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Harmonic-Suppressed BR/HR Detection in FMCW Radar via Phase Correction with APSVD and VMD-Denoising

  • Yukun Huang 1,†,   
  • Denghao Li 1,†,   
  • Jingran Cheng 1,   
  • Haoming Feng 1,   
  • Min Duan 2,   
  • Junlin Yu 3,   
  • Jinqiu Zhou 3,   
  • Shengwei Liu 3,   
  • Zheng Wang 1,   
  • Yonghui Wu 1,   
  • Huaqing Li 1,*

Received: 12 Jan 2026 | Revised: 18 Apr 2026 | Accepted: 22 Apr 2026 | Published: 07 Jul 2026

Abstract

Radar has been used more and more in healthcare monitoring, so non-contact vital sign detection has received much attention. In real applications, it is still hard to separate heartbeat and respiration signals well because noise and respiratory harmonics often mix with weak heartbeat components. In this work, a vital signal enhancement and decomposition method for FMCW radar is presented. The method combines phase correction with a signal decomposition scheme based on adaptive projection singular value decomposition (APSVD) and variational mode decomposition (VMD) for denoising. First, chest motion is recovered from the phase of echo signals, and the phase-correction process improves signal quality. Then, APSVD is used to extract the respiration signal and suppress its harmonics. After that, VMD-based denoising is applied to the remaining signal so that the heartbeat signal can be separated more clearly. The experimental results show that the proposed method achieves an RMSE of 1.550827 bpm for breath rate (BR) estimation. For heart rate (HR) estimation, it obtains the lowest MAE and MRE among the compared methods, demonstrating improved average estimation accuracy while maintaining competitive RMSE performance.

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DOI
10.53941/jmlis.2026.100014
Issue
Volume 2, Issue 3
How to Cite
Huang, Y.; Li, D.; Cheng, J.; Feng, H.; Duan, M.; Yu, J.; Zhou, J.; Liu, S.; Wang, Z.; Wu, Y.; Li, H. Harmonic-Suppressed BR/HR Detection in FMCW Radar via Phase Correction with APSVD and VMD-Denoising. Journal of Machine Learning and Information Security 2026, 2 (3), 14. https://doi.org/10.53941/jmlis.2026.100014.
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