Trouble with time lag between peaks

I have two series of data: (time,x) and (time,y) . My intention is to plot the time lag between the the peaks in x and y . Due to property of the system, the time interval between the successive peaks in X and Y is around 8. I have tried to use the function

 [pks1,locs1]=findpeaks(x,'minpeakdistance',8);
 [pks2,locs2]=findpeaks(y,'minpeakdistance',8);

In this way, after finding both peaks I could find the lag. The problem is due to the variation in noise level of both readings, I couldn't find the same number of peaks for both x and y, more to this, I can't maintain the distance 8 and some are way exaggerated. Is there anyway of tackling this problem , it's giving me hard time please help me.

[Image Analyst]

Can you post a screen shot of plots of the two signals so we know what we're dealing with?

[Ede gerlderlands]

Sorry, how can I send that?

[Image Analyst]

Try http://snag.gy. Just do alt-printscreen to copy window into the clipboard, then go to snag.gy and type control-v and tell us the URL it gives you. Put a blank line and then click the colored image icon and paste the url between the pair of double angle brackets.

[Ede gerlderlands]

http://snag.gy/a7Gz0.jpg

The yellow dots are the peak points while the blue and magenta are the x and y values.

Answer 1

[Image Analyst]

How do you know what is noise and what is a valid peak that you care about? Can you filter both signals with something and then compare denoised signals?

[Ede gerlderlands]

I did try to filter out but all the effort was futile. Because I know what the time difference between the peaks should be , is there a way to find the first peak and maintain that time difference such as sliding window? the 'minpeakdistance' in findpeak doesn't solve this issue.