关键词: 信噪比, 同步挤压小波变换, 随机噪声, 中值滤波, 小波变换

Abstract: Aiming at lowering the signal-to-noise ratio of a noisy signal, a synchrosqueezing wavelet transform-based denoising method is proposed. The transformation is a new method of wavelet transform, which can convert the time-domain signal into high-resolution time-frequency spectrum. Then, combining the idea of spectrum rearrangement to obtain the value of the synchrosqueezing transform by squeezing the interval value of any center frequency. The study finds that the synchrosqueezing wavelet transform can be used to compress the random noise into the point like noise or the particle noise, and the aggregation distribution. Based on the distribution of noise characteristics, the median filter can be used to achieve the purpose of suppressing noise, but through the traditional wavelet transform, the random noise is distributed in the size of the scale and relatively decentralized, with median filter can not achieve a good filtering effect. The comparison results show that the method has the ability of restraining noise.

Key words: signal to noise ratio, synchrosqueezing wavelet transform, random noise, median filter, wavelet transform