# How to filter very low amplitude staircase signal from a background noise

I have a staircase signal of a specific pattern that is drowned in a background noise. The ratio of signal to noise amplitude is nearly $$10^{-4}$$. I have attached the image of both with this post. I am an absolute noob in this field so please suggest me a direction on which path I should start to hunt for the solution.

I have tried to do fft on both of the signal and looked for any distinct signature to filter the background noise. Also I have tried with matched filtering and basic convolution techniques. But none of these seem to work. Your advice will be much appreciated. Thanks.

• With that much noise, I'd be surprised if the signal can be recovered. If you can't amplify the signal, then try to make the steps longer (much longer) to increase their energy and improve your chances of detection. – MBaz Oct 11 '19 at 1:45
• That is not so much "noise" as it is "interference." You might do better to try and characterize that interference and see if it is some how easier to recognize than your signal. You might also go back to the source of the data and see if the interference can be physically reduced before the signal is sampled. – JRE Oct 11 '19 at 10:54
• I agree that it would be a smart idea to treat as interference. Is there a way to estimate it and subtract it off? Just looking at the plot it seems unlikely but I don’t know the details. Just out of curiosity, what is the application? – Engineer Nov 10 '19 at 20:57