hafid

clc

% FREKUENSI SAMPLING & WAKTU
fs=8000;
t=0:1/fs:1;
N=length(t);

% PENGAMBILAN & PEMBAGIAN DATA
in=audioread('PSDKASUSA2.wav');
dt1=in(1:8001);
dt2=in(8001:16002);
dt3=in(16002:24003);
dt4=in(24003:32004);
dt5=in(32004:40005);
dt6=in(40005:48006);

% NILAI KOEFISIEN K
k1=round(697/fs*N);
k2=round(770/fs*N);
k3=round(852/fs*N);
k4=round(941/fs*N);
k5=round(1209/fs*N);
k6=round(1336/fs*N);
k7=round(1477/fs*N);

% FILTERING
a1=[1 -2*cos(2*pi*k1/N) 1];
a2=[1 -2*cos(2*pi*k2/N) 1];
a3=[1 -2*cos(2*pi*k3/N) 1];
a4=[1 -2*cos(2*pi*k4/N) 1];
a5=[1 -2*cos(2*pi*k5/N) 1];
a6=[1 -2*cos(2*pi*k6/N) 1];
a7=[1 -2*cos(2*pi*k7/N) 1];

% NADA 1
y1 = filter(1,a1,dt1);
y2 = filter(1,a2,dt1);
y3 = filter(1,a3,dt1);
y4 = filter(1,a4,dt1);
y5 = filter(1,a5,dt1);
y6 = filter(1,a6,dt1);
y7 = filter(1,a7,dt1);

% NADA 2
y1 = filter(1,a1,dt2);
y2 = filter(1,a2,dt2);
y3 = filter(1,a3,dt2);
y4 = filter(1,a4,dt2);
y5 = filter(1,a5,dt2);
y6 = filter(1,a6,dt2);
y7 = filter(1,a7,dt2);

% NADA 3
y1 = filter(1,a1,dt3);
y2 = filter(1,a2,dt3);
y3 = filter(1,a3,dt3);
y4 = filter(1,a4,dt3);
y5 = filter(1,a5,dt3);
y6 = filter(1,a6,dt3);
y7 = filter(1,a7,dt3);

% NADA 4
y1 = filter(1,a1,dt4);
y2 = filter(1,a2,dt4);
y3 = filter(1,a3,dt4);
y4 = filter(1,a4,dt4);
y5 = filter(1,a5,dt4);
y6 = filter(1,a6,dt4);
y7 = filter(1,a7,dt4);

% NADA 5
y1 = filter(1,a1,dt5);
y2 = filter(1,a2,dt5);
y3 = filter(1,a3,dt5);
y4 = filter(1,a4,dt5);
y5 = filter(1,a5,dt5);
y6 = filter(1,a6,dt5);
y7 = filter(1,a7,dt5);

% NADA 6
y1 = filter(1,a1,dt6);
y2 = filter(1,a2,dt6);
y3 = filter(1,a3,dt6);
y4 = filter(1,a4,dt6);
y5 = filter(1,a5,dt6);
y6 = filter(1,a6,dt6);
y7 = filter(1,a7,dt6);

% POWER TIAP FREKUENSI
m(1)=sqrt(y1(N)^2+y1(N-1)^2-2*cos(2*pi*k1/N)*y1(N)*y1(N-1));
m(2)=sqrt(y2(N)^2+y2(N-1)^2-2*cos(2*pi*k2/N)*y2(N)*y2(N-1));
m(3)=sqrt(y3(N)^2+y3(N-1)^2-2*cos(2*pi*k3/N)*y3(N)*y3(N-1));
m(4)=sqrt(y4(N)^2+y4(N-1)^2-2*cos(2*pi*k4/N)*y4(N)*y4(N-1));
m(5)=sqrt(y5(N)^2+y5(N-1)^2-2*cos(2*pi*k5/N)*y2(N)*y2(N-1));
m(6)=sqrt(y6(N)^2+y6(N-1)^2-2*cos(2*pi*k6/N)*y3(N)*y3(N-1));
m(7)=sqrt(y7(N)^2+y7(N-1)^2-2*cos(2*pi*k7/N)*y4(N)*y4(N-1));

f = [697 770 852 941 1209 1336 1477];
subplot(2,3,1)
stem(f,m);grid
xlabel('frequency (Hz)')
title ('DTMF Magnitude')