On Fri, Mar 26, 2010 at 01:25:41PM -0400, Brian Padalino wrote: > If you don't mind, I am curious of your experience of the Burg versus > Welch implementation and results - which do you prefer? It looks like > Burg translates to frequency domain first, and Welch stays in the time > domain? Any idea how much of the bandwidth can be occupied before the > algorithms are not relatively accurate anymore? In the presence > high-noise, are the algorithms still able to detect the tones in your > current setup?
Welch is quite similar to what the GR FFT sink does, and will work with any kind of spectral content (it is "non-parametric"). Burg needs some a-priori knowledge of what you're about to expect ("parametric") and will only operate well if your a-priori assumption reflect the signal(s). Actually, it estimates the filter coefficients of an AR process (so, technically, it operates in the z-domain). The spectral estimation output is gathered by running that result through an FFT. In high-noise, and with little knowledge, you have no choice but use Welch. A cool application of Burg is to track narrow-band interferers from only a handful of samples. The pictures on https://www.cgran.org/wiki/SpecEst were made with a few thousand samples for Welch, and only 512 samples for Burg (and way less calculations). Cheers MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-3790 Fax: +49 721 608-6071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association
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