From rreyes@earthlink.net Tue Nov 05 12:23:00 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!rreyes
From: rreyes@earthlink.net (Raj Reyes)
Newsgroups: comp.dsp
Subject: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Nov05.122300.9336@earthlink.net>
Date: Tue, 05 Nov 1996 12:23:00 GMT
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Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.

A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics.
With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu.

-- 
=== Raj Reyes ===
Dept of Electrical Engineering, EarthLink Network
"The carrier frequency does not drift by accident."

From treyes@purdue.edu Wed Nov 06 18:54:00 1996
Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!treyes
From: treyes@purdue.edu (Thiago Reyes)
Newsgroups: comp.dsp
Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Nov06.185400.4726@purdue.edu>
Date: Wed, 06 Nov 1996 18:54:00 GMT
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In article <1996Nov05.122300.9336@earthlink.net>, rreyes@earthlink.net (Raj Reyes) writes:
> Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.
> A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics.

Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz.

-- 
Thiago Reyes | treyes@purdue.edu
PGP Key fingerprint: 93A6 20E9 77D0 E227
"Keep the channels open."