximum modulating signal frequency of Fm(max)=5kHz.");
+
+//solution
+
+Fc=100*(10^3);
+Fm=5*(10^3);
+fm=3*(10^3);
+
+//(a)
+
+disp("(a)The lower sideband extends from the lowest possible lower side frequency to the carrier frequency or ");
+
+lsb=(Fc-Fm); 
+
+disp("kHz",(Fc/(10^3)),"kHz to",(lsb/(10^3)),"LSB = ");
+
+disp("The upper sideband extends from the carrier frequency to the highest possible upper side frequency is ");
+
+usb=(Fc+Fm);
+
+disp("kHz",(usb/(10^3)),"kHz to",(Fc/(10^3)),"USB = ");
+
+//(b)
+
+disp("(b)The bandwidth is equal to the difference between the maximum upper side frequency and the minimum lower side frequency. ");
+
+b=2*Fm;
+
+disp("kHz",(b/(10^3)),"B = ");
+
+//(c)
+
+disp("(c)The upper side frequency is the sum of the carrier and modulating frequency.");
+
+Fu=Fc+fm;
+
+disp("kHz",(Fu/(10^3)),"Fusf = ");
+
+disp("The lower side frequency is the difference between the carrier and modulating frequency.");
+
+Fl=Fc-fm;
+
+disp("kHz",(Fl/(10^3)),"Flsf = ");
+
+//(d)
+
+disp("(d)The output frequency spectrum is shown in figure.");
diff --git a/881/CH4/EX4.2/exa4_2.sce b/881/CH4/EX4.2/exa4_2.sce
new file mode 100755
index 000000000..95093144a
--- /dev/null
+++ b/881/CH4/EX4.2/exa4_2.sce
@@ -0,0 +1,48 @@
+clc;
+//Example 4.2
+//Page no 123
+
+
+//solution
+
+Fc=500; //kHz
+Fm=10; //kHz
+Ec=20;
+Em=7.5;
+
+disp("(a)The upper and lower side frequencies are simply the sum and difference frequencies, respectively ");
+
+fu=Fc+Fm;
+fl=Fc-Fm;
+
+disp('kHz',fl,'kHz and Flsf = ',fu,"Fusf = ");
+
+//(b)
+
+disp("(b)The modulation coefficient is determined from equation 4-1 (refer pgno 120)");
+
+m=Em/Ec;
+
+disp(m,"m = ");
+
+disp("Percent modulation is determine from equation 4-2 (refer pgno 120)");
+
+M=100*m;
+
+disp('%',M,"M = ");
+//(c)
+
+disp("(c)The peak amplitude of the modulated carrier and the upper and lower side frequencies is ");
+
+eu=((m*Ec)/2);
+
+disp('Vp',eu,"Eusf(modulated) = ");
+
+//(d)
+
+disp("(d)The maximum and minimum amplitude of the envelope are, ");
+
+Vm=Ec+Em;
+vm=Ec-Em;
+
+disp('Vp',vm,'Vp and Vmin = ',Vm,"Vmax = ");
diff --git a/881/CH4/EX4.3/exa4_3.sce b/881/CH4/EX4.3/exa4_3.sce
new file mode 100755
index 000000000..1351260d4
--- /dev/null
+++ b/881/CH4/EX4.3/exa4_3.sce
@@ -0,0 +1,32 @@
+clc;
+//Example 4.3
+//Page no 128
+//solution
+
+Fc=1; //MHz
+Fm=5; //kHz
+M=60; //%
+m=(M/100); 
+Pc=6; //KW
+
+
+//(a)
+
+disp("(a)Total average power delivered to the load ");
+
+Rl=(Pc*[1+m^2/2]);
+
+disp('KW',Rl,"Rl = ");
+
+//(b)
+
+disp("(b)The modulation signal power ");
+
+Vs=sqrt(100*(10^3)*Rl);
+ 
+disp('KV',(Vs/(10^3)),"Vs(RMS) = ");
+
+a=Vs*sqrt(2);
+
+disp('KV',(a/(10^3)),"Therefore, peak value of modulation signal =")
+
diff --git a/881/CH4/EX4.4/exa4_4.sce b/881/CH4/EX4.4/exa4_4.sce
new file mode 100755
index 000000000..fd67501b3
--- /dev/null
+++ b/881/CH4/EX4.4/exa4_4.sce
@@ -0,0 +1,64 @@
+clc;
+//Example 4.4
+//Page no 128
+
+Vc=10; //Vp
+m=1;
+Rl=10;
+m1=0.5;
+
+//(a)
+
+disp("(a)The carrier power is found by substituting into equation 4-18 (pgno 126): ");
+
+Pc=((Rl^2)/(2*Rl));
+
+disp('W',Pc,"Pc = ");
+
+disp("The upper and lower sideband power is found by substituting into equation 4-21 (pgno 127):");
+
+P=(((m^2)*Pc)/4);
+
+disp('W',P,"Pusb = Plsb = ");
+
+//(b)
+
+disp("(b)The total sideband power is ");
+
+Ps=(((m^2)*Pc)/2);
+
+disp('W',Ps,"Psbt = ");
+
+//(c)
+
+disp("(c)The total power in the modulated is found by substituting into equation 4-25 (pgno 127)");
+
+Pt=(5*[1+(m^2)/2]);
+
+disp('W',Pt,"Pt = ");
+
+//(d)
+
+disp("(d)The carrier power is found by substituting into equation 4-18 ");
+
+Pc1=Pc;
+
+disp('W',Pc1,"Pc ");
+
+disp("The upper and lower sideband power is found by substituting into equation 4-21 (pgno 127):");
+
+P1=(((m1^2)*Pc)/4);
+
+disp('W',P1,"Pusb = Plsb = ");
+
+disp("The total sideband power is ");
+
+Ps1=(((m1^2)*Pc)/2);
+
+disp('W',Ps1,"Psbt = ");
+
+disp("The total power in the modulated is found by substituting into equation 4-25 (pgno 127)");
+
+Pt1=(5*[1+(m1^2)/2]);
+
+disp('W',Pt1,"Pt = ");
diff --git a/881/CH4/EX4.5/exa4_5.sce b/881/CH4/EX4.5/exa4_5.sce
new file mode 100755
index 000000000..51d54d67d
--- /dev/null
+++ b/881/CH4/EX4.5/exa4_5.sce
@@ -0,0 +1,37 @@
+clc;
+//Example 4.5
+//Page no 131
+
+//Solution
+
+Rl=100; //ohm
+Fc=1;  //MHz
+Fm1=2; //kHz
+Fm2=3; //kHz
+Fm3=5; //kHz
+Ec=100; //V
+Em1=10; //V
+Em2=20; //V
+Em3=30; //V
+
+m1=(Em1/Ec);
+
+disp(m1,"m1 = ");
+
+m2=(Em2/Ec);
+
+disp(m2,"m1 = ");
+
+m3=(Em3/Ec);
+
+disp(m3,"m1 = ");
+
+m=sqrt((m1^2)+(m2^2)+(m3^2));
+
+disp(m,"Overall modulation index m = ");
+
+disp("Power in both the upper and lower sideband is same, which is given by ");
+
+Psb=((Ec^2*m^2)/(2*Rl*4));
+
+disp('W',Psb,"Psb = ");
diff --git a/881/CH4/EX4.6/exa4_6.sce b/881/CH4/EX4.6/exa4_6.sce
new file mode 100755
index 000000000..369cecb2c
--- /dev/null
+++ b/881/CH4/EX4.6/exa4_6.sce
@@ -0,0 +1,31 @@
+clc;
+//Example 4.6
+//Page no 133
+//Solution
+
+m=0.8;
+Aq=100;
+Fc=500; //kHz
+Vc=5*(10^-3); //mV
+Fm=1000; //Hz
+
+//(a)
+
+disp("(a)Substituting into equation 4-34(pgno 132), ");
+
+Am=Aq*(1+m);
+
+disp(Am," Amax = ");
+
+am=Aq*(1-m);
+
+disp(am,"Amin = ");
+
+//(b)
+
+Vom=Am*Vc;
+
+vom=am*Vc;
+
+disp('V',Vom,"(b)Vout(max) =  ");
+disp('V',vom,"Vout(min) =  ");
diff --git a/881/CH4/EX4.7/exa4_7.sce b/881/CH4/EX4.7/exa4_7.sce
new file mode 100755
index 000000000..032db4f7e
--- /dev/null
+++ b/881/CH4/EX4.7/exa4_7.sce
@@ -0,0 +1,34 @@
+clc;
+//Example 4.7
+//Page no 140
+//solution
+
+//(a)
+
+V=12; //dc
+Vm=2; //Vp
+Fm=4; //kHz
+Vb=4; //dc
+R1=100*(10^3); //kohm
+C1=0.001*(10^-6); //uF
+
+//(a)
+
+disp("(a)The carrier frequency is determine from equation 4-36(refer pgno 137): ");
+
+fc=(1/(R1*C1));
+Fc=fc/(10^2)
+
+disp('kHz',Fc,"fc =  ");
+
+//(b)
+
+disp("(b)The upper and lower side frequency are simply the sum and difference frequencies between the carrier and the modulating signal. ");
+
+fu=Fc+Fm;
+
+disp('kHz',fu,"Fusf =  ");
+
+fl=Fc-Fm;
+
+disp('kHz',fl,"Flsf =  ");
diff --git a/881/CH5/EX5.1/exa5_1.sce b/881/CH5/EX5.1/exa5_1.sce
new file mode 100755
index 000000000..38653f182
--- /dev/null
+++ b/881/CH5/EX5.1/exa5_1.sce
@@ -0,0 +1,19 @@
+clc;
+//Example 5.1
+//Page no 159
+
+//solution
+
+Brf=200; //kHz
+Bif=10; //kHz
+
+//Bandwidth improvement is found by substituting into equati
+BI=(Brf/Bif);
+
+disp(BI,"BI = ");
+
+disp("and noise figure improvement is found by substituting into equation 5-3 (refer pgno 157)");
+
+NF=10*log10(BI);
+
+disp('dB',NF,"NF = ")
diff --git a/881/CH5/EX5.2/exa5_2.sce b/881/CH5/EX5.2/exa5_2.sce
new file mode 100755
index 000000000..686931184
--- /dev/null
+++ b/881/CH5/EX5.2/exa5_2.sce
@@ -0,0 +1,21 @@
+clc;
+//Example 5.2
+//Page no 161
+
+
+
+//solution
+
+Q=54;
+
+disp("The bandwidth at the low frequency end ");
+
+B=(540/Q);
+
+disp('kHz',B,"B = ")
+
+disp("The bandwidth at the high frequency end  ");
+
+B1=(1600*(10^3)/Q);
+
+disp('Hz',round(B1),"B = ")
diff --git a/881/CH5/EX5.3/exa5_3.sce b/881/CH5/EX5.3/exa5_3.sce
new file mode 100755
index 000000000..659ec4980
--- /dev/null
+++ b/881/CH5/EX5.3/exa5_3.sce
@@ -0,0 +1,29 @@
+clc;
+//Example 5.3
+//Page no 165
+
+
+
+//solution
+
+fio=1355; //kHz
+fRF=900; //kHz
+fRFu=895; //kHz
+fRFl=905; //kHz
+
+
+
+fIF=fio-fRF;
+
+disp('kHz',fIF,"fIF = ");
+
+disp("The upper and lower intermediate are");
+
+fIFu=fio-fRFu;
+
+disp('kHz',fIFu,"fIF = ");
+
+fIFl=fio-fRFl;
+
+disp('kHz',fIFl,"fIF = ");
+
diff --git a/881/CH5/EX5.5/exa5_5.sce b/881/CH5/EX5.5/exa5_5.sce
new file mode 100755
index 000000000..aa581c475
--- /dev/null
+++ b/881/CH5/EX5.5/exa5_5.sce
@@ -0,0 +1,36 @@
+clc;
+//Example 5.5
+//Page no 172
+
+
+
+
+//solution
+
+Fl=1255; //kHz
+Fif=455; //kHz
+FRF=800; //kHz
+Q=120;
+
+//(a)
+
+Fim=Fl+Fif;
+
+disp('kHz',Fim,"(a)Image Frequency Fim = ");
+
+
+//(b)
+
+p=((Fim/FRF)-(FRF/Fim));
+
+IFRR=sqrt(1+(Q^2)*(p^2));
+
+disp(IFRR,"(b)IFRR = ");
+
+//(c)
+
+IFRR1=5.6;
+
+IFRRt=IFRR*IFRR1;
+
+disp(IFRRt,"(c)Combined IFRR of both the circuits = ");
diff --git a/881/CH5/EX5.6/exa5_6.sce b/881/CH5/EX5.6/exa5_6.sce
new file mode 100755
index 000000000..a46743b16
--- /dev/null
+++ b/881/CH5/EX5.6/exa5_6.sce
@@ -0,0 +1,54 @@
+clc;
+//Example 5.6
+//Page no 172
+
+
+//Solution
+
+FRF=27000; //MHz
+Fif=455; //kHz
+Q=100;
+
+//(a)
+
+disp("(a)From equation 5-7(refer pgno 165)");
+
+flo=FRF+Fif;
+
+Flo=(flo/(10^3));
+
+disp('MHz',Flo,"Flo = ");
+
+//(b)
+
+disp("(b)From equation 5-9 (refer pgno 171) ");
+
+fim=flo+Fif;
+
+Fim=(fim/(10^3));
+
+disp('MHz',Fim,"Flo = ");
+
+//(c)
+
+disp("(c)From equation 5-11 (refer pgno 171)");
+
+p=((fim/FRF)-(FRF/fim));
+
+IFRR=sqrt(1+(Q^2)*(p^2));
+
+disp(IFRR,"IFRR = ");
+
+//(d)
+
+fr=600
+
+fim1=fr+2*Fif;
+
+p1=((fim1/fr)-(fr/fim1));
+
+disp("(d)Rearranging equation 5-11 ");
+
+q=sqrt(((IFRR^2)-1)/(p1^2));
+
+disp(q,"Q = ");
diff --git a/881/CH5/EX5.7/exa5_7.sce b/881/CH5/EX5.7/exa5_7.sce
new file mode 100755
index 000000000..e0055af48
--- /dev/null
+++ b/881/CH5/EX5.7/exa5_7.sce
@@ -0,0 +1,65 @@
+clc;
+//Example 5.7
+//Page no 184
+
+
+//solution
+
+Fs=100; //MHz
+Fif=10.7; //MHz
+Q=100; 
+Q1=40;
+Q2=50;
+
+
+//(a)
+
+disp("(a)");
+
+flo=Fif+Fs;
+
+Fim=Fs+2*Fif;
+
+disp('MHz',Fim,"Fimage = ");
+
+p=((Fim/Fs)-(Fs/Fim));
+
+disp(p,"p = ");
+
+IFRR=sqrt(1+(Q^2)*(p^2));
+
+disp(IFRR,"IFRR = ");
+
+//(b)
+
+disp("(b)");
+
+ifrr=20*log10(IFRR);
+
+disp('dB',ifrr,"IFRR in dB = ");
+
+//(c)
+
+disp("(c)");
+
+fif=(455/(10^3));
+
+fim=Fs+2*fif;
+
+disp('MHZ',fim,"Fimage = ");
+
+p1=((fim/Fs)-(Fs/fim));
+
+disp(p1,"p = ");
+
+IFRR1=sqrt(1+(Q^2)*(p1^2));
+
+disp(IFRR1,"IFRR = ");
+
+//(d)
+
+disp("(d)Critical coupling factor of the primary and secondary circuit if IF transformer,");
+
+kc=(sqrt(Q1*Q2))^-1;
+
+disp(kc,"Kc = ");
diff --git a/881/CH5/EX5.8/exa5_8.sce b/881/CH5/EX5.8/exa5_8.sce
new file mode 100755
index 000000000..6c3d0e954
--- /dev/null
+++ b/881/CH5/EX5.8/exa5_8.sce
@@ -0,0 +1,33 @@
+clc;
+//Example 5.8
+//Page no 198
+
+
+
+
+//solution
+
+A=-80; //dB
+G1=33; //dB
+G2=47; //dB
+G3=25; //dB
+
+G=G1+G2+G3;
+
+disp('dB',G,"The sum of the gains is, ");
+
+L1=3; //dB
+L2=6; //dB
+L3=8; //dB
+
+L=L1+L2+L3;
+
+disp('dB',L,"The sum of the losses is, ");
+
+G4=G-L;
+
+disp('dB',G4,"Thus, net receiver gains is, ");
+
+B=A+G4;
+
+disp('dBm',B,"and the audio signal level is, ");
diff --git a/881/CH6/EX6.1/exa6_1.sce b/881/CH6/EX6.1/exa6_1.sce
new file mode 100755
index 000000000..ed3b1c387
--- /dev/null
+++ b/881/CH6/EX6.1/exa6_1.sce
@@ -0,0 +1,15 @@
+clc;

+//Example 6.1

+//Page no 224

+

+//solution

+

+f=1000; //kHz

+s=80;

+df=200; //khz

+

+disp("Substituting into Equation 6-3 (refer pgno 223)");

+

+Q=125000;

+

+disp(Q,"Q = ");

diff --git a/881/CH6/EX6.2/exa6_2.sce b/881/CH6/EX6.2/exa6_2.sce
new file mode 100755
index 000000000..ed4968794
--- /dev/null
+++ b/881/CH6/EX6.2/exa6_2.sce
@@ -0,0 +1,51 @@
+clc;
+//Example 6.2
+//Page no 230 
+
+
+//solution
+
+f0=30; //MHz
+f1=30.005 //MHz
+flo=20; //MHz
+fbfo=10; //MHz
+d=(0.001/100); //%
+
+//(a)
+
+
+disp("(a)The IF output from the RF mixer difference between the received signal frequency and the RF local oscillator frequency,");
+
+fu=f0-flo;
+fl=f1-flo;
+
+disp('MHz',fl,"MHz to",fu,"Fif = ");
+
+
+fm1=fu-fbfo;
+fm2=fl-fbfo;
+
+disp('kHz',(fm2*(10^3)),"kHz to",fm1,"fm = ");
+
+//(b)
+
+disp("(b)A 0.001% drift would cause a decrease in the RF local oscillator frequency of ");
+
+df=d*flo;
+
+disp('Hz',(df*(10^6)),"df = ");
+
+
+fl=(flo-df);
+fi=f0-fl;
+ff=f1-fl;
+
+disp('MHz',ff,"MHz to",fi,"Fif = ");
+
+
+fm3=fi-fbfo;
+fm4=ff-fbfo;
+
+disp('Hz',(fm4*(10^6)),"Hz to",(fm3*(10^6)),"fm = ");
+
+
diff --git a/881/CH6/EX6.3/exa6_3.sce b/881/CH6/EX6.3/exa6_3.sce
new file mode 100755
index 000000000..d72b5b7a8
--- /dev/null
+++ b/881/CH6/EX6.3/exa6_3.sce
@@ -0,0 +1,41 @@
+clc;
+//Example 6.3
+//Page no 231
+
+
+
+//Solution
+
+fbfo=10; //MHz
+
+//(a)
+
+disp("(a)The solution is identical to that provieded in example 6-2 ");
+
+Fi=30-20; //MHz
+Ff=30.005-20; //MHz
+
+disp('MHz',Ff,"MHz to",Fi,"Fif = ");
+
+disp("The demodulated information signal spectrum is simply the difference between the intermediate frequency band and the BFO frequency");
+
+fm1=Fi-fbfo;
+fm2=Ff-fbfo;
+
+disp('kHz',(fm2*(10^3)),"kHz to",fm1,"fm = ");
+
+//(b)
+
+disp("(b) ");
+
+FI=30.0006-20.0004; //MHz
+FF=30.0056-20.0004; //MHZ
+
+disp('MHz',FF,"MHz to",FI,"Fif = ");
+
+disp("The BFO frequency will also automatically adjust proportionally to 10.0002MHz, producing a demodulated information signal of ");
+
+Fm=FI-10.0002; //MHz
+Fm1=FF-10.0002; //MHz
+
+disp('kHz',(Fm1*(10^3)),"kHz to",Fm,"fm = ");
diff --git a/881/CH6/EX6.4/exa6_4.sce b/881/CH6/EX6.4/exa6_4.sce
new file mode 100755
index 000000000..15740d3cb
--- /dev/null
+++ b/881/CH6/EX6.4/exa6_4.sce
@@ -0,0 +1,36 @@
+clc;
+//Example 6.4
+//Page no 238
+
+
+
+//solution
+
+Frf=100; //kHz
+fs1=1.5; //kHz
+fs2=3; //kHz
+R=50; //Ohm
+E=5; //V
+
+//(a)
+
+disp("(a)The output frequency specctrum contains the two upper side frequencies: ");
+
+Fusf1=Frf+fs1;
+Fusf2=Frf+fs2;
+
+disp('kHz',Fusf2,"Fusf2 = ",'kHz',Fusf1,"Fusf1 = ");
+
+//(b)
+
+disp("(b)Substituting in equation 6-6 yields, ");
+
+PEP=([2*(0.707*E)^2]/R);
+
+disp('W',PEP,"PEP = ")
+
+disp("Substituting into equation 6-8 yields, ");
+
+Pavg=(PEP/2);
+
+disp('W',Pavg,"Pavg = ");
diff --git a/881/CH7/EX7.1/exa7_1.sce b/881/CH7/EX7.1/exa7_1.sce
new file mode 100755
index 000000000..01053aa14
--- /dev/null
+++ b/881/CH7/EX7.1/exa7_1.sce
@@ -0,0 +1,33 @@
+clc;
+//Example 7.1
+//Page No 253
+
+
+//Solution
+
+//(a)
+
+K1=5; //kHz/V
+Ap=2; //V
+k1=2.5; //rad/V
+fm=2; //kHz
+
+disp("(a)The peak frequency deviation is simply the product of the deviation sensitivity and the peak amplitude of the modulation signal, ");
+
+df=K1*Ap;
+
+disp('kHz',df,"df = ");
+
+disp("The modulation index is determined by substituting into equation 7-22(r)");
+
+m=df/fm;
+
+disp(m,"m = ");
+
+//(b)
+
+disp("The peak phase shift for a phase-modulation wave is the modulation index and is found by substituting into equation 7-15(refer pgno 250)");
+
+m1=k1*Ap;
+
+disp('rad',m1,"m = ");
diff --git a/881/CH7/EX7.11/exa7_11.sce b/881/CH7/EX7.11/exa7_11.sce
new file mode 100755
index 000000000..601fdc5c1
--- /dev/null
+++ b/881/CH7/EX7.11/exa7_11.sce
@@ -0,0 +1,35 @@
+clc;
+//Example 7.11
+//Page No 283
+
+
+//solution
+
+N=20;
+ft=88.8;
+dF=75;
+fm=15;
+
+//(a)
+
+fc=ft/N;
+
+disp('MHz',fc,"(a)fc = ");
+
+//(b)
+
+df=dF/20;
+
+disp('Hz',(df*10^3),"(b)df = ");
+
+//(c)
+
+dr=df/fm;
+
+disp(dr,"(d)DR = ");
+
+//(d)
+
+DR=dr*N;
+
+disp(DR,"(b)DR = ");
diff --git a/881/CH7/EX7.2/exa7_2.sce b/881/CH7/EX7.2/exa7_2.sce
new file mode 100755
index 000000000..42d675ae5
--- /dev/null
+++ b/881/CH7/EX7.2/exa7_2.sce
@@ -0,0 +1,23 @@
+clc;
+//Example 7.2
+//Page No 253
+
+
+//Solution
+
+wc=(6.28*10^6);
+wm=(6.283*10^3);
+
+disp("   Vpm(t)=A sin(wct + mp sin wmt) ","The mathematical expression for a phase-modulated wave is given as, ");
+
+fc=wc/(2*%pi);
+
+disp('MHz',round(fc/10^6),"(a)Carrier Frequency               fc = ");
+
+fm=wm/(2*%pi);
+
+disp('kHz',round(fm/10^3),"(b)Modulating Frequency             fm = ");
+        
+disp(10,"(c)Modulating index             mp = ");
+
+disp('rad',10,"(d)Peak phase deviation             d0 = ");
diff --git a/881/CH7/EX7.3/exa7_3.sce b/881/CH7/EX7.3/exa7_3.sce
new file mode 100755
index 000000000..9d3a1c8d0
--- /dev/null
+++ b/881/CH7/EX7.3/exa7_3.sce
@@ -0,0 +1,25 @@
+clc;
+//Example 7.3
+//Page No 257
+
+disp("Given: An FM modulator with a modulation index m=1, a modulating signal v,(t)=Vmsin(2pi1000t) and an unmodulated carrier vc(t)=10sin(2pi500kt).");
+
+//Solution
+
+//(a)
+
+disp("(a)From Table 7.3, a modulation index of 1 yields a reduced carrier component and three sets of significant side frequencies. ");
+
+//(b)
+
+disp("(b)The relative amplitudes of the carrier and side frequencies are, ");
+
+disp("                      J0= 0.77x(10) = 7.7 V");
+
+disp("                      J1= 0.44x(10) = 4.4 V");
+
+disp("                      J2= 0.11x(10) = 1.1 V");
+
+disp("                      J3= 0.02x(10) = 0.2 V");
+
+disp("(c)The frequency spectrum is shown in figure 7-6.");
diff --git a/881/CH7/EX7.4/exa7_4.sce b/881/CH7/EX7.4/exa7_4.sce
new file mode 100755
index 000000000..4f354e532
--- /dev/null
+++ b/881/CH7/EX7.4/exa7_4.sce
@@ -0,0 +1,49 @@
+clc;
+//Example 7.4
+//Page No 259
+
+disp("Given:  An FM modulator with a peak frequency deviation df=10kHz, a modulating signal frequency fm=10kHz, Vc=10V and a 500kHz carrier. ");
+
+//Solution
+
+df=10;
+
+fm=10;
+
+n=3;
+
+//(a)
+
+disp("(a)Substituting into equation 7-22(refer pgno 251) ");
+
+m=df/fm;
+
+disp(m,"m = ");
+
+disp("From Table 7.3")
+
+B=2*(n*fm);
+
+disp('kHz',B,"B = ");
+
+//(b)
+
+disp("(b)Substittuting into equation 7-34(refer pgno 259), the bandwidth is  ");
+
+b=2*(df+fm);
+
+disp('kHz',b,"B = ");
+
+//(c)
+
+disp("(c)The relative amplitudes of the carrier and side frequencies are, ");
+
+disp("                      J0= 0.77x(10) = 7.7 V");
+
+disp("                      J1= 0.44x(10) = 4.4 V");
+
+disp("                      J2= 0.11x(10) = 1.1 V");
+
+disp("                      J3= 0.02x(10) = 0.2 V");
+
+disp("The output frequency spectrum for the Bessel approximation is shown in figure 7-7.");
diff --git a/881/CH7/EX7.5/exa7_5.sce b/881/CH7/EX7.5/exa7_5.sce
new file mode 100755
index 000000000..4c0dadf82
--- /dev/null
+++ b/881/CH7/EX7.5/exa7_5.sce
@@ -0,0 +1,39 @@
+clc;
+//Example 7.5
+//Page No 260
+
+
+
+//Solution
+
+df=75; 
+
+fm=15;
+
+//(a)
+
+disp("(a)The deviation ratio is found by substituting into equation 7-35(refer pgno), ");
+
+DR=df/fm;
+
+disp(DR,"DR = ");
+
+disp("From Table 7.3);
+
+B=2*(8*fm);
+
+disp('kHz',B,"B = ");
+
+//(b)
+
+disp("(b)For an 37.5kHz frequency deviation and modulating signal frequency fm=7.5, the modulation index is, ");
+
+m=37.5/7.5;
+
+disp(m,"m = ");
+
+disp("and the bandwidth is, ");
+
+b=2*(8*7.5);
+
+disp('kHz',b,"B = ");
diff --git a/881/CH7/EX7.6/exa7_6.sce b/881/CH7/EX7.6/exa7_6.sce
new file mode 100755
index 000000000..5071fd8ad
--- /dev/null
+++ b/881/CH7/EX7.6/exa7_6.sce
@@ -0,0 +1,70 @@
+clc;
+//Example 7.6
+//Page No 261
+
+
+
+//solution
+
+K=0.75;
+fcp=500;
+K1=1.5;
+fcf=500;
+vm=2;
+fm=2;
+Vm=4;
+Fm=1;
+
+//(a)
+
+disp("(a) FM Modulator ");
+
+m=(vm*K1)/fm;
+
+disp(m,"m = ");
+
+disp("PM Modulator ");
+
+m1=vm*K;
+
+disp(m1,"m = ");
+
+disp("Since the modulation indexes are same the output spectrum is also the same, which is in figure 7-8(a) ");
+
+//(b)
+
+disp("(b) FM Modulator ");
+
+M=(Vm*K1)/fm;
+
+disp(M,"m = ");
+
+disp("PM Modulator ");
+
+M1=Vm*K;
+
+disp(M1,"m = ");
+
+disp("Again, since the modulation indexes are same the output spectrum is also the same, which is in figure 7-8(b) ");
+
+//(c)
+
+disp("(a) FM Modulator ");
+
+m2=(vm*K1)/Fm;
+
+disp(m2,"m = ");
+
+disp("PM Modulator ");
+
+m3=vm*K;
+
+disp(m3,"m = ");
+
+disp("Since the modulation indexes are not same the output spectrum are given in figures 7-8(c) and 7-8(d), respectively");
+
+
+
+
+
+
diff --git a/881/CH7/EX7.7/exa7_7.sce b/881/CH7/EX7.7/exa7_7.sce
new file mode 100755
index 000000000..135466b9c
--- /dev/null
+++ b/881/CH7/EX7.7/exa7_7.sce
@@ -0,0 +1,30 @@
+clc;

+//Example 7.7

+//Page No 265

+

+disp("Given: Conditions as per example 7-3 and assume a load resistance Rl=50");

+

+//solution

+

+Rl=50;

+Vc=10;

+vc=7.7;

+V1= 4.4;

+V2= 1.1;

+V3= 0.2;

+

+//(a)

+

+disp("(a)Substituting into equation 7-36 yields, ");

+

+Pc=(Vc^2)/(2*Rl);

+

+disp('W',Pc,"Pc = ")

+

+//(b)

+

+disp("(b)Substituting into equation 7-41 yields, ");

+

+Pt=((vc^2)/(2*Rl)+(V1^2)*2/(2*Rl)+(V2^2)*2/(2*Rl)+(V3^2)*2/(2*Rl));

+

+disp('W',Pt,"Pt = ");

diff --git a/881/CH7/EX7.8/exa7_8.sce b/881/CH7/EX7.8/exa7_8.sce
new file mode 100755
index 000000000..c0b896382
--- /dev/null
+++ b/881/CH7/EX7.8/exa7_8.sce
@@ -0,0 +1,51 @@
+clc;
+//Example 7.8
+//Page No 268
+
+
+
+//solution
+
+fc=110;
+fn=109.985;
+Vn=0.3;
+Vc=6;
+fd=75*(10^3);
+
+//(a)
+
+disp("(a)The frequency of the noise interference is the difference between the carrier frequency and the frequency of the single frequency interfering signal, ");
+
+n=fc-fn;
+
+disp('kHz',(n*10^3),"NI = ");
+
+//(b)
+
+disp("(b)substituting into equation 7-43 yields, ");
+
+t=Vn/Vc;
+
+disp('rad',t,"dt = ");
+
+disp("substituting into equation 7-47 yields, ");
+
+df=(Vn*n)/Vc;
+
+disp('Hz',(df*10^6),"df = ");
+
+//(c)
+
+a=Vc/Vn;
+
+disp(a,"(c)The voltage S/N ");
+
+disp("The voltage S/N ratio after demodulation is found by substituting into equation 7-49");
+
+sn=fd/(df*10^6);
+
+disp(sn,"S/N = ");
+
+ip=20*log10(100/20);
+;
+disp('dB',round(ip),"Thus, there is an signal to noise improvement of ")
diff --git a/881/CH8/EX8.1/exa8_1.sce b/881/CH8/EX8.1/exa8_1.sce
new file mode 100755
index 000000000..9ecef108f
--- /dev/null
+++ b/881/CH8/EX8.1/exa8_1.sce
@@ -0,0 +1,15 @@
+clc;
+//Example 8.1
+//Page no 298
+
+
+//Solution
+
+Kd=0.2; //V/kHz
+df=20; //kHz
+
+disp("Substituting into equation 8-2, the peak output voltage is ")
+
+Vo=Kd*df;
+
+disp('Vp',Vo,"vout(t) = ")
diff --git a/881/CH8/EX8.2/exa8_2.sce b/881/CH8/EX8.2/exa8_2.sce
new file mode 100755
index 000000000..b67ab8d07
--- /dev/null
+++ b/881/CH8/EX8.2/exa8_2.sce
@@ -0,0 +1,34 @@
+clc;
+//Example 8.2   
+//Page no 309
+
+
+
+//Solution
+
+B=200*(10^3); //kHz
+NF=8; //dB
+T=100; //K
+m=1; 
+
+a=37-17; //dB
+
+disp('dB',a," the prediction signal to noise ratio must be atleast, ");
+
+b=20+8; //dB
+
+disp('dB',b,"Therefore, for an overall receiver noise figure equal to 8dB, the S/N ratio at the input to the receiver must be atleast, ");
+
+disp("The receiver input noise power is, ");
+
+K=(1.38*(10^-23));
+
+N=10*log10((K*T*B)/0.001);
+
+disp('dBm',N,"N(dB) = ");
+
+disp("Consequently, the minimum receiver signal power for a 28dB S/N ratio is, ");
+
+S=N+28;
+
+disp('dBm',S,"S = ");
diff --git a/881/CH8/EX8.3/exa8_3.sce b/881/CH8/EX8.3/exa8_3.sce
new file mode 100755
index 000000000..dd56446df
--- /dev/null
+++ b/881/CH8/EX8.3/exa8_3.sce
@@ -0,0 +1,24 @@
+clc;
+//Example 8.3
+//Page No 309
+
+
+
+//Solution
+
+SN=29; //dB
+NF=4; //dB
+FMi=16; //dB
+
+disp("The predetection signal to noise ratio is ");
+
+pre=SN-NF;
+
+disp('dB',pre,"S/N(pre) = ");
+
+disp("The postdetection signal to noise ratio is ");
+
+pst=pre+FMi;
+
+disp('dB',pst,"S/N(post) = ");
+
diff --git a/881/CH8/EX8.4/exa8_4.sce b/881/CH8/EX8.4/exa8_4.sce
new file mode 100755
index 000000000..961c391b3
--- /dev/null
+++ b/881/CH8/EX8.4/exa8_4.sce
@@ -0,0 +1,20 @@
+clc;
+//Example 8.4
+//Page no 310
+
+
+
+//solution
+
+SN=38; //dB
+In=-112; //dBm
+FMi=17; //dB
+NF=5; //dB
+
+sn=SN-FMi+NF;
+
+disp('dB',sn,"The receiver input S/N is ");
+
+rs=In+sn;
+
+disp('dBm',rs,"Therefore, the minimum receive signal level is ");
diff --git a/881/CH9/EX9.15/exa9_15.sce b/881/CH9/EX9.15/exa9_15.sce
new file mode 100755
index 000000000..680b472fc
--- /dev/null
+++ b/881/CH9/EX9.15/exa9_15.sce
@@ -0,0 +1,22 @@
+clc;
+//Example 9.15
+//Page No 382
+
+
+//solution
+
+ebn0=14.7;
+cn=11.7;
+fb=10;
+
+disp("From Figure 9-48,");
+
+bfb=ebn0-cn;
+
+Bfb=exp(log10(bfb));
+
+disp('dB',round(Bfb),"B/fb = ");
+
+B=2*fb;
+
+disp('MHz',B,'B = ');
diff --git a/881/CH9/EX9.2/exa9_2.sce b/881/CH9/EX9.2/exa9_2.sce
new file mode 100755
index 000000000..2ad563761
--- /dev/null
+++ b/881/CH9/EX9.2/exa9_2.sce
@@ -0,0 +1,35 @@
+clc;
+//Example 9.2
+//Page no 339
+
+//solution
+
+fm=49;
+fs=51;
+fb=2; //nyquist rate
+
+
+//(a)
+disp("(a)The peak frequency deviation is determine from equation 9-14(refer pgno 338)");
+
+df=(fs-fm)/2;
+
+disp('kHz',df,"df = ");
+
+//(b)
+
+disp("(b)The minimum bandwidth is determined from equation 9-15(refer pgno 339)");
+
+B=2*(df+fb);
+
+disp('kHz',B,"B = ");
+
+//(c)
+
+disp("(c)For FSK, N=1 and the baud rate is determined from equation 9-11 as ");
+
+n=1;
+
+baud=fb*10^3/n;
+
+disp(baud,"baud = ");
diff --git a/881/CH9/EX9.3/exa9_3.sce b/881/CH9/EX9.3/exa9_3.sce
new file mode 100755
index 000000000..ffb0cdea8
--- /dev/null
+++ b/881/CH9/EX9.3/exa9_3.sce
@@ -0,0 +1,24 @@
+clc;
+//Example 9.3
+//Page no 340
+
+
+
+//solution
+
+fm=49;
+fs=51;
+fb=2;
+
+disp("The modulation index is determine from equation 9-17(refer pgno 340)");
+
+h=(fs-fm)/2;
+
+disp(h,"h = ");
+
+disp("From Bessel table, the bandwidth can be determine as follows, ");
+
+b=2*(3*h);
+
+disp('hz',b*10^3,"B = ");
+