Question

I have data set (voltage vs time) of a signal with frequency 450Hz and number of sample is 10000. How can I change frequency of a that data set and also add phase shift with that signal using Matlab code? Please explain your answer in details. I will be happy to give good review.

Answer 1

Given: Frequency of signal=450 Hz; No. of samples = 10000

1st part:

Frequency of any dataset (or signal) is characteristic of the source generating the signal. So, unless the source is changed the signal frequency cannot change. But, sampling frequency can be changed depending on the sensor and the data acquisition system used to collect the signal data.

2nd part:

Phase shift,

where, is the time delay and is the signal frequency. So, if is known, the time delay can be calculated as:

If 'x' is the acquired time-domain signal, it has 10000 points.

The signal, 'y', which is the phase shifted version of 'x' is obtained in MATLAB as:

for(i=;i<=10000;i++)

{

y(i-+1)=x(); //copies the signal contents in 'x' after the time delay, 't_d', to 'y'.

}

end