1. program for unit step,impulse response, sine,cos,

for unit step

clc;clear all;n=5;t=-n:1:n;x=[zeros(1,n),1,ones(1,n)];stem(t,x);xlabel('t');ylabel('magnitude');title('unit step signal');

for unit impulse

clc;clear all;n=5;t=-n:1:n;x=[zeros(1,n),1,zeros(1,n)];stem(t,x);xlabel('t');ylabel('magnitude');title('unit impulse signal');

for sine

clc;clear all;n=0:0.5:(2*pi);y=sin(n);stem(n,y);xlabel('n');ylabel('magnitude');title('sinusoidal signal');

for cos

clc;clear all;n=0:0.5:(2*pi);y=cos(n);stem(n,y);xlabel('n');ylabel('magnitude');title('cosine signal');

2. Program for DFT/IDFT

clc; x1 = input('Enter the sequence:'); n = input('Enter the length:'); m = fft(x1,n); disp('N-point DFT of a given sequence:'); disp(m); N = 0:1:n-1; subplot(1,2,1); stem(N,m); xlabel('Length'); ylabel('Magnitude of X(k)'); title('Magnitude spectrum:'); an = angle(m); subplot(1,2,2); stem(N,an); xlabel('Length'); ylabel('Phase of X(k)');title('Phase spectrum:');

3. Program for frequency response

clc;clear all;b = [1, 4]; a = [1, -5]; w = -2*pi: pi/256: 2*pi; [h] = freqz(b, a, w); subplot(2, 1, 1);plot(w, abs(h));xlabel('Frequency \omega');ylabel('Magnitude'); title('frequency response of given signal');grid;subplot(2, 1, 2);plot(w, angle(h)); xlabel('Frequency \omega');ylabel('Phase - Radians'); grid;

4. PROGRAM FOR FFT

clc;clear all;x=input('enter input sequence a(n)');n=length(x);y=fft(x,n);m=abs(y);subplot(1,2,1);stem(m);xlabel('time');ylabel('magnitude');title('m plot');p=angle(y);subplot(1,2,2);stem(p);xlabel('time');ylabel('phase in radians');title('phase plot');

5. Program for power spectrum

clc;clear all;t = 0:0.001:0.6; x = sin(2*pi*50*t)+sin(2*pi*120*t); y = x + 2*randn(size(t)); figure,plot(1000*t(1:50),y(1:50)); title('Signal Corrupted with Zero-Mean Random Noise');xlabel('time (milliseconds)'); Y = fft(y,512);Pyy = Y.* conj(Y) / 512; f = 1000*(0:256)/512; figure,plot(f,Pyy(1:257));title('Frequency content of y'); xlabel('frequency (Hz)');

19. program for interpolationclc;t=0:0.03:2;x=cos(2*pi*t);a=interp(x,2);b=interp(t,2);subplot(2,1,1);stem(t,x);xlabel('no. of signals');ylabel('i/p signals');subplot(2,1,2);stem(b,a);title('interpolated signal');

20. program for decimation

clc;t=0:0.03:2;x=cos(2*pi*t);a=decimate(x,2);b=decimate(t,2);subplot(2,1,1);stem(t,x);xlabel('no. of signals');ylabel('i/p signals');subplot(2,1,2);stem(b,a);title('decimated signal');6. program for FIR LOW PASS FILTER

clc; clear all; close all; rp=0.02;rs=0.01;fp=1000; fs=1500; f=10000; wp=2*fp/f; ws=2*fs/f; num=-20*log10(sqrt(rp*rs))-13; dem=14.6*(fs-fp)/f; n=ceil(num/dem); n1=n+1; if(rem(n,2)~=0) n1=n; n=n-1; endc=input('enter your choice of window function 1. rectangular 2. triangular 3.kaiser: \n '); if(c==1) y=rectwin(n1); disp('Rectangular window filter response'); endif (c==2) y=triang(n1); disp('Triangular window filter response'); endif(c==3) y=kaiser(n1); disp('kaiser window filter response'); end b=fir1(n,wp,'low',y); [h,o]=freqz(b,1,256);m=20*log10(abs(h));plot(o/pi,m); title('LPF'); ylabel('Gain in dB-->'); xlabel('Normalized frequency-->');

7. PROGRAM FOR FIR HIGH PASS

clc; clear all; close all; rp=0.02;rs=0.01;fp=1000; fs=1500; f=10000; wp=2*fp/f; ws=2*fs/f; num=-20*log10(sqrt(rp*rs))-13; dem=14.6*(fs-fp)/f; n=ceil(num/dem); n1=n+1; if(rem(n,2)~=0) n1=n; n=n-1; endc=input('enter your choice of window function 1. rectangular 2. triangular 3.kaiser: \n '); if(c==1) y=rectwin(n1); disp('Rectangular window filter response'); endif (c==2) y=triang(n1); disp('Triangular window filter response'); endif(c==3) y=kaiser(n1); disp('kaiser window filter response'); end b=fir1(n,wp,'high',y); [h,o]=freqz(b,1,256);m=20*log10(abs(h));plot(o/pi,m); title('HPF'); ylabel('Gain in dB-->'); xlabel('Normalized frequency-->');

8. program for FIR BAND PASS

clc; clear all; close all; rp=0.02;rs=0.01;fp=1000; fs=1500; f=10000; wp=2*fp/f; ws=2*fs/f; num=-20*log10(sqrt(rp*rs))-13; dem=14.6*(fs-fp)/f; n=ceil(num/dem); n1=n+1; if(rem(n,2)~=0) n1=n; n=n-1; endc=input('enter your choice of window function 1. rectangular 2. triangular 3.kaiser: \n '); if(c==1) y=rectwin(n1); disp('Rectangular window filter response'); endif (c==2) y=triang(n1); disp('Triangular window filter response'); endif(c==3) y=kaiser(n1); disp('kaiser window filter response'); endwn=[wp,ws];b=fir1(n,wn,'bandpass',y);[h,o]=freqz(b,1,256);m=20*log10(abs(h));plot(o/pi,m); title('BPF'); ylabel('Gain in dB-->'); xlabel('Normalized frequency-->');

9. PROGRAM FOR FIR BAND STOP

clc; clear all; close all; rp=0.02;rs=0.01;fp=1000; fs=1500; f=10000; wp=2*fp/f; ws=2*fs/f; num=-20*log10(sqrt(rp*rs))-13; dem=14.6*(fs-fp)/f; n=ceil(num/dem); n1=n+1; if(rem(n,2)~=0) n1=n; n=n-1; endc=input('enter your choice of window function 1. rectangular 2. triangular 3.kaiser: \n '); if(c==1) y=rectwin(n1); disp('Rectangular window filter response'); endif (c==2) y=triang(n1); disp('Triangular window filter response'); endif(c==3) y=kaiser(n1); disp('kaiser window filter response'); endwn=[wp,ws];b=fir1(n,wn,'stop',y);[h,o]=freqz(b,1,256);m=20*log10(abs(h));plot(o/pi,m); title('BSF'); ylabel('Gain in dB-->'); xlabel('Normalized frequency-->');

10. program for butterworth low pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=buttord(wp,ws,rp,rs,'s'); [b,a]=butter(n,wn,'low','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Low Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Low Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

11. program for butterworth high pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=buttord(wp,ws,rp,rs,'s'); [b,a]=butter(n,wn,'high','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR High Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR High Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

12. program for butterworth band pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=buttord(wp,ws,rp,rs,'s'); wn=[wp,ws];[b,a]=butter(n,wn,'bandpass','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Band Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Band Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

13. program for butterworth band stop

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=buttord(wp,ws,rp,rs,'s'); wn=[wp,ws];[b,a]=butter(n,wn,'stop','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Band Stop filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Band Stop filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

14. program for chebshev low pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=cheb1ord(wp,ws,rp,rs,'s'); [b,a]=cheby1(n,rp,wp,'low','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Low Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Low Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

15. program for chebshev high pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=cheb1ord(wp,ws,rp,rs,'s'); [b,a]=cheby1(n,rp,wp,'high','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR High Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR High Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

16. program for chebshev band pass

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=cheb1ord(wp,ws,rp,rs,'s'); wn=[wp,ws];[b,a]=cheby1(n,rp,wn,'bandpass','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Band Pass filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Band Pass filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->')

17. program for CHEBSHEV band stop

clc; clear all; rp=0.15; rs=60; fp=1500; fs=3000;f=7000; wp=2*fp/f;ws=2*fs/f; [n,wn]=cheb1ord(wp,ws,rp,rs,'s'); wn=[wp,ws];[b,a]=cheby1(n,rp,wn,'stop','s'); w=0:.01:pi; [h,om]=freqs(b,a,w); m=20*log10(abs(h)); subplot(2,1,1); plot(om/pi,m); title('magnitude response of IIR Band Stop filter is:');xlabel('(a) Normalized freq. -->');ylabel('Gain in dB-->');an=angle(h); subplot(2,1,2); plot(om/pi,an); title('phase response of IIR Band Stop filter is:'); xlabel('(b) Normalized freq. -->'); ylabel('Phase in radians-->');

18. %Generation of DTMF signals

Fs = 8000; % Sampling frequencyTs = 1/Fs;Numof_samples =input('enter the no of samples');dialnumber=input('enter the dial number');T = Ts*(0:Numof_samples-1)'; switch dialnumbercase 0 F1 = 941; F2 = 1336;case 1 F1 = 697; F2 = 1209;case 2 F1 = 697; F2 = 1336;case 3 F1 = 697; F2 = 1477;case 'A' F1 = 697; F2 = 1633;case 4 F1 = 770; F2 = 1209;case 5 F1 = 770; F2 = 1336;case 6 F1 = 770; F2 = 1477;case 'B' F1 = 770; F2 = 1633;case 7 F1 = 852; F2 = 1209;case 8 F1 = 852; F2 = 1336;case 9 F1 = 852; F2 = 1477;case 'C' F1 = 852;

F2 = 1633;case '*' F1 = 941; F2 = 1209;case '#' F1 = 941; F2 = 1477;otherwise F1 = 941; F2 = 1633;end;firstsine = cos(2*pi*F1*T); % first sinusoidal signalsecondsine = cos(2*pi*F2*T); % second sinusoidal signald = firstsine + secondsine; dtmfoutput = d ;figure(1); title('THE DTMF OUTPUT'); plot(dtmfoutput);

after 5 th program 19 and 20 programs mentioned

21. program for I/D sampling rate convertersclc;

close all; clear all; L = 7; M = 2; N = 30; n = 0:N-1; x = sin(2*pi*0.43*n) + sin(2*pi*0.31*n); y = resample(x,L,M); subplot(2,1,1); stem(n,x(1:N)); axis([0 29 -2.2 2.2]); title('Input Sequence'); xlabel('Time index n'); ylabel('Amplitude'); subplot(2,1,2); m = 0:(N*L/M)-1; stem(m,y(1:N*L/M)); axis([0 (N*L/M)-1 -2.2 2.2]); title('Output Sequence'); xlabel('Time index n'); ylabel('Amplitude');