Title :
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
fDate :
4/1/1994 12:00:00 AM
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;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
