How to separate noise from signal?
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I have got a question regarding noise removal.
I am doing a sensor project, and I need to measure output signal from the sensors. Theoretically speaking, output signal should be sine wave.However, sensor itself has got sine-wave-like noise. Therefore the supercomposition of two waves forms weired output signal.
Now, I have two separated excel files, one is noise, the other one is output signal (Weired shaped one). I'm wondering how to get net output signal (without noise).
By the way, two waves have different frequencies and amplitudes.
Thanks so much for your help.
Image Analyst on 5 Sep 2013
Take the FFT. Find the two largest peaks - these represent your dominant frequency. Zero out everything else, then inverse FFT. You'll have only the dominant harmonic remaining in your output signal. All the noise (at any other frequency) will be filtered away.
rifat on 4 Sep 2013
You can pass your signal through a bandpass filter centered around the frequency of your original (without noise) output and adjust the bandwidth.
Youssef Khmou on 5 Sep 2013
Chad on 6 Sep 2013
Or you can cross correlate the output signal with a sine wave of known frequency. Try xcorr and fft.
Did something similar in my statistical analysis class.
Also read up on correlation and auto corelation and cross correlation