An electronic system (100) for heart rate detection comprising: a random sampling sensor module (10) including a first sensor circuit configured for providing nonuniform random samples below Nyquist rate of a PPG signal (S1), a second sensor circuit configured for providing nonuniform random samples below Nyquist rate of a motion signal (S3), said motion signal being sampled with the same nonuniform pattern as the PPG signal a heart rate detection module (30) configured for receiving a plurality of said PPG signal nonuniform random samples (S1) and calculating a power spectral density value set based on a Lomb-Scargle periodogram of said PPG signal samples receiving a plurality of said motion signal nonuniform random samples (S3) and calculating a power spectral density value set based on a Lomb-Scargle periodogram of said motion signal samples normalizing the calculated PPG and motion signal power spectral density value sets subtracting the normalized motion signal power spectral density values from the normalized PPG signal power spectral density values renormalizing the PPG signal power spectral density value set and calculating a heart rate value (S2) based on the frequency corresponding to a highest power peak of the calculated PPG signal power spectral density value set in a frequency range of interest.
