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基于(LAPS)(光寻址电位传感器)技术的生化传感器中的光生电流是一种微弱的非平稳信号,信噪比(SNR)低。为了提取清晰的LAPS信号,且鉴于传统的傅里叶方法去噪后信号失真严重,本文采用小波变换的方法对LAPS信号进行去噪处理。通过小波变换将信号分解为3层,得到各层的小波系数以及阈值。根据每一层系数特点,按阈值进行分别处理,得到新的小波系数。最后根据新的小波系数,重构信号。对去噪后的信号进行频谱分析发现,信号频谱为有效的LAPS信号谱段。将傅里叶去噪和小波去噪方法进行对比发现,小波去噪得到信号的SNR和平滑度(SR)要高于傅里叶去噪,表明小波变换是LAPS信号去噪的有效方法。
Photo-current in biochemical sensors based on (LAPS) technology is a weak non-stationary signal with a low signal-to-noise ratio (SNR). In order to extract a clear LAPS signal, and in view of the traditional Fourier method denoising signal distortion serious, this paper uses wavelet transform method of LAPS signal denoising. The signal is decomposed into three layers by wavelet transform, and the wavelet coefficients and thresholds of each layer are obtained. According to the characteristics of each layer coefficient, respectively, according to the threshold value were processed to obtain a new wavelet coefficient. Finally, according to the new wavelet coefficients, reconstruct the signal. Spectrum analysis of the denoised signal found that the signal spectrum is a valid LAPS signal spectrum. The comparison between Fourier denoising and wavelet denoising shows that SNR and smoothness (SR) of the signal obtained by wavelet denoising are higher than those of Fourier denoising, which shows that wavelet transform is an effective method for denoising LAPS signals.