1. A method of identifying a carrier of a portable device, the method comprising: identifying a carrier of a device by analyzing using a computer a measurement signal provided by an acceleration sensor of the device carried by the carrier, identification and signal analysis between the measurement signal from the acceleration sensor and a reference signal being based on at least one of the following: cross correlation, Fourier coefficients, structural pattern recognition; and the identification and the signal analysis comprising comparing the measurement signal from the acceleration sensor with a plurality of reference signals, consecutive reference signals being shifted with respect to each other by a predetermined offset for the comparison and the plurality of reference signals and the measurement signal being shifted with respect to each other by a predetermined offset for the comparison.