how can i estimate the period of a signal exist in a loaded file?

how can i estimate the period of a signal exist in a loaded file?

[Geoff Hayes]

Amira - more information is required. Please update the body of your question with (at the very least) some context surrounding the contents of the loaded file.

[amira ramadan]

that's the file , required the period of the signals s1 and s2

[Star Strider]

What is the time base of each of your signals?

• Sampling frequency (both s1 and s2)?
• Signal length in seconds (both s1 and s2)?

It is not possible to calculate the period of either signal without this information.

Answer 1

[Geoff Hayes]

The first thing that you can do, is to plot the signals:

load sig_period.mat
figure;
plot(s1);
figure;
plot(s2);

It will be clear from both figures that the signal repeats. For s1, the repeated pattern is 1 2 3 4 5 4, while for s2 the repeated pattern is 1 1 2 3. For each signal, you have provided 120 samples. What is the sampling rate? Is this one second worth of data? Two seconds? Denote the sampling frequency (i.e. the number of samples taken from the signal per second) by Fs (I'm assuming the same sampling frequency for each signal).

The frequency of s1 is f1 = Fs/6 Hertz, and the frequency of s2 is f2 = Fs/4 Hertz.

The period of any signal is the reciprocal of the frequency, T = 1/ f.