clc;

clear all;

pkg load signal;

% Raw IQ data

fd = fopen('FM93_8Msps.wav', 'r');

[data] = fread(fd, inf, 'int8');

fclose(fd);

I = data(1: 2: end);

Q = data(2: 2: end);

% Move spectrum from center 93MHz to 95Mhz

%S = I .+ Q*1i;

%dt = 1/8e6;

% Move 2MHz

%for k = 1 : length(I)

%    S(k) = S(k) * exp(-1i*2e6*2*pi*dt*k);

%end

%I = real(S);

%Q = imag(S);

%R = zeros(1, 2*length(I));

%R(1: 2: end) = I;

%R(2: 2: end) = Q;

%fd = fopen('FM95_8Msps.wav', 'w');

%fwrite(fd, R, 'int8');

%fclose(fd);

B = fir1(51, 0.02);

A = [1];

I = filter(B, A, I);

Q = filter(B, A, Q);

I = I(1: 50: end);

Q = Q(1: 50: end);

% 160Ksps

S = I .+ Q*1i;

% Demod

d = S(1: end - 1) .* conj(S(2: end));

s = atan2(imag(d), real(d))/pi;

B = fir1(21, 0.1);

A = [1];

s = filter(B, A, s);

s = s(1: 10: end);

% Replay

loops = 10;

% 16Ksps

while loops--

    sound(s, 16000);

end