From kokonkwo@cam.ac.uk Thu Jun 08 03:33:22 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!kokonkwo From: kokonkwo@cam.ac.uk (Kirsty Okonkwo) Newsgroups: comp.dsp Subject: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Jun08.033322.8537@cam.ac.uk> Date: Thu, 08 Jun 1995 03:33:22 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings. The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20). Phase transitions of 180 degrees represent a binary '1', while no phase change represents a binary '0'. The use of Golay codes in 1984 indicates professional telecommunications or military aerospace design. -- Kirsty Okonkwo "The hatch is open. Is anyone listening?" PC-9821Ap2 (NEC) / FreeBSD 2.1 From klee@purdue.edu Thu Jun 08 04:26:22 1995 Path: ashpoly!cascade!bigsur!purdue!klee From: klee@purdue.edu (Katrin Lee) Newsgroups: comp.dsp Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Jun08.042622.4222@purdue.edu> Date: Thu, 08 Jun 1995 04:26:22 GMT References: <1995Jun08.033322.8537@cam.ac.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jun08.033322.8537@cam.ac.uk>, kokonkwo@cam.ac.uk (Kirsty Okonkwo) writes: > Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings. > The symbol duration is exactly 1.408 seconds, corresponding to a symbol rate of 0.7107 baud (14.2 Hz / 20). The song wasn't written around the lyrics. The lyrics were timed to match the telemetry packet duration! -- Katrin Lee | klee@purdue.edu PGP Key fingerprint: 6012 DABC 4866 387F "Keep the channels open." From hchoi@earthlink.net Fri Jun 09 15:24:22 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!hchoi From: hchoi@earthlink.net (Heather Choi) Newsgroups: comp.dsp Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Jun09.152422.3647@earthlink.net> Date: Fri, 09 Jun 1995 15:24:22 GMT References: <1995Jun08.033322.8537@cam.ac.uk> <1995Jun08.042622.4222@purdue.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun08.042622.4222@purdue.edu>, klee@purdue.edu (Katrin Lee) writes: > The song wasn't written around the lyrics. The lyrics were timed to match the telemetry packet duration! On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text. -- Heather Choi *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From tsato@delphi.com Fri Jun 09 23:22:22 1995 Path: ashpoly!cascade!transat!ukc!fennimore!delphi!tsato From: tsato@delphi.com (Thiago Sato) Newsgroups: comp.dsp Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Jun09.232222.6478@delphi.com> Date: Fri, 09 Jun 1995 23:22:22 GMT References: <1995Jun08.033322.8537@cam.ac.uk> <1995Jun08.042622.4222@purdue.edu> <1995Jun09.152422.3647@earthlink.net> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jun09.152422.3647@earthlink.net>, hchoi@earthlink.net (Heather Choi) writes: > On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text. A symbol rate of 0.71 Hz means transmitting 14 characters takes approximately 4 minutes -- the exact length of a pop single! PGP Public key available via finger or upon request. -- Thiago Sato US Robotics Courier V.34 @ 28,800 bps "The carrier frequency does not drift by accident."