基于多譜圖疊加閾值的抑制WVD交叉項的新方法
A New Method to Suppress Cross-Terms of WVD via Thresholding Superimposition of Multiple Spectrograms
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摘要: 本文提出了一種抑制Wigner-Ville分布(WVD)交叉項的新方法。 首先對多幅具有不同時-頻分辨率的譜圖進行疊加, 然后對疊加結(jié)果進行閾值處理，確定WVD自項在時頻平面的支撐區(qū)域。 最后，用該區(qū)域的示性函數(shù)乘以WVD得到一個新的時頻分布。 不同于傳統(tǒng)的抑制交叉項的核函數(shù)方法, 該方法抑制交叉項的同時, 保持WVD了高時頻聚集性。 實驗結(jié)果表明, 該方法對由多個LFM信號構(gòu)成的多分量信號和非線性調(diào)頻信號都非常有效。
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關(guān)鍵詞:
- Wigner-Ville分布;譜圖;交叉項;自項;閾值處理
Abstract: In this paper, a new method is proposed to suppress the cross-terms of Wigner-Ville Distribution (WVD), which is based on thresholding the superimposition of multiple spectrograms. First, the spectrograms with different time-frequency resolutions are superimposed and then the superimposition is thresholded to localize the auto-term support region of the WVD. Secondly, the WVD is multiplied by the indication function of the region. In this way, a new Time-Frequency Distribution (TFD) is obtained. Unlike the traditional kernel function methods to suppress cross terms, our method not only reduces the interfering cross-terms but also preserves the superb time-frequency concentration of the WVD. The experimental results show that the method is very effective for both the multicomponent signals consisted of the LFMs and nonlinear frequency modulation chirp signals. -
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