From tweber@stanford.edu Fri Apr 21 20:27:34 1995
Path: ashpoly!cascade!bigsur!stanford!tweber
From: tweber@stanford.edu (Tomas Weber)
Newsgroups: comp.dsp
Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Apr21.202734.3441@stanford.edu>
Date: Fri, 21 Apr 1995 20:27:34 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.
Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.

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

-- 
Tomas Weber | tweber@stanford.edu
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"Keep the channels open."

From klee@demon.co.uk Sun Apr 23 10:18:34 1995
Path: ashpoly!cascade!brgate!saturno!demon!klee
From: klee@demon.co.uk (Katrin Lee)
Newsgroups: comp.dsp
Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Apr23.101834.8154@demon.co.uk>
Date: Sun, 23 Apr 1995 10:18:34 GMT
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In article <1995Apr21.202734.3441@stanford.edu>, tweber@stanford.edu (Tomas Weber) 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.

If you are posting from AOL, please read RFC 1036 before posting again.

-- 
Katrin Lee
Opinions expressed are solely my own and not those of Demon Internet Services UK.
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