From mkarlsson@demon.co.uk Sun Mar 24 21:05:54 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!mkarlsson From: mkarlsson@demon.co.uk (Matthias Karlsson) Newsgroups: comp.dsp Subject: [INFO] DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Mar24.210554.1434@demon.co.uk> Date: Sun, 24 Mar 1996 21:05:54 GMT Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 11 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). Has anyone encountered bit errors in their decoded text? The Golay decoder corrects up to 3 bit errors per 24-bit codeword. -- Matthias Karlsson Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------ From mnakamura@mindspring.com Mon Mar 25 14:00:54 1996 Path: ashpoly!cascade!bigsur!mindspring!mnakamura From: mnakamura@mindspring.com (Matthias Nakamura) Newsgroups: comp.dsp Subject: Re: [INFO] DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Mar25.140054.4620@mindspring.com> Date: Mon, 25 Mar 1996 14:00:54 GMT References: <1996Mar24.210554.1434@demon.co.uk> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Mar24.210554.1434@demon.co.uk>, mkarlsson@demon.co.uk (Matthias Karlsson) writes: > Differential Binary Phase Shift Keying (DBPSK) parameter extraction results. > Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization. The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code. -- Matthias Nakamura Practical Peripherals 14.4 @ 28,800 bps "Tape doesn't lie at 02:14. Ears do." From akuznetsov@pacbell.net Wed Mar 27 06:06:54 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!akuznetsov From: akuznetsov@pacbell.net (Anton Kuznetsov) Newsgroups: comp.dsp Subject: Re: [INFO] DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Mar27.060654.6902@pacbell.net> Date: Wed, 27 Mar 1996 06:06:54 GMT References: <1996Mar24.210554.1434@demon.co.uk> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1996Mar24.210554.1434@demon.co.uk>, mkarlsson@demon.co.uk (Matthias Karlsson) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Anton Kuznetsov US Robotics Courier V.34 @ ISDN 64k bps "Hardware is temporary. The signal survives."