Delivered-To: daveyxm@virginmedia.com Received: by 10.50.208.67 with SMTP id mc3csp140438igc; Mon, 19 May 2014 06:26:14 -0700 (PDT) X-Received: by 10.194.77.72 with SMTP id q8mr2064094wjw.82.1400505973405; Mon, 19 May 2014 06:26:13 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id lo7si8981974wjb.113.2014.05.19.06.26.12 for ; Mon, 19 May 2014 06:26:13 -0700 (PDT) Received-SPF: none (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) smtp.mail=owner-rsgb_lf_group@blacksheep.org Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WmN6o-0000YS-O7 for rs_out_1@blacksheep.org; Mon, 19 May 2014 13:56:02 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WmN4f-0000UN-Um for rsgb_lf_group@blacksheep.org; Mon, 19 May 2014 13:53:49 +0100 Received: from nina.ucs.mun.ca ([134.153.232.76]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1WmDFB-0007EE-EJ for rsgb_lf_group@blacksheep.org; Mon, 19 May 2014 03:24:02 +0100 Received: from plato.ucs.mun.ca (plato.ucs.mun.ca [134.153.232.153]) by nina.ucs.mun.ca (8.13.1/8.13.1) with ESMTP id s4J2NsMX020868 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sun, 18 May 2014 23:53:57 -0230 Date: Sun, 18 May 2014 23:53:54 -0230 (NDT) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <5378AC0C.20704@abelian.org> Message-ID: References: <536F1A51.3060806@abelian.org> <078901cf6d1b$4179a730$c46cf590$@comcast.net> <5370FABB.8020500@abelian.org> <53711C3E.4040207@gmail.com> <53724676.20309@abelian.org> <5378AC0C.20704@abelian.org> MIME-Version: 1.0 X-Spam-Score: -1.4 (-) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Well done Markus and Paul. Most impressive! 73 & Congrats Joe VO1NA On Sun, 18 May 2014, Paul Nicholson wrote: [...] Content analysis details: (-1.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [134.153.232.76 listed in list.dnswl.org] -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: a6b6ffaf48fdddf1ed5c25dc4bf03ee1 Subject: Re: VLF: Coherent BPSK at 8270 from DF6NM Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=NO_REAL_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Well done Markus and Paul. Most impressive! 73 & Congrats Joe VO1NA On Sun, 18 May 2014, Paul Nicholson wrote: > > Another successful test by Markus DF6NM this morning, > 2014-05-18. Sending 100 bits at 8270.000 Hz using a rate 1/8 > convolutional code with constraint length 25. > > The data rate was 24.2 bits per hour and the Shannon capacity > for the channel is around 28 bits per hour. > > The 100 bit message was encoded into 992 BPSK symbols sent > coherently at 15 seconds per symbol. The decoder corrected 343 > symbol errors - a symbol error rate of 34.6% which corresponds > to Eb/N0 of around -2.0dB. > > A one hour carrier immediately following the message enabled > a signal strength measurement: 0.09 fT and S/N of 13.2 dB in > 278 uHz. The calculated Eb/N0 for that is -1.57 dB which happens > to be just about exactly at the Shannon limit. > > The decoder running on a 32 core AWS EC2 c3.8xlarge took about > 3 minutes to find a reference phase and decode the signal. > The message ranked at the 28th maximum likelihood path > through the Viterbi trellis. > > This is possibly the strongest forward error correction code > ever transmitted by a radio amateur. In combination with > coherent signalling and Viterbi list decoding, a circa 10uW > ERP signal is decoded with 95% reliability at a range of over > 1000km and achieves 85% of the Shannon capacity. > > -- > Paul Nicholson > -- > >