Improving Wavelet De-Noise By Means of Shifting-Scale-Method

Wavelet is commonly used at signal de-noise and the methodologies of wavelet de-noise become more and more scheming and complex. In this paper we propose a very simple but effective method, shifting-scale-method, to improve signal denoise using wavelet by firstly unveiling that low signal/noise coefficient ratio in wavelet domain is one of major baffles forwarding effective wavelet de-noising; then discussing the signal/noise coefficient ratio as a Game Playing problem and finally concluding that increasing the signal sampling frequency can raise signal/noise coefficient ratio in wavelet domain and get improved de-noise result. The proposed approach is especially useful for medical or geological signal de-noise where, compared with the frequency of the signal in electronic field, the significant frequency of the signal under study is usually much lower than the highest sampling frequency of the instrument that measures the signal, so that it is easier to improve de-noise result by measuring the signal at a higher sampling frequency. According to the study in this paper, when the sampling frequency is above 4 times or 8 times the highest signal frequency, the high frequency components of the signal can be well kept after wavelet de-noise.