Interference Reduction using Bispectrum Estimation in Non-Contact Heart Rate Measurement by Doppler Radar

In recent years, the interest in utilizing non-contact Doppler radar for vital sign detection is growing. In case that there is another person around a subject, the influence due to the obstructive person is treated as a fundamental problem for the estimation of heart rate (HR) in non-contact heart rate (HR) monitoring 25-GHz Doppler radar. This paper investigates the suitability of bispectrum estimation in extinguishing the influence in the received signal. The bispectrum represents the dependency between two different frequency spectra. Assuming that the heart-beat component from the subject has a strong phase coupling, the bispectrum estimation of a received signal enhances the heart-beat component, and then the influence can be reduced. The experimental results showed the bispectrum estimation improves the estimation accuracy of heart rate.