%% Lab5 p 1

sigBeat = makeBeatStruct(10, 1300, 13, 0, 0, 0, 5);


%subplot(2,1, 1);
plot(sigBeat.times, sigBeat.values);
%subplot(2,1,2);
%plotspec( xx, 8000, 1024 ), colorbar, grid on;   %-- with negative frequencies



function sigBeat = makeBeatStruct( B, fc, fdelta, phase1, phase2, startTime, endTime )
       %
       %--- Create a structure that has all the parameters defining a beat signal as used
       %    in Equations (3) and (4)
       tt = startTime: 1/8000 : endTime;
       sigBeat.times = tt;
       sigBeat.values = B*cos(2*pi*fdelta.*tt + phase1).*cos(2*pi*fc.*tt + phase2);


       sigBeat.f1 = fdelta+fc;
       sigBeat.f2 = fdelta-fc;
       sigBeat.X1 = (B/2)*(phase1+phase2);
       sigBeat.X2 = (B/2)*(phase1-phase2);
end