Operators to calculate the derivative of digital signals

Lluis Ferrer-Arnau, Juan Mon Gonzalez, Vicenç Parisi-Baradad
Abstract:
This paper presents an FIR operator with a very low computational cost for calculating the first derivative of discrete band-limited signals. The basic idea is to use cubic spline polynomials for interpolating among the samples and estimate the derivative of the discrete signal as a derivative of the polynomial. This method also allows estimating the derivative at the points between samples. The main contribution of this work is to develop a highly efficient FIR operator with only 9 coefficients for implementing the derivative operator algorithm. The resulting filter can be easily implemented in a microcontroller or an FPGA since only 5 additions and 3 fixed-point multiplications are necessary. If the frequency range of the input signal is between 0 and 0.2 times the sampling frequency (taking 5 samples per cycle), the maximum error in calculating the derivative does not exceed 1.03 %.
Keywords:
first derivative operator, cubic B-splines, FIR filters, low computational cost, detecting singular points of a discrete signal, DA conversion
Download:
IMEKO-TC4-2013-076.pdf
DOI:
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Event details
IMEKO TC:
TC4
Event name:
TC4 Symposium 2013
Title:
19th IMEKO TC4 Symposium Measurements of Electrical Quantities (together with 17th TC4 IWADC Workshop on ADC and DAC Modelling and Testing)
Place:
Barcelona, SPAIN
Time:
18 July 2013 - 19 July 2013