2 signals to 1 channel ? use FFT

How can I change 2 signal to 1 channel.

m1(t)= (A1 Cos2 pi F1 t)

m1(t)= (A2 Cos2 pi F2 t) to one channel

thank you for help.

[Jan]

The question is not clear. Please use standard Matlab syntax, because I cannot imagine what "m1(t)= (A1 Cos2 pi F1 t)" means. Defining "m1" twice is at least confusing.

[Hünkar Hançer]

Teacher asked like this. İ asked today him. He said, u can use fft. Some question. 2 signal to 1 channel. He said just this..didnt explain.

Answer 1

[Jan]

Do you want to concatenate the signals? Then cat is the right command. Or do you want to add the signals? Then add them using + and perhaps you need a normalization afterwards, if any values exceed the allowed range:

S = S / max(abs(S(:));

[Hünkar Hançer]

Teacher asked like this. İ asked today him. He said, u can use fft. Some question. 2 signal to 1 channel. He said just this..didnt explain.

Answer 2

[Daniel kiracofe]

assuming that t is a vector containing time intervals, and that F1 and F2 are frequencies, and A1 and A2 are amplitudes, then I assume that what you want is this:

m1 = A1* cos(2 * pi * F1 * t) + A2 * cos( 2 *pi F2* t)

If that is not what you want then I don't understand the question.

[Hünkar Hançer]

today, teacher told me , u should use tdm-pcm function. and he said, to signal must go 1 channel.

[Daniel kiracofe]

ah. tdm means "time division multiplexing". https://en.wikipedia.org/wiki/Time-division_multiplexing

I don't know if there is a specific function to do that in matlab. and I don't know how to do using an FFT. But it's basically just interleaving the samples. if you have 2 vectors called m1 and m2, each of length N, you can just do this:

for i = 1:N tdm_signal(2*i-1) = m1(i); tdm_signal(2*i ) = m2(i); end