FIR FILTER USING DIFFERENT WINDOW MATLAB PROGRAM

FIR FILTER USING DIFFERENT WINDOW

 

 

f=input('Samplin rate in Hz, f=');

fp=input('pass band edge frequency in Hz=');

fs=input('stop band edge frequency in Hz=');

rp=input('pass band ripple in dB=');

rs=input('minimum stop band attenuation in dB=');

wp=2*fp/f;

ws=2*fs/f;

[N,wn]=cheb1ord(wp,ws,rp,rs);

 

%Hann window

 

Hw=hann(N+1);

B=fir1(N,wn,Hw);

[H,omega]=freqz(B,1,256);

gain=20*log(abs(H));

subplot(2,2,1);

plot(omega/pi,gain);

grid;

xlabel('omega/pi');

ylabel('Gain in dB');

title('FIR LPF using HANN window');

 

%Hamming window

 

Hw=hamming(N+1);

B=fir1(N,wn,Hw);

[H,omega]=freqz(B,1,256);

gain=20*log(abs(H));

subplot(2,2,2);

plot(omega/pi,gain);

grid;

xlabel('omega/pi');

ylabel('Gain in dB');

title('FIR LPF using HAMMING window');

 

%Rectangular window

 

Hw=rectwin(N+1);

B=fir1(N,wn,Hw);

[H,omega]=freqz(B,1,256);

gain=20*log(abs(H));

subplot(2,2,3);

plot(omega/pi,gain);

grid;

xlabel('omega/pi');

ylabel('Gain in dB');

title('FIR LPF using RECTANGULAR window');

 

%Triangular window

 

Hw=triang(N+1);

B=fir1(N,wn,Hw);

[H,omega]=freqz(B,1,256);

gain=20*log(abs(H));

subplot(2,2,4);

plot(omega/pi,gain);

grid;

xlabel('omega/pi');

ylabel('Gain in dB');

title('FIR LPF using TRIANGULAR window');

 

 

 

 

 

 

 

 

Observation:

 

Samplin rate in Hz,f=2000

pass band edge frequency in Hz=200

stop band edge frequency in Hz=300

pass band ripple in dB=6

minimum stop band attenuation in dB=30