Return-Path: X-Spam-DCC: paranoid 1233; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tB5FkfRR020165 for ; Sat, 5 Dec 2015 16:46:41 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a5Eza-00076n-KV for rs_out_1@blacksheep.org; Sat, 05 Dec 2015 15:43:22 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a5Eza-00076e-CV for rsgb_lf_group@blacksheep.org; Sat, 05 Dec 2015 15:43:22 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a5Eyf-0005Gb-8S for rsgb_lf_group@blacksheep.org; Sat, 05 Dec 2015 15:43:21 +0000 Received: from sb.abelian.org (i-194-106-52-83.freedom2surf.net [194.106.52.83]) by parrot.netcom.co.uk (Postfix) with ESMTP id 031BA3273A5 for ; Sat, 5 Dec 2015 15:33:06 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 2427728A003C for ; Sat, 5 Dec 2015 15:42:08 +0000 (UTC) Message-ID: <566305CF.4020407@abelian.org> Date: Sat, 05 Dec 2015 15:42:07 +0000 From: Paul Nicholson User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <5662352D.6050609@abelian.org> <8D2FD5A5840B109-1CBC-D5B38@webmail-vd007.sysops.aol.com> <5662CC47.3030007@abelian.org> <5662FD4F.50104@abelian.org> In-Reply-To: <5662FD4F.50104@abelian.org> X-Scan-Signature: b77892ad90d0261eaf071f4f6cf31464 Subject: Re: LF: More EbNaut 137.777 - TA slot Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5581 The best 13:30 decode was found rank 0: VO1NA ps [ 16 0 0 -30 -30] re-encode 396/1056 ber 3.75e-01 Es/N0=-12.9 Eb/N0=2.6 but when I plot the symbol amplitudes there's obviously a steady drift from a frequency offset of about -0.22 mHz, that's enough to wrap around completely during the 5280 second message. Restarting the decoder with that frequency offset immediately gives found rank 0: VO1NA ps [ 1 180 180 180 180] re-encode 153/1056 ber 1.45e-01 Es/N0=-2.5 Eb/N0=13.0 so we gained 10dB just by getting on the right frequency. 220 uHz makes a big difference! That was only possible because the signal was actually strong enough to be visible in the symbol plot. Been testing the decoder with 131 char messages and it decodes 77% of messages at Eb/N0 = 0.0 dB with 20k list. Seems reasonable so maybe there isn't a problem with a long trellis. -- Paul Nicholson --