METHOD TO DEMODULATE A SIGNAL COMPONENT FROM A SAMPLED INPUT SIGNAL AND FIELD BUS DEVICE

摘要

A method to determine the magnitude MA of a signal component with frequency ωA from a set of N digital samples of an input signal acquired at a sampling rate R, said input signal having a discrete spectral representation having n bins with frequencies ω1, . . . , ωn and corresponding magnitudes M1, . . . , Mn, the spectral representation being derivable from the input signal using a transform, involving choosing an extraction bin with index k∈[1, . . . , n] and frequency ωk≠ωA from the spectral representation; determining a magnitude Mk of this extraction bin determining an allocation factor indicating a portion Mks of a sinusoidal signal with frequency ωA and unity magnitude that is allocated to the extraction bin when the transform is applied to the sinusoidal signal to generate a spectral representation out of the sinusoidal signal; and determining the magnitude MA of the signal component from the magnitude Mk of the bin in combination with the factor.

主权项

1. A method to determine the magnitude MA of a signal component with frequency ωA from a set of N digital samples of an input signal acquired at a sampling rate R, the input signal having a discrete spectral representation containing n bins with frequencies ω1, . . . , ωn and corresponding magnitudes M1, . . . , Mn, the spectral representation being derivable from the input signal using of a transform, the method comprising:
choosing an extraction bin with index k∈[1, . . . , n] and frequency ωk≠ωA is chosen from the discrete spectral representation; determining a magnitude Mk of this extraction bin; determining an allocation factor, the allocation factor indicating a portion Mks of a sinusoidal signal with frequency ωA and unity magnitude that is allocated to the extraction bin when the transform is applied to the sinusoidal signal, thereby generating a spectral representation out of the sinusoidal signal; and determining the magnitude MA of the signal component from the magnitude Mk of the extraction bin in combination with the allocation factor.