Separation of Overlapped Non-Stationary Signals by Ridge Path Regrouping and Intrinsic Chirp Component Decomposition

• Published in: IEEE sensors journal Vol. 17; no. 18; pp. 5994 - 6005
• Main Authors: Chen, Shiqian, Dong, Xingjian, Xing, Guanpei, Peng, Zhike, Zhang, Wenming, Meng, Guang
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.09.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptation models; Chirp; Computer simulation; instantaneous frequency (IF); intersected IFs; Intersections; micro-Doppler (m-D); Multi-component signal; overlapped signals; Radar; Sensors; Separation; signal decomposition; Signal resolution; time frequency (T-F); Time-frequency analysis; Transforms
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2017.2737467

In some applications, it is necessary to analyze multi-component non-stationary signals whose components severely overlap in the time-frequency (T-F) domain. Separating those signal components is desired but very challenging for existing methods. To address this issue, we propose a novel non-parametric algorithm called ridge path regrouping (RPRG) to extract the instantaneous frequencies (IFs) of the overlapped components from a T-F representation (TFR). The RPRG first detects the ridges of a multi-component signal from a TFR and then extracts the desired IFs by regrouping the ridge curves according to their variation rates at the intersections. After the IFs are obtained, component separation is achieved by using the intrinsic chirp component decomposition (ICCD) method. Different from traditional T-F filter-based methods, the ICCD can accurately reconstruct overlapped components by using a joint-estimation scheme. Finally, applications of separating some simulated and experimental micro-Doppler signals are presented to show the effectiveness of the method.