1. Experiment 1
Aim:To generate periodic and aperiodic discrete time signalsin MATLAB and perform basic operations: folding,
shifting, addition multiplication and scaling.
act:1(a) original signal
4
Activity 1.
3.5
x (n) = 2- (n/3) -5 ≤ n ≤-1 3
2.5
2 0≤n≤4
amplitude
2
(i) Sketch 100 samples of x (n) (ii) fold x(n) and then delay by five
1.5
samples (iii) Delay x (n) by five samples and then fold (iv)
Sketch -2x (-n - 4) 1
0.5
Program
0 act 1(b) folded and shifted
-5 -4 -3 -2 -1 0 1 2 3 4
clc; 4
time
3.5
clearall;
3
closeall; 2.5
amplitude
n1=linspace(-5,-1,50); 2
n2=linspace(0,4,50);
1.5
x1=2-(n1/3);
x2=2-(n2*0); 1
n=[n1,n2]; 0.5
x3=[x1,x2];
figure('name','activity 1(a) original signal') 0
1 2 3 4 5 6 7 8 9 10
stem(n,x3,'color','green'); time
xlabel('time') 4
act 1(c) shift and fold
ylabel('amplitude')
3.5
title('act:1(a) original signal')
%% activity 1(b) 3
[x4,n4]=sigfold(x3,n); 2.5
[x5,n5]=sigshift(x4,n4,5);
amplitude
figure('name','activity 1(b)') 2
stem(n5,x5); 1.5
xlabel('time')
1
ylabel('amplitude')
title('act 1(b) folded and shifted') 0.5
%%activity 1 .(c) 0
[x6,n6]=sigshift(x3,n,5); -9
0
-8 -7 -6 -5 act:1(d)
time
-4 -3 -2 -1 0
[x7,n7]=sigfold(x6,n6);
figure('name','activity 1 (c) shift and fold') -1
stem(n7,x7); -2
xlabel('time','color','red')
-3
ylabel('amplitude','color','red')
amplitude
title('act 1(c) shift and fold') -4
%% act 1(d) -5
[x8,n8]=sigfold(x3,n);
[x9,n9]=sigshift(x8,n8,4); -6
y=-(2*x9) -7
figure('name','act 1(d)')
stem(n9,y,'color','black') -8
0 1 2 3 4 5 6 7 8 9
time
xlabel('time','color','black')
ylabel('amplitude','color','black')
title('act:1(d)')
Saurabh Raj (101098)

2. Activity 2.
x (n) = 2n+ sin (0.2πn) -15 ≤ n ≤ 15
(i) Plot x (n) u (2-n) (ii) Plot x (n-2) [-2δ (n -4) -5δ (n -5) +3δ (n -6)] (iii) Plot even part of x (n)
(iv)Plot odd part of x (n) plot of x(n) plot of x(n) plot of x(n)
30 1 0
1) 0.9
n=-15:15; 20 -5
0.8
x=2*n+sin(0.2*pi*n);
[n1,x1]=unitstep(0,-15,15); 0.7
10 -10
[x2,n2]=sigfold(x1,n1);
0.6
[x3,n3]=sigshift(x2,n2,2);
amplitude
amplitude
amplitude
y=x.*x3; 0 0.5 -15
subplot(1,3,1),stem(n,x)
0.4
title('plot of x(n)')
-10 -20
xlabel('time') 0.3
ylabel('amplitude')
0.2
subplot(1,3,2),stem(n3,x3,'color','green') -20 -25
title('plot of x(n)') 0.1
xlabel('time')
ylabel('amplitude') -30
-20 0 20
0
-20 0 20
-30
-20 0 20
subplot(1,3,3),stem(n3,y,'color','green') time time time
title('plot of x(n)')
xlabel('time')
ylabel('amplitude')
plot of impulse signal plot of shifted x(n) plot of y(n)
2) 3 30 0
[na,ya]=impulse(4,-15,15)
-5
[nb,yb]=impulse(5,-15,15) 2
[nc,yc]=impulse(-6,-15,15) 20
-10
n6=na+nb+nc 1
y=(-2*ya)+(-5*yb)+(3*yc) -15
10
0
n=-15:15 -20
amplitude
amplitude
x=2*n+sin(0.2*pi*n) amplitude
[x1,n1]=sigshift(x,n,2); -1 0 -25
y1=y.*x1;
-30
subplot(1,3,1),stem(n6,y) -2
xlabel('time') -10
-35
ylabel('amplitude') -3
title('plot of impulse signal') -40
subplot(1,3,2),stem(n1,x1) -20
-4
xlabel('time') -45
ylabel('amplitude')
title('plot of shifted x(n)') -5 -30 -50
-50 0 50 -20 0 20 -20 0 20
subplot(1,3,3),stem(n1,y1) time time time
xlabel('time')
ylabel('amplitude')
title('plot of y(n)')
Saurabh Raj (101098)

3. (iii)
n=-15:15;
x=2*n+sin(0.2*pi*n); plot of x(n) plot of folded x(n) plot of x(n)+x(-n) plot of even part of x(n)
30 30 1 1
[x1,n1]=sigfold(x,n);
[x2,n2]=sigadd(x1,n1,x,n); 0.8 0.8
y=x2/2;
20 20
subplot(1,4,1),stem(n,x) 0.6 0.6
title('plot of x(n)')
xlabel('time') 10 10
0.4 0.4
ylabel('amplitude')
0.2 0.2
subplot(1,4,2),stem(n1,x1)
amplitude
amplitude
amplitude
amplitude
title('plot of folded x(n)') 0 0 0 0
xlabel('time')
ylabel('amplitude') -0.2 -0.2
subplot(1,4,3),stem(n2,x2) -10 -10
-0.4 -0.4
title('plot of x(n)+x(-n)')
xlabel('time') -0.6 -0.6
ylabel('amplitude') -20 -20
subplot(1,4,4),stem(n2,y) -0.8 -0.8
title('plot of even part of x(n)')
xlabel('time') -30
-20 0 20
-30
-20 0 20
-1
-20 0 20
-1
-20 0 20
ylabel('amplitude') time time time time
plot of x(n) plot of folded x(n) plot of x(n)+x(-n) plot of even part of x(n)
(iv) 30 30 60 30
n=-15:15;
x=2*n+sin(0.2*pi*n); 20 20 40 20
[x1,n1]=sigfold(x,n);
[x2,n2]=sigadd(-1*x1,n1,x,n);
y=x2/2;
10 10 20 10
subplot(1,4,1),stem(n,x)
title('plot of x(n)')
amplitude
amplitude
amplitude
amplitude
xlabel('time')
ylabel('amplitude') 0 0 0 0
subplot(1,4,2),stem(n1,x1)
title('plot of folded x(n)')
xlabel('time') -10 -10 -20 -10
ylabel('amplitude')
subplot(1,4,3),stem(n2,x2)
title('plot of x(n)+x(-n)') -20 -20 -40 -20
xlabel('time')
ylabel('amplitude')
subplot(1,4,4),stem(n2,y)
title('plot of even part of x(n)') -30 -30 -60 -30
-20 0 20 -20 0 20 -20 0 20 -20 0 20
xlabel('time') time time time time
ylabel('amplitude')
Saurabh Raj (101098)

4. Activity 3.
x (n) = [2 -3 4 -1 5 3 0 -2 6]
↑
(i)Plot x (n) (ii)Plotx (-n)(iii)Ploteven part ofx (n)(iv)Plotodd part ofx (n)
clc
clearall
closeall
n=-4:4;
x=[2 -3 4 -1 5 3 0 -2 6]
subplot(2,2,1),stem(n,x,'color','red');
xlabel('n--->','color','red')
ylabel('amplitude','color','red')
title('activity 3a','color','red')
[x1,n1]=sigfold(x,n);
subplot(2,2,2),stem(n1,x1,'color','green');
xlabel('n-->','color','green')
ylabel('amplitude','color','green')
title('activity 3b','color','green')
[x2,n2]=sigadd(x,n,x1,n1);
y1=x2/2;
subplot(2,2,3),stem(n2,y1,'color','red');
xlabel('n->','color','red')
ylabel('amplitude','color','red')
title('even part of x[n]','color','red')
x3=-x1;
[x4,n4]=sigadd(x,n,x3,n1);
y2=x4/2;
subplot(2,2,4),stem(n4,y2);
xlabel(' ...n...')
ylabel('---x[n]--->')
title('odd part of x[n]')
activity 3a activity 3b
10 10
5 5
amplitude
amplitude
0 0
-5 -5
-4 -2 0 2 4 -4 -2 0 2 4
n---> n-->
even part of x[n] odd part of x[n]
5 2
1
amplitude
---x[n]--->
0 0
-1
-5 -2
-4 -2 0 2 4 -4 -2 0 2 4
n-> ...n...
Saurabh Raj (101098)