Dear,
I am currently looking for a method (or technique) to measure the phase difference between two sinusoidal signals. Because I can not find an efficient digital processing technique for that, could you advise me on one or more techniques to detect sine phase difference?
I have 2 sine signals delayed each other. I just need a DSP technique to find the delay between them (give in time o angle).
Leonardo Andrés Pérez
It's defiantly not my field of expertise, so probably not the most efficient solution, but you can multiply the two signals, you'll get a beat frequency at frequency that is the subtraction of the two signals and a simple fft will yield the proper time delay. you'll also receive the high frequency of the sum. like this:
sin(3X)*sin(3X+1)=1/2 (cos(1) - cos(1 + 6 X))
So you'll need to apply a LPF on the fft.
hope that helps
A simple solution is to convert this analog signal to digital one with the use of ADC and with implementation of zero crossing detection algorithm on both the signal you can find out phase difference between two.
If your one signal is fixed (if it is reference one) then phase difference can be identified by converting other signal into digital one. You can process that data in real time environment with the use of processor/ controller/FPGA or any DSP processor or you can acquire digital data in PC then you can find out phase difference with the programming software.
If you need more information leave your email address, so I can send out it in more detail.
Leonardo.
Sample the two sinusoids at twice the Nyquist rate (four times the frequency of the sinusoids), take the FFT of the two sampled signals to obtain their spectra, then do a correlation of the two spectra; the phase difference between sinusoids will be available as the ARGUMENT of the complex number that appears on the FIRST bin of the correlation. For maximum accuracy the sampling must be done at exactly 4 times the frequency of the sinusoids
Dear Armando,
Thank you for your reply. I already applied the cross-correlation technique succesfully.
BR,
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