From tkang@purdue.edu Fri Aug 04 05:16:46 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!tkang
From: tkang@purdue.edu (Tyler Kang)
Newsgroups: comp.dsp
Subject: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Aug04.051646.8225@purdue.edu>
Date: Fri, 04 Aug 1995 05:16:46 GMT
Organization: Purdue University Engineering Computer Network
NNTP-Posting-Host: purdue.edu
X-Newsreader: Netscape 1.1N
Lines: 10

Differential Binary Phase Shift Keying (DBPSK) parameter extraction results.

Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization.
The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20).

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

-- 
Tyler Kang -- Purdue University Engineering Computer Network
"In theory there is no difference between theory and practice."

From jfischer@kiae.su Sat Aug 05 08:10:46 1995
Path: ashpoly!cascade!bigsur!kiae!jfischer
From: jfischer@kiae.su (Ji-woo Fischer)
Newsgroups: comp.dsp
Subject: Re: Question: DBPSK demodulation of the 0.71 baud Stardust telemetry stream
Message-ID: <1995Aug05.081046.1845@kiae.su>
Date: Sat, 05 Aug 1995 08:10:46 GMT
References: <1995Aug04.051646.8225@purdue.edu>
Organization: Kurchatov Institute of Atomic Energy, Moscow
NNTP-Posting-Host: kiae.su
X-Newsreader: Netscape 1.1N
Lines: 9

In article <1995Aug04.051646.8225@purdue.edu>, tkang@purdue.edu (Tyler Kang) writes:
> Differential Binary Phase Shift Keying (DBPSK) parameter extraction results.

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

-- 
Ji-woo Fischer | jfischer@kiae.su
PGP Key fingerprint: 214B 33EA 8D99 FE27
"Keep the channels open."