I'm trying to understand the difference between the sums and products of two sine signals. I also wonder where and how these two situations are used in practice.
Fs = 100e6;
t = 0:1/Fs:0.1;
x = sin(2*pi*10*t);
y = sin(2*pi*1e3*t);
mult_sig = x.*y;
add_sig = x+y;
The sum and fft of the two signals are as follows:
The product and fft of the two signals are as follows:
Could you give the mathematical background and examples of its practical use? Isn't it strange that different frequencies appear especially in fft graphs?