1. Synteza i analiza filtru NOI (dolnoprzepustowego)

1. Charakterystyka częstotliwościowa.

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*Tp/2));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

[H,F]=freqz(L,M,512,fp);

plot(F,abs(H))

grid on

1. Charakterystyka fazowa.

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*(Tp/2)));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

[H,F]=freqz(L,M,512,fp);

P=angle(H)*180/pi;

plot(F,P)

grid on

1. Opóźnienie fazowe

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*(Tp/2)));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

phasedelay(L,M,512,fp)

grid on

1. Odpowiedz na skok jednostkowy.

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*(Tp/2)));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

[o,ts]=stepz(L,M);

plot(ts,o)

grid on

1. Analiza filtu SOI

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

stem(0:N-1,abs(H))

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

L=ifft(H)

impz(L,1)

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

stem(0:N-1,L)

Charakterystyka częstotliwościowa widmowa

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

[H,F]=freqz(L,1,512,fp);

plot(F,abs(H))

Charakterystyka częstotliwościowa z oknem wygładzającym

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

Lw=L.*hamming(N)';

[H,F]=freqz(Lw,1,512,fp);

plot(F,abs(H))

Charakterystyka fazowa

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

Lw=L.*hamming(N)';

[H,F]=freqz(Lw,1,512,fp);

P=angle(H)*180/pi;

plot(F,P);

grid on

Opóźnienie fazowe

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

h=ifft(H)

L-[h];

Lw=L.*hamming(N)';

M=1;

phasedelay(L,M,512,fp);

grid on

1. Filtracja

Sygnał zaszumiony

N=40;

fodc=400;

fp=2000;

t=(0:(1/fp):0.16);

signal=5*sin(100*pi*t)+2.5*sin(2*pi*(fodc+150)*t);

plot(t,signal)

grid on;

Furier

N=40;

fodc=400;

fp=2000;

t=(0:(1/fp):0.16);

signal=5*sin(100*pi*t)+2.5*sin(2*pi*(fodc+150)*t);

Le = length(t)-1;

signal1 = abs(fft(signal))/(Le/2);

ff = 0:(fp./Le):fp;

plot(ff,signal1)

grid on;

Filtr NOI

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*Tp/2));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

N=40;

fodc=400;

fp=2000;

t=(0:(1/fp):0.16);

signal=5*sin(100*pi*t)+2.5*sin(2*pi*(fodc+150)*t);

signal1_f = filter(L,M,signal);

plot(t,signal1_f)

grid on;

gr=10;

wga=0.7874;

fp=1000+gr*100;

fgc=200+gr*10;

wgc=2*pi*fgc;

Tp=1/fp;

A=wga*(1/tan(wgc*Tp/2));

L=[1 2 1];

M=[(1+1.73*A+A^2) (-2*A^2+2) (A^2-1.73*A+1)];

N=40;

fodc=400;

fp=2000;

t=(0:(1/fp):0.16);

signal=5*sin(100*pi*t)+2.5*sin(2*pi*(fodc+150)*t);

signal1_fw = abs(fft(signal1_f))/(Le/2);

plot(ff,signal1_fw)

grid on;

FILTR SOI

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

L=ifft(H);

signal1_f = filter(L,H,signal);

plot(t,signal1_f)

grid on;

fp=2000;

fodc=400;

f1=50;

N=fp/f1 ;

deltaf=fp/N

H=[exp(-i*(0:8)*pi*(N-1)/N),zeros(1,23),exp(i*(N-(32:39))*pi*(N-1)/N)]

L=ifft(H);

signal1_fw = abs(fft(signal1_f))/(Le/2);

plot(ff,signal1_fw)

grid on;

WNIOSKI