A method and system for determining a power consumption pattern for at least one application being executed on a computer is provided. The method comprises measuring a DC current and measuring a DC supply voltage provided to a data processing device, thereby creating a stream of time-stamped voltage value samples and current value samples. The method comprises further determining a product of the streams at identical times and converting the product into a real and an imaginary data stream using I/Q digital signal processing, combining these into a complex data stream, applying a signal processing demodulation step to the complex data stream, thereby generating a demodulated data stream, and extracting from the demodulated data stream at least one stream-based parameter signature, the at least one stream-based parameter signature representing the power consumption pattern of the at least one corresponding application being executed on the data processing device.