effective methods to eliminate White Noise


Thread Starter


Does anyone out there know any effective methods that can eliminate White Noise? (I know that one cannot use LowPassFilter, HighPassFilter, or any of the ordinary filters to do the job).

Plus, how to identifyy that the noises appended on the signal is White Noise?

Thanks a million!

Curt Wuollet

White noise has a constant power distribution across the frequency spectrum of interest. You can sample and do an FFT or use a spectrum analyzer. If it's white moise you will see the entire noise floor rise. Effective methods depend on your signal bandwidth. If you have a single frequency a tuned amplifier will largly remove out of band noise. It will still amplify components falling in the passband. The best method to eliminate white moise is at the source. Perhaps a better description of your problem
would help. In instrumentation, most broaband noise comes from the electronics. Devices woth very low noise are available and someone who
has analog design experience, (like me) should be most helpful.



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Elimination usually is a process of trial and error. However, it should start with a quantitative measurement to confirm that it is "white" noise. An oft-forgotten tool is the oscilloscope. The RMS value is essentially continuous, and not from power frequency pickup, ie, 50/60 Hz or their multiples. Then, the noise waveform level in Volts (rms) will approximately equal Volts (peak-peak) divided by 8... ignoring
occasional extreme peaks

Henry W. Otts presents some detail in his book:

"Noise Reduction Techniques in Electronic Systems;"

Publisher- Wiley Interscience;

ISBN 0-471-65726-3

If you are unable to obtain a copy, I can send you an extrapolation via the A-List, or by Fax.

Phil Corso, PE
Fax: 561-487-8776