Simultaneous Removal of Harmonic Interference and White Noise by Combining Multi-Rate Signal Processing and Wavelet Denoising Techniques

In this paper anew method is presented for simultaneous removal of harmonic interference and white noise by combining multi-rate signal processing and wavelet denoising techniques. The contaminated signal is first resampled to a higher but the nearest frequency that meets a prerequisite. The signal is then transformed into the time-scale domain by the orthogonal wavelet decomposition (OWD). In each sub-band of the time-scale domain, multi-rate signal processing is used to remove harmonic interference and wavelet shrinkage is used to remove white noise. Compared with the wavelet packet decomposition (WPD), the orthogonal wavelet decomposition is more time-efficient. Evaluation of the new method is carried out by using four test signals and comparison with the direct wavelet shrinkage method is given.