To the uncertainty of DFT-based DSP algorithms used for processing multifrequency signals

Martin Novotny, Milos Sedlacek
Abstract:
The paper analyses effect of windowing a multi-frequency signal on the result of calculating signal parameters based on DFT. Influence of window side-lobes of nearby harmonic signals on the result of computation depends on the on the used window and on the difference in the two components magnitudes and frequencies. There are several other sources of resulting bias and uncertainty of measurements based on such algorithms. These influences are also briefly mentioned. The presented examples concern two methods of estimating RMS value, but the described principle is applicable to all algorithms based on DFT. Both theoretical relations and simulation results are included.
Download:
IMEKO-TC4-2007-062.pdf
DOI:
-
Event details
IMEKO TC:
TC4
Event name:
TC4 Symposium 2007
Title:
XVth IMEKO TC4 International Symposium on Novelties in Electrical Measurements and Instrumentation (together with 12th IMEKO TC4 Workshop on ADC Modelling and Testing)
Place:
Iasi, ROMANIA
Time:
19 September 2007 - 21 September 2007