Paper Details

This paper defines the concept of adaptive noise cancelling, an alternative method of estimating signals corruptedby additive no`q ise or interference. The method uses a primary input containing the corrupted Signal and a reference inputcontaining noise correlated in some unknown way with the primary noise. The reference input is adaptively filtered andsubtracted from the primary input to obtain the signal estimate. Wiener solutions are developed to describe asymptoticadaptive performance and output signal-to-noise ratio for stationary stochastic inputs, including single and multiplereference inputs. These solutions show that when the reference input is free of signal and certain other conditions are metnoise in the primary input can be essentially eliminated without signal distortion. It is further shown that in wiener filter withnarrow bandwidth, infinite null, and the capability of treating periodic interference the adaptive noise canceller acts astracking the exact frequency of the interference; in this case the canceller behaves as a linear, time-invariant system, with theadaptive filter results presented that illustrate the usefulness of the adaptive noise cancelling on a dynamic rather than astatic solution. In the first stage the narrowband noise is reduced by using the ALE technique. The second stage gets a signalwith ideally only the wideband noise which is reduced using the NLMS technique. The reference input is adaptively filteredand subtracted from primary input to obtain signal estimate.

Ekta, Deepti Chaudhary, “ADAPTIVE NOISE CANCELLATION USING WEINER FILTER”, International Journal of Advance Engineering and Research Development (IJAERD), Vol. 1, Issue 8, pp. 175-178, August 2014.