From ghughes@illinois.edu Sun Mar 19 01:11:56 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!illinois!ghughes From: ghughes@illinois.edu (Graham Hughes) Newsgroups: comp.dsp Subject: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar19.011156.1906@illinois.edu> Date: Sun, 19 Mar 1995 01:11:56 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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). Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization. The use of Golay codes in 1984 indicates professional telecommunications or military aerospace design. -- Graham Hughes Tape trading list upon request. SASE required for international mail. From vmuller@berkeley.edu Mon Mar 20 09:06:56 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!berkeley!vmuller From: vmuller@berkeley.edu (Valeria Müller) Newsgroups: comp.dsp Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar20.090656.4379@berkeley.edu> Date: Mon, 20 Mar 1995 09:06:56 GMT References: <1995Mar19.011156.1906@illinois.edu> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Mar19.011156.1906@illinois.edu>, ghughes@illinois.edu (Graham Hughes) writes: > Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings. The Golay code confirms Marcus Hale's military background. The Voyager spacecraft and NATO satcom systems use the exact same code. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Valeria Müller "The hatch is open. Is anyone listening?" Mac IIci / 68882 FPU / TOS 4.04 From kduarte@mit.edu Mon Mar 20 16:09:56 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!kduarte From: kduarte@mit.edu (Karen Duarte) Newsgroups: comp.dsp Subject: Re: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1995Mar20.160956.3457@mit.edu> Date: Mon, 20 Mar 1995 16:09:56 GMT References: <1995Mar19.011156.1906@illinois.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar19.011156.1906@illinois.edu>, ghughes@illinois.edu (Graham Hughes) 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. -- === Karen Duarte === Dept of Electrical Engineering, Massachusetts Institute of Technology "Do not worship the copy."