clc, close all, clear all
%%Zadanie 1

%Data
fs = 5000; %Sample freq
fm = 1; %1
fc = 100; %Carrier freq
Am = 1;
Ac = 0.5;
kf = 20;
b = (kf*Ac)/fm;
t = 0:1/fs:((4/fm)-(1/fs));

%Modulated signal
msignal = Am*cos(2*pi*fm*t);
c_msignal = cumsum(msignal)/fs;

msignal2 = square(2*pi*fm*t)*(1.5/2)+0.15;
c_msignal2 = cumsum(msignal2)/fs;

xfm = cos(2*pi*fc*t).*cos(2*pi*b*c_msignal)-sin(2*pi*fc*t).*sin(2*pi*b*c_msignal);
xfm2 = cos(2*pi*fc*t).*cos(2*pi*b*c_msignal2)-sin(2*pi*fc*t).*sin(2*pi*b*c_msignal2);
xfm_func = fmmod(msignal,fc,fs,b);
xfm_func2 = fmmod(msignal2,fc,fs,b);

%Spectres
NoOfProbes = 2^nextpow2( length(xfm) );
xfm_spec = 20*log10(abs(fft(xfm,NoOfProbes)/NoOfProbes));
xfm_spec2 = 20*log10(abs(fft(xfm2,NoOfProbes)/NoOfProbes));

f_w_b=fs/2*linspace(-1,1,NoOfProbes);

%Modulation (1st - sin signal)
figure(1)
subplot(4,1,1);
plot(msignal);grid;
title('Message signal');
%xlim([20000 100000]);
subplot(4,1,2);
plot(xfm);grid;
title('Modulated signal');
%xlim([20000 100000]);
subplot(4,1,3);
plot(xfm_func);grid
title('Modulated signal with fmmod function');
%xlim([20000 100000]);
subplot(4,1,4);
plot(f_w_b,[xfm_spec(NoOfProbes/2+2:end), xfm_spec(1:NoOfProbes/2+1)]);grid
title('Spectre of modulated sin signal');
ylabel('FFT [dB]','FontSize',12);

%Modulation (2nd - square signal)
figure(2)
subplot(4,1,1);
plot(msignal2);grid;
title('Message signal');
%xlim([20000 100000]);
subplot(4,1,2);
plot(xfm2);grid;
title('Modulated signal');
%xlim([20000 100000]);
subplot(4,1,3);
plot(xfm_func2);grid
title('Modulated signal with fmmod function');
%xlim([20000 100000]);
subplot(4,1,4);
plot(f_w_b,[xfm_spec2(NoOfProbes/2+2:end),xfm_spec2(1:NoOfProbes/2+1)]);grid
title('Spectre of modulated square signal');
xlabel('f [Hz]','FontSize',12);
ylabel('FFT [dB]','FontSize',12);

msignalPower = rms(msignal)*rms(msignal)
c_msignalPower = rms(c_msignal)*rms(c_msignal)
xfmPower = rms(xfm)*rms(xfm)
xfm2Power = rms(xfm2)*rms(xfm2)

s = hilbert(xfm).*exp(sqrt(-1)*2*pi*fc*t);
figure;
plot(s)
Z = fmdemod(xfm,fc,fs,b);

%Waskopasmowa - b musi byc male
%%