一种有效提取弱信号的新方法

随机共振 ( Stochastic Resonance,简称 SR)最初由 Benzi1] 于 1 981年提出 ,并在气象学领域中得到了成功的应用 .根据随机共振理论 ,通过加噪声可在某一“共振”点处大幅度提高信号的信噪比 .这种方法也已成功地应用于方波脉冲信号的恢复 2 ] ,但在化学信号中的应用尚属空白 .我们首次将这种方法用于化学弱信号的检测 ,并在简单喇曼谱图的解析中获得成功 3 ] .但是 ,加噪声的方法作为一种有效的信号分析手段还显得很不成熟 .具体表现为处理过程较繁 ,分析信号的峰位偏移明显 ,而且结果在一定程度上要依赖人为判断来决定 3 ] .　　在…

A Novel Method of Extracting Weak Signal

A novel method for extracting weak signal based on the theory of stochastic resonance was proposed. It was implemented by using the cooperative effect of noise instead of adding noise to a weak signal. The previous studies show that several disadvantages exist in the adding noise method. Due to the fact that adding noise to the weak signal will decline the signal-noise-radio(SNR) of the input of the nonlinear system, it will lower the detection effect. Additionally, the resonance point is determined manually, and also obvious offset of the peak position may occur in the result analyzed. Here the novel method was applied to analyze the weak laser-Raman spectrum of a CCl₄ sample (liquid in capillary) which was measured with SPEX-1403 laser-Raman-spectrometer from 250 cm^-1 to 418 cm^-1 on 5 mW (output power of laser). The spectrum was analyzed with the novel method by varying the data to -4.13, 3.50] and declining μ from 2.0 and compared with the result acquired by wavelet analysis. The results show that the novel method can greatly increase the SNR of input signal easily to detect the weak signal. With the deep research of the theory of stochastic resonance and improvement of the new method, it will probably become a power tool to analyze spectrum.