I am new to signal processing and are trying to retrieve
the main frequency from a signal sampled with a samp.freq.
of 1kHz. I have been looking at a lot at different FFT:s
and I would like some help to understand them.
To find out how this stuff works I start with creating a
sinussignal in Matlab with the frequency of 1.029Hz
If I perform an FFT on this signal the plot shows me a
frequency of 1.5Hz. What is the reason for this?
I have noticed that if I fix the edges of the signal so the
the sinus wave starts in the amplitude zero and end at
zero, then the FFT plot shows a frequency at 1.5027 which
is closer to what I set the sinussignal to be.
Can anyone explain this and what is the best way to get the
real frequency(1.5029)?
when u tell sin starts at 0 phase and ends with 0 phase, gives correct results? then whatz happening is called fft leakage(for the signal which is not this case).
google out the topic for fft leakage.