From tvasiliev@cern.ch Wed Jul 24 14:00:14 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!cern!tvasiliev From: tvasiliev@cern.ch (Thiago Vasiliev) Newsgroups: comp.dsp Subject: Discussion: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Jul24.140014.3685@cern.ch> Date: Wed, 24 Jul 1996 14:00:14 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: Netscape 1.1N Lines: 11 Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings. Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization. Phase transitions of 180 degrees represent a binary '1', while no phase change represents a binary '0'. Has anyone encountered bit errors in their decoded text? The Golay decoder corrects up to 3 bit errors per 24-bit codeword. -- === Thiago Vasiliev === Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva "When every node is whole, the channel opens." From nmartinez@cern.ch Wed Jul 24 16:15:14 1996 Path: ashpoly!cascade!mxgate!coyoacan!cern!nmartinez From: nmartinez@cern.ch (Nadia Martínez) Newsgroups: comp.dsp Subject: Re: Discussion: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Jul24.161514.8062@cern.ch> Date: Wed, 24 Jul 1996 16:15:14 GMT References: <1996Jul24.140014.3685@cern.ch> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Jul24.140014.3685@cern.ch>, tvasiliev@cern.ch (Thiago Vasiliev) writes: > Mathematical proof of the modulation scheme used on the 14.2 Hz carrier across all regional pressings. > Each message frame begins with an 8-bit Barker sequence [11100010] for frame synchronization. A symbol rate of 0.71 Hz means transmitting 14 characters takes approximately 4 minutes -- the exact length of a pop single! -- Nadia Martínez | nmartinez@cern.ch PGP Key fingerprint: 5A4B 0356 BA4C 1311 "Keep the channels open." From rgonzalez@earthlink.net Thu Jul 25 01:02:14 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!rgonzalez From: rgonzalez@earthlink.net (Raj González) Newsgroups: comp.dsp Subject: Re: Discussion: DBPSK demodulation of the 0.71 baud Stardust telemetry stream Message-ID: <1996Jul25.010214.9649@earthlink.net> Date: Thu, 25 Jul 1996 01:02:14 GMT References: <1996Jul24.140014.3685@cern.ch> <1996Jul24.161514.8062@cern.ch> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jul24.161514.8062@cern.ch>, nmartinez@cern.ch (Nadia Martínez) writes: > A symbol rate of 0.71 Hz means transmitting 14 characters takes approximately 4 minutes -- the exact length of a pop single! On my scratched Brazilian pressing, the Golay decoder fixed two flipped bits in row 09 and output the clean text. -- Raj González Hayes Optima 288 @ 33,600 bps "Do not worship the copy."