I am working on a project where i am trying to remove noise from signal in real time. I have decided to use adaptive LMS algorithm. If x(n): input signal corrupted with noise y(n): output from filter; e(n): the error signal that controls the weights of filter Now do i need to generate another local noise source and feed it to the filter? Does the corrupted signal go directly into the filter or only the e(n) and the locally generated noise(refrence signal) go into the filter? Does the filter work just like it does in a linear predictor mode? Is the output of filter (called anti-noise) add up with the corrupted signal to produce e(n)? Is this e(n) the output (or the noise free signal)?
Adaptive noise cancellation
Started by ●March 21, 2009
Reply by ●March 23, 20092009-03-23
Hello derif, there is an article [1] of Bernard Widrow "Adaptive Noise Cancelling: Principles and Applications". In Chapter "F. Cancelling Periodic Interference without an External Reference Source" he explains this problem. Right before the FIR filter a fixed delay is inserted. This allows to have correlated signals (eg. single tone) separated from uncorrelated (eg. noise). If your 'noise' signal is known you may generate it yourself and insert this signal as usual in an LMS algorithm in the reference input. Regards Alois [1] http://www-isl.stanford.edu/~widrow/publications.html , Papers nr. 31