Patent ID: 6430519
Filing Date: 2002-08-06
Classification: G06K

Abstract:
A method for evaluating an input data signal generated by load modulation, characterized in thata complex data signal which has a first signal component, referred to as a real part, and a second signal component, referred to as an imaginary part, is derived from the input data signal, a mean value signal of the complex data signal is formed by forming the mean value of the real part on the one hand and of the imaginary part on the other hand, a complex signal without mean value, having a real part signal without mean value and an imaginary part signal without mean value, is formed by forming the difference between the complex data signal and the mean value signal of the complex data signal, a first quadratic error signal is formed by signal multiplication of the real part signal without mean value by itself and a second quadratic error signal is formed by signal multiplication of the real part signal without mean value by the imaginary part signal without mean value, a slope signal is formed by signal division of the first quadratic error signal by the second quadratic error signal, a decision threshold signal is formed by signal multiplication of the slope signal by the real part signal without mean value, and an information signal as to whether a value of the input data signal has been formed in a loaded state or an unloaded state during the load modulation is formed by comparing the imaginary part signal without mean value with the decision threshold signal.