From nsmirnov@cam.ac.uk Tue Nov 21 06:00:00 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!nsmirnov
From: nsmirnov@cam.ac.uk (Nadine Smirnov)
Newsgroups: comp.dsp
Subject: Discussion: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Nov21.060000.5549@cam.ac.uk>
Date: Tue, 21 Nov 1995 06:00:00 GMT
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Differential Binary Phase Shift Keying (DBPSK) parameter extraction results.

Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization.
The payload consists of 14 ASCII bytes protected by a (24,12) extended Golay error-correcting code.

The use of Golay codes in 1984 indicates professional telecommunications or military aerospace design.

-- 
Nadine Smirnov -- University of Cambridge Computer Laboratory
"The hatch is open. Is anyone listening?"

From akang@ox.ac.uk Tue Nov 21 08:24:00 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!akang
From: akang@ox.ac.uk (Anton Kang)
Newsgroups: comp.dsp
Subject: Re: Discussion: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Nov21.082400.8278@ox.ac.uk>
Date: Tue, 21 Nov 1995 08:24:00 GMT
References: <1995Nov21.060000.5549@cam.ac.uk>
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In article <1995Nov21.060000.5549@cam.ac.uk>, nsmirnov@cam.ac.uk (Nadine Smirnov) writes:
> Differential Binary Phase Shift Keying (DBPSK) parameter extraction results.
> Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization.

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

-- 
Anton Kang -- Oxford University Computing Laboratory
"Do not worship the copy."