How Can I Time Shift a Signal in Matlab?

[Shaddyab]

Hi!

How can I time shift (ts) a real signal (N samples, T time period, dt
sample rate, Fs sampling frequency) using matlab:

Timeshift signal = ifft (fft(signal)*exp(2*i*pi*Fs*ts)) ?
I am trying to do it this way and it is not working?

For example how would you shift a Cos signal to fit on a Sin signal ( Phase shift of pi/2 or time shift of ts)

Thanks.

 

[Shaddyab]

the 'sin' 'cos' was only an example, I am talking about general case.
I need to know how to do it with FFT, i know that it has something to do with the symmetry of the transformation, i just do not know how to do it.

Thanks

 

[oswaler]

Hello!

To time shift a signal in Matlab, you can use the "circshift" function. This function shifts the elements of a signal circularly, which can be used to simulate a time shift. The syntax for this function is:

shifted_signal = circshift(signal, n)

where "n" is the number of samples you want to shift the signal by. For a time shift of ts, you can calculate the number of samples to shift by using the formula: n = ts/dt. This will shift the signal by the desired time shift.

In your case, if you want to shift a cosine signal to fit on a sine signal, you can use the "circshift" function as follows:

shifted_cos = circshift(cos_signal, pi/2) % for a phase shift of pi/2 or time shift of ts

Note that this will only work if the length of the cosine signal is the same as the length of the sine signal. If they are different, you will need to resample the signals to have the same length before applying the time shift.

I hope this helps! Let me know if you have any further questions.