EC 6120 and EC 5102 DSP MATLAB PROGRAMS DAY 2

GENERATION OF UNIT STEP SEQUENCE

clear all; clc; close all

%generate unit step sequence for N=20.

N=20;

xn=[ones(1,N) zeros(1,N)];

n=0:1:N*2-1;

subplot(2,1,1),stem(n,xn);

subplot(2,1,2),plot(n,xn);

xlabel('n');

ylabel('xn');

title('Unit Step Sequence');

GENERATION OF EXPONENTIALLY INCREASING AND DECREASING SIGNALS

clear all; clc; close all

% Plot an exponential sequence (0.7)^n

N=30;

n=0:N-1;

e=exp(j*pi);

a=0.7*e;

xn=a.^n;

subplot(2,2,1),stem(n,xn);

subplot(2,2,2),plot(n,xn);

xlabel('n');

ylabel('xn');

title('Exponential Decreasing Sequence');

a=-0.7*e;

xn=a.^n;

xn=a.^n;

subplot(2,2,3),stem(n,xn);

subplot(2,2,4),plot(n,xn);

xlabel('n');

ylabel('xn');

title('Exponential Decreasing Sequence');

figure

a=1.7*e;

xn=a.^n;

xn=a.^n;

subplot(2,2,1),stem(n,xn);

subplot(2,2,2),plot(n,xn);

xlabel('n');

ylabel('xn');

title('Exponential Increasing Sequence');

a=-1.7*e;

xn=a.^n;

xn=a.^n;

subplot(2,2,3),stem(n,xn);

subplot(2,2,4),plot(n,xn);

xlabel('n');

ylabel('xn');

title('Exponential Increasing Sequence');

GENERATION OF COSINE AND SINE WAVES OF 100HZ WITH 2KHZ SAMPLING

clear all; clc; close all

% Plot an sinusoidal sequence

fs=2000;%Sampling freq of 2KHz

n=0:1/fs:1;

xn=cos(2*pi*100*n);

subplot(2,2,1),stem(n(1:50),xn(1:50));

subplot(2,2,2),plot(n(1:50),xn(1:50));

xlabel('n');

ylabel('xn');

title('Sinusoidal Sequence');

xn=sin(2*pi*100*n);

subplot(2,2,3),stem(n(1:50),xn(1:50));

subplot(2,2,4),plot(n(1:50),xn(1:50));

xlabel('n');

ylabel('xn');

title('Sinusoidal Sequence');

PLOTTING OF TRAINGULAR, SAWTOOTH AND SQUARE WAVES WITHOUT USING MATLAB IN BULIT COMMANDS TO GET ACCUSTOMED TO PLOT FEATURES AND FOR LOOP TECHNIQUES

clear all; clc; close all

%TRAINGUALAR WAVE PLOT

y=0:0.5:2;

for j=0:3

x=(4*j)+y;

plot(x,y)

hold on

end

for k=0:3;

x=(4*k)-y

plot(x,y)

hold on

end

hold off

%SAWTOOTH WAVE PLOT

figure

y=0:.5:2

for j=0:8

a=(2*j)+y

plot(a,y,'b')

hold on

end

x=2:2:18

for k=0:.01:2;

b=k;

plot(x,b,'b')

hold on

end

hold off

%SQUARE WAVE PLOT

figure

y=0:.001:2;

for j=0:2:12;

x=y;

plot(j,x,'r');

hold on;

end

for k=0:4:12;

x=k+y;

m=2;

plot(x,m,'r')

hold on

end

for k=2:4:12;

x=k+y;

m=0;

plot(x,m,'r');

hold on;

end

hold off

axis([0 12 -0.5 2.5])

GENERATION OF DIFFERENT SINOSOIDAL SIGNALS TO SHOW ALISING EFFECT IN DSP

clear all; clc; close all

% Plot an sinusoidal sequence and compare aliasing

fs=2000;%Sampling freq of 2KHz can work for frequencies upto 1KHz only

n=0:1/fs:1;

f1=100; % f1=100Hz

f2=300; % f2=300Hz

xn1=cos(2*pi*f1*n);

xn2=cos(2*pi*f2*n);

xn=xn1+xn2;

subplot(2,2,1),stem(n(1:50),xn(1:50));

subplot(2,2,2),plot(n(1:50),xn(1:50),'b', n(1:50),xn1(1:50),'g', n(1:50),xn2(1:50),'r');

xlabel('n');

ylabel('xn');

title('Sinusoidal Sequence');

f1a=2000-100; % f2=1900Hz

f2a=2000-300; % f2=1700Hz

xn1a=cos(2*pi*f1a*n);

xn2a=cos(2*pi*f2a*n);

xna=xn1a+xn2a;

subplot(2,2,3),stem(n(1:50),xna(1:50));

subplot(2,2,4),plot(n(1:50),xna(1:50),'b', n(1:50),xn1a(1:50),'g', n(1:50),xn2a(1:50),'r');

xlabel('n');

ylabel('xn');

title('Sinusoidal Sequence');

figure

fre1=300; % fre1=300Hz

a1=cos(2*pi*fre1*n);

fre2=2000-300; % fre2=1700Hz

a2=cos(2*pi*fre2*n);

fre3=2000+300; % fre1=2300Hz

a3=cos(2*pi*fre3*n);

subplot(3,1,1),stem(n(1:50),a1(1:50));

subplot(3,1,2),stem(n(1:50),a2(1:50));

subplot(3,1,3),stem(n(1:50),a3(1:50));