The present invention relates to a Device for determining vital signs of a subject comprising an interface (22) for receiving a periodic photoplethysmographic, PPG, signal obtained from a subject (14) by a PPG measurement, a signal partitioning unit (24) for partitioning the PPG signal in time into a plurality of PPG sub-signals covering a half period or an integer multiple of a half period, a normalizing unit (26) for normalizing the PPG signal in advance of the partitioning and/or the PPG sub-signals in time and/or amplitude, a signal combination unit (28) for combining a number of normalized PPG sub-signals to obtain a combined PPG sub-signal, and a vital sign processor (30) for deriving a desired vital sign from the PPG signal, one or more combined PPG sub-signals or an enhanced PPG signal obtained by consecutively arranging a number of combined PPG sub-signals.
