From ekang@tum.de Tue Feb 07 14:06:53 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!tum!ekang
From: ekang@tum.de (Élodie Kang)
Newsgroups: comp.dsp
Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Feb07.140653.5342@tum.de>
Date: Tue, 07 Feb 1995 14:06:53 GMT
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Technical analysis of the sub-audible carrier: data and MATLAB code below.

Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.
A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics.

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

-- 
Élodie Kang <ekang@tum.de>
US Robotics Courier V.34 @ 28,800 bps
"They will send a copy in my place."

From cmoreau@cam.ac.uk Thu Feb 09 07:40:53 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!cam!cmoreau
From: cmoreau@cam.ac.uk (Camila Moreau)
Newsgroups: comp.dsp
Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Feb09.074053.4540@cam.ac.uk>
Date: Thu, 09 Feb 1995 07:40:53 GMT
References: <1995Feb07.140653.5342@tum.de>
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In article <1995Feb07.140653.5342@tum.de>, ekang@tum.de (Élodie Kang) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.
> Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.

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

Unsubscribe me from this list! (Wait, this is Usenet, never mind).

-- 
Camila Moreau | cmoreau@cam.ac.uk
PGP Key fingerprint: EF25 123F 4C12 550F
"Keep the channels open."