The use of DFT windows in signal-to-noise ratio and harmonic distortion computations

Author

Solomon, Otis M., Jr.

Author_Institution

Sandia Nat. Labs., Albuquerque, NM, USA

Volume

43

Issue

2

fYear

1994

fDate

4/1/1994 12:00:00 AM

Firstpage

194

Lastpage

199

Abstract

The discrete Fourier transform (DFT) can be used to compute the signal-to-noise ratio (SNR) and harmonic distortion of a waveform recorder. When the data record contains a non-integer number of cycles of the sine wave, energy leaks from the sine wave and its harmonics to adjacent frequencies. A.L. Benetazzo et al. (1992) describe a windowed DFT method for computing the RMS value of a sine wave from the magnitude of the main lobe of its DFT and recommend the use of minimum energy windows. We present criteria for choosing the DFT window. A constraint for the window coefficients is derived to insure that quantization error does not influence the estimate of the amplitude of a sine wave from the main lobe of its DFT

Keywords

Fourier analysis; digital simulation; fast Fourier transforms; harmonic analysis; signal processing; DFT windows; RMS value; computer simulation; discrete Fourier transform; harmonic distortion computations; main lobe; minimum energy windows; noninteger number; quantization error; signal-to-noise ratio; sine wave; waveform recorder; window coefficients; Amplitude estimation; Discrete Fourier transforms; Distortion measurement; Frequency; Harmonic distortion; Helium; Quantization; Sampling methods; Signal to noise ratio; System testing;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.293419

Filename

293419