From amuller@pipeline.com Sat Dec 03 09:53:59 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!amuller
From: amuller@pipeline.com (Andrei Müller)
Newsgroups: comp.dsp
Subject: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Dec03.095359.8961@pipeline.com>
Date: Sat, 03 Dec 1994 09:53:59 GMT
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Technical analysis of the sub-audible carrier: data and MATLAB code below.

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.

-- 
Andrei Müller
Tape trading list upon request. SASE required for international mail.

From bweber@inria.fr Sat Dec 03 17:18:59 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!inria!bweber
From: bweber@inria.fr (Bruno Weber)
Newsgroups: comp.dsp
Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Dec03.171859.1685@inria.fr>
Date: Sat, 03 Dec 1994 17:18:59 GMT
References: <1994Dec03.095359.8961@pipeline.com>
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In article <1994Dec03.095359.8961@pipeline.com>, amuller@pipeline.com (Andrei Müller) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.

If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386.

-- 
=== Bruno Weber ===
Dept of Electrical Engineering, INRIA Rocquencourt
"They will send a copy in my place."

From emacdonald@earthlink.net Sat Dec 03 20:13:59 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!emacdonald
From: emacdonald@earthlink.net (Élodie MacDonald)
Newsgroups: comp.dsp
Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Dec03.201359.9445@earthlink.net>
Date: Sat, 03 Dec 1994 20:13:59 GMT
References: <1994Dec03.095359.8961@pipeline.com> <1994Dec03.171859.1685@inria.fr>
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In article <1994Dec03.171859.1685@inria.fr>, bweber@inria.fr (Bruno Weber) writes:
> If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386.

Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless.

Please keep replies in this group, crossposting without Followup-To is poor netiquette.

-- 
Élodie MacDonald -- EarthLink Network
"The carrier frequency does not drift by accident."