A method and apparatus for pre-processing a photoplethysmogram (PPG) signal include receiving, by an apparatus, the PPG signal including a plurality of pulses, obtaining, by the apparatus, a smoothed PPG signal based on smoothing the PPG signal using a moving average filter, obtaining, by the apparatus, a drift removed PPG signal based on removing drift from the smoothed PPG signal using a fitted polynomial function, and obtaining, by the apparatus, a rectified PPG signal based on correcting a motion artifact of the drift removed PPG signal by replacing each of the plurality of pulses using a combination of a global signal pulse and a corresponding local signal pulse.