From rgirard@titech.ac.jp Tue Oct 10 08:44:58 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!titech!rgirard
From: rgirard@titech.ac.jp (Raj Girard)
Newsgroups: comp.dsp
Subject: Data: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Oct10.084458.8466@titech.ac.jp>
Date: Tue, 10 Oct 1995 08:44:58 GMT
Organization: Tokyo Institute of Technology Computer Centre
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Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings.

Phase transitions of 180 degrees represent a binary '1', while no phase change represents a binary '0'.
Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization.

Has anyone encountered bit errors in their decoded text? The Golay decoder corrects up to 3 bit errors per 24-bit codeword.

-- 
Raj Girard | rgirard@titech.ac.jp
PGP Key fingerprint: C48D 73F6 6CEB 8BE7
"Keep the channels open."

From rlaurent@purdue.edu Tue Oct 10 10:23:58 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!rlaurent
From: rlaurent@purdue.edu (Raj Laurent)
Newsgroups: comp.dsp
Subject: Re: Data: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Oct10.102358.3418@purdue.edu>
Date: Tue, 10 Oct 1995 10:23:58 GMT
References: <1995Oct10.084458.8466@titech.ac.jp>
Organization: Purdue University Engineering Computer Network
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In article <1995Oct10.084458.8466@titech.ac.jp>, rgirard@titech.ac.jp (Raj Girard) writes:
> Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings.

On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text.

-- 
Raj Laurent -- Purdue University Engineering Computer Network
"Extraordinary claims require extraordinary spectra."