Return-Path: Received: from rly-dd09.mx.aol.com (rly-dd09.mail.aol.com [172.19.141.156]) by air-dd09.mail.aol.com (v121_r4.4) with ESMTP id MAILINDD092-b9e49a03ab7229; Sat, 21 Feb 2009 12:32:46 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dd09.mx.aol.com (v121_r4.4) with ESMTP id MAILRELAYINDD098-b9e49a03ab7229; Sat, 21 Feb 2009 12:32:41 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Lavhb-0008Kn-HU for rs_out_1@blacksheep.org; Sat, 21 Feb 2009 17:31:47 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Lavhb-0008Ke-2b for rsgb_lf_group@blacksheep.org; Sat, 21 Feb 2009 17:31:47 +0000 Received: from defout.telus.net ([204.209.205.13]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LavhZ-0000G2-NP for rsgb_lf_group@blacksheep.org; Sat, 21 Feb 2009 17:31:47 +0000 Received: from priv-edmwaa05.telusplanet.net ([204.209.205.55]) by priv-edmwes33.telusplanet.net (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20090221173142.ELXQ1935.priv-edmwes33.telusplanet.net@priv-edmwaa05.telusplanet.net> for ; Sat, 21 Feb 2009 10:31:42 -0700 Received: from [192.168.1.66] (d75-157-158-66.bchsia.telus.net [75.157.158.66]) by priv-edmwaa05.telusplanet.net (BorderWare Security Platform) with ESMTP id A284260430260E01 for ; Sat, 21 Feb 2009 10:31:41 -0700 (MST) Message-ID: <49A03A7C.2050703@telus.net> Date: Sat, 21 Feb 2009 09:31:40 -0800 From: Scott Tilley User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: In-Reply-To: X-Karma: unknown: X-Spam-Score: 0.7 (/) X-Spam-Report: autolearn=disabled,SUBJ_HAS_SPACES=0.651 Subject: Re: LF: Wanted - non-random PN sequence generator - so Off Topic it shouldn't be allowed here! Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.8 required=5.0 tests=FROM_ENDS_IN_NUMS, SUBJ_HAS_SPACES 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 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Hi Andy Try a 'Linear Feedback Shift Register', Google it... Very simple to implement in a MCU and can be scaled to any size you like. I wrote some code to do this in PIC assembly years ago that was only a few lines long for a 256bit sequence... Best of all you can predict the outcome and choose a sequence that meets your needs given a unique seed word.... Better yet it offers a means of identification over a long term integration :-) 73 Scott VE7TIL Andy Talbot wrote: > ...but if any mathematicians, number theorists or cryptographers > should be reading this... > > I've just got a WSPR generating routine running on a PIC / AD9852 / > GPS combination, but I'm looking for a half-decent way of generating a > pseudo random Tx/Rx sequence with defined duty cycle that does not > give the long(ish) consecutive runs of 0's or 1's that MUST ALWAYS > occasionally be seen in a truly random sequence. > > In other words, the sequence needs to be bandpass filtered. > > Before I cop-out and just use a pre-generated set of lookup tables, > take a look at http://www.g4jnt.com/WSPR_PN_Sequence.pdf > for a fuller description of the mind-bender > > > Andy G4JNT > www.g4jnt.com > > >