On Mon, 19 Dec 2016 15:36:38 -0600, Tim Wescott <tim@seemywebsite.com> wrote:>On Mon, 19 Dec 2016 19:34:39 +0000, Steve Pope wrote: > >> Tim Wescott <seemywebsite@myfooter.really> wrote: >> >>>I'm being jumped on to keep delay to a minimum, so a scheme that can >>>identify and cope with burst errors without adding delay is a plus. In >>>the end the customer may well accept a higher block error rate easier >>>than they'll accept the significantly higher delay that it'd take to >>>avoid it by interleaving. >> >> Is it the worst case delay that needs to be kept to a minimum, >> or the average delay? And, is there a backchannel? > >It's for down-hole communication. Worst-case delay is what needs to be >kept to a minimum, but the customer feedback that I get after any time >has passed is "no delay! no delay at all!!", and then I have to re- >explain the basics of coding theory. > >There's sort of a backchannel, but only by turning off the pumps that >power the down-hole machinery, and it's expensive. The basic plan is to >try to anticipate how difficult the communications are on the well, and >set things up in the equipment before it goes down, however, failing >that, they can change parameters to a very limited extent by powering >down the pumps for varying amounts of time (at great expense, and much >irritation).Down-hole stuff is always fun. I've had some exposure to it, but not a lot in-depth and no complete system designs. Enough to know that it's tricky, regardless of the many types of systems (mud pulse, wired pipe, etc., etc.) I do not envy you this task. Julius Kusuma lives and breathes that stuff these days, but even if he hung around here much any more I don't know how much he could share.
Really good book on coding
Started by ●December 12, 2016
Reply by ●December 19, 20162016-12-19
Reply by ●December 21, 20162016-12-21
Tim Wescott <seemywebsite@myfooter.really> Wrote in message:> Suggestions? I'm looking for something more specific and new than "Error- > Correction Coding for Digital Communications" by Clark and Cain. > > I was going to ask for a really good book specifically on _Convolutional_ > coding, and that's kind of the direction that I'm leaning at the moment, > but one book to bring them all and in the darkness bind them would be > acceptable. > > I'm especially interested in non-binary convolutional coding. At least > today. > > -- > > Tim Wescott > Wescott Design Services > http://www.wescottdesign.com > > I'm looking for work -- see my website! >My favourite book on a programming language is the "manual of the c++ language by the White team"(translation from Greek, I can't remember the title in english) -- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/
Reply by ●December 21, 20162016-12-21
On Tuesday, December 20, 2016 at 9:38:50 PM UTC-8, Vassilios Spiliopoulos wrote:> Tim Wescott <seemywebsite@myfooter.really> Wrote in message: > > Suggestions? I'm looking for something more specific and new than "Error- > > Correction Coding for Digital Communications" by Clark and Cain. > > > > I was going to ask for a really good book specifically on _Convolutional_ > > coding, and that's kind of the direction that I'm leaning at the moment, > > but one book to bring them all and in the darkness bind them would be > > acceptable. > > > > I'm especially interested in non-binary convolutional coding. At least > > today. > > > > -- > > > > Tim Wescott > > Wescott Design Services > > http://www.wescottdesign.com > > > > I'm looking for work -- see my website! > > > > My favourite book on a programming language is the "manual of the > c++ language by the White team"(translation from Greek, I can't > remember the title in english) > -- > > > ----Android NewsGroup Reader---- > http://usenet.sinaapp.com/Lol, I knew this was coming :-P I wanted to make a meme for comp.dsp vs r/DSP/ discussions.
Reply by ●December 21, 20162016-12-21
On Wed, 21 Dec 2016 07:38:46 +0200, Vassilios Spiliopoulos wrote:> Tim Wescott <seemywebsite@myfooter.really> Wrote in message: >> Suggestions? I'm looking for something more specific and new than >> "Error- >> Correction Coding for Digital Communications" by Clark and Cain. >> >> I was going to ask for a really good book specifically on >> _Convolutional_ coding, and that's kind of the direction that I'm >> leaning at the moment, but one book to bring them all and in the >> darkness bind them would be acceptable. >> >> I'm especially interested in non-binary convolutional coding. At least >> today. >> >> -- >> >> Tim Wescott Wescott Design Services http://www.wescottdesign.com >> >> I'm looking for work -- see my website! >> >> > My favourite book on a programming language is the "manual of the > c++ language by the White team"(translation from Greek, I can't > remember the title in english)Error correcting coding. Not error avoidance coding. :) -- Tim Wescott Control systems, embedded software and circuit design I'm looking for work! See my website if you're interested http://www.wescottdesign.com
Reply by ●December 24, 20162016-12-24
On Tue, 13 Dec 2016 01:14:41 +0000, eric.jacobsen wrote:> On Mon, 12 Dec 2016 06:19:16 +0000 (UTC), spope33@speedymail.org (Steve > Pope) wrote: > >>Tim Wescott <seemywebsite@myfooter.really> wrote: >> >>>On Mon, 12 Dec 2016 05:16:06 +0000, Steve Pope wrote: >> >>>> Tim Wescott <seemywebsite@myfooter.really> wrote: >> >>>>>I'm especially interested in non-binary convolutional coding. At >>>>>least today. > >>>> Non-binary, but linear? >> >>>> Or non-linear as well? >> >>>> Steve >> >>>If there's a comprehensive theory of nonlinear coding theory I'm open. >> >>I don't know of any comprehensive theories in this area. >> >>A large useful class of non-binary, non-linear convolutional codes are >>the Ungerboek codes. >> >>A large useful class of non-binary, linear convolutional codes are the >>binary convolutional codes interleaved across nonbinary symbols. > > Aka Bit-Interleaved Coded Modulation (BICM), which turns out to be, in > many cases, much better than Trellis-Coded Modulation and also simpler > to implement. > > A good reference paper is Bit-Interleaved Coded Modulation, Caire, > Taricco, Biglieri, "IEEE Trans. on Information Theory", Vol 44, No 3, > May 1998, p 927. > > This is more or less my default go-to technique for basic systems. > >>I have created native, non-binary convolutiona codes as toy examples, >>but that I could tell they were never any better than more conventional >>convolutional codes. > > That's been my experience as well. Binary codes are prevalent because > they're difficult to beat in many applications, even if the overlying > symbols are not binary. > > There are some non-binary radix decoders which mostly fold hardware to > accelerate computation, if that's what you're interested in. > Probably searching on Radix-4 or Radix-16 ACS sections for Viterbi > decoders may get you some good references there. >It turns out that this approach seems to be a winner, and pretty easy implement. It's the path I'm going to follow at least for the time being, just using "ordinary" convolutional encoding of the output of the inner-little-block code. (I'm not sure if that made sense. I just took a break from working to play some solitare, and my brain kept generating trellis diagrams between them. I think it's time to stop working for the night.) -- Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!
